static RETSIGTYPE signal_cleanup(int signum) {
CtdlLogPrintf(CTDL_DEBUG, "Caught signal %d; shutting down.\n", signum);
- CtdlThreadStopAll();
exit_signal = signum;
}
* whole Citadel service would come down whenever a single client
* socket breaks.
*/
- //signal(SIGPIPE, SIG_IGN);
- signal(SIGPIPE, signal_cleanup);
+ signal(SIGPIPE, SIG_IGN);
+}
+
+
+
+/*
+ * Obtain a semaphore lock to begin a critical section.
+ * but only if no one else has one
+ */
+int try_critical_section(int which_one)
+{
+ /* For all types of critical sections except those listed here,
+ * ensure nobody ever tries to do a critical section within a
+ * transaction; this could lead to deadlock.
+ */
+ if ( (which_one != S_FLOORCACHE)
+#ifdef DEBUG_MEMORY_LEAKS
+ && (which_one != S_DEBUGMEMLEAKS)
+#endif
+ && (which_one != S_RPLIST)
+ ) {
+ cdb_check_handles();
+ }
+ return (pthread_mutex_trylock(&Critters[which_one]));
}
*/
/*static pthread_mutex_t thread_gc_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t thread_gc_cond = PTHREAD_COND_INITIALIZER;
-*/static pthread_t GC_thread;
+*/
+static pthread_t GC_thread;
static char *CtdlThreadStates[CTDL_THREAD_LAST_STATE];
+double CtdlThreadLoadAvg = 0;
+double CtdlThreadWorkerAvg = 0;
/*
* Pinched the following bits regarding signals from Kannel.org
*/
}
+void ctdl_thread_internal_cleanup(void)
+{
+ int i;
+
+ for (i=0; i<CTDL_THREAD_LAST_STATE; i++)
+ {
+ free (CtdlThreadStates[i]);
+ }
+}
+
void ctdl_thread_internal_init(void)
{
struct CtdlThreadNode *this_thread;
CtdlThreadStates[CTDL_THREAD_STOP_REQ] = strdup("Thread Stop Requested");
CtdlThreadStates[CTDL_THREAD_SLEEPING] = strdup("Thread Sleeping");
CtdlThreadStates[CTDL_THREAD_RUNNING] = strdup("Thread Running");
-
+ CtdlThreadStates[CTDL_THREAD_BLOCKED] = strdup("Thread Blocked");
/* Get ourself a thread entry */
this_thread = malloc(sizeof(struct CtdlThreadNode));
CtdlThreadList = this_thread;
if (this_thread->next)
this_thread->next->prev = this_thread;
+ /* Set up start times */
+ gettimeofday(&this_thread->start_time, NULL); /* Time this thread started */
+ memcpy(&this_thread->last_state_change, &this_thread->start_time, sizeof (struct timeval)); /* Changed state so mark it. */
}
+
+/*
+ * A function to update a threads load averages
+ */
+ void ctdl_thread_internal_update_avgs(struct CtdlThreadNode *this_thread)
+ {
+ struct timeval now, result;
+ double last_duration;
+
+ gettimeofday(&now, NULL);
+ timersub(&now, &(this_thread->last_state_change), &result);
+ // result now has a timeval for the time we spent in the last state since we last updated
+ last_duration = (double)result.tv_sec + ((double)result.tv_usec / (double) 1000000);
+ if (this_thread->state == CTDL_THREAD_SLEEPING)
+ this_thread->avg_sleeping += last_duration;
+ if (this_thread->state == CTDL_THREAD_RUNNING)
+ this_thread->avg_running += last_duration;
+ if (this_thread->state == CTDL_THREAD_BLOCKED)
+ this_thread->avg_blocked += last_duration;
+ memcpy (&this_thread->last_state_change, &now, sizeof (struct timeval));
+}
+
+/*
+ * A function to chenge the state of a thread
+ */
+void ctdl_thread_internal_change_state (struct CtdlThreadNode *this_thread, enum CtdlThreadState new_state)
+{
+ /*
+ * Wether we change state or not we need update the load values
+ */
+ pthread_mutex_lock(&this_thread->ThreadMutex); /* To prevent race condition of a sleeping thread */
+ ctdl_thread_internal_update_avgs(this_thread);
+ if ((new_state == CTDL_THREAD_STOP_REQ) && (this_thread->state > CTDL_THREAD_STOP_REQ))
+ this_thread->state = new_state;
+ if (((new_state == CTDL_THREAD_SLEEPING) || (new_state == CTDL_THREAD_BLOCKED)) && (this_thread->state == CTDL_THREAD_RUNNING))
+ this_thread->state = new_state;
