database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-18 17:42:25 +03:00
Code Activity

Adjust nodeFunctionscan.c to reset transient memory context between calls

Browse Source 
to the table function, thus preventing memory leakage accumulation across
calls.  This means that SRFs need to be careful to distinguish permanent
and local storage; adjust code and documentation accordingly.  Patch by
Joe Conway, very minor tweaks by Tom Lane.
This commit is contained in:
Tom Lane
2002-08-29 17:14:33 +00:00
parent 0201dac1c3
commit e4186762ff
10 changed files with 154 additions and 134 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
src/include/funcapi.h
View File

@ -9,7 +9,7 @@
*
* Copyright (c) 2002, PostgreSQL Global Development Group
*
* $Id: funcapi.h,v 1.5 2002/08/29 00:17:06 tgl Exp $
* $Id: funcapi.h,v 1.6 2002/08/29 17:14:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -101,13 +101,14 @@ typedef struct FuncCallContext
AttInMetadata *attinmeta;
/*
* memory context used to initialize structure
* memory context used for structures which must live for multiple calls
*
* fmctx is set by SRF_FIRSTCALL_INIT() for you, and used by
* SRF_RETURN_DONE() for cleanup. It is primarily for internal use
* by the API.
* multi_call_memory_ctx is set by SRF_FIRSTCALL_INIT() for you, and used
* by SRF_RETURN_DONE() for cleanup. It is the most appropriate memory
* context for any memory that is to be re-used across multiple calls
* of the SRF.
*/
MemoryContext fmctx;
MemoryContext multi_call_memory_ctx;
} FuncCallContext;
@ -160,17 +161,22 @@ extern HeapTuple BuildTupleFromCStrings(AttInMetadata *attinmeta, char **values)
* {
* FuncCallContext *funcctx;
* Datum result;
* MemoryContext oldcontext;
* <user defined declarations>
*
* if(SRF_IS_FIRSTCALL())
* if (SRF_IS_FIRSTCALL())
* {
* <user defined code>
* funcctx = SRF_FIRSTCALL_INIT();
* // switch context when allocating stuff to be used in later calls
* oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
* <user defined code>
* <if returning composite>
* <obtain slot>
* funcctx->slot = slot;
* <endif returning composite>
* <user defined code>
* // return to original context when allocating transient memory
* MemoryContextSwitchTo(oldcontext);
* }
* <user defined code>
* funcctx = SRF_PERCALL_SETUP();