granicus.if.org Git - postgresql/blob - src/backend/tcop/postgres.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * postgres.c
   4  *        POSTGRES C Backend Interface
   5  *
   6  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.421 2004/06/24 21:03:08 tgl Exp $
  12  *
  13  * NOTES
  14  *        this is the "main" module of the postgres backend and
  15  *        hence the main module of the "traffic cop".
  16  *
  17  *-------------------------------------------------------------------------
  18  */
  19
  20 #include "postgres.h"
  21
  22 #include <unistd.h>
  23 #include <signal.h>
  24 #include <fcntl.h>
  25 #include <sys/socket.h>
  26 #include <errno.h>
  27 #if HAVE_SYS_SELECT_H
  28 #include <sys/select.h>
  29 #endif
  30 #ifdef HAVE_GETOPT_H
  31 #include <getopt.h>
  32 #endif
  33
  34 #include "access/printtup.h"
  35 #include "access/xlog.h"
  36 #include "catalog/pg_type.h"
  37 #include "commands/async.h"
  38 #include "commands/prepare.h"
  39 #include "commands/trigger.h"
  40 #include "libpq/libpq.h"
  41 #include "libpq/pqformat.h"
  42 #include "libpq/pqsignal.h"
  43 #include "miscadmin.h"
  44 #include "nodes/print.h"
  45 #include "optimizer/cost.h"
  46 #include "optimizer/planner.h"
  47 #include "parser/analyze.h"
  48 #include "parser/parser.h"
  49 #include "rewrite/rewriteHandler.h"
  50 #include "storage/freespace.h"
  51 #include "storage/ipc.h"
  52 #include "storage/pg_shmem.h"
  53 #include "storage/proc.h"
  54 #include "storage/sinval.h"
  55 #include "tcop/fastpath.h"
  56 #include "tcop/pquery.h"
  57 #include "tcop/tcopprot.h"
  58 #include "tcop/utility.h"
  59 #include "utils/guc.h"
  60 #include "utils/lsyscache.h"
  61 #include "utils/memutils.h"
  62 #include "utils/ps_status.h"
  63 #include "mb/pg_wchar.h"
  64
  65 #include "pgstat.h"
  66
  67 extern int      optind;
  68 extern char *optarg;
  69
  70 /* ----------------
  71  *              global variables
  72  * ----------------
  73  */
  74 const char *debug_query_string; /* for pgmonitor and
  75                                                                  * log_min_error_statement */
  76
  77 /* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
  78 CommandDest whereToSendOutput = Debug;
  79
  80 /* note: these declarations had better match tcopprot.h */
  81 sigjmp_buf      Warn_restart;
  82
  83 bool            Warn_restart_ready = false;
  84 bool            InError = false;
  85
  86 /* flag for logging end of session */
  87 bool        Log_disconnections = false;
  88
  89 LogStmtLevel log_statement = LOGSTMT_NONE;
  90
  91 /* GUC variable for maximum stack depth (measured in kilobytes) */
  92 int                     max_stack_depth = 2048;
  93
  94
  95 /* ----------------
  96  *              private variables
  97  * ----------------
  98  */
  99
 100 /* max_stack_depth converted to bytes for speed of checking */
 101 static int      max_stack_depth_bytes = 2048*1024;
 102
 103 /* stack base pointer (initialized by PostgresMain) */
 104 static char *stack_base_ptr = NULL;
 105
 106
 107 /*
 108  * Flag to mark SIGHUP. Whenever the main loop comes around it
 109  * will reread the configuration file. (Better than doing the
 110  * reading in the signal handler, ey?)
 111  */
 112 static volatile sig_atomic_t got_SIGHUP = false;
 113
 114 /*
 115  * Flag to keep track of whether we have started a transaction.
 116  * For extended query protocol this has to be remembered across messages.
 117  */
 118 static bool xact_started = false;
 119
 120 /*
 121  * Flags to implement skip-till-Sync-after-error behavior for messages of
 122  * the extended query protocol.
 123  */
 124 static bool doing_extended_query_message = false;
 125 static bool ignore_till_sync = false;
 126
 127 /*
 128  * If an unnamed prepared statement exists, it's stored here.
 129  * We keep it separate from the hashtable kept by commands/prepare.c
 130  * in order to reduce overhead for short-lived queries.
 131  */
 132 static MemoryContext unnamed_stmt_context = NULL;
 133 static PreparedStatement *unnamed_stmt_pstmt = NULL;
 134
 135
 136 static bool EchoQuery = false;  /* default don't echo */
 137
 138 /*
 139  * people who want to use EOF should #define DONTUSENEWLINE in
 140  * tcop/tcopdebug.h
 141  */
 142 #ifndef TCOP_DONTUSENEWLINE
 143 static int      UseNewLine = 1;         /* Use newlines query delimiters (the
 144                                                                  * default) */
 145
 146 #else
 147 static int      UseNewLine = 0;         /* Use EOF as query delimiters */
 148 #endif   /* TCOP_DONTUSENEWLINE */
 149
 150
 151 /* ----------------------------------------------------------------
 152  *              decls for routines only used in this file
 153  * ----------------------------------------------------------------
 154  */
 155 static int      InteractiveBackend(StringInfo inBuf);
 156 static int      SocketBackend(StringInfo inBuf);
 157 static int      ReadCommand(StringInfo inBuf);
 158 static void start_xact_command(void);
 159 static void finish_xact_command(void);
 160 static void SigHupHandler(SIGNAL_ARGS);
 161 static void FloatExceptionHandler(SIGNAL_ARGS);
 162 static void log_disconnections(int code, Datum arg);
 163
 164
 165 /* ----------------------------------------------------------------
 166  *              routines to obtain user input
 167  * ----------------------------------------------------------------
 168  */
 169
 170 /* ----------------
 171  *      InteractiveBackend() is called for user interactive connections
 172  *
 173  *      the string entered by the user is placed in its parameter inBuf,
 174  *      and we act like a Q message was received.
 175  *
 176  *      EOF is returned if end-of-file input is seen; time to shut down.
 177  * ----------------
 178  */
 179
 180 static int
 181 InteractiveBackend(StringInfo inBuf)
 182 {
 183         int                     c;                              /* character read from getc() */
 184         bool            end = false;    /* end-of-input flag */
 185         bool            backslashSeen = false;  /* have we seen a \ ? */
 186
 187         /*
 188          * display a prompt and obtain input from the user
 189          */
 190         printf("backend> ");
 191         fflush(stdout);
 192
 193         /* Reset inBuf to empty */
 194         inBuf->len = 0;
 195         inBuf->data[0] = '\0';
 196         inBuf->cursor = 0;
 197
 198         for (;;)
 199         {
 200                 if (UseNewLine)
 201                 {
 202                         /*
 203                          * if we are using \n as a delimiter, then read characters
 204                          * until the \n.
 205                          */
 206                         while ((c = getc(stdin)) != EOF)
 207                         {
 208                                 if (c == '\n')
 209                                 {
 210                                         if (backslashSeen)
 211                                         {
 212                                                 /* discard backslash from inBuf */
 213                                                 inBuf->data[--inBuf->len] = '\0';
 214                                                 backslashSeen = false;
 215                                                 continue;
 216                                         }
 217                                         else
 218                                         {
 219                                                 /* keep the newline character */
 220                                                 appendStringInfoChar(inBuf, '\n');
 221                                                 break;
 222                                         }
 223                                 }
 224                                 else if (c == '\\')
 225                                         backslashSeen = true;
 226                                 else
 227                                         backslashSeen = false;
 228
 229                                 appendStringInfoChar(inBuf, (char) c);
 230                         }
 231
 232                         if (c == EOF)
 233                                 end = true;
 234                 }
 235                 else
 236                 {
 237                         /*
 238                          * otherwise read characters until EOF.
 239                          */
 240                         while ((c = getc(stdin)) != EOF)
 241                                 appendStringInfoChar(inBuf, (char) c);
 242
 243                         if (inBuf->len == 0)
 244                                 end = true;
 245                 }
 246
 247                 if (end)
 248                         return EOF;
 249
 250                 /*
 251                  * otherwise we have a user query so process it.
 252                  */
 253                 break;
 254         }
 255
 256         /* Add '\0' to make it look the same as message case. */
 257         appendStringInfoChar(inBuf, (char) '\0');
 258
 259         /*
 260          * if the query echo flag was given, print the query..
 261          */
 262         if (EchoQuery)
 263                 printf("statement: %s\n", inBuf->data);
 264         fflush(stdout);
 265
 266         return 'Q';
 267 }
 268
 269 /* ----------------
 270  *      SocketBackend()         Is called for frontend-backend connections
 271  *
 272  *      Returns the message type code, and loads message body data into inBuf.
 273  *
 274  *      EOF is returned if the connection is lost.
 275  * ----------------
 276  */
 277 static int
 278 SocketBackend(StringInfo inBuf)
 279 {
 280         int                     qtype;
 281
 282         /*
 283          * Get message type code from the frontend.
 284          */
 285         qtype = pq_getbyte();
 286
 287         if (qtype == EOF)                       /* frontend disconnected */
 288         {
 289                 ereport(COMMERROR,
 290                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 291                                  errmsg("unexpected EOF on client connection")));
 292                 return qtype;
 293         }
 294
 295         /*
 296          * Validate message type code before trying to read body; if we have
 297          * lost sync, better to say "command unknown" than to run out of
 298          * memory because we used garbage as a length word.
 299          *
 300          * This also gives us a place to set the doing_extended_query_message
 301          * flag as soon as possible.
 302          */
 303         switch (qtype)
 304         {
 305                 case 'Q':                               /* simple query */
 306                         doing_extended_query_message = false;
 307                         if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
 308                         {
 309                                 /* old style without length word; convert */
 310                                 if (pq_getstring(inBuf))
 311                                 {
 312                                         ereport(COMMERROR,
 313                                                         (errcode(ERRCODE_PROTOCOL_VIOLATION),
 314                                                  errmsg("unexpected EOF on client connection")));
 315                                         return EOF;
 316                                 }
 317                         }
 318                         break;
 319
 320                 case 'F':                               /* fastpath function call */
 321                         /* we let fastpath.c cope with old-style input of this */
 322                         doing_extended_query_message = false;
 323                         break;
 324
 325                 case 'X':                               /* terminate */
 326                         doing_extended_query_message = false;
 327                         ignore_till_sync = false;
 328                         break;
 329
 330                 case 'B':                               /* bind */
 331                 case 'C':                               /* close */
 332                 case 'D':                               /* describe */
 333                 case 'E':                               /* execute */
 334                 case 'H':                               /* flush */
 335                 case 'P':                               /* parse */
 336                         doing_extended_query_message = true;
 337                         /* these are only legal in protocol 3 */
 338                         if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
 339                                 ereport(FATAL,
 340                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 341                                          errmsg("invalid frontend message type %d", qtype)));
 342                         break;
 343
 344                 case 'S':                               /* sync */
 345                         /* stop any active skip-till-Sync */
 346                         ignore_till_sync = false;
 347                         /* mark not-extended, so that a new error doesn't begin skip */
 348                         doing_extended_query_message = false;
 349                         /* only legal in protocol 3 */
 350                         if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
 351                                 ereport(FATAL,
 352                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 353                                          errmsg("invalid frontend message type %d", qtype)));
 354                         break;
 355
 356                 case 'd':                               /* copy data */
 357                 case 'c':                               /* copy done */
 358                 case 'f':                               /* copy fail */
 359                         doing_extended_query_message = false;
 360                         /* these are only legal in protocol 3 */
 361                         if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
 362                                 ereport(FATAL,
 363                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
 364                                          errmsg("invalid frontend message type %d", qtype)));
 365                         break;
 366
 367                 default:
 368
 369                         /*
 370                          * Otherwise we got garbage from the frontend.  We treat this
 371                          * as fatal because we have probably lost message boundary
 372                          * sync, and there's no good way to recover.
 373                          */
 374                         ereport(FATAL,
 375                                         (errcode(ERRCODE_PROTOCOL_VIOLATION),
 376                                          errmsg("invalid frontend message type %d", qtype)));
 377                         break;
 378         }
 379
 380         /*
 381          * In protocol version 3, all frontend messages have a length word
 382          * next after the type code; we can read the message contents
 383          * independently of the type.
 384          */
 385         if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
 386         {
 387                 if (pq_getmessage(inBuf, 0))
 388                         return EOF;                     /* suitable message already logged */
 389         }
 390
 391         return qtype;
 392 }
 393
 394 /* ----------------
 395  *              ReadCommand reads a command from either the frontend or
 396  *              standard input, places it in inBuf, and returns the
 397  *              message type code (first byte of the message).
 398  *              EOF is returned if end of file.
 399  * ----------------
 400  */
 401 static int
 402 ReadCommand(StringInfo inBuf)
 403 {
 404         int                     result;
 405
 406         if (whereToSendOutput == Remote)
 407                 result = SocketBackend(inBuf);
 408         else
 409                 result = InteractiveBackend(inBuf);
 410         return result;
 411 }
 412
 413
 414 /*
 415  * Parse a query string and pass it through the rewriter.
 416  *
 417  * A list of Query nodes is returned, since the string might contain
 418  * multiple queries and/or the rewriter might expand one query to several.
 419  *
 420  * NOTE: this routine is no longer used for processing interactive queries,
 421  * but it is still needed for parsing of SQL function bodies.
 422  */
 423 List *
 424 pg_parse_and_rewrite(const char *query_string,  /* string to execute */
 425                                          Oid *paramTypes,       /* parameter types */
 426                                          int numParams)         /* number of parameters */
 427 {
 428         List       *raw_parsetree_list;
 429         List       *querytree_list;
 430         ListCell   *list_item;
 431
 432         /*
 433          * (1) parse the request string into a list of raw parse trees.
 434          */
 435         raw_parsetree_list = pg_parse_query(query_string);
 436
 437         /*
 438          * (2) Do parse analysis and rule rewrite.
 439          */
 440         querytree_list = NIL;
 441         foreach(list_item, raw_parsetree_list)
 442         {
 443                 Node       *parsetree = (Node *) lfirst(list_item);
 444
 445                 querytree_list = list_concat(querytree_list,
 446                                                            pg_analyze_and_rewrite(parsetree,
 447                                                                                                           paramTypes,
 448                                                                                                           numParams));
 449         }
 450
 451         return querytree_list;
 452 }
 453
 454 /*
 455  * Do raw parsing (only).
 456  *
 457  * A list of parsetrees is returned, since there might be multiple
 458  * commands in the given string.
