Add BackendXidGetPid().

This commit is contained in:
Tatsuo Ishii 2005-08-20 01:26:36 +00:00
parent f57e3f4cf3
commit bc3991c185
2 changed files with 41 additions and 2 deletions

View File

@ -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 $
*
*-------------------------------------------------------------------------
*/
@ -685,6 +685,44 @@ BackendPidGetProc(int pid)
return result;
}
/*
* 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
*/

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/procarray.h,v 1.3 2005/07/31 17:19:22 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/procarray.h,v 1.4 2005/08/20 01:26:29 ishii Exp $
*
*-------------------------------------------------------------------------
*/
@ -27,6 +27,7 @@ extern bool TransactionIdIsActive(TransactionId xid);
extern TransactionId GetOldestXmin(bool allDbs);
extern PGPROC *BackendPidGetProc(int pid);
extern int BackendXidGetPid(TransactionId xid);
extern bool IsBackendPid(int pid);
extern bool DatabaseHasActiveBackends(Oid databaseId, bool ignoreMyself);