diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c
index 5fda53d02c6c65244fe1eeb4f35eff8335609370..dde2412a6ea4bcb055d7c3f0cc790b0bde62d2be 100644
--- a/src/backend/commands/async.c
+++ b/src/backend/commands/async.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.78 2001/06/12 05:55:49 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.79 2001/06/17 22:27:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -82,7 +82,6 @@
#include "catalog/catname.h"
#include "catalog/pg_listener.h"
#include "commands/async.h"
-#include "lib/dllist.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
@@ -100,10 +99,11 @@ extern CommandDest whereToSendOutput;
/*
* State for outbound notifies consists of a list of all relnames NOTIFYed
* in the current transaction. We do not actually perform a NOTIFY until
- * and unless the transaction commits. pendingNotifies is NULL if no
- * NOTIFYs have been done in the current transaction.
+ * and unless the transaction commits. pendingNotifies is NIL if no
+ * NOTIFYs have been done in the current transaction. The List nodes and
+ * referenced strings are all palloc'd in TopTransactionContext.
*/
-static Dllist *pendingNotifies = NULL;
+static List *pendingNotifies = NIL;
/*
* State for inbound notifies consists of two flags: one saying whether
@@ -121,16 +121,16 @@ static volatile int notifyInterruptOccurred = 0;
/* True if we've registered an on_shmem_exit cleanup */
static bool unlistenExitRegistered = false;
+bool Trace_notify = false;
+
static void Async_UnlistenAll(void);
static void Async_UnlistenOnExit(void);
static void ProcessIncomingNotify(void);
static void NotifyMyFrontEnd(char *relname, int32 listenerPID);
-static int AsyncExistsPendingNotify(char *relname);
+static bool AsyncExistsPendingNotify(const char *relname);
static void ClearPendingNotifies(void);
-bool Trace_notify = false;
-
/*
*--------------------------------------------------------------
@@ -150,26 +150,23 @@ bool Trace_notify = false;
void
Async_Notify(char *relname)
{
- char *notifyName;
-
if (Trace_notify)
elog(DEBUG, "Async_Notify: %s", relname);
- if (!pendingNotifies)
- pendingNotifies = DLNewList();
/* no point in making duplicate entries in the list ... */
- if (!AsyncExistsPendingNotify(relname))
+ if (! AsyncExistsPendingNotify(relname))
{
-
/*
- * We allocate list memory from the global malloc pool to ensure
- * that it will live until we want to use it. This is probably
- * not necessary any longer, since we will use it before the end
- * of the transaction. DLList only knows how to use malloc()
- * anyway, but we could probably palloc() the strings...
+ * The name list needs to live until end of transaction, so
+ * store it in the top transaction context.
*/
- notifyName = strdup(relname);
- DLAddHead(pendingNotifies, DLNewElem(notifyName));
+ MemoryContext oldcontext;
+
+ oldcontext = MemoryContextSwitchTo(TopTransactionContext);
+
+ pendingNotifies = lcons(pstrdup(relname), pendingNotifies);
+
+ MemoryContextSwitchTo(oldcontext);
}
}
@@ -352,7 +349,7 @@ Async_Unlisten(char *relname, int pid)
*--------------------------------------------------------------
*/
static void
-Async_UnlistenAll()
+Async_UnlistenAll(void)
{
Relation lRel;
TupleDesc tdesc;
@@ -401,7 +398,6 @@ Async_UnlistenAll()
static void
Async_UnlistenOnExit(void)
{
-
/*
* We need to start/commit a transaction for the unlisten, but if
* there is already an active transaction we had better abort that one
@@ -438,7 +434,7 @@ Async_UnlistenOnExit(void)
*--------------------------------------------------------------
*/
void
-AtCommit_Notify()
+AtCommit_Notify(void)
{
Relation lRel;
TupleDesc tdesc;
@@ -449,7 +445,7 @@ AtCommit_Notify()
char repl[Natts_pg_listener],
nulls[Natts_pg_listener];
- if (!pendingNotifies)
+ if (pendingNotifies == NIL)
return; /* no NOTIFY statements in this
* transaction */
@@ -579,7 +575,7 @@ AtCommit_Notify()
*--------------------------------------------------------------
*/
void
-AtAbort_Notify()
+AtAbort_Notify(void)
{
ClearPendingNotifies();
}
@@ -601,7 +597,6 @@ AtAbort_Notify()
* per above
*--------------------------------------------------------------
*/
-
void
Async_NotifyHandler(SIGNAL_ARGS)
{
@@ -671,7 +666,6 @@ Async_NotifyHandler(SIGNAL_ARGS)
* PostgresMain calls this the first time.
* --------------------------------------------------------------
*/
-
void
EnableNotifyInterrupt(void)
{
@@ -729,7 +723,6 @@ EnableNotifyInterrupt(void)
* is disabled until the next EnableNotifyInterrupt call.
* --------------------------------------------------------------
*/
-
void
DisableNotifyInterrupt(void)
{
@@ -848,8 +841,9 @@ ProcessIncomingNotify(void)
elog(DEBUG, "ProcessIncomingNotify: done");
}
-/* Send NOTIFY message to my front end. */
-
+/*
+ * Send NOTIFY message to my front end.
+ */
static void
NotifyMyFrontEnd(char *relname, int32 listenerPID)
{
@@ -874,50 +868,32 @@ NotifyMyFrontEnd(char *relname, int32 listenerPID)
elog(NOTICE, "NOTIFY for %s", relname);
}
-/* Does pendingNotifies include the given relname?
- *
- * NB: not called unless pendingNotifies != NULL.
- */
-
-static int
-AsyncExistsPendingNotify(char *relname)
+/* Does pendingNotifies include the given relname? */
+static bool
+AsyncExistsPendingNotify(const char *relname)
{
- Dlelem *p;
+ List *p;
- for (p = DLGetHead(pendingNotifies);
- p != NULL;
- p = DLGetSucc(p))
+ foreach(p, pendingNotifies)
{
/* Use NAMEDATALEN for relname comparison. DZ - 26-08-1996 */
- if (strncmp((const char *) DLE_VAL(p), relname, NAMEDATALEN) == 0)
- return 1;
+ if (strncmp((const char *) lfirst(p), relname, NAMEDATALEN) == 0)
+ return true;
}
- return 0;
+ return false;
}
/* Clear the pendingNotifies list. */
-
static void
-ClearPendingNotifies()
+ClearPendingNotifies(void)
{
- Dlelem *p;
-
- if (pendingNotifies)
- {
-
- /*
- * Since the referenced strings are malloc'd, we have to scan the
- * list and delete them individually. If we used palloc for the
- * strings then we could just do DLFreeList to get rid of both the
- * list nodes and the list base...
- */
- while ((p = DLRemHead(pendingNotifies)) != NULL)
- {
- free(DLE_VAL(p));
- DLFreeElem(p);
- }
- DLFreeList(pendingNotifies);
- pendingNotifies = NULL;
- }
+ /*
+ * We used to have to explicitly deallocate the list members and nodes,
+ * because they were malloc'd. Now, since we know they are palloc'd
+ * in TopTransactionContext, we need not do that --- they'll go away
+ * automatically at transaction exit. We need only reset the list head
+ * pointer.
+ */
+ pendingNotifies = NIL;
}