 459  *
 460  * NOTE: for interactive queries, it is important to keep this routine
 461  * separate from the analysis & rewrite stages.  Analysis and rewriting
 462  * cannot be done in an aborted transaction, since they require access to
 463  * database tables.  So, we rely on the raw parser to determine whether
 464  * we've seen a COMMIT or ABORT command; when we are in abort state, other
 465  * commands are not processed any further than the raw parse stage.
 466  */
 467 List *
 468 pg_parse_query(const char *query_string)
 469 {
 470         List       *raw_parsetree_list;
 471         ListCell   *parsetree_item;
 472
 473         if (log_statement == LOGSTMT_ALL)
 474                 ereport(LOG,
 475                                 (errmsg("statement: %s", query_string)));
 476
 477         if (log_parser_stats)
 478                 ResetUsage();
 479
 480         raw_parsetree_list = raw_parser(query_string);
 481
 482         /* do log_statement tests for mod and ddl */
 483         if (log_statement == LOGSTMT_MOD ||
 484                 log_statement == LOGSTMT_DDL)
 485         {
 486                 foreach(parsetree_item, raw_parsetree_list)
 487                 {
 488                         Node       *parsetree = (Node *) lfirst(parsetree_item);
 489                         const char *commandTag;
 490
 491                         if (IsA(parsetree, ExplainStmt) &&
 492                                 ((ExplainStmt *)parsetree)->analyze)
 493                                 parsetree = (Node *)(((ExplainStmt *)parsetree)->query);
 494
 495                         if (IsA(parsetree, PrepareStmt))
 496                                 parsetree = (Node *)(((PrepareStmt *)parsetree)->query);
 497
 498                         if (IsA(parsetree, SelectStmt))
 499                                 continue;       /* optimization for frequent command */
 500
 501                         if (log_statement == LOGSTMT_MOD &&
 502                                 (IsA(parsetree, InsertStmt) ||
 503                                  IsA(parsetree, UpdateStmt) ||
 504                                  IsA(parsetree, DeleteStmt) ||
 505                                  IsA(parsetree, TruncateStmt) ||
 506                                  (IsA(parsetree, CopyStmt) &&
 507                                   ((CopyStmt *)parsetree)->is_from)))   /* COPY FROM */
 508                         {
 509                                 ereport(LOG,
 510                                                 (errmsg("statement: %s", query_string)));
 511                                 break;
 512                         }
 513                         commandTag = CreateCommandTag(parsetree);
 514                         if (strncmp(commandTag, "CREATE ", strlen("CREATE ")) == 0 ||
 515                                 strncmp(commandTag, "ALTER ", strlen("ALTER ")) == 0 ||
 516                                 strncmp(commandTag, "DROP ", strlen("DROP ")) == 0 ||
 517                                 IsA(parsetree, GrantStmt) ||    /* GRANT or REVOKE */
 518                                 IsA(parsetree, CommentStmt))
 519                         {
 520                                 ereport(LOG,
 521                                                 (errmsg("statement: %s", query_string)));
 522                                 break;
 523                         }
 524                 }
 525         }
 526
 527         if (log_parser_stats)
 528                 ShowUsage("PARSER STATISTICS");
 529
 530         return raw_parsetree_list;
 531 }
 532
 533 /*
 534  * Given a raw parsetree (gram.y output), and optionally information about
 535  * types of parameter symbols ($n), perform parse analysis and rule rewriting.
 536  *
 537  * A list of Query nodes is returned, since either the analyzer or the
 538  * rewriter might expand one query to several.
 539  *
 540  * NOTE: for reasons mentioned above, this must be separate from raw parsing.
 541  */
 542 List *
 543 pg_analyze_and_rewrite(Node *parsetree, Oid *paramTypes, int numParams)
 544 {
 545         List       *querytree_list;
 546
 547         /*
 548          * (1) Perform parse analysis.
 549          */
 550         if (log_parser_stats)
 551                 ResetUsage();
 552
 553         querytree_list = parse_analyze(parsetree, paramTypes, numParams);
 554
 555         if (log_parser_stats)
 556                 ShowUsage("PARSE ANALYSIS STATISTICS");
 557
 558         /*
 559          * (2) Rewrite the queries, as necessary
 560          */
 561         querytree_list = pg_rewrite_queries(querytree_list);
 562
 563         return querytree_list;
 564 }
 565
 566 /*
 567  * Perform rewriting of a list of queries produced by parse analysis.
 568  */
 569 List *
 570 pg_rewrite_queries(List *querytree_list)
 571 {
 572         List       *new_list = NIL;
 573         ListCell   *list_item;
 574
 575         if (log_parser_stats)
 576                 ResetUsage();
 577
 578         /*
 579          * rewritten queries are collected in new_list.  Note there may be
 580          * more or fewer than in the original list.
 581          */
 582         foreach(list_item, querytree_list)
 583         {
 584                 Query      *querytree = (Query *) lfirst(list_item);
 585
 586                 if (Debug_print_parse)
 587                         elog_node_display(DEBUG1, "parse tree", querytree,
 588                                                           Debug_pretty_print);
 589
 590                 if (querytree->commandType == CMD_UTILITY)
 591                 {
 592                         /* don't rewrite utilities, just dump 'em into new_list */
 593                         new_list = lappend(new_list, querytree);
 594                 }
 595                 else
 596                 {
 597                         /* rewrite regular queries */
 598                         List       *rewritten = QueryRewrite(querytree);
 599
 600                         new_list = list_concat(new_list, rewritten);
 601                 }
 602         }
 603
 604         querytree_list = new_list;
 605
 606         if (log_parser_stats)
 607                 ShowUsage("REWRITER STATISTICS");
 608
 609 #ifdef COPY_PARSE_PLAN_TREES
 610
 611         /*
 612          * Optional debugging check: pass querytree output through
 613          * copyObject()
 614          */
 615         new_list = (List *) copyObject(querytree_list);
 616         /* This checks both copyObject() and the equal() routines... */
 617         if (!equal(new_list, querytree_list))
 618                 elog(WARNING, "copyObject() failed to produce an equal parse tree");
 619         else
 620                 querytree_list = new_list;
 621 #endif
 622
 623         if (Debug_print_rewritten)
 624                 elog_node_display(DEBUG1, "rewritten parse tree", querytree_list,
 625                                                   Debug_pretty_print);
 626
 627         return querytree_list;
 628 }
 629
 630
 631 /* Generate a plan for a single already-rewritten query. */
 632 Plan *
 633 pg_plan_query(Query *querytree, ParamListInfo boundParams)
 634 {
 635         Plan       *plan;
 636
 637         /* Utility commands have no plans. */
 638         if (querytree->commandType == CMD_UTILITY)
 639                 return NULL;
 640
 641         if (log_planner_stats)
 642                 ResetUsage();
 643
 644         /* call the optimizer */
 645         plan = planner(querytree, false, 0, boundParams);
 646
 647         if (log_planner_stats)
 648                 ShowUsage("PLANNER STATISTICS");
 649
 650 #ifdef COPY_PARSE_PLAN_TREES
 651         /* Optional debugging check: pass plan output through copyObject() */
 652         {
 653                 Plan       *new_plan = (Plan *) copyObject(plan);
 654
 655                 /*
 656                  * equal() currently does not have routines to compare Plan nodes,
 657                  * so don't try to test equality here.  Perhaps fix someday?
 658                  */
 659 #ifdef NOT_USED
 660                 /* This checks both copyObject() and the equal() routines... */
 661                 if (!equal(new_plan, plan))
 662                         elog(WARNING, "copyObject() failed to produce an equal plan tree");
 663                 else
 664 #endif
 665                         plan = new_plan;
 666         }
 667 #endif
 668
 669         /*
 670          * Print plan if debugging.
 671          */
 672         if (Debug_print_plan)
 673                 elog_node_display(DEBUG1, "plan", plan, Debug_pretty_print);
 674
 675         return plan;
 676 }
 677
 678 /*
 679  * Generate plans for a list of already-rewritten queries.
 680  *
 681  * If needSnapshot is TRUE, we haven't yet set a snapshot for the current
 682  * query.  A snapshot must be set before invoking the planner, since it
 683  * might try to evaluate user-defined functions.  But we must not set a
 684  * snapshot if the list contains only utility statements, because some
 685  * utility statements depend on not having frozen the snapshot yet.
 686  * (We assume that such statements cannot appear together with plannable
 687  * statements in the rewriter's output.)
 688  */
 689 List *
 690 pg_plan_queries(List *querytrees, ParamListInfo boundParams,
 691                                 bool needSnapshot)
 692 {
 693         List       *plan_list = NIL;
 694         ListCell   *query_list;
 695
 696         foreach(query_list, querytrees)
 697         {
 698                 Query      *query = (Query *) lfirst(query_list);
 699                 Plan       *plan;
 700
 701                 if (query->commandType == CMD_UTILITY)
 702                 {
 703                         /* Utility commands have no plans. */
 704                         plan = NULL;
 705                 }
 706                 else
 707                 {
 708                         if (needSnapshot)
 709                         {
 710                                 SetQuerySnapshot();
 711                                 needSnapshot = false;
 712                         }
 713                         plan = pg_plan_query(query, boundParams);
 714                 }
 715
 716                 plan_list = lappend(plan_list, plan);
 717         }
 718
 719         return plan_list;
 720 }
 721
 722
 723 /*
 724  * exec_simple_query
 725  *
 726  * Execute a "simple Query" protocol message.
 727  */
 728 static void
 729 exec_simple_query(const char *query_string)
 730 {
 731         CommandDest dest = whereToSendOutput;
 732         MemoryContext oldcontext;
 733         List       *parsetree_list;
 734         ListCell   *parsetree_item;
 735         struct timeval start_t,
 736                                 stop_t;
 737         bool            save_log_duration = log_duration;
 738         int                     save_log_min_duration_statement = log_min_duration_statement;
 739         bool            save_log_statement_stats = log_statement_stats;
 740
 741         /*
 742          * Report query to various monitoring facilities.
 743          */
 744         debug_query_string = query_string;
 745
 746         pgstat_report_activity(query_string);
 747
 748         /*
 749          * We use save_log_* so "SET log_duration = true"  and "SET
 750          * log_min_duration_statement = true" don't report incorrect time
 751          * because gettimeofday() wasn't called. Similarly,
 752          * log_statement_stats has to be captured once.
 753          */
 754         if (save_log_duration || save_log_min_duration_statement != -1)
 755                 gettimeofday(&start_t, NULL);
 756
 757         if (save_log_statement_stats)
 758                 ResetUsage();
 759
 760         /*
 761          * Start up a transaction command.      All queries generated by the
 762          * query_string will be in this same command block, *unless* we find a
 763          * BEGIN/COMMIT/ABORT statement; we have to force a new xact command
 764          * after one of those, else bad things will happen in xact.c. (Note
 765          * that this will normally change current memory context.)
 766          */
 767         start_xact_command();
 768
 769         /*
 770          * Zap any pre-existing unnamed statement.      (While not strictly
 771          * necessary, it seems best to define simple-Query mode as if it used
 772          * the unnamed statement and portal; this ensures we recover any
 773          * storage used by prior unnamed operations.)
 774          */
 775         unnamed_stmt_pstmt = NULL;
 776         if (unnamed_stmt_context)
 777         {
 778                 DropDependentPortals(unnamed_stmt_context);
 779                 MemoryContextDelete(unnamed_stmt_context);
 780         }
 781         unnamed_stmt_context = NULL;
 782
 783         /*
 784          * Switch to appropriate context for constructing parsetrees.
 785          */
 786         oldcontext = MemoryContextSwitchTo(MessageContext);
 787
 788         QueryContext = CurrentMemoryContext;
 789
 790         /*
 791          * Do basic parsing of the query or queries (this should be safe even
 792          * if we are in aborted transaction state!)
 793          */
 794         parsetree_list = pg_parse_query(query_string);
 795
 796         /*
 797          * Switch back to transaction context to enter the loop.
 798          */
 799         MemoryContextSwitchTo(oldcontext);
 800
 801         /*
 802          * Run through the raw parsetree(s) and process each one.
 803          */
 804         foreach(parsetree_item, parsetree_list)
 805         {
 806                 Node       *parsetree = (Node *) lfirst(parsetree_item);
 807                 const char *commandTag;
 808                 char            completionTag[COMPLETION_TAG_BUFSIZE];
 809                 List       *querytree_list,
 810                                    *plantree_list;
 811                 Portal          portal;
 812                 DestReceiver *receiver;
 813                 int16           format;
 814
 815                 /*
 816                  * Get the command name for use in status display (it also becomes
 817                  * the default completion tag, down inside PortalRun).  Set
 818                  * ps_status and do any special start-of-SQL-command processing
 819                  * needed by the destination.
 820                  */
 821                 commandTag = CreateCommandTag(parsetree);
 822
 823                 set_ps_display(commandTag);
 824
 825                 BeginCommand(commandTag, dest);
 826
 827                 /*
 828                  * If we are in an aborted transaction, reject all commands except
 829                  * COMMIT/ABORT.  It is important that this test occur before we
 830                  * try to do parse analysis, rewrite, or planning, since all those
 831                  * phases try to do database accesses, which may fail in abort
 832                  * state. (It might be safe to allow some additional utility
 833                  * commands in this state, but not many...)
 834                  */
 835                 if (IsAbortedTransactionBlockState())
 836                 {
 837                         bool            allowit = false;
 838
 839                         if (IsA(parsetree, TransactionStmt))
 840                         {
 841                                 TransactionStmt *stmt = (TransactionStmt *) parsetree;
 842
 843                                 if (stmt->kind == TRANS_STMT_COMMIT ||
 844                                         stmt->kind == TRANS_STMT_ROLLBACK)
 845                                         allowit = true;
 846                         }
 847
 848                         if (!allowit)
 849                                 ereport(ERROR,
 850                                                 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
 851                                                  errmsg("current transaction is aborted, "
 852                                          "commands ignored until end of transaction block")));
 853                 }
 854
 855                 /* Make sure we are in a transaction command */
 856                 start_xact_command();
 857
 858                 /* If we got a cancel signal in parsing or prior command, quit */
 859                 CHECK_FOR_INTERRUPTS();
 860
 861                 /*
 862                  * OK to analyze, rewrite, and plan this query.
 863                  *
 864                  * Switch to appropriate context for constructing querytrees (again,
 865                  * these must outlive the execution context).