+ if ((new_state == CTDL_THREAD_RUNNING) && ((this_thread->state == CTDL_THREAD_SLEEPING) || (this_thread->state == CTDL_THREAD_BLOCKED)))
+ this_thread->state = new_state;
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+}
+
+
/*
* A function to tell all threads to exit
*/
void CtdlThreadStopAll(void)
{
+ //FIXME: The signalling of the condition should not be in the critical_section
+ // We need to build a list of threads we are going to signal and then signal them afterwards
+
struct CtdlThreadNode *this_thread;
begin_critical_section(S_THREAD_LIST);
{
if (this_thread->thread_func) // Don't tell garbage collector to stop
{
- pthread_mutex_lock(&this_thread->ThreadMutex); /* To prevent race condition of a sleeping thread */
- if (this_thread->state > CTDL_THREAD_STOP_REQ)
- this_thread->state = CTDL_THREAD_STOP_REQ;
- pthread_mutex_unlock(&this_thread->ThreadMutex);
+ ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_STOP_REQ);
+// pthread_mutex_lock(&this_thread->ThreadMutex);
pthread_cond_signal(&this_thread->ThreadCond);
+// pthread_mutex_unlock(&this_thread->ThreadMutex);
CtdlLogPrintf(CTDL_DEBUG, "Thread system stopping thread \"%s\" (%ld).\n", this_thread->name, this_thread->tid);
}
this_thread = this_thread->next;
while(this_thread)
{
if (!this_thread->thread_func)
+ {
+// pthread_mutex_lock(&this_thread->ThreadMutex);
pthread_cond_signal(&this_thread->ThreadCond);
-
+// pthread_mutex_unlock(&this_thread->ThreadMutex);
+ }
this_thread = this_thread->next;
}
end_critical_section(S_THREAD_LIST);
return num_threads;
}
+int CtdlThreadGetWorkers(void)
+{
+ return num_workers;
+}
+
/*
* A function to find the thread structure for this thread
*/
this_thread = thread;
if (!this_thread)
{
- CtdlLogPrintf(CTDL_WARNING, "Thread system WARNING. Attempt to CtdlThreadRename() a non thread.\n");
+ CtdlLogPrintf(CTDL_WARNING, "Thread system WARNING. Attempt to CtdlThreadRename() a non thread. %s\n", name);
return NULL;
}
begin_critical_section(S_THREAD_LIST);
+ old_name = this_thread->name;
if (name)
- {
- old_name = this_thread->name;
this_thread->name = strdup (name);
- free(old_name);
- }
- old_name = strdup(this_thread->name);
+ else
+ old_name = strdup(old_name);
end_critical_section (S_THREAD_LIST);
return (old_name);
}
}
begin_critical_section(S_THREAD_LIST);
- this_thread->state = CTDL_THREAD_CANCELLED;
+ ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_CANCELLED);
pthread_cancel(this_thread->tid);
end_critical_section (S_THREAD_LIST);
}
/*
* A function for a thread to check if it has been asked to stop
*/
-int CtdlThreadCheckStop(void)
+int CtdlThreadCheckStop(struct CtdlThreadNode *this_thread)
{
- struct CtdlThreadNode *this_thread;
-
- this_thread = CtdlThreadSelf();
if (!this_thread)
{
CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, CtdlThreadCheckStop() called by a non thread.\n");
CtdlThreadStopAll();
return -1;
}
+ pthread_mutex_lock(&this_thread->ThreadMutex);
if(this_thread->state == CTDL_THREAD_STOP_REQ)
{
this_thread->state = CTDL_THREAD_STOPPING;
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
return -1;
}
- else if(this_thread->state < CTDL_THREAD_STOP_REQ)
+ else if((this_thread->state < CTDL_THREAD_STOP_REQ) && (this_thread->state > CTDL_THREAD_CREATE))
+ {
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
return -1;
-
+ }
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
return 0;
}
return; // Don't stop garbage collector
begin_critical_section (S_THREAD_LIST);
- pthread_mutex_lock(&this_thread->ThreadMutex); /* To prevent race condition of a sleeping thread */
- if (this_thread->state > CTDL_THREAD_STOP_REQ)
- this_thread->state = CTDL_THREAD_STOP_REQ;
- pthread_mutex_unlock(&this_thread->ThreadMutex);
+ ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_STOP_REQ);
+// pthread_mutex_lock(&this_thread->ThreadMutex);
pthread_cond_signal(&this_thread->ThreadCond);
+// pthread_mutex_unlock(&this_thread->ThreadMutex);
end_critical_section(S_THREAD_LIST);
}
struct timespec wake_time;
struct timeval time_now;
struct CtdlThreadNode *self;
- int state;
self = CtdlThreadSelf();
}
begin_critical_section(S_THREAD_LIST);
+ ctdl_thread_internal_change_state (self, CTDL_THREAD_SLEEPING);
pthread_mutex_lock(&self->ThreadMutex); /* Prevent something asking us to awaken before we've gone to sleep */
- state = self->state;
- if (state == CTDL_THREAD_RUNNING)
- self->state = CTDL_THREAD_SLEEPING;
end_critical_section(S_THREAD_LIST);
- if(state != CTDL_THREAD_RUNNING)
- {
- CtdlLogPrintf(CTDL_DEBUG, "CtdlThreadSleep() called by a thread that is not running.\n");
- pthread_mutex_unlock(&self->ThreadMutex);
- return;
- }
-
memset (&wake_time, 0, sizeof(struct timespec));
gettimeofday(&time_now, NULL);
wake_time.tv_sec = time_now.tv_sec + secs;
wake_time.tv_nsec = time_now.tv_usec * 10;
pthread_cond_timedwait(&self->ThreadCond, &self->ThreadMutex, &wake_time);
begin_critical_section(S_THREAD_LIST);
- if (self->state == CTDL_THREAD_SLEEPING) /* Don't change state if something else changed it while we were asleep */
- self->state = state;
pthread_mutex_unlock(&self->ThreadMutex);
+ ctdl_thread_internal_change_state (self, CTDL_THREAD_RUNNING);
end_critical_section(S_THREAD_LIST);
}
#ifdef HAVE_BACKTRACE
eCrash_UnregisterThread();
#endif
+ pthread_mutex_lock(&this_thread->ThreadMutex);
this_thread->state = CTDL_THREAD_EXITED; // needs to be last thing else house keeping will unlink us too early
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
end_critical_section(S_THREAD_LIST);
- CtdlThreadGC();
+// CtdlThreadGC();
}
+/*
+ * A quick function to show the load averages
+ */
+void ctdl_thread_internal_calc_loadavg(void)
+{
+ struct CtdlThreadNode *that_thread;
+ double load_avg, worker_avg;
+ int workers = 0;
+ that_thread = CtdlThreadList;
+ load_avg = 0;
+ worker_avg = 0;
+ while(that_thread)
+ {
+ /* Update load averages */
+ pthread_mutex_lock(&that_thread->ThreadMutex);
+ ctdl_thread_internal_update_avgs(that_thread);
+ that_thread->load_avg = that_thread->avg_sleeping + that_thread->avg_running + that_thread->avg_blocked;
+ that_thread->load_avg = that_thread->avg_running / that_thread->load_avg * 100;
+ that_thread->avg_sleeping /= 2;
+ that_thread->avg_running /= 2;
+ that_thread->avg_blocked /= 2;
+ load_avg += that_thread->load_avg;
+ if (that_thread->flags & CTDLTHREAD_WORKER)
+ {
+ worker_avg += that_thread->load_avg;
+ workers++;
+ }
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "CtdlThread, \"%s\" (%ld) \"%s\" %f %f %f %f.\n",
+ that_thread->name,
+ that_thread->tid,
+ CtdlThreadStates[that_thread->state],
+ that_thread->avg_sleeping,
+ that_thread->avg_running,
+ that_thread->avg_blocked,
+ that_thread->load_avg);
+#endif
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ that_thread = that_thread->next;
+ }
+ CtdlThreadLoadAvg = load_avg/num_threads;
+ CtdlThreadWorkerAvg = worker_avg/workers;
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_INFO, "System load average %f, workers averag %f, threads %d, workers %d, sessions %d\n", CtdlThreadLoadAvg, CtdlThreadWorkerAvg, num_threads, num_workers, num_sessions);
+#endif
+}
/*
*/
void ctdl_internal_thread_gc (void)
{
- struct CtdlThreadNode *this_thread, *that_thread = NULL;
+ struct CtdlThreadNode *this_thread, *that_thread;
int workers = 0;
- /*
- * Wait on the condition variable that tells us garbage collection is needed
- * We wake up every 10 seconds just in case someone forgot to inform us of a thread exiting
