Back-patch fix for bugs in pgstat_initstats.

diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 17c11682cf9e0cd60244a57474a8615c6418f7c4..859182c49ae28b77510f545766509d6d738e4226 100644 (file)
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -16,7 +16,7 @@
  *
  *     Copyright (c) 2001, PostgreSQL Global Development Group
  *
- *     $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.31 2002/10/24 23:19:13 tgl Exp $
+ *     $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.31.2.1 2003/07/22 19:00:36 tgl Exp $
  * ----------
  */
 #include "postgres.h"
@@ -75,13 +75,15 @@ static int  pgStatPid;
 static long pgStatNumMessages = 0;
 
 static bool pgStatRunningInCollector = FALSE;
+
 static int     pgStatTabstatAlloc = 0;
 static int     pgStatTabstatUsed = 0;
 static PgStat_MsgTabstat **pgStatTabstatMessages = NULL;
+#define TABSTAT_QUANTUM                4       /* we alloc this many at a time */
+
 static int     pgStatXactCommit = 0;
 static int     pgStatXactRollback = 0;
 
-
 static TransactionId pgStatDBHashXact = InvalidTransactionId;
 static HTAB *pgStatDBHash = NULL;
 static HTAB *pgStatBeDead = NULL;
@@ -752,32 +754,37 @@ pgstat_initstats(PgStat_Info *stats, Relation rel)
        }
 
        /*
-        * On the first of all calls initialize the message buffers.
+        * On the first of all calls create some message buffers.
         */
-       if (pgStatTabstatAlloc == 0)
+       if (pgStatTabstatMessages == NULL)
        {
-               pgStatTabstatAlloc = 4;
-               pgStatTabstatMessages = (PgStat_MsgTabstat **)
-                       malloc(sizeof(PgStat_MsgTabstat *) * pgStatTabstatAlloc);
-               if (pgStatTabstatMessages == NULL)
+               PgStat_MsgTabstat *newMessages;
+               PgStat_MsgTabstat **msgArray;
+
+               newMessages = (PgStat_MsgTabstat *)
+                       malloc(sizeof(PgStat_MsgTabstat) * TABSTAT_QUANTUM);
+               if (newMessages == NULL)
                {
-                       elog(LOG, "PGSTATBE: malloc() failed");
+                       elog(LOG, "out of memory");
                        return;
                }
-               for (i = 0; i < pgStatTabstatAlloc; i++)
+               msgArray = (PgStat_MsgTabstat **)
+                       malloc(sizeof(PgStat_MsgTabstat *) * TABSTAT_QUANTUM);
+               if (msgArray == NULL)
                {
-                       pgStatTabstatMessages[i] = (PgStat_MsgTabstat *)
-                               malloc(sizeof(PgStat_MsgTabstat));
-                       if (pgStatTabstatMessages[i] == NULL)
-                       {
-                               elog(LOG, "PGSTATBE: malloc() failed");
-                               return;
-                       }
+                       free(newMessages);
+                       elog(LOG, "out of memory");
+                       return;
                }
+               MemSet(newMessages, 0, sizeof(PgStat_MsgTabstat) * TABSTAT_QUANTUM);
+               for (i = 0; i < TABSTAT_QUANTUM; i++)
+                       msgArray[i] = newMessages++;
+               pgStatTabstatMessages = msgArray;
+               pgStatTabstatAlloc = TABSTAT_QUANTUM;
        }
 
        /*
-        * Lookup the so far used table slots for this relation.
+        * Search the already-used message slots for this relation.
         */
        for (mb = 0; mb < pgStatTabstatUsed; mb++)
        {
@@ -799,7 +806,6 @@ pgstat_initstats(PgStat_Info *stats, Relation rel)
                 */
                i = pgStatTabstatMessages[mb]->m_nentries++;
                useent = &pgStatTabstatMessages[mb]->m_entry[i];
-               memset(useent, 0, sizeof(PgStat_TableEntry));
                useent->t_id = rel_id;
                stats->tabentry = (void *) useent;
                return;
@@ -810,27 +816,31 @@ pgstat_initstats(PgStat_Info *stats, Relation rel)
         */
        if (pgStatTabstatUsed >= pgStatTabstatAlloc)
        {
-               pgStatTabstatAlloc += 4;
-               pgStatTabstatMessages = (PgStat_MsgTabstat **)
-                       realloc(pgStatTabstatMessages,
-                                       sizeof(PgStat_MsgTabstat *) * pgStatTabstatAlloc);
-               if (pgStatTabstatMessages == NULL)
+               int             newAlloc = pgStatTabstatAlloc + TABSTAT_QUANTUM;
+               PgStat_MsgTabstat *newMessages;
+               PgStat_MsgTabstat **msgArray;
+
+               newMessages = (PgStat_MsgTabstat *)
+                       malloc(sizeof(PgStat_MsgTabstat) * TABSTAT_QUANTUM);
+               if (newMessages == NULL)
                {
-                       pgStatTabstatAlloc -= 4;
-                       elog(LOG, "PGSTATBE: malloc() failed");
+                       elog(LOG, "out of memory");
                        return;
                }
-               for (i = pgStatTabstatUsed; i < pgStatTabstatAlloc; i++)
+               msgArray = (PgStat_MsgTabstat **)
+                       realloc(pgStatTabstatMessages,
+                                       sizeof(PgStat_MsgTabstat *) * newAlloc);
+               if (msgArray == NULL)
                {
-                       pgStatTabstatMessages[i] = (PgStat_MsgTabstat *)
-                               malloc(sizeof(PgStat_MsgTabstat));
-                       if (pgStatTabstatMessages[i] == NULL)
-                       {
-                               pgStatTabstatAlloc -= 4;
-                               elog(LOG, "PGSTATBE: malloc() failed");
-                               return;
-                       }
+                       free(newMessages);
+                       elog(LOG, "out of memory");
+                       return;
                }
+               MemSet(newMessages, 0, sizeof(PgStat_MsgTabstat) * TABSTAT_QUANTUM);
+               for (i = 0; i < TABSTAT_QUANTUM; i++)
+                       msgArray[pgStatTabstatAlloc + i] = newMessages++;
+               pgStatTabstatMessages = msgArray;
+               pgStatTabstatAlloc = newAlloc;
        }
 
        /*
@@ -839,10 +849,8 @@ pgstat_initstats(PgStat_Info *stats, Relation rel)
        mb = pgStatTabstatUsed++;
        pgStatTabstatMessages[mb]->m_nentries = 1;
        useent = &pgStatTabstatMessages[mb]->m_entry[0];
-       memset(useent, 0, sizeof(PgStat_TableEntry));
        useent->t_id = rel_id;
        stats->tabentry = (void *) useent;
-       return;
 }