 866                  */
 867                 oldcontext = MemoryContextSwitchTo(MessageContext);
 868
 869                 querytree_list = pg_analyze_and_rewrite(parsetree, NULL, 0);
 870
 871                 plantree_list = pg_plan_queries(querytree_list, NULL, true);
 872
 873                 /* If we got a cancel signal in analysis or planning, quit */
 874                 CHECK_FOR_INTERRUPTS();
 875
 876                 /*
 877                  * Create unnamed portal to run the query or queries in. If there
 878                  * already is one, silently drop it.
 879                  */
 880                 portal = CreatePortal("", true, true);
 881
 882                 PortalDefineQuery(portal,
 883                                                   query_string,
 884                                                   commandTag,
 885                                                   querytree_list,
 886                                                   plantree_list,
 887                                                   MessageContext);
 888
 889                 /*
 890                  * Start the portal.  No parameters here.
 891                  */
 892                 PortalStart(portal, NULL);
 893
 894                 /*
 895                  * Select the appropriate output format: text unless we are doing
 896                  * a FETCH from a binary cursor.  (Pretty grotty to have to do
 897                  * this here --- but it avoids grottiness in other places.      Ah,
 898                  * the joys of backward compatibility...)
 899                  */
 900                 format = 0;                             /* TEXT is default */
 901                 if (IsA(parsetree, FetchStmt))
 902                 {
 903                         FetchStmt  *stmt = (FetchStmt *) parsetree;
 904
 905                         if (!stmt->ismove)
 906                         {
 907                                 Portal          fportal = GetPortalByName(stmt->portalname);
 908
 909                                 if (PortalIsValid(fportal) &&
 910                                         (fportal->cursorOptions & CURSOR_OPT_BINARY))
 911                                         format = 1; /* BINARY */
 912                         }
 913                 }
 914                 PortalSetResultFormat(portal, 1, &format);
 915
 916                 /*
 917                  * Now we can create the destination receiver object.
 918                  */
 919                 receiver = CreateDestReceiver(dest, portal);
 920
 921                 /*
 922                  * Switch back to transaction context for execution.
 923                  */
 924                 MemoryContextSwitchTo(oldcontext);
 925
 926                 /*
 927                  * Run the portal to completion, and then drop it (and the
 928                  * receiver).
 929                  */
 930                 (void) PortalRun(portal,
 931                                                  FETCH_ALL,
 932                                                  receiver,
 933                                                  receiver,
 934                                                  completionTag);
 935
 936                 (*receiver->rDestroy) (receiver);
 937
 938                 PortalDrop(portal, false);
 939
 940                 if (IsA(parsetree, TransactionStmt))
 941                 {
 942                         /*
 943                          * If this was a transaction control statement, commit it. We
 944                          * will start a new xact command for the next command (if
 945                          * any).
 946                          */
 947                         finish_xact_command();
 948                 }
 949                 else if (lnext(parsetree_item) == NULL)
 950                 {
 951                         /*
 952                          * If this is the last parsetree of the query string, close
 953                          * down transaction statement before reporting
 954                          * command-complete.  This is so that any end-of-transaction
 955                          * errors are reported before the command-complete message is
 956                          * issued, to avoid confusing clients who will expect either a
 957                          * command-complete message or an error, not one and then the
 958                          * other.  But for compatibility with historical Postgres
 959                          * behavior, we do not force a transaction boundary between
 960                          * queries appearing in a single query string.
 961                          */
 962                         finish_xact_command();
 963                 }
 964                 else
 965                 {
 966                         /*
 967                          * We need a CommandCounterIncrement after every query, except
 968                          * those that start or end a transaction block.
 969                          */
 970                         CommandCounterIncrement();
 971                 }
 972
 973                 /*
 974                  * Tell client that we're done with this query.  Note we emit
 975                  * exactly one EndCommand report for each raw parsetree, thus one
 976                  * for each SQL command the client sent, regardless of rewriting.
 977                  * (But a command aborted by error will not send an EndCommand
 978                  * report at all.)
 979                  */
 980                 EndCommand(completionTag, dest);
 981         }                                                       /* end loop over parsetrees */
 982
 983         /*
 984          * Close down transaction statement, if one is open.
 985          */
 986         finish_xact_command();
 987
 988         /*
 989          * If there were no parsetrees, return EmptyQueryResponse message.
 990          */
 991         if (!parsetree_list)
 992                 NullCommand(dest);
 993
 994         QueryContext = NULL;
 995
 996         /*
 997          * Combine processing here as we need to calculate the query duration
 998          * in both instances.
 999          */
1000         if (save_log_duration || save_log_min_duration_statement != -1)
1001         {
1002                 long            usecs;
1003
1004                 gettimeofday(&stop_t, NULL);
1005                 if (stop_t.tv_usec < start_t.tv_usec)
1006                 {
1007                         stop_t.tv_sec--;
1008                         stop_t.tv_usec += 1000000;
1009                 }
1010                 usecs = (long) (stop_t.tv_sec - start_t.tv_sec) * 1000000 + (long) (stop_t.tv_usec - start_t.tv_usec);
1011
1012                 if (save_log_duration)
1013                         ereport(LOG,
1014                                         (errmsg("duration: %ld.%03ld ms",
1015                                                         (long) ((stop_t.tv_sec - start_t.tv_sec) * 1000 +
1016                                                         (stop_t.tv_usec - start_t.tv_usec) / 1000),
1017                                                         (long) (stop_t.tv_usec - start_t.tv_usec) % 1000)));
1018
1019                 /*
1020                  * Output a duration_statement to the log if the query has exceeded
1021                  * the min duration, or if we are to print all durations.
1022                  */
1023                 if (save_log_min_duration_statement == 0 ||
1024                         (save_log_min_duration_statement > 0 &&
1025                          usecs >= save_log_min_duration_statement * 1000))
1026                         ereport(LOG,
1027                                         (errmsg("duration: %ld.%03ld ms  statement: %s",
1028                                                         (long) ((stop_t.tv_sec - start_t.tv_sec) * 1000 +
1029                                                         (stop_t.tv_usec - start_t.tv_usec) / 1000),
1030                                                         (long) (stop_t.tv_usec - start_t.tv_usec) % 1000,
1031                                                         query_string)));
1032         }
1033
1034         if (save_log_statement_stats)
1035                 ShowUsage("QUERY STATISTICS");
1036
1037         debug_query_string = NULL;
1038 }
1039
1040 /*
1041  * exec_parse_message
1042  *
1043  * Execute a "Parse" protocol message.
1044  */
1045 static void
1046 exec_parse_message(const char *query_string,    /* string to execute */
1047                                    const char *stmt_name,               /* name for prepared stmt */
1048                                    Oid *paramTypes,             /* parameter types */
1049                                    int numParams)               /* number of parameters */
1050 {
1051         MemoryContext oldcontext;
1052         List       *parsetree_list;
1053         const char *commandTag;
1054         List       *querytree_list,
1055                            *plantree_list,
1056                            *param_list;
1057         bool            is_named;
1058         bool            save_log_statement_stats = log_statement_stats;
1059
1060         /*
1061          * Report query to various monitoring facilities.
1062          */
1063         debug_query_string = query_string;
1064
1065         pgstat_report_activity(query_string);
1066
1067         set_ps_display("PARSE");
1068
1069         if (save_log_statement_stats)
1070                 ResetUsage();
1071
1072         /*
1073          * Start up a transaction command so we can run parse analysis etc.
1074          * (Note that this will normally change current memory context.)
1075          * Nothing happens if we are already in one.
1076          */
1077         start_xact_command();
1078
1079         /*
1080          * Switch to appropriate context for constructing parsetrees.
1081          *
1082          * We have two strategies depending on whether the prepared statement is
1083          * named or not.  For a named prepared statement, we do parsing in
1084          * MessageContext and copy the finished trees into the prepared
1085          * statement's private context; then the reset of MessageContext
1086          * releases temporary space used by parsing and planning.  For an
1087          * unnamed prepared statement, we assume the statement isn't going to
1088          * hang around long, so getting rid of temp space quickly is probably
1089          * not worth the costs of copying parse/plan trees.  So in this case,
1090          * we set up a special context for the unnamed statement, and do all
1091          * the parsing/planning therein.
1092          */
1093         is_named = (stmt_name[0] != '\0');
1094         if (is_named)
1095         {
1096                 /* Named prepared statement --- parse in MessageContext */
1097                 oldcontext = MemoryContextSwitchTo(MessageContext);
1098         }
1099         else
1100         {
1101                 /* Unnamed prepared statement --- release any prior unnamed stmt */
1102                 unnamed_stmt_pstmt = NULL;
1103                 if (unnamed_stmt_context)
1104                 {
1105                         DropDependentPortals(unnamed_stmt_context);
1106                         MemoryContextDelete(unnamed_stmt_context);
1107                 }
1108                 unnamed_stmt_context = NULL;
1109                 /* create context for parsing/planning */
1110                 unnamed_stmt_context =
1111                         AllocSetContextCreate(TopMemoryContext,
1112                                                                   "unnamed prepared statement",
1113                                                                   ALLOCSET_DEFAULT_MINSIZE,
1114                                                                   ALLOCSET_DEFAULT_INITSIZE,
1115                                                                   ALLOCSET_DEFAULT_MAXSIZE);
1116                 oldcontext = MemoryContextSwitchTo(unnamed_stmt_context);
1117         }
1118
1119         QueryContext = CurrentMemoryContext;
1120
1121         /*
1122          * Do basic parsing of the query or queries (this should be safe even
1123          * if we are in aborted transaction state!)
1124          */
1125         parsetree_list = pg_parse_query(query_string);
1126
1127         /*
1128          * We only allow a single user statement in a prepared statement. This
1129          * is mainly to keep the protocol simple --- otherwise we'd need to
1130          * worry about multiple result tupdescs and things like that.
1131          */
1132         if (list_length(parsetree_list) > 1)
1133                 ereport(ERROR,
1134                                 (errcode(ERRCODE_SYNTAX_ERROR),
1135                                  errmsg("cannot insert multiple commands into a prepared statement")));
1136
1137         if (parsetree_list != NIL)
1138         {
1139                 Node       *parsetree = (Node *) linitial(parsetree_list);
1140                 int                     i;
1141
1142                 /*
1143                  * Get the command name for possible use in status display.
1144                  */
1145                 commandTag = CreateCommandTag(parsetree);
1146
1147                 /*
1148                  * If we are in an aborted transaction, reject all commands except
1149                  * COMMIT/ROLLBACK.  It is important that this test occur before
1150                  * we try to do parse analysis, rewrite, or planning, since all
1151                  * those phases try to do database accesses, which may fail in
1152                  * abort state. (It might be safe to allow some additional utility
1153                  * commands in this state, but not many...)
1154                  */
1155                 if (IsAbortedTransactionBlockState())
1156                 {
1157                         bool            allowit = false;
1158
1159                         if (IsA(parsetree, TransactionStmt))
1160                         {
1161                                 TransactionStmt *stmt = (TransactionStmt *) parsetree;
1162
1163                                 if (stmt->kind == TRANS_STMT_COMMIT ||
1164                                         stmt->kind == TRANS_STMT_ROLLBACK)
1165                                         allowit = true;
1166                         }
1167
1168                         if (!allowit)
1169                                 ereport(ERROR,
1170                                                 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1171                                                  errmsg("current transaction is aborted, "
1172                                          "commands ignored until end of transaction block")));
1173                 }
1174
1175                 /*
1176                  * OK to analyze, rewrite, and plan this query.  Note that the
1177                  * originally specified parameter set is not required to be
1178                  * complete, so we have to use parse_analyze_varparams().
1179                  */
1180                 if (log_parser_stats)
1181                         ResetUsage();
1182
1183                 querytree_list = parse_analyze_varparams(parsetree,
1184                                                                                                  &paramTypes,
1185                                                                                                  &numParams);
1186
1187                 /*
1188                  * Check all parameter types got determined, and convert array
1189                  * representation to a list for storage.
1190                  */
1191                 param_list = NIL;
1192                 for (i = 0; i < numParams; i++)
1193                 {
1194                         Oid                     ptype = paramTypes[i];
1195
1196                         if (ptype == InvalidOid || ptype == UNKNOWNOID)
1197                                 ereport(ERROR,
1198                                                 (errcode(ERRCODE_INDETERMINATE_DATATYPE),
1199                                   errmsg("could not determine data type of parameter $%d",
1200                                                  i + 1)));
1201                         param_list = lappend_oid(param_list, ptype);
1202                 }
1203
1204                 if (log_parser_stats)
1205                         ShowUsage("PARSE ANALYSIS STATISTICS");
1206
1207                 querytree_list = pg_rewrite_queries(querytree_list);
1208
1209                 /*
1210                  * If this is the unnamed statement and it has parameters, defer
1211                  * query planning until Bind.  Otherwise do it now.
1212                  */
1213                 if (!is_named && numParams > 0)
1214                         plantree_list = NIL;
1215                 else
1216                         plantree_list = pg_plan_queries(querytree_list, NULL, true);
1217         }
1218         else
1219         {
1220                 /* Empty input string.  This is legal. */
1221                 commandTag = NULL;
1222                 querytree_list = NIL;
1223                 plantree_list = NIL;
1224                 param_list = NIL;
1225         }
1226
1227         /* If we got a cancel signal in analysis or planning, quit */
1228         CHECK_FOR_INTERRUPTS();
1229
1230         /*
1231          * Store the query as a prepared statement.  See above comments.
1232          */
1233         if (is_named)
1234         {
1235                 StorePreparedStatement(stmt_name,
1236                                                            query_string,
1237                                                            commandTag,
1238                                                            querytree_list,
1239                                                            plantree_list,
1240                                                            param_list);
1241         }
1242         else
1243         {
1244                 PreparedStatement *pstmt;
1245
1246                 pstmt = (PreparedStatement *) palloc0(sizeof(PreparedStatement));
1247                 /* query_string needs to be copied into unnamed_stmt_context */
1248                 pstmt->query_string = pstrdup(query_string);
1249                 /* the rest is there already */
1250                 pstmt->commandTag = commandTag;
1251                 pstmt->query_list = querytree_list;
1252                 pstmt->plan_list = plantree_list;
1253                 pstmt->argtype_list = param_list;
1254                 pstmt->context = unnamed_stmt_context;
1255                 /* Now the unnamed statement is complete and valid */
1256                 unnamed_stmt_pstmt = pstmt;
1257         }
1258
1259         MemoryContextSwitchTo(oldcontext);
1260
1261         QueryContext = NULL;
1262
1263         /*
1264          * We do NOT close the open transaction command here; that only
1265          * happens when the client sends Sync.  Instead, do
1266          * CommandCounterIncrement just in case something happened during
1267          * parse/plan.
