1 files changed, 50 insertions, 0 deletions
diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c
index d4939415f07..377733377be 100644
--- a/src/backend/postmaster/bgworker.c
+++ b/src/backend/postmaster/bgworker.c
@@ -996,6 +996,56 @@ WaitForBackgroundWorkerStartup(BackgroundWorkerHandle *handle, pid_t *pidp)
 }
 
 /*
+ * Wait for a background worker to stop.
+ *
+ * If the worker hasn't yet started, or is running, we wait for it to stop
+ * and then return BGWH_STOPPED.  However, if the postmaster has died, we give
+ * up and return BGWH_POSTMASTER_DIED, because it's the postmaster that
+ * notifies us when a worker's state changes.
+ */
+BgwHandleStatus
+WaitForBackgroundWorkerShutdown(BackgroundWorkerHandle *handle)
+{
+	BgwHandleStatus status;
+	int			rc;
+	bool		save_set_latch_on_sigusr1;
+
+	save_set_latch_on_sigusr1 = set_latch_on_sigusr1;
+	set_latch_on_sigusr1 = true;
+
+	PG_TRY();
+	{
+		for (;;)
+		{
+			pid_t		pid;
+
+			CHECK_FOR_INTERRUPTS();
+
+			status = GetBackgroundWorkerPid(handle, &pid);
+			if (status == BGWH_STOPPED)
+				return status;
+
+			rc = WaitLatch(&MyProc->procLatch,
+						   WL_LATCH_SET | WL_POSTMASTER_DEATH, 0);
+
+			if (rc & WL_POSTMASTER_DEATH)
+				return BGWH_POSTMASTER_DIED;
+
+			ResetLatch(&MyProc->procLatch);
+		}
+	}
+	PG_CATCH();
+	{
+		set_latch_on_sigusr1 = save_set_latch_on_sigusr1;
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	set_latch_on_sigusr1 = save_set_latch_on_sigusr1;
+	return status;
+}
+
+/*
  * Instruct the postmaster to terminate a background worker.
  *
  * Note that it's safe to do this without regard to whether the worker is