- */
-
- CtdlThreadSleep(10);
-
/* Handle exiting of garbage collector thread */
if(num_threads == 1)
CtdlThreadList->state = CTDL_THREAD_EXITED;
+#ifdef WITH_THREADLOG
CtdlLogPrintf(CTDL_DEBUG, "Thread system running garbage collection.\n");
+#endif
/*
* Woke up to do garbage collection
*/
- begin_critical_section(S_THREAD_LIST);
this_thread = CtdlThreadList;
while(this_thread)
{
that_thread = this_thread;
this_thread = this_thread->next;
- CtdlLogPrintf(CTDL_DEBUG, "CtdlThread, \"%s\" (%ld) \"%s\".\n", that_thread->name, that_thread->tid, CtdlThreadStates[that_thread->state]);
/* Do we need to clean up this thread? */
if (that_thread->state != CTDL_THREAD_EXITED)
{
if (pthread_equal(that_thread->tid, pthread_self()) && that_thread->thread_func)
{ /* Sanity check */
- end_critical_section(S_THREAD_LIST);
CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, a thread is trying to clean up after itself.\n");
- CtdlThreadStopAll();
+ abort();
return;
}
if (num_threads <= 0)
{ /* Sanity check */
- end_critical_section (S_THREAD_LIST);
CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, num_threads <= 0 and trying to do Garbage Collection.\n");
- CtdlThreadStopAll();
+ abort();
return;
}
pthread_cond_destroy(&that_thread->ThreadCond);
pthread_attr_destroy(&that_thread->attr);
free(that_thread);
- that_thread = NULL;
}
/* Sanity check number of worker threads */
if (workers != num_workers)
{
- end_critical_section(S_THREAD_LIST);
- CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, discrepancy in number of worker threads. Counted %d, should be %d.\n", workers, num_workers);
- return;
+ CtdlLogPrintf(CTDL_EMERG,
+ "Thread system PANIC, discrepancy in number of worker threads. Counted %d, should be %d.\n",
+ workers, num_workers
+ );
+ abort();
}
-
- end_critical_section(S_THREAD_LIST);
}
* can continue its execution.
*/
begin_critical_section(S_THREAD_LIST);
+ // Register the cleanup function to take care of when we exit.
+ pthread_cleanup_push(ctdl_internal_thread_cleanup, NULL);
// Get our thread data structure
this_thread = (struct CtdlThreadNode *) arg;
- this_thread->state = CTDL_THREAD_RUNNING;
+ /* Only change to running state if we weren't asked to stop during the create cycle
+ * Other wise there is a window to allow this threads creation to continue to full grown and
+ * therby prevent a shutdown of the server.
+ */
+ if (!CtdlThreadCheckStop(this_thread))
+ this_thread->state = CTDL_THREAD_RUNNING;
+
this_thread->pid = getpid();
+ gettimeofday(&this_thread->start_time, NULL); /* Time this thread started */
+ memcpy(&this_thread->last_state_change, &this_thread->start_time, sizeof (struct timeval)); /* Changed state so mark it. */
end_critical_section(S_THREAD_LIST);
// Tell the world we are here
CtdlLogPrintf(CTDL_NOTICE, "Created a new thread \"%s\" (%ld). \n", this_thread->name, this_thread->tid);
- // Register the cleanup function to take care of when we exit.
- pthread_cleanup_push(ctdl_internal_thread_cleanup, NULL);
/*
- * run the thread to do the work
+ * run the thread to do the work but only if we haven't been asked to stop
*/
- ret = (this_thread->thread_func)(this_thread->user_args);
+ if (!CtdlThreadCheckStop(this_thread))
+ ret = (this_thread->thread_func)(this_thread->user_args);
/*
* Our thread is exiting either because it wanted to end or because the server is stopping
this_thread->flags = flags;
this_thread->thread_func = thread_func;
this_thread->user_args = args;
+ /* Set this new thread with an avg_blocked of 2. We do this so that its creation affects the
+ * load average for the system. If we don't do this then we create a mass of threads at the same time
+ * because the creation didn't affect the load average.