1268          */
1269         CommandCounterIncrement();
1270
1271         /*
1272          * Send ParseComplete.
1273          */
1274         if (whereToSendOutput == Remote)
1275                 pq_putemptymessage('1');
1276
1277         if (save_log_statement_stats)
1278                 ShowUsage("PARSE MESSAGE STATISTICS");
1279
1280         debug_query_string = NULL;
1281 }
1282
1283 /*
1284  * exec_bind_message
1285  *
1286  * Process a "Bind" message to create a portal from a prepared statement
1287  */
1288 static void
1289 exec_bind_message(StringInfo input_message)
1290 {
1291         const char *portal_name;
1292         const char *stmt_name;
1293         int                     numPFormats;
1294         int16      *pformats = NULL;
1295         int                     numParams;
1296         int                     numRFormats;
1297         int16      *rformats = NULL;
1298         int                     i;
1299         PreparedStatement *pstmt;
1300         Portal          portal;
1301         ParamListInfo params;
1302         bool            isaborted = IsAbortedTransactionBlockState();
1303
1304         pgstat_report_activity("<BIND>");
1305
1306         set_ps_display("BIND");
1307
1308         /*
1309          * Start up a transaction command so we can call functions etc. (Note
1310          * that this will normally change current memory context.) Nothing
1311          * happens if we are already in one.
1312          */
1313         start_xact_command();
1314
1315         /* Switch back to message context */
1316         MemoryContextSwitchTo(MessageContext);
1317
1318         /* Get the fixed part of the message */
1319         portal_name = pq_getmsgstring(input_message);
1320         stmt_name = pq_getmsgstring(input_message);
1321
1322         /* Get the parameter format codes */
1323         numPFormats = pq_getmsgint(input_message, 2);
1324         if (numPFormats > 0)
1325         {
1326                 pformats = (int16 *) palloc(numPFormats * sizeof(int16));
1327                 for (i = 0; i < numPFormats; i++)
1328                         pformats[i] = pq_getmsgint(input_message, 2);
1329         }
1330
1331         /* Get the parameter value count */
1332         numParams = pq_getmsgint(input_message, 2);
1333
1334         if (numPFormats > 1 && numPFormats != numParams)
1335                 ereport(ERROR,
1336                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1337                 errmsg("bind message has %d parameter formats but %d parameters",
1338                            numPFormats, numParams)));
1339
1340         /* Find prepared statement */
1341         if (stmt_name[0] != '\0')
1342                 pstmt = FetchPreparedStatement(stmt_name, true);
1343         else
1344         {
1345                 /* special-case the unnamed statement */
1346                 pstmt = unnamed_stmt_pstmt;
1347                 if (!pstmt)
1348                         ereport(ERROR,
1349                                         (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
1350                                    errmsg("unnamed prepared statement does not exist")));
1351         }
1352
1353         if (numParams != list_length(pstmt->argtype_list))
1354                 ereport(ERROR,
1355                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1356                                  errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d",
1357                                         numParams, stmt_name, list_length(pstmt->argtype_list))));
1358
1359         /*
1360          * Create the portal.  Allow silent replacement of an existing portal
1361          * only if the unnamed portal is specified.
1362          */
1363         if (portal_name[0] == '\0')
1364                 portal = CreatePortal(portal_name, true, true);
1365         else
1366                 portal = CreatePortal(portal_name, false, false);
1367
1368         /*
1369          * Fetch parameters, if any, and store in the portal's memory context.
1370          *
1371          * In an aborted transaction, we can't risk calling user-defined
1372          * functions, but we can't fail to Bind either, so bind all parameters
1373          * to null values.
1374          */
1375         if (numParams > 0)
1376         {
1377                 ListCell   *l;
1378                 MemoryContext oldContext;
1379
1380                 oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
1381
1382                 params = (ParamListInfo)
1383                         palloc0((numParams + 1) * sizeof(ParamListInfoData));
1384
1385                 i = 0;
1386                 foreach(l, pstmt->argtype_list)
1387                 {
1388                         Oid                     ptype = lfirst_oid(l);
1389                         int32           plength;
1390                         bool            isNull;
1391
1392                         plength = pq_getmsgint(input_message, 4);
1393                         isNull = (plength == -1);
1394
1395                         if (!isNull)
1396                         {
1397                                 const char *pvalue = pq_getmsgbytes(input_message, plength);
1398
1399                                 if (isaborted)
1400                                 {
1401                                         /* We don't bother to check the format in this case */
1402                                         isNull = true;
1403                                 }
1404                                 else
1405                                 {
1406                                         int16           pformat;
1407                                         StringInfoData pbuf;
1408                                         char            csave;
1409
1410                                         if (numPFormats > 1)
1411                                                 pformat = pformats[i];
1412                                         else if (numPFormats > 0)
1413                                                 pformat = pformats[0];
1414                                         else
1415                                                 pformat = 0;    /* default = text */
1416
1417                                         /*
1418                                          * Rather than copying data around, we just set up a
1419                                          * phony StringInfo pointing to the correct portion of
1420                                          * the message buffer.  We assume we can scribble on
1421                                          * the message buffer so as to maintain the convention
1422                                          * that StringInfos have a trailing null.  This is
1423                                          * grotty but is a big win when dealing with very
1424                                          * large parameter strings.
1425                                          */
1426                                         pbuf.data = (char *) pvalue;
1427                                         pbuf.maxlen = plength + 1;
1428                                         pbuf.len = plength;
1429                                         pbuf.cursor = 0;
1430
1431                                         csave = pbuf.data[plength];
1432                                         pbuf.data[plength] = '\0';
1433
1434                                         if (pformat == 0)
1435                                         {
1436                                                 Oid                     typinput;
1437                                                 Oid                     typioparam;
1438                                                 char       *pstring;
1439
1440                                                 getTypeInputInfo(ptype, &typinput, &typioparam);
1441
1442                                                 /*
1443                                                  * We have to do encoding conversion before
1444                                                  * calling the typinput routine.
1445                                                  */
1446                                                 pstring = (char *)
1447                                                         pg_client_to_server((unsigned char *) pbuf.data,
1448                                                                                                 plength);
1449                                                 params[i].value =
1450                                                         OidFunctionCall3(typinput,
1451                                                                                          CStringGetDatum(pstring),
1452                                                                                          ObjectIdGetDatum(typioparam),
1453                                                                                          Int32GetDatum(-1));
1454                                                 /* Free result of encoding conversion, if any */
1455                                                 if (pstring != pbuf.data)
1456                                                         pfree(pstring);
1457                                         }
1458                                         else if (pformat == 1)
1459                                         {
1460                                                 Oid                     typreceive;
1461                                                 Oid                     typioparam;
1462
1463                                                 /*
1464                                                  * Call the parameter type's binary input
1465                                                  * converter
1466                                                  */
1467                                                 getTypeBinaryInputInfo(ptype, &typreceive, &typioparam);
1468
1469                                                 params[i].value =
1470                                                         OidFunctionCall2(typreceive,
1471                                                                                          PointerGetDatum(&pbuf),
1472                                                                                          ObjectIdGetDatum(typioparam));
1473
1474                                                 /* Trouble if it didn't eat the whole buffer */
1475                                                 if (pbuf.cursor != pbuf.len)
1476                                                         ereport(ERROR,
1477                                                                         (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
1478                                                                          errmsg("incorrect binary data format in bind parameter %d",
1479                                                                                         i + 1)));
1480                                         }
1481                                         else
1482                                         {
1483                                                 ereport(ERROR,
1484                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1485                                                                  errmsg("unsupported format code: %d",
1486                                                                                 pformat)));
1487                                         }
1488
1489                                         /* Restore message buffer contents */
1490                                         pbuf.data[plength] = csave;
1491                                 }
1492                         }
1493
1494                         params[i].kind = PARAM_NUM;
1495                         params[i].id = i + 1;
1496                         params[i].isnull = isNull;
1497
1498                         i++;
1499                 }
1500
1501                 params[i].kind = PARAM_INVALID;
1502
1503                 MemoryContextSwitchTo(oldContext);
1504         }
1505         else
1506                 params = NULL;
1507
1508         /* Get the result format codes */
1509         numRFormats = pq_getmsgint(input_message, 2);
1510         if (numRFormats > 0)
1511         {
1512                 rformats = (int16 *) palloc(numRFormats * sizeof(int16));
1513                 for (i = 0; i < numRFormats; i++)
1514                         rformats[i] = pq_getmsgint(input_message, 2);
1515         }
1516
1517         pq_getmsgend(input_message);
1518
1519         /*
1520          * If we didn't plan the query before, do it now.  This allows the
1521          * planner to make use of the concrete parameter values we now have.
1522          *
1523          * This happens only for unnamed statements, and so switching into
1524          * the statement context for planning is correct (see notes in
1525          * exec_parse_message).
1526          */
1527         if (pstmt->plan_list == NIL && pstmt->query_list != NIL &&
1528                 !isaborted)
1529         {
1530                 MemoryContext oldContext = MemoryContextSwitchTo(pstmt->context);
1531
1532                 pstmt->plan_list = pg_plan_queries(pstmt->query_list, params, true);
1533                 MemoryContextSwitchTo(oldContext);
1534         }
1535
1536         /*
1537          * Define portal and start execution.
1538          */
1539         PortalDefineQuery(portal,
1540                                           pstmt->query_string,
1541                                           pstmt->commandTag,
1542                                           pstmt->query_list,
1543                                           pstmt->plan_list,
1544                                           pstmt->context);
1545
1546         PortalStart(portal, params);
1547
1548         /*
1549          * Apply the result format requests to the portal.
1550          */
1551         PortalSetResultFormat(portal, numRFormats, rformats);
1552
1553         /*
1554          * Send BindComplete.
1555          */
1556         if (whereToSendOutput == Remote)
1557                 pq_putemptymessage('2');
1558 }
1559
1560 /*
1561  * exec_execute_message
1562  *
1563  * Process an "Execute" message for a portal
1564  */
1565 static void
1566 exec_execute_message(const char *portal_name, long max_rows)
1567 {
1568         CommandDest dest;
1569         DestReceiver *receiver;
1570         Portal          portal;
1571         bool            is_trans_stmt = false;
1572         bool            is_trans_exit = false;
1573         bool            completed;
1574         char            completionTag[COMPLETION_TAG_BUFSIZE];
1575
1576         /* Adjust destination to tell printtup.c what to do */
1577         dest = whereToSendOutput;
1578         if (dest == Remote)
1579                 dest = RemoteExecute;
1580
1581         portal = GetPortalByName(portal_name);
1582         if (!PortalIsValid(portal))
1583                 ereport(ERROR,
1584                                 (errcode(ERRCODE_UNDEFINED_CURSOR),
1585                                  errmsg("portal \"%s\" does not exist", portal_name)));
1586
1587         /*
1588          * If the original query was a null string, just return
1589          * EmptyQueryResponse.
1590          */
1591         if (portal->commandTag == NULL)
1592         {
1593                 Assert(portal->parseTrees == NIL);
1594                 NullCommand(dest);
1595                 return;
1596         }
1597
1598         if (portal->sourceText)
1599         {
1600                 debug_query_string = portal->sourceText;
1601                 pgstat_report_activity(portal->sourceText);
1602         }
1603         else
1604         {
1605                 debug_query_string = "execute message";
1606                 pgstat_report_activity("<EXECUTE>");
1607         }
1608
1609         set_ps_display(portal->commandTag);
1610
1611         BeginCommand(portal->commandTag, dest);
1612
1613         /* Check for transaction-control commands */
1614         if (list_length(portal->parseTrees) == 1)
1615         {
1616                 Query      *query = (Query *) linitial(portal->parseTrees);
1617
1618                 if (query->commandType == CMD_UTILITY &&
1619                         query->utilityStmt != NULL &&
1620                         IsA(query->utilityStmt, TransactionStmt))
1621                 {
1622                         TransactionStmt *stmt = (TransactionStmt *) query->utilityStmt;
1623
1624                         is_trans_stmt = true;
1625                         if (stmt->kind == TRANS_STMT_COMMIT ||
1626                                 stmt->kind == TRANS_STMT_ROLLBACK)
1627                                 is_trans_exit = true;
1628                 }
1629         }
1630
1631         /*
1632          * Create dest receiver in MessageContext (we don't want it in
1633          * transaction context, because that may get deleted if portal
1634          * contains VACUUM).
1635          */
1636         receiver = CreateDestReceiver(dest, portal);
1637
1638         /*
1639          * Ensure we are in a transaction command (this should normally be the
1640          * case already due to prior BIND).
1641          */
1642         start_xact_command();
1643
1644         /*
1645          * If we are in aborted transaction state, the only portals we can
1646          * actually run are those containing COMMIT or ROLLBACK commands.
1647          */
1648         if (IsAbortedTransactionBlockState())
1649         {
1650                 if (!is_trans_exit)
1651                         ereport(ERROR,
1652                                         (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1653                                          errmsg("current transaction is aborted, "
1654                                          "commands ignored until end of transaction block")));
1655         }
1656
1657         /* Check for cancel signal before we start execution */
1658         CHECK_FOR_INTERRUPTS();
1659
1660         /*
1661          * Okay to run the portal.
1662          */
1663         if (max_rows <= 0)
1664                 max_rows = FETCH_ALL;
1665
1666         completed = PortalRun(portal,
1667                                                   max_rows,
1668                                                   receiver,
1669                                                   receiver,
1670                                                   completionTag);
1671
1672         (*receiver->rDestroy) (receiver);
1673
1674         if (completed)
1675         {
1676                 if (is_trans_stmt)
1677                 {
1678                         /*
1679                          * If this was a transaction control statement, commit it.      We
1680                          * will start a new xact command for the next command (if
1681                          * any).
1682                          */
1683                         finish_xact_command();
1684                 }
1685                 else
1686                 {
1687                         /*
1688                          * We need a CommandCounterIncrement after every query, except
1689                          * those that start or end a transaction block.
