Fix dblink and tablefunc to not return with the wrong CurrentMemoryContext.

Per buildfarm results.

diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index e09d6f16f6973c037ad4f544566f51ee1efcb17d..9c92ee51760e8bad5e1f85ea195ca8f3e87b336a 100644 (file)
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -8,7 +8,7 @@
  * Darko Prenosil <[email protected]>
  * Shridhar Daithankar <[email protected]>
  *
- * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.69 2008/01/14 02:49:47 tgl Exp $
+ * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.69.2.1 2008/11/30 23:24:01 tgl Exp $
  * Copyright (c) 2001-2008, PostgreSQL Global Development Group
  * ALL RIGHTS RESERVED;
  *
@@ -226,7 +226,6 @@ dblink_connect(PG_FUNCTION_ARGS)
    char       *connstr = NULL;
    char       *connname = NULL;
    char       *msg;
-   MemoryContext oldcontext;
    PGconn     *conn = NULL;
    remoteConn *rconn = NULL;
 
@@ -240,13 +239,11 @@ dblink_connect(PG_FUNCTION_ARGS)
    else if (PG_NARGS() == 1)
        connstr = GET_STR(PG_GETARG_TEXT_P(0));
 
-   oldcontext = MemoryContextSwitchTo(TopMemoryContext);
-
    if (connname)
-       rconn = (remoteConn *) palloc(sizeof(remoteConn));
-   conn = PQconnectdb(connstr);
+       rconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext,
+                                                 sizeof(remoteConn));
 
-   MemoryContextSwitchTo(oldcontext);
+   conn = PQconnectdb(connstr);
 
    if (PQstatus(conn) == CONNECTION_BAD)
    {
@@ -583,10 +580,10 @@ dblink_fetch(PG_FUNCTION_ARGS)
        funcctx = SRF_FIRSTCALL_INIT();
 
        /*
-        * switch to memory context appropriate for multiple function calls
+        * Try to execute the query.  Note that since libpq uses malloc,
+        * the PGresult will be long-lived even though we are still in
+        * a short-lived memory context.
         */
-       oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
        res = PQexec(conn, buf.data);
        if (!res ||
            (PQresultStatus(res) != PGRES_COMMAND_OK &&
@@ -633,9 +630,6 @@ dblink_fetch(PG_FUNCTION_ARGS)
                break;
        }
 
-       /* make sure we have a persistent copy of the tupdesc */
-       tupdesc = CreateTupleDescCopy(tupdesc);
-
        /* check result and tuple descriptor have the same number of columns */
        if (PQnfields(res) != tupdesc->natts)
            ereport(ERROR,
@@ -643,14 +637,25 @@ dblink_fetch(PG_FUNCTION_ARGS)
                     errmsg("remote query result rowtype does not match "
                            "the specified FROM clause rowtype")));
 
-       /* fast track when no results */
+       /*
+        * fast track when no results.  We could exit earlier, but then
+        * we'd not report error if the result tuple type is wrong.
+        */
        if (funcctx->max_calls < 1)
        {
-           if (res)
-               PQclear(res);
+           PQclear(res);
            SRF_RETURN_DONE(funcctx);
        }
 
+       /*
+        * switch to memory context appropriate for multiple function calls,
+        * so we can make long-lived copy of tupdesc etc
+        */
+       oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+       /* make sure we have a persistent copy of the tupdesc */
+       tupdesc = CreateTupleDescCopy(tupdesc);
+
        /* store needed metadata for subsequent calls */
        attinmeta = TupleDescGetAttInMetadata(tupdesc);
        funcctx->attinmeta = attinmeta;
@@ -841,7 +846,10 @@ dblink_record_internal(FunctionCallInfo fcinfo, bool is_async, bool do_get)
                res = PQgetResult(conn);
                /* NULL means we're all done with the async results */
                if (!res)
+               {
+                   MemoryContextSwitchTo(oldcontext);
                    SRF_RETURN_DONE(funcctx);
+               }
            }
 
            if (!res ||
@@ -855,6 +863,7 @@ dblink_record_internal(FunctionCallInfo fcinfo, bool is_async, bool do_get)
                    DBLINK_RES_ERROR_AS_NOTICE("sql error");
                    if (freeconn)
                        PQfinish(conn);
+                   MemoryContextSwitchTo(oldcontext);
                    SRF_RETURN_DONE(funcctx);
                }
            }
@@ -925,6 +934,7 @@ dblink_record_internal(FunctionCallInfo fcinfo, bool is_async, bool do_get)
            {
                if (res)
                    PQclear(res);
+               MemoryContextSwitchTo(oldcontext);
                SRF_RETURN_DONE(funcctx);
            }
 
@@ -1296,8 +1306,11 @@ dblink_get_pkey(PG_FUNCTION_ARGS)
            funcctx->user_fctx = results;
        }
        else
+       {
            /* fast track when no results */
+           MemoryContextSwitchTo(oldcontext);
            SRF_RETURN_DONE(funcctx);
+       }
 
        MemoryContextSwitchTo(oldcontext);
    }

diff --git a/contrib/tablefunc/tablefunc.c b/contrib/tablefunc/tablefunc.c
index bfac89e4146b1344675b3e00de2e311b72f7b348..9c9d0aa7a29f499bea7fae2517a4da6561d7f691 100644 (file)
--- a/contrib/tablefunc/tablefunc.c
+++ b/contrib/tablefunc/tablefunc.c
@@ -378,11 +378,6 @@ crosstab(PG_FUNCTION_ARGS)
        /* create a function context for cross-call persistence */
        funcctx = SRF_FIRSTCALL_INIT();
 
-       /*
-        * switch to memory context appropriate for multiple function calls
-        */
-       oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
        /* Connect to SPI manager */
        if ((ret = SPI_connect()) < 0)
            /* internal error */
@@ -423,9 +418,6 @@ crosstab(PG_FUNCTION_ARGS)
            SRF_RETURN_DONE(funcctx);
        }
 
-       /* SPI switches context on us, so reset it */
-       MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
        /* get a tuple descriptor for our result type */
        switch (get_call_result_type(fcinfo, NULL, &tupdesc))
        {
@@ -445,9 +437,6 @@ crosstab(PG_FUNCTION_ARGS)
                break;
        }
 
-       /* make sure we have a persistent copy of the tupdesc */
-       tupdesc = CreateTupleDescCopy(tupdesc);
-
        /*
         * Check that return tupdesc is compatible with the data we got from
         * SPI, at least based on number and type of attributes
@@ -458,6 +447,14 @@ crosstab(PG_FUNCTION_ARGS)
                     errmsg("return and sql tuple descriptions are " \
                            "incompatible")));
 
+       /*
+        * switch to memory context appropriate for multiple function calls
+        */
+       oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+       /* make sure we have a persistent copy of the tupdesc */
+       tupdesc = CreateTupleDescCopy(tupdesc);
+
        /*
         * Generate attribute metadata needed later to produce tuples from raw
         * C strings