+ */
+ this_thread->avg_blocked = 2;
pthread_mutex_init (&(this_thread->ThreadMutex), NULL);
pthread_cond_init (&(this_thread->ThreadCond), NULL);
#ifdef HAVE_BACKTRACE
eCrash_RegisterThread(this_thread->name, 0);
#endif
+ ctdl_thread_internal_calc_loadavg();
return this_thread;
}
+/*
+ * A warapper function for select so we can show a thread as blocked
+ */
+int CtdlThreadSelect(int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timeval *timeout, struct CtdlThreadNode *self)
+{
+ int ret;
+
+ ctdl_thread_internal_change_state(self, CTDL_THREAD_BLOCKED);
+ ret = select(n, readfds, writefds, exceptfds, timeout);
+ ctdl_thread_internal_change_state(self, CTDL_THREAD_RUNNING);
+ return ret;
+}
/*
* Purge all sessions which have the 'kill_me' flag set.
void dead_session_purge(int force) {
struct CitContext *ptr, *ptr2; /* general-purpose utility pointer */
struct CitContext *rem = NULL; /* list of sessions to be destroyed */
-
+
if (force == 0) {
if ( (time(NULL) - last_purge) < 5 ) {
return; /* Too soon, go away */
}
time(&last_purge);
- begin_critical_section(S_SESSION_TABLE);
+ if (try_critical_section(S_SESSION_TABLE))
+ return;
+
ptr = ContextList;
while (ptr) {
ptr2 = ptr;
}
--num_sessions;
-
/* And put it on our to-be-destroyed list */
ptr2->next = rem;
rem = ptr2;
-
}
}
end_critical_section(S_SESSION_TABLE);
rem = rem->next;
free(ptr);
}
-
- /* Raise the size of the worker thread pool if necessary. */
- begin_critical_section(S_THREAD_LIST);
- if ( (num_sessions > num_workers)
- && (num_workers < config.c_max_workers) ) {
- ctdl_internal_create_thread(NULL, CTDLTHREAD_BIGSTACK + CTDLTHREAD_WORKER, worker_thread, NULL);
- }
- end_critical_section(S_THREAD_LIST);
- // FIXME: reduce the number of worker threads too
}
struct timeval tv;
int force_purge = 0;
int m;
-
+
+ CT_PUSH();
+
cdb_allocate_tsd();
- while (!CtdlThreadCheckStop()) {
+ while (!CtdlThreadCheckStop(CT)) {
/* make doubly sure we're not holding any stale db handles
* which might cause a deadlock.
}
}
- if (!CtdlThreadCheckStop()) {
+ if (!CtdlThreadCheckStop(CT)) {
tv.tv_sec = 1; /* wake up every second if no input */
tv.tv_usec = 0;
- retval = select(highest + 1, &readfds, NULL, NULL, &tv);
+ retval = CtdlThreadSelect(highest + 1, &readfds, NULL, NULL, &tv, CT);
}
- if (CtdlThreadCheckStop()) return(NULL);
+ if (CtdlThreadCheckStop(CT)) return(NULL);
/* Now figure out who made this select() unblock.
* First, check for an error or exit condition.
if (errno != EINTR) {
CtdlLogPrintf(CTDL_EMERG, "Exiting (%s)\n", strerror(errno));
CtdlThreadStopAll();
- } else if (!CtdlThreadCheckStop()) {
+ } else if (!CtdlThreadCheckStop(CT)) {
CtdlLogPrintf(CTDL_DEBUG, "Un handled select failure.\n");
goto do_select;
}
}
- else if(retval == 0) {
- goto SKIP_SELECT;
- }
+// else if(retval == 0) {
+// goto SKIP_SELECT;
+// }
/* Next, check to see if it's a new client connecting
* on a master socket.
*/
dead_session_purge(force_purge);
do_housekeeping();
- check_sched_shutdown();
}
/* If control reaches this point, the server is shutting down */
return(NULL);
projects / citadel.git / blobdiff