1690                          */
1691                         CommandCounterIncrement();
1692                 }
1693
1694                 /* Send appropriate CommandComplete to client */
1695                 EndCommand(completionTag, dest);
1696         }
1697         else
1698         {
1699                 /* Portal run not complete, so send PortalSuspended */
1700                 if (whereToSendOutput == Remote)
1701                         pq_putemptymessage('s');
1702         }
1703
1704         debug_query_string = NULL;
1705 }
1706
1707 /*
1708  * exec_describe_statement_message
1709  *
1710  * Process a "Describe" message for a prepared statement
1711  */
1712 static void
1713 exec_describe_statement_message(const char *stmt_name)
1714 {
1715         PreparedStatement *pstmt;
1716         TupleDesc       tupdesc;
1717         ListCell   *l;
1718         StringInfoData buf;
1719
1720         /* Find prepared statement */
1721         if (stmt_name[0] != '\0')
1722                 pstmt = FetchPreparedStatement(stmt_name, true);
1723         else
1724         {
1725                 /* special-case the unnamed statement */
1726                 pstmt = unnamed_stmt_pstmt;
1727                 if (!pstmt)
1728                         ereport(ERROR,
1729                                         (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
1730                                    errmsg("unnamed prepared statement does not exist")));
1731         }
1732
1733         if (whereToSendOutput != Remote)
1734                 return;                                 /* can't actually do anything... */
1735
1736         /*
1737          * First describe the parameters...
1738          */
1739         pq_beginmessage(&buf, 't'); /* parameter description message type */
1740         pq_sendint(&buf, list_length(pstmt->argtype_list), 2);
1741
1742         foreach(l, pstmt->argtype_list)
1743         {
1744                 Oid                     ptype = lfirst_oid(l);
1745
1746                 pq_sendint(&buf, (int) ptype, 4);
1747         }
1748         pq_endmessage(&buf);
1749
1750         /*
1751          * Next send RowDescription or NoData to describe the result...
1752          */
1753         tupdesc = FetchPreparedStatementResultDesc(pstmt);
1754         if (tupdesc)
1755         {
1756                 List       *targetlist;
1757
1758                 if (ChoosePortalStrategy(pstmt->query_list) == PORTAL_ONE_SELECT)
1759                         targetlist = ((Query *) linitial(pstmt->query_list))->targetList;
1760                 else
1761                         targetlist = NIL;
1762                 SendRowDescriptionMessage(tupdesc, targetlist, NULL);
1763         }
1764         else
1765                 pq_putemptymessage('n');        /* NoData */
1766
1767 }
1768
1769 /*
1770  * exec_describe_portal_message
1771  *
1772  * Process a "Describe" message for a portal
1773  */
1774 static void
1775 exec_describe_portal_message(const char *portal_name)
1776 {
1777         Portal          portal;
1778
1779         portal = GetPortalByName(portal_name);
1780         if (!PortalIsValid(portal))
1781                 ereport(ERROR,
1782                                 (errcode(ERRCODE_UNDEFINED_CURSOR),
1783                                  errmsg("portal \"%s\" does not exist", portal_name)));
1784
1785         if (whereToSendOutput != Remote)
1786                 return;                                 /* can't actually do anything... */
1787
1788         if (portal->tupDesc)
1789         {
1790                 List       *targetlist;
1791
1792                 if (portal->strategy == PORTAL_ONE_SELECT)
1793                         targetlist = ((Query *) linitial(portal->parseTrees))->targetList;
1794                 else
1795                         targetlist = NIL;
1796                 SendRowDescriptionMessage(portal->tupDesc, targetlist,
1797                                                                   portal->formats);
1798         }
1799         else
1800                 pq_putemptymessage('n');        /* NoData */
1801 }
1802
1803
1804 /*
1805  * Convenience routines for starting/committing a single command.
1806  */
1807 static void
1808 start_xact_command(void)
1809 {
1810         if (!xact_started)
1811         {
1812                 ereport(DEBUG3,
1813                                 (errmsg_internal("StartTransactionCommand")));
1814                 StartTransactionCommand();
1815
1816                 /* Set statement timeout running, if any */
1817                 if (StatementTimeout > 0)
1818                         enable_sig_alarm(StatementTimeout, true);
1819
1820                 xact_started = true;
1821         }
1822 }
1823
1824 static void
1825 finish_xact_command(void)
1826 {
1827         if (xact_started)
1828         {
1829                 /* Invoke IMMEDIATE constraint triggers */
1830                 DeferredTriggerEndQuery();
1831
1832                 /* Cancel any active statement timeout before committing */
1833                 disable_sig_alarm(true);
1834
1835                 /* Now commit the command */
1836                 ereport(DEBUG3,
1837                                 (errmsg_internal("CommitTransactionCommand")));
1838
1839                 CommitTransactionCommand();
1840
1841 #ifdef MEMORY_CONTEXT_CHECKING
1842                 /* Check all memory contexts that weren't freed during commit */
1843                 /* (those that were, were checked before being deleted) */
1844                 MemoryContextCheck(TopMemoryContext);
1845 #endif
1846
1847 #ifdef SHOW_MEMORY_STATS
1848                 /* Print mem stats after each commit for leak tracking */
1849                 if (ShowStats)
1850                         MemoryContextStats(TopMemoryContext);
1851 #endif
1852
1853                 xact_started = false;
1854         }
1855 }
1856
1857
1858 /* --------------------------------
1859  *              signal handler routines used in PostgresMain()
1860  * --------------------------------
1861  */
1862
1863 /*
1864  * quickdie() occurs when signalled SIGQUIT by the postmaster.
1865  *
1866  * Some backend has bought the farm,
1867  * so we need to stop what we're doing and exit.
1868  */
1869 void
1870 quickdie(SIGNAL_ARGS)
1871 {
1872         PG_SETMASK(&BlockSig);
1873
1874         /*
1875          * Ideally this should be ereport(FATAL), but then we'd not get
1876          * control back (perhaps could fix by doing local sigsetjmp?)
1877          */
1878         ereport(WARNING,
1879                         (errcode(ERRCODE_CRASH_SHUTDOWN),
1880                 errmsg("terminating connection because of crash of another server process"),
1881            errdetail("The postmaster has commanded this server process to roll back"
1882                                  " the current transaction and exit, because another"
1883                                  " server process exited abnormally and possibly corrupted"
1884                                  " shared memory."),
1885                          errhint("In a moment you should be able to reconnect to the"
1886                                          " database and repeat your command.")));
1887
1888         /*
1889          * DO NOT proc_exit() -- we're here because shared memory may be
1890          * corrupted, so we don't want to try to clean up our transaction.
1891          * Just nail the windows shut and get out of town.
1892          *
1893          * Note we do exit(1) not exit(0).      This is to force the postmaster into
1894          * a system reset cycle if some idiot DBA sends a manual SIGQUIT to a
1895          * random backend.      This is necessary precisely because we don't clean
1896          * up our shared memory state.
1897          */
1898         exit(1);
1899 }
1900
1901 /*
1902  * Shutdown signal from postmaster: abort transaction and exit
1903  * at soonest convenient time
1904  */
1905 void
1906 die(SIGNAL_ARGS)
1907 {
1908         int                     save_errno = errno;
1909
1910         /* Don't joggle the elbow of proc_exit */
1911         if (!proc_exit_inprogress)
1912         {
1913                 InterruptPending = true;
1914                 ProcDiePending = true;
1915
1916                 /*
1917                  * If it's safe to interrupt, and we're waiting for input or a
1918                  * lock, service the interrupt immediately
1919                  */
1920                 if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
1921                         CritSectionCount == 0)
1922                 {
1923                         /* bump holdoff count to make ProcessInterrupts() a no-op */
1924                         /* until we are done getting ready for it */
1925                         InterruptHoldoffCount++;
1926                         DisableNotifyInterrupt();
1927                         DisableCatchupInterrupt();
1928                         /* Make sure CheckDeadLock won't run while shutting down... */
1929                         LockWaitCancel();
1930                         InterruptHoldoffCount--;
1931                         ProcessInterrupts();
1932                 }
1933         }
1934
1935         errno = save_errno;
1936 }
1937
1938 /*
1939  * Timeout or shutdown signal from postmaster during client authentication.
1940  * Simply exit(0).
1941  *
1942  * XXX: possible future improvement: try to send a message indicating
1943  * why we are disconnecting.  Problem is to be sure we don't block while
1944  * doing so, nor mess up the authentication message exchange.
1945  */
1946 void
1947 authdie(SIGNAL_ARGS)
1948 {
1949         exit(0);
1950 }
1951
1952 /*
1953  * Query-cancel signal from postmaster: abort current transaction
1954  * at soonest convenient time
1955  */
1956 static void
1957 StatementCancelHandler(SIGNAL_ARGS)
1958 {
1959         int                     save_errno = errno;
1960
1961         /*
1962          * Don't joggle the elbow of proc_exit, nor an already-in-progress
1963          * abort
1964          */
1965         if (!proc_exit_inprogress && !InError)
1966         {
1967                 InterruptPending = true;
1968                 QueryCancelPending = true;
1969
1970                 /*
1971                  * If it's safe to interrupt, and we're waiting for a lock,
1972                  * service the interrupt immediately.  No point in interrupting if
1973                  * we're waiting for input, however.
1974                  */
1975                 if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
1976                         CritSectionCount == 0)
1977                 {
1978                         /* bump holdoff count to make ProcessInterrupts() a no-op */
1979                         /* until we are done getting ready for it */
1980                         InterruptHoldoffCount++;
1981                         if (LockWaitCancel())
1982                         {
1983                                 DisableNotifyInterrupt();
1984                                 DisableCatchupInterrupt();
1985                                 InterruptHoldoffCount--;
1986                                 ProcessInterrupts();
1987                         }
1988                         else
1989                                 InterruptHoldoffCount--;
1990                 }
1991         }
1992
1993         errno = save_errno;
1994 }
1995
1996 /* signal handler for floating point exception */
1997 static void
1998 FloatExceptionHandler(SIGNAL_ARGS)
1999 {
2000         ereport(ERROR,
2001                         (errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
2002                          errmsg("floating-point exception"),
2003                    errdetail("An invalid floating-point operation was signaled. "
2004                                          "This probably means an out-of-range result or an "
2005                                          "invalid operation, such as division by zero.")));
2006 }
2007
2008 /* SIGHUP: set flag to re-read config file at next convenient time */
2009 static void
2010 SigHupHandler(SIGNAL_ARGS)
2011 {
2012         got_SIGHUP = true;
2013 }
2014
2015
2016 /*
2017  * ProcessInterrupts: out-of-line portion of CHECK_FOR_INTERRUPTS() macro
2018  *
2019  * If an interrupt condition is pending, and it's safe to service it,
2020  * then clear the flag and accept the interrupt.  Called only when
2021  * InterruptPending is true.
2022  */
2023 void
2024 ProcessInterrupts(void)
2025 {
2026         /* OK to accept interrupt now? */
2027         if (InterruptHoldoffCount != 0 || CritSectionCount != 0)
2028                 return;
2029         InterruptPending = false;
2030         if (ProcDiePending)
2031         {
2032                 ProcDiePending = false;
2033                 QueryCancelPending = false;             /* ProcDie trumps QueryCancel */
2034                 ImmediateInterruptOK = false;   /* not idle anymore */
2035                 DisableNotifyInterrupt();
2036                 DisableCatchupInterrupt();
2037                 ereport(FATAL,
2038                                 (errcode(ERRCODE_ADMIN_SHUTDOWN),
2039                  errmsg("terminating connection due to administrator command")));
2040         }
2041         if (QueryCancelPending)
2042         {
2043                 QueryCancelPending = false;
2044                 ImmediateInterruptOK = false;   /* not idle anymore */
2045                 DisableNotifyInterrupt();
2046                 DisableCatchupInterrupt();
2047                 ereport(ERROR,
2048                                 (errcode(ERRCODE_QUERY_CANCELED),
2049                                  errmsg("canceling query due to user request")));
2050         }
2051         /* If we get here, do nothing (probably, QueryCancelPending was reset) */
2052 }
2053
2054
2055 /*
2056  * check_stack_depth: check for excessively deep recursion
2057  *
2058  * This should be called someplace in any recursive routine that might possibly
2059  * recurse deep enough to overflow the stack.  Most Unixen treat stack
2060  * overflow as an unrecoverable SIGSEGV, so we want to error out ourselves
2061  * before hitting the hardware limit.  Unfortunately we have no direct way
2062  * to detect the hardware limit, so we have to rely on the admin to set a
2063  * GUC variable for it ...
2064  */
2065 void
2066 check_stack_depth(void)
2067 {
2068         char    stack_top_loc;
2069         int             stack_depth;
2070
2071         /*
2072          * Compute distance from PostgresMain's local variables to my own
2073          *
2074          * Note: in theory stack_depth should be ptrdiff_t or some such, but
2075          * since the whole point of this code is to bound the value to something
2076          * much less than integer-sized, int should work fine.
2077          */
2078         stack_depth = (int) (stack_base_ptr - &stack_top_loc);
2079         /*
2080          * Take abs value, since stacks grow up on some machines, down on others
2081          */
2082         if (stack_depth < 0)
2083                 stack_depth = -stack_depth;
2084         /*
2085          * Trouble?
2086          *
2087          * The test on stack_base_ptr prevents us from erroring out if called
2088          * during process setup or in a non-backend process.  Logically it should
2089          * be done first, but putting it here avoids wasting cycles during normal
2090          * cases.
2091          */
2092         if (stack_depth > max_stack_depth_bytes &&
2093                 stack_base_ptr != NULL)
2094         {
2095                 ereport(ERROR,
2096                                 (errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
2097                                  errmsg("stack depth limit exceeded"),
2098                                  errhint("Increase the configuration parameter \"max_stack_depth\".")));
2099         }
2100 }
2101
2102 /* GUC assign hook to update max_stack_depth_bytes from max_stack_depth */
2103 bool
2104 assign_max_stack_depth(int newval, bool doit, GucSource source)
2105 {
2106         /* Range check was already handled by guc.c */
2107         if (doit)
2108                 max_stack_depth_bytes = newval * 1024;
2109         return true;
2110 }
2111
2112
2113 static void
2114 usage(const char *progname)
2115 {
2116         printf(gettext("%s is the PostgreSQL stand-alone backend.  It is not\nintended to be used by normal users.\n\n"), progname);
2117
2118         printf(gettext("Usage:\n  %s [OPTION]... [DBNAME]\n\n"), progname);
2119         printf(gettext("Options:\n"));
2120 #ifdef USE_ASSERT_CHECKING
2121         printf(gettext("  -A 1|0          enable/disable run-time assert checking\n"));
2122 #endif
2123         printf(gettext("  -B NBUFFERS     number of shared buffers\n"));
2124         printf(gettext("  -c NAME=VALUE   set run-time parameter\n"));
2125         printf(gettext("  -d 0-5          debugging level (0 is off)\n"));
2126         printf(gettext("  -D DATADIR      database directory\n"));
2127         printf(gettext("  -e              use European date input format (DMY)\n"));
2128         printf(gettext("  -E              echo query before execution\n"));
2129         printf(gettext("  -F              turn fsync off\n"));
2130         printf(gettext("  -N              do not use newline as interactive query delimiter\n"));
2131         printf(gettext("  -o FILENAME     send stdout and stderr to given file\n"));
2132         printf(gettext("  -P              disable system indexes\n"));
2133         printf(gettext("  -s              show statistics after each query\n"));
2134         printf(gettext("  -S WORK-MEM     set amount of memory for sorts (in kbytes)\n"));
2135         printf(gettext("  --describe-config  describe configuration parameters, then exit\n"));
2136         printf(gettext("  --help          show this help, then exit\n"));
2137         printf(gettext("  --version       output version information, then exit\n"));
2138         printf(gettext("\nDeveloper options:\n"));
2139         printf(gettext("  -f s|i|n|m|h    forbid use of some plan types\n"));
2140         printf(gettext("  -i              do not execute queries\n"));
2141         printf(gettext("  -O              allow system table structure changes\n"));
2142         printf(gettext("  -t pa|pl|ex     show timings after each query\n"));
2143         printf(gettext("  -W NUM          wait NUM seconds to allow attach from a debugger\n"));
2144         printf(gettext("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
2145 }
2146
2147
2148
2149 /* ----------------------------------------------------------------
2150  * PostgresMain
2151  *         postgres main loop -- all backends, interactive or otherwise start here
2152  *
2153  * argc/argv are the command line arguments to be used.  (When being forked
2154  * by the postmaster, these are not the original argv array of the process.)
