diff options
Diffstat (limited to 'src/backend/storage/ipc/procarray.c')
| -rw-r--r-- | src/backend/storage/ipc/procarray.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 1e2783dea80..87b1228ae6d 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -23,7 +23,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.4 2005/07/31 17:19:18 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.5 2005/08/20 01:26:36 ishii Exp $ * *------------------------------------------------------------------------- */ @@ -686,6 +686,44 @@ BackendPidGetProc(int pid) } /* + * BackendXidGetPid -- get a backend's pid given its XID + * + * Returns 0 if not found or it's a prepared transaction. Note that + * it is up to the caller to be sure that the question remains + * meaningful for long enough for the answer to be used ... + * + * Only main transaction Ids are considered. This function is mainly + * useful for determining what backend owns a lock. + */ +int +BackendXidGetPid(TransactionId xid) +{ + int result = 0; + ProcArrayStruct *arrayP = procArray; + int index; + + if (xid == InvalidTransactionId) /* never match invalid xid */ + return 0; + + LWLockAcquire(ProcArrayLock, LW_SHARED); + + for (index = 0; index < arrayP->numProcs; index++) + { + PGPROC *proc = arrayP->procs[index]; + + if (proc->xid == xid) + { + result = proc->pid; + break; + } + } + + LWLockRelease(ProcArrayLock); + + return result; +} + +/* * IsBackendPid -- is a given pid a running backend */ bool |