From a60c9e33e96a8f3694d94143d65ec6ee1fb3414b Mon Sep 17 00:00:00 2001
From: Hiroshi Inoue <inoue@tpf.co.jp>
Date: Mon, 21 Feb 2000 02:42:37 +0000
Subject: [PATCH] fix the TODO * Allow PQrequestCancel() to terminate when in
waiting-for-lock state Changes are limited to BACKEND,however.
---
src/backend/storage/lmgr/proc.c | 45 +++++++++++++++++++++++++--------
src/backend/tcop/postgres.c | 15 +++++++++--
src/include/miscadmin.h | 3 ++-
3 files changed, 49 insertions(+), 14 deletions(-)
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 01097fcd2fe..dafab7ebfd3 100644
--- 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 1f333f46af0..71087295313 100644
--- 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 df3de38611b..c80e7608333 100644
--- 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
--
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