2155  * username is the (possibly authenticated) PostgreSQL user name to be used
2156  * for the session.
2157  * ----------------------------------------------------------------
2158  */
2159 int
2160 PostgresMain(int argc, char *argv[], const char *username)
2161 {
2162         int                     flag;
2163         const char *dbname = NULL;
2164         char       *potential_DataDir = NULL;
2165         bool            secure;
2166         int                     errs = 0;
2167         int                     debug_flag = 0;
2168         GucContext      ctx,
2169                                 debug_context;
2170         GucSource       gucsource;
2171         char       *tmp;
2172         int                     firstchar;
2173         char            stack_base;
2174         StringInfoData  input_message;
2175         volatile bool send_rfq = true;
2176
2177         /*
2178          * Catch standard options before doing much else.  This even works on
2179          * systems without getopt_long.
2180          */
2181         if (!IsUnderPostmaster && argc > 1)
2182         {
2183                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
2184                 {
2185                         usage(argv[0]);
2186                         exit(0);
2187                 }
2188                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
2189                 {
2190                         puts(PG_VERSIONSTR);
2191                         exit(0);
2192                 }
2193         }
2194
2195         /*
2196          * initialize globals (already done if under postmaster, but not if
2197          * standalone; cheap enough to do over)
2198          */
2199         MyProcPid = getpid();
2200
2201         /*
2202          * Fire up essential subsystems: error and memory management
2203          *
2204          * If we are running under the postmaster, this is done already.
2205          */
2206         if (!IsUnderPostmaster)
2207                 MemoryContextInit();
2208
2209         set_ps_display("startup");
2210
2211         SetProcessingMode(InitProcessing);
2212
2213         /* Set up reference point for stack depth checking */
2214         stack_base_ptr = &stack_base;
2215
2216         /* Compute paths, if we didn't inherit them from postmaster */
2217         if (my_exec_path[0] == '\0')
2218         {
2219                 if (find_my_exec(argv[0], my_exec_path) < 0)
2220                         elog(FATAL, "%s: could not locate my own executable path",
2221                                  argv[0]);
2222         }
2223
2224         if (pkglib_path[0] == '\0')
2225                 get_pkglib_path(my_exec_path, pkglib_path);
2226
2227         /*
2228          * Set default values for command-line options.
2229          */
2230         EchoQuery = false;
2231
2232         if (!IsUnderPostmaster)
2233         {
2234                 InitializeGUCOptions();
2235                 potential_DataDir = getenv("PGDATA");
2236         }
2237
2238         /* ----------------
2239          *      parse command line arguments
2240          *
2241          *      There are now two styles of command line layout for the backend:
2242          *
2243          *      For interactive use (not started from postmaster) the format is
2244          *              postgres [switches] [databasename]
2245          *      If the databasename is omitted it is taken to be the user name.
2246          *
2247          *      When started from the postmaster, the format is
2248          *              postgres [secure switches] -p databasename [insecure switches]
2249          *      Switches appearing after -p came from the client (via "options"
2250          *      field of connection request).  For security reasons we restrict
2251          *      what these switches can do.
2252          * ----------------
2253          */
2254
2255         /* all options are allowed until '-p' */
2256         secure = true;
2257         ctx = debug_context = PGC_POSTMASTER;
2258         gucsource = PGC_S_ARGV;         /* initial switches came from command line */
2259
2260         while ((flag = getopt(argc, argv, "A:B:c:D:d:Eef:FiNOPo:p:S:st:v:W:-:")) != -1)
2261                 switch (flag)
2262                 {
2263                         case 'A':
2264 #ifdef USE_ASSERT_CHECKING
2265                                 SetConfigOption("debug_assertions", optarg, ctx, gucsource);
2266 #else
2267                                 ereport(WARNING,
2268                                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2269                                                  errmsg("assert checking is not compiled in")));
2270 #endif
2271                                 break;
2272
2273                         case 'B':
2274
2275                                 /*
2276                                  * specify the size of buffer pool
2277                                  */
2278                                 SetConfigOption("shared_buffers", optarg, ctx, gucsource);
2279                                 break;
2280
2281                         case 'D':                       /* PGDATA directory */
2282                                 if (secure)
2283                                         potential_DataDir = optarg;
2284                                 break;
2285
2286                         case 'd':                       /* debug level */
2287                                 {
2288                                         /*
2289                                          * Client option can't decrease debug level. We have
2290                                          * to do the test here because we group priv and
2291                                          * client set GUC calls below, after we know the final
2292                                          * debug value.
2293                                          */
2294                                         if (ctx != PGC_BACKEND || atoi(optarg) > debug_flag)
2295                                         {
2296                                                 debug_flag = atoi(optarg);
2297                                                 debug_context = ctx;    /* save context for use
2298                                                                                                  * below */
2299                                                 /* Set server debugging level. */
2300                                                 if (debug_flag != 0)
2301                                                 {
2302                                                         char       *debugstr = palloc(strlen("debug") + strlen(optarg) + 1);
2303
2304                                                         sprintf(debugstr, "debug%s", optarg);
2305                                                         SetConfigOption("log_min_messages", debugstr, ctx, gucsource);
2306                                                         pfree(debugstr);
2307
2308                                                 }
2309                                                 else
2310
2311                                                         /*
2312                                                          * -d0 allows user to prevent postmaster debug
2313                                                          * from propagating to backend.  It would be
2314                                                          * nice to set it to the postgresql.conf value
2315                                                          * here.
2316                                                          */
2317                                                         SetConfigOption("log_min_messages", "notice",
2318                                                                                         ctx, gucsource);
2319                                         }
2320                                 }
2321                                 break;
2322
2323                         case 'E':
2324
2325                                 /*
2326                                  * E - echo the query the user entered
2327                                  */
2328                                 EchoQuery = true;
2329                                 break;
2330
2331                         case 'e':
2332
2333                                 /*
2334                                  * Use European date input format (DMY)
2335                                  */
2336                                 SetConfigOption("datestyle", "euro", ctx, gucsource);
2337                                 break;
2338
2339                         case 'F':
2340
2341                                 /*
2342                                  * turn off fsync
2343                                  */
2344                                 SetConfigOption("fsync", "false", ctx, gucsource);
2345                                 break;
2346
2347                         case 'f':
2348
2349                                 /*
2350                                  * f - forbid generation of certain plans
2351                                  */
2352                                 tmp = NULL;
2353                                 switch (optarg[0])
2354                                 {
2355                                         case 's':       /* seqscan */
2356                                                 tmp = "enable_seqscan";
2357                                                 break;
2358                                         case 'i':       /* indexscan */
2359                                                 tmp = "enable_indexscan";
2360                                                 break;
2361                                         case 't':       /* tidscan */
2362                                                 tmp = "enable_tidscan";
2363                                                 break;
2364                                         case 'n':       /* nestloop */
2365                                                 tmp = "enable_nestloop";
2366                                                 break;
2367                                         case 'm':       /* mergejoin */
2368                                                 tmp = "enable_mergejoin";
2369                                                 break;
2370                                         case 'h':       /* hashjoin */
2371                                                 tmp = "enable_hashjoin";
2372                                                 break;
2373                                         default:
2374                                                 errs++;
2375                                 }
2376                                 if (tmp)
2377                                         SetConfigOption(tmp, "false", ctx, gucsource);
2378                                 break;
2379
2380                         case 'N':
2381
2382                                 /*
2383                                  * N - Don't use newline as a query delimiter
2384                                  */
2385                                 UseNewLine = 0;
2386                                 break;
2387
2388                         case 'O':
2389
2390                                 /*
2391                                  * allow system table structure modifications
2392                                  */
2393                                 if (secure)             /* XXX safe to allow from client??? */
2394                                         allowSystemTableMods = true;
2395                                 break;
2396
2397                         case 'P':
2398
2399                                 /*
2400                                  * ignore system indexes
2401                                  *
2402                                  * As of PG 7.4 this is safe to allow from the client,
2403                                  * since it only disables reading the system indexes,
2404                                  * not writing them.  Worst case consequence is slowness.
2405                                  */
2406                                 IgnoreSystemIndexes(true);
2407                                 break;
2408
2409                         case 'o':
2410
2411                                 /*
2412                                  * o - send output (stdout and stderr) to the given file
2413                                  */
2414                                 if (secure)
2415                                         StrNCpy(OutputFileName, optarg, MAXPGPATH);
2416                                 break;
2417
2418                         case 'p':
2419                                 /*
2420                                  * p - special flag passed if backend was forked by a
2421                                  * postmaster.
2422                                  */
2423                                 if (secure)
2424                                 {
2425                                         dbname = strdup(optarg);
2426
2427                                         secure = false;         /* subsequent switches are NOT
2428                                                                                  * secure */
2429                                         ctx = PGC_BACKEND;
2430                                         gucsource = PGC_S_CLIENT;
2431                                 }
2432                                 break;
2433
2434                         case 'S':
2435
2436                                 /*
2437                                  * S - amount of sort memory to use in 1k bytes
2438                                  */
2439                                 SetConfigOption("work_mem", optarg, ctx, gucsource);
2440                                 break;
2441
2442                         case 's':
2443
2444                                 /*
2445                                  * s - report usage statistics (timings) after each query
2446                                  */
2447                                 SetConfigOption("log_statement_stats", "true", ctx, gucsource);
2448                                 break;
2449
2450                         case 't':
2451                                 /* ---------------
2452                                  *      tell postgres to report usage statistics (timings) for
2453                                  *      each query
2454                                  *
2455                                  *      -tpa[rser] = print stats for parser time of each query
2456                                  *      -tpl[anner] = print stats for planner time of each query
2457                                  *      -te[xecutor] = print stats for executor time of each query
2458                                  *      caution: -s can not be used together with -t.
2459                                  * ----------------
2460                                  */
2461                                 tmp = NULL;
2462                                 switch (optarg[0])
2463                                 {
2464                                         case 'p':
2465                                                 if (optarg[1] == 'a')
2466                                                         tmp = "log_parser_stats";
2467                                                 else if (optarg[1] == 'l')
2468                                                         tmp = "log_planner_stats";
2469                                                 else
2470                                                         errs++;
2471                                                 break;
2472                                         case 'e':
2473                                                 tmp = "log_executor_stats";
2474                                                 break;
2475                                         default:
2476                                                 errs++;
2477                                                 break;
2478                                 }
2479                                 if (tmp)
2480                                         SetConfigOption(tmp, "true", ctx, gucsource);
2481                                 break;
2482
2483                         case 'v':
2484                                 if (secure)
2485                                         FrontendProtocol = (ProtocolVersion) atoi(optarg);
2486                                 break;
2487
2488                         case 'W':
2489
2490                                 /*
2491                                  * wait N seconds to allow attach from a debugger
2492                                  */
2493                                 pg_usleep(atoi(optarg)*1000000L);
2494                                 break;
2495
2496                         case 'c':
2497                         case '-':
2498                                 {
2499                                         char       *name,
2500                                                            *value;
2501
2502                                         ParseLongOption(optarg, &name, &value);
2503                                         if (!value)
2504                                         {
2505                                                 if (flag == '-')
2506                                                         ereport(ERROR,
2507                                                                         (errcode(ERRCODE_SYNTAX_ERROR),
2508                                                                          errmsg("--%s requires a value",
2509                                                                                         optarg)));
2510                                                 else
2511                                                         ereport(ERROR,
2512                                                                         (errcode(ERRCODE_SYNTAX_ERROR),
2513                                                                          errmsg("-c %s requires a value",
2514                                                                                         optarg)));
2515                                         }
2516
2517                                         SetConfigOption(name, value, ctx, gucsource);
2518                                         free(name);
2519                                         if (value)
2520                                                 free(value);
2521                                         break;
2522                                 }
2523
2524                         default:
2525                                 errs++;
2526                                 break;
2527                 }
2528
2529
2530         /*
2531          * -d is not the same as setting log_min_messages because it enables
2532          * other output options.
2533          */
2534         if (debug_flag >= 1)
2535         {
2536                 SetConfigOption("log_connections", "true", debug_context, gucsource);
2537                 SetConfigOption("log_disconnections", "true", debug_context, gucsource);
2538         }
2539         if (debug_flag >= 2)
2540                 SetConfigOption("log_statement", "all", debug_context, gucsource);
2541         if (debug_flag >= 3)
2542                 SetConfigOption("debug_print_parse", "true", debug_context, gucsource);
2543         if (debug_flag >= 4)
2544                 SetConfigOption("debug_print_plan", "true", debug_context, gucsource);
2545         if (debug_flag >= 5)
2546                 SetConfigOption("debug_print_rewritten", "true", debug_context, gucsource);
2547
2548         /*
2549          * Process any additional GUC variable settings passed in startup
2550          * packet.
2551          */
2552         if (MyProcPort != NULL)
2553         {
2554                 ListCell   *gucopts = list_head(MyProcPort->guc_options);
2555
2556                 while (gucopts)
2557                 {
2558                         char *name;
2559                         char *value;
2560
2561                         name = lfirst(gucopts);
2562                         gucopts = lnext(gucopts);
2563
2564                         value = lfirst(gucopts);
2565                         gucopts = lnext(gucopts);
2566
2567                         SetConfigOption(name, value, PGC_BACKEND, PGC_S_CLIENT);
2568                 }
2569
2570                 /*
2571                  * set up handler to log session end.
