Hunting a bug in scheduled threads that caused a segflt. Got it and

[citadel.git] / citadel / sysdep.c

diff --git a/citadel/sysdep.c b/citadel/sysdep.c
index 90fff43e59c600d10af566abb15a42f3c0941d5b..67f47405257f7f375ed4367e54deb762ff7aabe2 100644 (file)
--- a/citadel/sysdep.c
+++ b/citadel/sysdep.c
@@ -1519,6 +1519,7 @@ void CtdlThreadGC (void)
 {
        struct CtdlThreadNode *this_thread, *that_thread;
        int workers = 0;
+       int ret=0;
        
        begin_critical_section(S_THREAD_LIST);
        
@@ -1585,11 +1586,17 @@ void CtdlThreadGC (void)
                /*
                 * Join on the thread to do clean up and prevent memory leaks
                 * Also makes sure the thread has cleaned up after itself before we remove it from the list
-                * If that thread has no function it must be the garbage collector
+                * We can join on the garbage collector thread the join should just return EDEADLCK
                 */
-               if (that_thread->thread_func)
-                       pthread_join (that_thread->tid, NULL);
-               
+               ret = pthread_join (that_thread->tid, NULL);
+               if (ret == EDEADLK)
+                       CtdlLogPrintf(CTDL_DEBUG, "Garbage collection on own thread.\n");
+               else if (ret == EINVAL)
+                       CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, that thread already joined on.\n");
+               else if (ret == ESRCH)
+                       CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, no thread to join on.\n");
+               else if (ret != 0)
+                       CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, pthread_join returned an unknown error.\n");
                /*
                 * Now we own that thread entry
                 */
@@ -1969,6 +1976,10 @@ void ctdl_thread_internal_check_scheduled(void)
        
        now = time(NULL);
        
+#ifdef WITH_THREADLOG
+       CtdlLogPrintf(CTDL_DEBUG, "Checking for scheduled threads to start.\n");
+#endif
+
        this_thread = CtdlThreadSchedList;
        while(this_thread)
        {
@@ -1978,19 +1989,26 @@ void ctdl_thread_internal_check_scheduled(void)
                if (now > that_thread->when)
                {
                        /* Unlink from schedule list */
-                       if (that_thread->next)
-                               that_thread->next->prev = that_thread->prev;
                        if (that_thread->prev)
                                that_thread->prev->next = that_thread->next;
                        else
                                CtdlThreadSchedList = that_thread->next;
-                       
+                       if (that_thread->next)
+                               that_thread->next->prev = that_thread->prev;
+                               
+                       that_thread->next = that_thread->prev = NULL;
+#ifdef WITH_THREADLOG
+                       CtdlLogPrintf(CTDL_DEBUG, "About to start scheduled thread \"%s\".\n", that_thread->name);
+#endif
                        begin_critical_section(S_THREAD_LIST);
                        if (CT->state > CTDL_THREAD_STOP_REQ)
                        {       /* Only start it if the system is not stopping */
                                pthread_mutex_lock(&that_thread->ThreadMutex);
                                if (ctdl_thread_internal_start_scheduled (that_thread) == NULL)
                                {
+#ifdef WITH_THREADLOG
+                       CtdlLogPrintf(CTDL_DEBUG, "Failed to start scheduled thread \"%s\".\n", that_thread->name);
+#endif
                                        pthread_mutex_unlock(&that_thread->ThreadMutex);
                                        pthread_mutex_destroy(&(that_thread->ThreadMutex));
                                        pthread_cond_destroy(&(that_thread->ThreadCond));
@@ -2001,14 +2019,20 @@ void ctdl_thread_internal_check_scheduled(void)
                                }
                                else
                                {
-                                       CtdlLogPrintf(CTDL_INFO, "Thread system, Started a sceduled thread \"%s\".\n",
-                                               that_thread->name);
+                                       CtdlLogPrintf(CTDL_INFO, "Thread system, Started a scheduled thread \"%s\" (%ld).\n",
+                                               that_thread->name, that_thread->tid);
                                        pthread_mutex_unlock(&that_thread->ThreadMutex);
                                        ctdl_thread_internal_calc_loadavg();
                                }
                        }
                        end_critical_section(S_THREAD_LIST);
                }
+               else
+               {
+#ifdef WITH_THREADLOG
+                       CtdlLogPrintf(CTDL_DEBUG, "Thread \"%s\" will start in %ld seconds.\n", that_thread->name, that_thread->when - time(NULL));
+#endif
+               }
        }
        end_critical_section(S_SCHEDULE_LIST);
 }