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Don't create hash-table of zero size in TaskHashCreate(). 

hash_create(), called by TaskHashCreate(), doesn't work correctly for a
zero sized hash table. This triggers valgrind errors, and could
potentially cause crashes even without valgring.

This currently happens for Jobs with 0 tasks. These probably should be
optimized away before reaching TaskHashCreate(), but that's a bigger
change.
pull/834/head
Andres Freund 2016-10-03 13:05:05 -07:00
parent 6d050bc9f8
commit de32b7bbad
1 changed files with 9 additions and 0 deletions
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9
src/backend/distributed/executor/multi_task_tracker_executor.c
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@ -519,6 +519,15 @@ TaskHashCreate(uint32 taskHashSize)
int hashFlags = 0; int hashFlags = 0;
HTAB *taskHash = NULL; HTAB *taskHash = NULL;
/*
* Can't create a hashtable of size 0. Normally that shouldn't happen, but
* shard pruning currently can lead to this (Job with 0 Tasks). See #833.
*/
if (taskHashSize == 0)
{
taskHashSize = 2;
}
memset(&info, 0, sizeof(info)); memset(&info, 0, sizeof(info));
info.keysize = sizeof(TaskMapKey); info.keysize = sizeof(TaskMapKey);
info.entrysize = sizeof(TaskMapEntry); info.entrysize = sizeof(TaskMapEntry);