fix the TODO

* Allow PQrequestCancel() to terminate when in waiting-for-lock state
Changes are limited to BACKEND,however.

diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 01097fcd2fe642ebada361535a2b3b6cd020fce8..dafab7ebfd38e45b771c5c4ac57ae8c94e0828bb 100644 (file)
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.67 2000/01/26 05:57:02 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.68 2000/02/21 02:42:36 inoue Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -47,7 +47,7 @@
  *             This is so that we can support more backends. (system-wide semaphore
  *             sets run out pretty fast.)                                -ay 4/95
  *
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.67 2000/01/26 05:57:02 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.68 2000/02/21 02:42:36 inoue Exp $
  */
 #include <sys/time.h>
 #include <unistd.h>
@@ -312,6 +312,34 @@ InitProcess(IPCKey key)
        on_shmem_exit(ProcKill, (caddr_t) MyProcPid);
 }
 
+/* -----------------------
+ * get off the wait queue
+ * -----------------------
+ */
+static void
+GetOffWaitqueue(PROC *proc)
+{
+       LockLockTable();
+       if (proc->links.next != INVALID_OFFSET)
+       {
+               int     lockmode = proc->token;
+               Assert(proc->waitLock->waitProcs.size > 0);
+               SHMQueueDelete(&(proc->links));
+               --proc->waitLock->waitProcs.size;
+               Assert(proc->waitLock->nHolding > 0);
+               Assert(proc->waitLock->nHolding > proc->waitLock->nActive);
+               --proc->waitLock->nHolding;
+               Assert(proc->waitLock->holders[lockmode] > 0);
+               --proc->waitLock->holders[lockmode];
+               if (proc->waitLock->activeHolders[lockmode] ==
+                       proc->waitLock->holders[lockmode])
+                       proc->waitLock->waitMask &= ~(1 << lockmode);
+       }
+       SHMQueueElemInit(&(proc->links));
+       UnlockLockTable();
+
+       return;
+}
 /*
  * ProcReleaseLocks() -- release all locks associated with this process
  *
@@ -322,6 +350,7 @@ ProcReleaseLocks()
        if (!MyProc)
                return;
        LockReleaseAll(1, &MyProc->lockQueue);
+       GetOffWaitqueue(MyProc);
 }
 
 /*
@@ -405,15 +434,7 @@ ProcKill(int exitStatus, int pid)
         * get off the wait queue
         * ----------------
         */
-       LockLockTable();
-       if (proc->links.next != INVALID_OFFSET)
-       {
-               Assert(proc->waitLock->waitProcs.size > 0);
-               SHMQueueDelete(&(proc->links));
-               --proc->waitLock->waitProcs.size;
-       }
-       SHMQueueElemInit(&(proc->links));
-       UnlockLockTable();
+       GetOffWaitqueue(proc);
 
        return;
 }
@@ -569,6 +590,7 @@ ins:;
        timeval.it_value.tv_sec = \
                (DeadlockCheckTimer ? DeadlockCheckTimer : DEADLOCK_CHECK_TIMER);
 
+       SetLockWaiting(true);
        do
        {
                MyProc->errType = NO_ERROR;             /* reset flag after deadlock check */
@@ -588,6 +610,7 @@ ins:;
                                                 IpcExclusiveLock);
        } while (MyProc->errType == STATUS_NOT_FOUND);          /* sleep after deadlock
                                                                                                                 * check */
+       SetLockWaiting(false);
 
        /* ---------------
         * We were awoken before a timeout - now disable the timer

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 1f333f46af0d687842c7282415bff94db9795ff9..71087295313bc78ad99c0ca3ca98c56846f64fd6 100644 (file)
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.144 2000/02/20 04:26:35 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.145 2000/02/21 02:42:35 inoue Exp $
  *
  * NOTES
  *       this is the "main" module of the postgres backend and
@@ -810,11 +810,21 @@ FloatExceptionHandler(SIGNAL_ARGS)
 }
 
 
+static bool    lockWaiting = false;
+void SetLockWaiting(bool waiting)
+{
+       lockWaiting = waiting;
+}
 /* signal handler for query cancel signal from postmaster */
 static void
 QueryCancelHandler(SIGNAL_ARGS)
 {
        QueryCancel = true;
+       if (lockWaiting)
+       {
+               lockWaiting = false;
+               elog(ERROR, "Query Cancel requested while waiting lock");
+       }
 }
 
 void
@@ -1503,7 +1513,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
        if (!IsUnderPostmaster)
        {
                puts("\nPOSTGRES backend interactive interface ");
-               puts("$Revision: 1.144 $ $Date: 2000/02/20 04:26:35 $\n");
+               puts("$Revision: 1.145 $ $Date: 2000/02/21 02:42:35 $\n");
        }
 
        /*
@@ -1573,6 +1583,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
                firstchar = ReadCommand(parser_input);
 
                QueryCancel = false;    /* forget any earlier CANCEL signal */
+               lockWaiting = false;
 
                /* ----------------
                 *       (4) disable async.c's signal handler.

diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index df3de38611b0a340124c995380a7e6ad62986c63..c80e7608333ad6174115ca9bb11a41836d1b5b89 100644 (file)
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: miscadmin.h,v 1.51 2000/02/18 09:29:06 inoue Exp $
+ * $Id: miscadmin.h,v 1.52 2000/02/21 02:42:37 inoue Exp $
  *
  * NOTES
  *       some of the information in this file will be moved to
@@ -214,6 +214,7 @@ extern ProcessingMode Mode;
 extern void IgnoreSystemIndexes(bool mode);
 extern bool IsIgnoringSystemIndexes(void);
 extern bool IsCacheInitialized(void);
+extern void SetLockWaiting(bool);
 
 /* 
  * "postmaster.pid" is a file containing postmaster's pid, being