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;
 }