diff options
Diffstat (limited to 'src/backend/access/transam/parallel.c')
| -rw-r--r-- | src/backend/access/transam/parallel.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c index 8eea092fb46..bf2e691f577 100644 --- a/src/backend/access/transam/parallel.c +++ b/src/backend/access/transam/parallel.c @@ -432,6 +432,9 @@ LaunchParallelWorkers(ParallelContext *pcxt) if (pcxt->nworkers == 0) return; + /* We need to be a lock group leader. */ + BecomeLockGroupLeader(); + /* If we do have workers, we'd better have a DSM segment. */ Assert(pcxt->seg != NULL); @@ -952,6 +955,19 @@ ParallelWorkerMain(Datum main_arg) */ /* + * Join locking group. We must do this before anything that could try + * to acquire a heavyweight lock, because any heavyweight locks acquired + * to this point could block either directly against the parallel group + * leader or against some process which in turn waits for a lock that + * conflicts with the parallel group leader, causing an undetected + * deadlock. (If we can't join the lock group, the leader has gone away, + * so just exit quietly.) + */ + if (!BecomeLockGroupMember(fps->parallel_master_pgproc, + fps->parallel_master_pid)) + return; + + /* * Load libraries that were loaded by original backend. We want to do * this before restoring GUCs, because the libraries might define custom * variables. |