From: Wilfried Goesgens <dothebart@citadel.org>
Date: Sat, 20 Apr 2013 10:48:45 +0000 (+0200)
Subject: THREADS: re-install the max workers & min spare workers configs; lock thread count... 
X-Git-Tag: v8.20~56
X-Git-Url: https://code.citadel.org/?p=citadel.git;a=commitdiff_plain;h=f2f392abe416b03750cb053fd0780f62c85d3ae4

THREADS: re-install the max workers & min spare workers configs; lock thread count operations.
---

diff --git a/citadel/sysdep.c b/citadel/sysdep.c
index 1caf2ce10..4ea07f3ed 100644
--- a/citadel/sysdep.c
+++ b/citadel/sysdep.c
@@ -1157,7 +1157,9 @@ void *worker_thread(void *blah) {
 	CitContext *con = NULL;         /* Temporary context pointer */
 	int i;
 
+	pthread_mutex_lock(&ThreadCountMutex);
 	++num_workers;
+	pthread_mutex_unlock(&ThreadCountMutex);
 
 	while (!server_shutting_down) {
 
@@ -1339,7 +1341,10 @@ do_select:	force_purge = 0;
 
 SKIP_SELECT:
 		/* We're bound to a session */
+		pthread_mutex_lock(&ThreadCountMutex);
 		++active_workers;
+		pthread_mutex_unlock(&ThreadCountMutex);
+
 		if (bind_me != NULL) {
 			become_session(bind_me);
 
@@ -1373,11 +1378,22 @@ SKIP_SELECT:
 
 		dead_session_purge(force_purge);
 		do_housekeeping();
+
+		pthread_mutex_lock(&ThreadCountMutex);
 		--active_workers;
+		if (active_workers + config.c_min_workers < num_workers)
+		{
+			num_workers--;
+			pthread_mutex_unlock(&ThreadCountMutex);
+			return (NULL);
+		}
+		pthread_mutex_unlock(&ThreadCountMutex);
 	}
 
 	/* If control reaches this point, the server is shutting down */
+	pthread_mutex_lock(&ThreadCountMutex);
 	--num_workers;
+	pthread_mutex_unlock(&ThreadCountMutex);
 	return(NULL);
 }
 
diff --git a/citadel/threads.c b/citadel/threads.c
index 4a4fe5163..bea9665c3 100644
--- a/citadel/threads.c
+++ b/citadel/threads.c
@@ -63,6 +63,7 @@ pthread_mutex_t Critters[MAX_SEMAPHORES];	/* Things needing locking */
 struct thread_tsd masterTSD;
 int server_shutting_down = 0;			/* set to nonzero during shutdown */
 
+pthread_mutex_t ThreadCountMutex;;
 
 
 void InitializeSemaphores(void)
@@ -191,6 +192,8 @@ void go_threading(void)
 		abort();
 	}
 
+	pthread_mutex_init(&ThreadCountMutex, NULL);
+
 	/* Second call to module init functions now that threading is up */
 	initialise_modules(1);
 
@@ -198,10 +201,10 @@ void go_threading(void)
 	CtdlThreadCreate(worker_thread);
 
 	/* The supervisor thread monitors worker threads and spawns more of them if it finds that
-	 * they are all in use.  FIXME make the 256 max threads a configurable value.
+	 * they are all in use.
 	 */
 	while (!server_shutting_down) {
-		if ((active_workers == num_workers) && (num_workers < 256)) {
+		if ((active_workers == num_workers) && (num_workers < config.c_max_workers)) {
 			CtdlThreadCreate(worker_thread);
 		}
 		usleep(1000000);
diff --git a/citadel/threads.h b/citadel/threads.h
index 2119e0239..11bad4f09 100644
--- a/citadel/threads.h
+++ b/citadel/threads.h
@@ -45,4 +45,7 @@ void go_threading(void);
 void InitializeMasterTSD(void);
 void CtdlThreadCreate(void *(*start_routine)(void*));
 
+
+extern pthread_mutex_t ThreadCountMutex;;
+
 #endif // THREADS_H