database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-28 23:42:10 +03:00
Code Activity

Invent pre-commit/pre-prepare/pre-subcommit events for xact callbacks.

Browse Source 
Currently it's only possible for loadable modules to get control during
post-commit cleanup of a transaction.  That doesn't work too well if they
want to do something that could throw an error; for example, an FDW might
need to issue a remote commit, which could well fail.  To improve matters,
extend the existing APIs for XactCallback and SubXactCallback functions
to provide new pre-commit events for this purpose.

The release notes will need to mention that existing callback functions
should be checked to make sure they don't do something unwanted when one
of the new event types occurs.  In the examples within our source tree,
contrib/sepgsql was fine but plpgsql had been a bit too cute.
This commit is contained in:
Tom Lane
2013-02-14 20:35:08 -05:00
parent 4765dd7921
commit fdaf44862b
3 changed files with 27 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
src/pl/plpgsql/src/pl_exec.c
View File

@ -6150,7 +6150,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
* expect the regular abort recovery procedures to release everything of
* interest.
*/
if (event != XACT_EVENT_ABORT)
if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
{
/* Shouldn't be any econtext stack entries left at commit */
Assert(simple_econtext_stack == NULL);
@ -6159,7 +6159,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
FreeExecutorState(simple_eval_estate);
simple_eval_estate = NULL;
}
else
else if (event == XACT_EVENT_ABORT)
{
simple_econtext_stack = NULL;
simple_eval_estate = NULL;
@ -6178,19 +6178,19 @@ void
plpgsql_subxact_cb(SubXactEvent event, SubTransactionId mySubid,
SubTransactionId parentSubid, void *arg)
{
if (event == SUBXACT_EVENT_START_SUB)
return;
while (simple_econtext_stack != NULL &&
simple_econtext_stack->xact_subxid == mySubid)
if (event == SUBXACT_EVENT_COMMIT_SUB || event == SUBXACT_EVENT_ABORT_SUB)
{
SimpleEcontextStackEntry *next;
while (simple_econtext_stack != NULL &&
simple_econtext_stack->xact_subxid == mySubid)
{
SimpleEcontextStackEntry *next;
FreeExprContext(simple_econtext_stack->stack_econtext,
(event == SUBXACT_EVENT_COMMIT_SUB));
next = simple_econtext_stack->next;
pfree(simple_econtext_stack);
simple_econtext_stack = next;
FreeExprContext(simple_econtext_stack->stack_econtext,
(event == SUBXACT_EVENT_COMMIT_SUB));
next = simple_econtext_stack->next;
pfree(simple_econtext_stack);
simple_econtext_stack = next;
}
}
}