Async_NotifyHandler must save and restore ImmediateInterruptOK. Fixes

known problem with failure to respond to 'pg_ctl stop -m fast', and
probable problems if SIGINT or SIGTERM arrives while processing a
SIGUSR2 interrupt that arrived while waiting for a new client query.

diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c
index 84f7fc4195e15e230ee372e788280a451e3bde9b..3c71c449e1a9210a7f6c555c87d7955cdb01db5c 100644 (file)
--- a/src/backend/commands/async.c
+++ b/src/backend/commands/async.c
@@ -613,6 +613,16 @@ Async_NotifyHandler(SIGNAL_ARGS)
 
        if (notifyInterruptEnabled)
        {
+               bool            save_ImmediateInterruptOK = ImmediateInterruptOK;
+
+               /*
+                * We may be called while ImmediateInterruptOK is true; turn it off
+                * while messing with the NOTIFY state.  (We would have to save
+                * and restore it anyway, because PGSemaphore operations inside
+                * ProcessIncomingNotify() might reset it.)
+                */
+               ImmediateInterruptOK = false;
+
                /*
                 * I'm not sure whether some flavors of Unix might allow another
                 * SIGUSR2 occurrence to recursively interrupt this routine. To
@@ -640,6 +650,13 @@ Async_NotifyHandler(SIGNAL_ARGS)
                                        elog(DEBUG, "Async_NotifyHandler: done");
                        }
                }
+
+               /*
+                * Restore ImmediateInterruptOK, and check for interrupts if needed.
+                */
+               ImmediateInterruptOK = save_ImmediateInterruptOK;
+               if (save_ImmediateInterruptOK)
+                       CHECK_FOR_INTERRUPTS();
        }
        else
        {