[Bf-blender-cvs] [b520d46] depsgraph_refactor: Removed the users refcount and mutex from the DepsgraphScheduler.

[Lukas Tönne]

Commit: b520d46dba1d2c0805d960d74f94ba68e879f595
Author: Lukas Tönne
Date:   Sun May 25 14:54:02 2014 +0200
https://developer.blender.org/rBb520d46dba1d2c0805d960d74f94ba68e879f595

Removed the users refcount and mutex from the DepsgraphScheduler.

This was introduced by cycles to automatically disable the render
engine when it's not in use, but doesn't make a lot of sense for the
dependency graph. It adds unnecessary complexity here.

===================================================================

M	source/blender/depsgraph/util/depsgraph_util_task.cpp
M	source/blender/depsgraph/util/depsgraph_util_task.h

===================================================================

diff --git a/source/blender/depsgraph/util/depsgraph_util_task.cpp b/source/blender/depsgraph/util/depsgraph_util_task.cpp
index e5906be..e3005ef 100644
--- a/source/blender/depsgraph/util/depsgraph_util_task.cpp
+++ b/source/blender/depsgraph/util/depsgraph_util_task.cpp
@@ -163,7 +163,7 @@ void DepsgraphTaskPool::stop()
 	BLI_assert(num == 0);
 }
 
-bool DepsgraphTaskPool::canceled()
+bool DepsgraphTaskPool::canceled() const
 {
 	return do_cancel;
 }
@@ -197,8 +197,6 @@ void DepsgraphTaskPool::num_increase()
 
 /* Task Scheduler */
 
-ThreadMutex DepsgraphTaskScheduler::mutex;
-int DepsgraphTaskScheduler::users = 0;
 DepsgraphTaskScheduler::Threads DepsgraphTaskScheduler::threads;
 bool DepsgraphTaskScheduler::do_exit = false;
 
@@ -208,52 +206,33 @@ ThreadCondition DepsgraphTaskScheduler::queue_cond;
 
 void DepsgraphTaskScheduler::init(int num_threads)
 {
-	BLI_mutex_lock(&mutex);
+	do_exit = false;
 	
-	/* multiple cycles instances can use this task scheduler, sharing the same
-	 * threads, so we keep track of the number of users. */
-	if(users == 0) {
-		do_exit = false;
-		
-		if(num_threads == 0) {
-			/* automatic number of threads */
-			num_threads = BLI_system_thread_count();
-		}
-		
-		/* launch threads that will be waiting for work */
-		threads.resize(num_threads);
-		
-		for(size_t i = 0; i < threads.size(); i++)
-			threads[i] = new Thread(&DepsgraphTaskScheduler::thread_run, i);
+	if(num_threads == 0) {
+		/* automatic number of threads */
+		num_threads = BLI_system_thread_count();
 	}
 	
-	users++;
+	/* launch threads that will be waiting for work */
+	threads.resize(num_threads);
 	
-	BLI_mutex_unlock(&mutex);
+	for(size_t i = 0; i < threads.size(); i++)
+		threads[i] = new Thread(&DepsgraphTaskScheduler::thread_run, i);
 }
 
 void DepsgraphTaskScheduler::exit()
 {
-	BLI_mutex_lock(&mutex);
+	/* stop all waiting threads */
+	do_exit = true;
+	BLI_condition_notify_all(&queue_cond);
 	
-	BLI_assert(users > 0);
-	users--;
-	
-	if(users == 0) {
-		/* stop all waiting threads */
-		do_exit = true;
-		BLI_condition_notify_all(&queue_cond);
-		
-		/* delete threads */
-		for (Threads::const_iterator it = threads.begin(); it != threads.end(); ++it) {
-			Thread *t = *it;
-			t->join();
-			delete t;
-		}
-		threads.clear();
+	/* delete threads */
+	for (Threads::const_iterator it = threads.begin(); it != threads.end(); ++it) {
+		Thread *t = *it;
+		t->join();
+		delete t;
 	}
-	
-	BLI_mutex_unlock(&mutex);
+	threads.clear();
 }
 
 bool DepsgraphTaskScheduler::thread_wait_pop(Entry& entry)
diff --git a/source/blender/depsgraph/util/depsgraph_util_task.h b/source/blender/depsgraph/util/depsgraph_util_task.h
index 2ad0ef1..8156587 100644
--- a/source/blender/depsgraph/util/depsgraph_util_task.h
+++ b/source/blender/depsgraph/util/depsgraph_util_task.h
@@ -78,13 +78,13 @@ public:
 	 * instead can just put the calling thread to sleep
 	 * and let the scheduler handle tasks
 	 */
-	void wait_work();	/* work and wait until all tasks are done */
+	void wait_work();		/* work and wait until all tasks are done */
 #endif
-	void wait();		/* wait until all tasks are done */
-	void cancel();		/* cancel all tasks, keep worker threads running */
-	void stop();		/* stop all worker threads */
+	void wait();			/* wait until all tasks are done */
+	void cancel();			/* cancel all tasks, keep worker threads running */
+	void stop();			/* stop all worker threads */
 	
-	bool canceled();	/* for worker threads, test if canceled */
+	bool canceled() const;	/* for worker threads, test if canceled */
 	
 protected:
 	friend class DepsgraphTaskScheduler;
@@ -112,9 +112,6 @@ public:
 	/* number of threads that can work on task */
 	static int num_threads() { return threads.size(); }
 	
-	/* test if any session is using the scheduler */
-	static bool active() { return users != 0; }
-
 protected:
 	friend class DepsgraphTaskPool;
 
@@ -141,8 +138,6 @@ protected:
 	};
 	typedef priority_queue<Entry, std::vector<Entry>, cmp_entry> Queue;
 	
-	static ThreadMutex mutex;           /* mutex for creating/freeing task pools */
-	static int users;                   /* number of active task pools using the scheduler */
 	static Threads threads;             /* worker threads */
 	static bool do_exit;