Fix shutdown_initiate() not to start multiple shutdown threads

This happened when you cancelled shutdown and initiated another one
before the old shutdown thread noticed the cancellation.

diff --git a/src/server/shutdown.c b/src/server/shutdown.c
index 8e1c2438cf96f285b542ed437827ffb36efe2f73..f7fb456c54733210d5167b9ab18326f45f05b11a 100644 (file)
--- a/src/server/shutdown.c
+++ b/src/server/shutdown.c
@@ -42,9 +42,16 @@
 #include "server.h"
 
 int shutdown_pending;
+static empth_t *shutdown_thread;
 
 static void shutdown_sequence(void *unused);
 
+/*
+ * Initiate shutdown in MINS_FROM_NOW minutes.
+ * If MINS_FROM_NOW is negative, cancel any pending shutdown instead.
+ * Return -1 on error, zero when no shutdown was pending, positive
+ * number when a pending shutdown was modified.
+ */
 int
 shutdown_initiate(int mins_from_now)
 {
@@ -60,14 +67,18 @@ shutdown_initiate(int mins_from_now)
 
     shutdown_pending = mins_from_now + 1;
 
-    if (old_pending) {
-       pr_wall("The shutdown time has been changed to %d minutes!\n",
-               mins_from_now);
+    if (shutdown_thread) {
+       if (old_pending)
+           pr_wall("The shutdown time has been changed to %d minutes!\n",
+                   mins_from_now);
        /* FIXME wake up shutdown_sequence() */
     } else {
-       if (!empth_create(shutdown_sequence, 50 * 1024, 0,
-                         "shutdownSeq", NULL))
+       shutdown_thread = empth_create(shutdown_sequence, 50 * 1024, 0,
+                                      "shutdownSeq", NULL);
+       if (!shutdown_thread) {
+           shutdown_pending = 0;
            return -1;
+       }
     }
 
     return old_pending;
@@ -104,4 +115,6 @@ shutdown_sequence(void *unused)
        /* FIXME error due to late wakeup accumulates */
        empth_sleep(now + 60);
     }
+
+    shutdown_thread = NULL;
 }