diff options
Diffstat (limited to 'src/backend/storage')
| -rw-r--r-- | src/backend/storage/lmgr/proc.c | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 4ae977154ac..3248e136c9a 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -1287,12 +1287,53 @@ ProcWaitForSignal(void) void ProcSendSignal(int pid) { - PGPROC *proc = BackendPidGetProc(pid); + PGPROC *proc = NULL; + + proc = BackendPidGetProc(pid); + + if (proc == NULL) + { + /* use volatile pointer to prevent code rearrangement */ + volatile PROC_HDR *procglobal = ProcGlobal; + + SpinLockAcquire(ProcStructLock); + + /* + * Check to see whether it is the Startup process we wish to signal. + * This call is made by the buffer manager when it wishes to wake up a + * process that has been waiting for a pin in so it can obtain a + * cleanup lock using LockBufferForCleanup(). Startup is not a normal + * backend, so BackendPidGetProc() will not return any pid at all. So + * we remember the information for this special case. + */ + if (pid == procglobal->startupProcPid) + proc = procglobal->startupProc; + + SpinLockRelease(ProcStructLock); + } if (proc != NULL) PGSemaphoreUnlock(&proc->sem); } +/* + * Record the PID and PGPROC structures for the Startup process, for use in + * ProcSendSignal(). See comments there for further explanation. + */ +void +PublishStartupProcessInformation(void) +{ + /* use volatile pointer to prevent code rearrangement */ + volatile PROC_HDR *procglobal = ProcGlobal; + + SpinLockAcquire(ProcStructLock); + + procglobal->startupProc = MyProc; + procglobal->startupProcPid = MyProcPid; + + SpinLockRelease(ProcStructLock); +} + /***************************************************************************** * SIGALRM interrupt support |