mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Avoid deep recursion when assigning XIDs to multiple levels of subxacts.

Browse Source 
Backpatch to 8.0.

Andres Freund, with cleanup and adjustment for older branches by me.
This commit is contained in:
Robert Haas 2010-07-23 00:43:17 +00:00
parent 7fce4dc6cc
commit 733959b961
1 changed files with 25 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/backend/access/transam/xact.c
View File

@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.274.2.3 2010/01/24 21:49:31 tgl Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.274.2.4 2010/07/23 00:43:17 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@ -399,10 +399,32 @@ AssignTransactionId(TransactionState s)
/*
* Ensure parent(s) have XIDs, so that a child always has an XID later
* than its parent.
* than its parent. Musn't recurse here, or we might get a stack overflow
* if we're at the bottom of a huge stack of subtransactions none of which
* have XIDs yet.
*/
if (isSubXact && !TransactionIdIsValid(s->parent->transactionId))
AssignTransactionId(s->parent);
{
TransactionState p = s->parent;
TransactionState *parents;
size_t parentOffset = 0;
parents = palloc(sizeof(TransactionState) * s->nestingLevel);
while (p != NULL && !TransactionIdIsValid(p->transactionId))
{
parents[parentOffset++] = p;
p = p->parent;
}
/*
* This is technically a recursive call, but the recursion will
* never be more than one layer deep.
*/
while (parentOffset != 0)
AssignTransactionId(parents[--parentOffset]);
pfree(parents);
}
/*
* Generate a new Xid and record it in PG_PROC and pg_subtrans.