2572                  */
2573                 if (IsUnderPostmaster && Log_disconnections)
2574                         on_proc_exit(log_disconnections,0);
2575         }
2576
2577         if (!IsUnderPostmaster)
2578         {
2579                 if (!potential_DataDir)
2580                 {
2581                         write_stderr("%s does not know where to find the database system data.\n"
2582                                                  "You must specify the directory that contains the database system\n"
2583                                                  "either by specifying the -D invocation option or by setting the\n"
2584                                                  "PGDATA environment variable.\n",
2585                                                  argv[0]);
2586                         proc_exit(1);
2587                 }
2588                 SetDataDir(potential_DataDir);
2589         }
2590         Assert(DataDir);
2591
2592         /* Acquire configuration parameters, unless inherited from postmaster */
2593         if (!IsUnderPostmaster)
2594         {
2595                 ProcessConfigFile(PGC_POSTMASTER);
2596
2597                 /* If timezone is not set, determine what the OS uses */
2598                 pg_timezone_initialize();
2599         }
2600
2601         /*
2602          * Set up signal handlers and masks.
2603          *
2604          * Note that postmaster blocked all signals before forking child process,
2605          * so there is no race condition whereby we might receive a signal
2606          * before we have set up the handler.
2607          *
2608          * Also note: it's best not to use any signals that are SIG_IGNored in
2609          * the postmaster.      If such a signal arrives before we are able to
2610          * change the handler to non-SIG_IGN, it'll get dropped.  Instead,
2611          * make a dummy handler in the postmaster to reserve the signal. (Of
2612          * course, this isn't an issue for signals that are locally generated,
2613          * such as SIGALRM and SIGPIPE.)
2614          */
2615         pqsignal(SIGHUP, SigHupHandler);        /* set flag to read config file */
2616         pqsignal(SIGINT, StatementCancelHandler);       /* cancel current query */
2617         pqsignal(SIGTERM, die);         /* cancel current query and exit */
2618         pqsignal(SIGQUIT, quickdie);    /* hard crash time */
2619         pqsignal(SIGALRM, handle_sig_alarm);            /* timeout conditions */
2620
2621         /*
2622          * Ignore failure to write to frontend. Note: if frontend closes
2623          * connection, we will notice it and exit cleanly when control next
2624          * returns to outer loop.  This seems safer than forcing exit in the
2625          * midst of output during who-knows-what operation...
2626          */
2627         pqsignal(SIGPIPE, SIG_IGN);
2628         pqsignal(SIGUSR1, CatchupInterruptHandler);
2629         pqsignal(SIGUSR2, NotifyInterruptHandler);
2630         pqsignal(SIGFPE, FloatExceptionHandler);
2631
2632         /*
2633          * Reset some signals that are accepted by postmaster but not by
2634          * backend
2635          */
2636         pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some
2637                                                                  * platforms */
2638
2639         pqinitmask();
2640
2641         /* We allow SIGQUIT (quickdie) at all times */
2642 #ifdef HAVE_SIGPROCMASK
2643         sigdelset(&BlockSig, SIGQUIT);
2644 #else
2645         BlockSig &= ~(sigmask(SIGQUIT));
2646 #endif
2647
2648         PG_SETMASK(&BlockSig);          /* block everything except SIGQUIT */
2649
2650
2651         if (IsUnderPostmaster)
2652         {
2653                 /* noninteractive case: nothing should be left after switches */
2654                 if (errs || argc != optind || dbname == NULL)
2655                 {
2656                         ereport(FATAL,
2657                                         (errcode(ERRCODE_SYNTAX_ERROR),
2658                                          errmsg("invalid command-line arguments for server process"),
2659                                          errhint("Try \"%s --help\" for more information.", argv[0])));
2660                 }
2661
2662                 XLOGPathInit();
2663
2664                 BaseInit();
2665         }
2666         else
2667         {
2668                 /* interactive case: database name can be last arg on command line */
2669                 if (errs || argc - optind > 1)
2670                 {
2671                         ereport(FATAL,
2672                                         (errcode(ERRCODE_SYNTAX_ERROR),
2673                                          errmsg("%s: invalid command-line arguments",
2674                                                         argv[0]),
2675                                          errhint("Try \"%s --help\" for more information.", argv[0])));
2676                 }
2677                 else if (argc - optind == 1)
2678                         dbname = argv[optind];
2679                 else if ((dbname = username) == NULL)
2680                 {
2681                         ereport(FATAL,
2682                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2683                                          errmsg("%s: no database nor user name specified",
2684                                                         argv[0])));
2685                 }
2686
2687                 /*
2688                  * Validate we have been given a reasonable-looking DataDir (if
2689                  * under postmaster, assume postmaster did this already).
2690                  */
2691                 ValidatePgVersion(DataDir);
2692
2693                 /*
2694                  * Create lockfile for data directory.
2695                  */
2696                 CreateDataDirLockFile(DataDir, false);
2697
2698                 XLOGPathInit();
2699                 BaseInit();
2700
2701                 /*
2702                  * Start up xlog for standalone backend, and register to have it
2703                  * closed down at exit.
2704                  */
2705                 StartupXLOG();
2706                 on_shmem_exit(ShutdownXLOG, 0);
2707
2708                 /*
2709                  * Read any existing FSM cache file, and register to write one out
2710                  * at exit.
2711                  */
2712                 LoadFreeSpaceMap();
2713                 on_shmem_exit(DumpFreeSpaceMap, 0);
2714         }
2715
2716         /*
2717          * General initialization.
2718          *
2719          * NOTE: if you are tempted to add code in this vicinity, consider
2720          * putting it inside InitPostgres() instead.  In particular, anything
2721          * that involves database access should be there, not here.
2722          */
2723         ereport(DEBUG3,
2724                         (errmsg_internal("InitPostgres")));
2725         InitPostgres(dbname, username);
2726
2727         SetProcessingMode(NormalProcessing);
2728
2729         /*
2730          * Send this backend's cancellation info to the frontend.
2731          */
2732         if (whereToSendOutput == Remote &&
2733                 PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
2734         {
2735                 StringInfoData buf;
2736
2737                 pq_beginmessage(&buf, 'K');
2738                 pq_sendint(&buf, (int32) MyProcPid, sizeof(int32));
2739                 pq_sendint(&buf, (int32) MyCancelKey, sizeof(int32));
2740                 pq_endmessage(&buf);
2741                 /* Need not flush since ReadyForQuery will do it. */
2742         }
2743
2744         /* Welcome banner for standalone case */
2745         if (whereToSendOutput == Debug)
2746                 printf("\nPostgreSQL stand-alone backend %s\n", PG_VERSION);
2747
2748         /*
2749          * Create the memory context we will use in the main loop.
2750          *
2751          * MessageContext is reset once per iteration of the main loop, ie, upon
2752          * completion of processing of each command message from the client.
2753          */
2754         MessageContext = AllocSetContextCreate(TopMemoryContext,
2755                                                                                    "MessageContext",
2756                                                                                    ALLOCSET_DEFAULT_MINSIZE,
2757                                                                                    ALLOCSET_DEFAULT_INITSIZE,
2758                                                                                    ALLOCSET_DEFAULT_MAXSIZE);
2759
2760         /* ----------
2761          * Tell the statistics collector that we're alive and
2762          * to which database we belong.
2763          * ----------
2764          */
2765         pgstat_bestart();
2766
2767         /*
2768          * POSTGRES main processing loop begins here
2769          *
2770          * If an exception is encountered, processing resumes here so we abort
2771          * the current transaction and start a new one.
2772          */
2773
2774         if (sigsetjmp(Warn_restart, 1) != 0)
2775         {
2776                 /*
2777                  * NOTE: if you are tempted to add more code in this if-block,
2778                  * consider the probability that it should be in
2779                  * AbortTransaction() instead.
2780                  *
2781                  * Make sure we're not interrupted while cleaning up.  Also forget
2782                  * any pending QueryCancel request, since we're aborting anyway.
2783                  * Force InterruptHoldoffCount to a known state in case we
2784                  * ereport'd from inside a holdoff section.
2785                  */
2786                 ImmediateInterruptOK = false;
2787                 QueryCancelPending = false;
2788                 InterruptHoldoffCount = 1;
2789                 CritSectionCount = 0;   /* should be unnecessary, but... */
2790                 disable_sig_alarm(true);
2791                 QueryCancelPending = false;             /* again in case timeout occurred */
2792                 DisableNotifyInterrupt();
2793                 DisableCatchupInterrupt();
2794                 debug_query_string = NULL;
2795
2796                 /*
2797                  * Make sure we are in a valid memory context during recovery.
2798                  *
2799                  * We use ErrorContext in hopes that it will have some free space
2800                  * even if we're otherwise up against it...
2801                  */
2802                 MemoryContextSwitchTo(ErrorContext);
2803
2804                 /* Do the recovery */
2805                 ereport(DEBUG2,
2806                                 (errmsg_internal("AbortCurrentTransaction")));
2807                 AbortCurrentTransaction();
2808
2809                 /*
2810                  * Now return to normal top-level context and clear ErrorContext
2811                  * for next time.
2812                  */
2813                 MemoryContextSwitchTo(TopMemoryContext);
2814                 MemoryContextResetAndDeleteChildren(ErrorContext);
2815                 ActivePortal = NULL;
2816                 PortalContext = NULL;
2817                 QueryContext = NULL;
2818
2819                 /*
2820                  * Clear flag to indicate that we got out of error recovery mode
2821                  * successfully.  (Flag was set in elog.c before longjmp().)
2822                  */
2823                 InError = false;
2824                 xact_started = false;
2825
2826                 /*
2827                  * Clear flag that causes accounting for cost based vacuum.
2828                  */
2829                 VacuumCostActive = false;
2830
2831                 /*
2832                  * If we were handling an extended-query-protocol message,
2833                  * initiate skip till next Sync.  This also causes us not to issue
2834                  * ReadyForQuery (until we get Sync).
2835                  */
2836                 if (doing_extended_query_message)
2837                         ignore_till_sync = true;
2838
2839                 /*
2840                  * Exit interrupt holdoff section we implicitly established above.
2841                  */
2842                 RESUME_INTERRUPTS();
2843         }
2844
2845         Warn_restart_ready = true;      /* we can now handle ereport(ERROR) */
2846
2847         PG_SETMASK(&UnBlockSig);
2848
2849         if (!ignore_till_sync)
2850                 send_rfq = true;                /* initially, or after error */
2851
2852         /*
2853          * Non-error queries loop here.
2854          */
2855
2856         for (;;)
2857         {
2858                 /*
2859                  * At top of loop, reset extended-query-message flag, so that any
2860                  * errors encountered in "idle" state don't provoke skip.
2861                  */
2862                 doing_extended_query_message = false;
2863
2864                 /*
2865                  * Release storage left over from prior query cycle, and create a
2866                  * new query input buffer in the cleared MessageContext.
2867                  */
2868                 MemoryContextSwitchTo(MessageContext);
2869                 MemoryContextResetAndDeleteChildren(MessageContext);
2870
2871                 initStringInfo(&input_message);
2872
2873                 /*
2874                  * (1) If we've reached idle state, tell the frontend we're ready
2875                  * for a new query.
2876                  *
2877                  * Note: this includes fflush()'ing the last of the prior output.
2878                  *
2879                  * This is also a good time to send collected statistics to the
2880                  * collector, and to update the PS stats display.  We avoid doing
2881                  * those every time through the message loop because it'd slow down
2882                  * processing of batched messages.
2883                  */
2884                 if (send_rfq)
2885                 {
2886                         pgstat_report_tabstat();
2887
2888                         if (IsTransactionOrTransactionBlock())
2889                         {
2890                                 set_ps_display("idle in transaction");
2891                                 pgstat_report_activity("<IDLE> in transaction");
2892                         }
2893                         else
2894                         {
2895                                 set_ps_display("idle");
2896                                 pgstat_report_activity("<IDLE>");
2897                         }
2898
2899                         ReadyForQuery(whereToSendOutput);
2900                         send_rfq = false;
2901                 }
2902
2903                 /*
2904                  * (2) deal with pending asynchronous NOTIFY from other backends,
2905                  * and enable async.c's signal handler to execute NOTIFY directly.
2906                  * Then set up other stuff needed before blocking for input.
2907                  */
2908                 QueryCancelPending = false;             /* forget any earlier CANCEL
2909                                                                                  * signal */
2910
2911                 EnableNotifyInterrupt();
2912                 EnableCatchupInterrupt();
2913
2914                 /* Allow "die" interrupt to be processed while waiting */
2915                 ImmediateInterruptOK = true;
2916                 /* and don't forget to detect one that already arrived */
2917                 QueryCancelPending = false;
2918                 CHECK_FOR_INTERRUPTS();
2919
2920                 /*
2921                  * (3) read a command (loop blocks here)
2922                  */
2923                  if (!in_fatal_exit)
2924                         firstchar = ReadCommand(&input_message);
2925                 else
2926                         firstchar = EOF;
2927
2928                 /*
2929                  * (4) disable async signal conditions again.
2930                  */
2931                 ImmediateInterruptOK = false;
2932                 QueryCancelPending = false;             /* forget any CANCEL signal */
2933
2934                 DisableNotifyInterrupt();
2935                 DisableCatchupInterrupt();
2936
2937                 /*
2938                  * (5) check for any other interesting events that happened while
2939                  * we slept.
2940                  */
2941                 if (got_SIGHUP)
2942                 {
2943                         got_SIGHUP = false;
2944                         ProcessConfigFile(PGC_SIGHUP);
2945                 }
2946
2947                 /*
2948                  * (6) process the command.  But ignore it if we're skipping till
2949                  * Sync.
2950                  */
2951                 if (ignore_till_sync && firstchar != EOF)
2952                         continue;
2953
2954                 switch (firstchar)
2955                 {
2956                         case 'Q':                       /* simple query */
2957                                 {
2958                                         const char *query_string;
2959
2960                                         query_string = pq_getmsgstring(&input_message);
2961                                         pq_getmsgend(&input_message);
2962
2963                                         exec_simple_query(query_string);
2964
2965                                         send_rfq = true;
2966                                 }
2967                                 break;
2968
2969                         case 'P':                       /* parse */
2970                                 {
2971                                         const char *stmt_name;
2972                                         const char *query_string;
2973                                         int                     numParams;
2974                                         Oid                *paramTypes = NULL;
2975
2976                                         stmt_name = pq_getmsgstring(&input_message);
2977                                         query_string = pq_getmsgstring(&input_message);
2978                                         numParams = pq_getmsgint(&input_message, 2);
2979                                         if (numParams > 0)
2980                                         {
2981                                                 int                     i;
2982
2983                                                 paramTypes = (Oid *) palloc(numParams * sizeof(Oid));
2984                                                 for (i = 0; i < numParams; i++)
2985                                                         paramTypes[i] = pq_getmsgint(&input_message, 4);
2986                                         }
2987                                         pq_getmsgend(&input_message);
2988
2989                                         exec_parse_message(query_string, stmt_name,
2990                                                                            paramTypes, numParams);
2991                                 }
2992                                 break;
2993
2994                         case 'B':                       /* bind */
2995
2996                                 /*
2997                                  * this message is complex enough that it seems best to
2998                                  * put the field extraction out-of-line
2999                                  */
3000                                 exec_bind_message(&input_message);
3001                                 break;
3002
3003                         case 'E':                       /* execute */
3004                                 {
3005                                         const char *portal_name;
3006                                         int                     max_rows;
3007
3008                                         portal_name = pq_getmsgstring(&input_message);
3009                                         max_rows = pq_getmsgint(&input_message, 4);
3010                                         pq_getmsgend(&input_message);
3011
3012                                         exec_execute_message(portal_name, max_rows);
3013                                 }
3014                                 break;
3015
3016                         case 'F':                       /* fastpath function call */
3017                                 /* Tell the collector what we're doing */
3018                                 pgstat_report_activity("<FASTPATH> function call");
3019
3020                                 /* start an xact for this function invocation */
3021                                 start_xact_command();
3022
3023                                 /* switch back to message context */
3024                                 MemoryContextSwitchTo(MessageContext);
3025
3026                                 if (HandleFunctionRequest(&input_message) == EOF)
3027                                 {
3028                                         /* lost frontend connection during F message input */
3029
3030                                         /*
3031                                          * Reset whereToSendOutput to prevent ereport from
3032                                          * attempting to send any more messages to client.
3033                                          */
3034                                         if (whereToSendOutput == Remote)
3035                                                 whereToSendOutput = None;
3036
3037                                         proc_exit(0);
3038                                 }
3039
3040                                 /* commit the function-invocation transaction */
3041                                 finish_xact_command();
3042
3043                                 send_rfq = true;
3044                                 break;
3045
3046                         case 'C':                       /* close */
3047                                 {
3048                                         int                     close_type;
3049                                         const char *close_target;
3050
3051                                         close_type = pq_getmsgbyte(&input_message);
3052                                         close_target = pq_getmsgstring(&input_message);
3053                                         pq_getmsgend(&input_message);
3054
3055                                         switch (close_type)
3056                                         {
3057                                                 case 'S':
3058                                                         if (close_target[0] != '\0')
3059                                                                 DropPreparedStatement(close_target, false);
3060                                                         else
3061                                                         {
3062                                                                 /* special-case the unnamed statement */
3063                                                                 unnamed_stmt_pstmt = NULL;
3064                                                                 if (unnamed_stmt_context)
3065                                                                 {
3066                                                                         DropDependentPortals(unnamed_stmt_context);
3067                                                                         MemoryContextDelete(unnamed_stmt_context);
3068                                                                 }
3069                                                                 unnamed_stmt_context = NULL;
3070                                                         }
3071                                                         break;
3072                                                 case 'P':
3073                                                         {
3074                                                                 Portal          portal;
3075
3076                                                                 portal = GetPortalByName(close_target);
3077                                                                 if (PortalIsValid(portal))
3078                                                                         PortalDrop(portal, false);
3079                                                         }
3080                                                         break;
3081                                                 default:
3082                                                         ereport(ERROR,
3083                                                                         (errcode(ERRCODE_PROTOCOL_VIOLATION),
3084                                                            errmsg("invalid CLOSE message subtype %d",
3085                                                                           close_type)));
3086                                                         break;
3087                                         }
3088
3089                                         if (whereToSendOutput == Remote)
3090                                                 pq_putemptymessage('3');                /* CloseComplete */
3091                                 }
3092                                 break;
3093
3094                         case 'D':                       /* describe */
3095                                 {
3096                                         int                     describe_type;
3097                                         const char *describe_target;
3098
3099                                         describe_type = pq_getmsgbyte(&input_message);
3100                                         describe_target = pq_getmsgstring(&input_message);
3101                                         pq_getmsgend(&input_message);
3102
3103                                         switch (describe_type)
3104                                         {
3105                                                 case 'S':
3106                                                         exec_describe_statement_message(describe_target);
3107                                                         break;
3108                                                 case 'P':
3109                                                         exec_describe_portal_message(describe_target);
3110                                                         break;
3111                                                 default:
3112                                                         ereport(ERROR,
3113                                                                         (errcode(ERRCODE_PROTOCOL_VIOLATION),
3114                                                         errmsg("invalid DESCRIBE message subtype %d",
3115                                                                    describe_type)));
3116                                                         break;
3117                                         }
3118                                 }
3119                                 break;
3120
3121                         case 'H':                       /* flush */
3122                                 pq_getmsgend(&input_message);
3123                                 if (whereToSendOutput == Remote)
3124                                         pq_flush();
3125                                 break;
3126
3127                         case 'S':                       /* sync */
3128                                 pq_getmsgend(&input_message);
3129                                 finish_xact_command();
3130                                 send_rfq = true;
3131                                 break;
3132
3133                                 /*
3134                                  * 'X' means that the frontend is closing down the socket.
3135                                  * EOF means unexpected loss of frontend connection.
3136                                  * Either way, perform normal shutdown.
3137                                  */
3138                         case 'X':
3139                         case EOF:
3140
3141                                 /*
3142                                  * Reset whereToSendOutput to prevent ereport from
3143                                  * attempting to send any more messages to client.
3144                                  */
3145                                 if (whereToSendOutput == Remote)
3146                                         whereToSendOutput = None;
3147
3148                                 /*
3149                                  * NOTE: if you are tempted to add more code here, DON'T!
3150                                  * Whatever you had in mind to do should be set up as an
3151                                  * on_proc_exit or on_shmem_exit callback, instead.
3152                                  * Otherwise it will fail to be called during other
3153                                  * backend-shutdown scenarios.
3154                                  */
3155                                 proc_exit(!in_fatal_exit ? 0 : proc_exit_inprogress ||
3156                                                                                                 !IsUnderPostmaster);
3157
3158                         case 'd':                       /* copy data */
3159                         case 'c':                       /* copy done */
3160                         case 'f':                       /* copy fail */
3161
3162                                 /*
3163                                  * Accept but ignore these messages, per protocol spec; we
3164                                  * probably got here because a COPY failed, and the
3165                                  * frontend is still sending data.
3166                                  */
3167                                 break;
3168
3169                         default:
3170                                 ereport(FATAL,
3171                                                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
3172                                                  errmsg("invalid frontend message type %d",
3173                                                                 firstchar)));
3174                 }
3175         }                                                       /* end of input-reading loop */
3176
3177         /* can't get here because the above loop never exits */
3178         Assert(false);
3179
3180         return 1;                                       /* keep compiler quiet */
3181 }
3182
3183 #ifndef HAVE_GETRUSAGE
3184 #include "rusagestub.h"
3185 #else
3186 #include <sys/resource.h>
3187 #endif   /* HAVE_GETRUSAGE */
3188
3189 static struct rusage Save_r;
3190 static struct timeval Save_t;
3191
3192 void
3193 ResetUsage(void)
3194 {
3195         getrusage(RUSAGE_SELF, &Save_r);
3196         gettimeofday(&Save_t, NULL);
3197         ResetBufferUsage();
3198         /* ResetTupleCount(); */
3199 }
3200
3201 void
3202 ShowUsage(const char *title)
3203 {
3204         StringInfoData str;
3205         struct timeval user,
3206                                 sys;
3207         struct timeval elapse_t;
3208         struct rusage r;
3209         char       *bufusage;
3210
3211         getrusage(RUSAGE_SELF, &r);
3212         gettimeofday(&elapse_t, NULL);
3213         memcpy((char *) &user, (char *) &r.ru_utime, sizeof(user));
3214         memcpy((char *) &sys, (char *) &r.ru_stime, sizeof(sys));
3215         if (elapse_t.tv_usec < Save_t.tv_usec)
3216         {
3217                 elapse_t.tv_sec--;
3218                 elapse_t.tv_usec += 1000000;
3219         }
3220         if (r.ru_utime.tv_usec < Save_r.ru_utime.tv_usec)
3221         {
3222                 r.ru_utime.tv_sec--;
3223                 r.ru_utime.tv_usec += 1000000;
3224         }
3225         if (r.ru_stime.tv_usec < Save_r.ru_stime.tv_usec)
3226         {
3227                 r.ru_stime.tv_sec--;
3228                 r.ru_stime.tv_usec += 1000000;
3229         }
3230
3231         /*
3232          * the only stats we don't show here are for memory usage -- i can't
3233          * figure out how to interpret the relevant fields in the rusage
3234          * struct, and they change names across o/s platforms, anyway. if you
3235          * can figure out what the entries mean, you can somehow extract
3236          * resident set size, shared text size, and unshared data and stack
3237          * sizes.
3238          */
3239         initStringInfo(&str);
3240
3241         appendStringInfo(&str, "! system usage stats:\n");
3242         appendStringInfo(&str,
3243                         "!\t%ld.%06ld elapsed %ld.%06ld user %ld.%06ld system sec\n",
3244                                          (long) (elapse_t.tv_sec - Save_t.tv_sec),
3245                                          (long) (elapse_t.tv_usec - Save_t.tv_usec),
3246                                          (long) (r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec),
3247                                    (long) (r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec),
3248                                          (long) (r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec),
3249                                   (long) (r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec));
3250         appendStringInfo(&str,
3251                                          "!\t[%ld.%06ld user %ld.%06ld sys total]\n",
3252                                          (long) user.tv_sec,
3253                                          (long) user.tv_usec,
3254                                          (long) sys.tv_sec,
3255                                          (long) sys.tv_usec);
3256 /* BeOS has rusage but only has some fields, and not these... */
3257 #if defined(HAVE_GETRUSAGE)
3258         appendStringInfo(&str,
3259                                          "!\t%ld/%ld [%ld/%ld] filesystem blocks in/out\n",
3260                                          r.ru_inblock - Save_r.ru_inblock,
3261         /* they only drink coffee at dec */
3262                                          r.ru_oublock - Save_r.ru_oublock,
3263                                          r.ru_inblock, r.ru_oublock);
3264         appendStringInfo(&str,
3265                   "!\t%ld/%ld [%ld/%ld] page faults/reclaims, %ld [%ld] swaps\n",
3266                                          r.ru_majflt - Save_r.ru_majflt,
3267                                          r.ru_minflt - Save_r.ru_minflt,
3268                                          r.ru_majflt, r.ru_minflt,
3269                                          r.ru_nswap - Save_r.ru_nswap,
3270                                          r.ru_nswap);
3271         appendStringInfo(&str,
3272          "!\t%ld [%ld] signals rcvd, %ld/%ld [%ld/%ld] messages rcvd/sent\n",
3273                                          r.ru_nsignals - Save_r.ru_nsignals,
3274                                          r.ru_nsignals,
3275                                          r.ru_msgrcv - Save_r.ru_msgrcv,
3276                                          r.ru_msgsnd - Save_r.ru_msgsnd,
3277                                          r.ru_msgrcv, r.ru_msgsnd);
3278         appendStringInfo(&str,
3279                  "!\t%ld/%ld [%ld/%ld] voluntary/involuntary context switches\n",
3280                                          r.ru_nvcsw - Save_r.ru_nvcsw,
3281                                          r.ru_nivcsw - Save_r.ru_nivcsw,
3282                                          r.ru_nvcsw, r.ru_nivcsw);
3283 #endif   /* HAVE_GETRUSAGE */
3284
3285         bufusage = ShowBufferUsage();
3286         appendStringInfo(&str, "! buffer usage stats:\n%s", bufusage);
3287         pfree(bufusage);
3288
3289         /* remove trailing newline */
3290         if (str.data[str.len - 1] == '\n')
3291                 str.data[--str.len] = '\0';
3292
3293         ereport(LOG,
3294                         (errmsg_internal("%s", title),
3295                          errdetail("%s", str.data)));
3296
3297         pfree(str.data);
3298 }
3299
3300 /*
3301  * on_proc_exit handler to log end of session
3302  */
3303 static void
3304 log_disconnections(int code, Datum arg)
3305 {
3306         Port *port = MyProcPort;
3307         struct timeval end;
3308         int  hours, minutes, seconds;
3309
3310         char session_time[20];
3311         char uname[6+NAMEDATALEN];
3312         char dbname[10+NAMEDATALEN];
3313         char remote_host[7 + NI_MAXHOST];
3314         char remote_port[7 + NI_MAXSERV];
3315
3316         snprintf(uname, sizeof(uname)," user=%s",port->user_name);
3317         snprintf(dbname, sizeof(dbname)," database=%s",port->database_name);
3318         snprintf(remote_host,sizeof(remote_host)," host=%s",
3319                          port->remote_host);
3320         snprintf(remote_port,sizeof(remote_port)," port=%s",port->remote_port);
3321
3322
3323         gettimeofday(&end,NULL);
3324
3325         if (end.tv_usec < port->session_start.tv_usec)
3326         {
3327                 end.tv_sec--;
3328                 end.tv_usec += 1000000;
3329         }
3330         end.tv_sec -= port->session_start.tv_sec;
3331         end.tv_usec -= port->session_start.tv_usec;
3332
3333         hours = end.tv_sec / 3600;
3334         end.tv_sec %= 3600;
3335         minutes = end.tv_sec / 60;
3336         seconds = end.tv_sec % 60;
3337
3338         /* if time has gone backwards for some reason say so, or print time */
3339
3340         if (end.tv_sec < 0)
3341                 snprintf(session_time,sizeof(session_time),"negative!");
3342         else
3343                 /* for stricter accuracy here we could round - this is close enough */
3344                 snprintf(session_time, sizeof(session_time),
3345                          "%d:%02d:%02d.%02d",
3346                          hours, minutes, seconds, (int) (end.tv_usec/10000));
3347
3348         ereport(
3349                 LOG,
3350                 (errmsg("disconnection: session time: %s%s%s%s%s",
3351                                 session_time,uname,dbname,remote_host,remote_port)));
3352
3353 }