Fix #34783: smoke simulation crash when changing frame while preview rendering.

Added a mutex lock for smoke data access. The render was already working with a
copy of the volume data, so it's just a short lock to copy things and should not
block the UI much.

2 files changed, 36 insertions, 2 deletions

diff --git a/source/blender/blenlib/BLI_threads.h b/source/blender/blenlib/BLI_threads.h
index ec8e567c0ef..614cd4ee59d 100644
--- a/source/blender/blenlib/BLI_threads.h
+++ b/source/blender/blenlib/BLI_threads.h
@@ -92,9 +92,13 @@ typedef pthread_mutex_t ThreadMutex;
 #define BLI_MUTEX_INITIALIZER   PTHREAD_MUTEX_INITIALIZER
 
 void BLI_mutex_init(ThreadMutex *mutex);
+void BLI_mutex_end(ThreadMutex *mutex);
+
+ThreadMutex *BLI_mutex_alloc(void);
+void BLI_mutex_free(ThreadMutex *mutex);
+
 void BLI_mutex_lock(ThreadMutex *mutex);
 void BLI_mutex_unlock(ThreadMutex *mutex);
-void BLI_mutex_end(ThreadMutex *mutex);
 
 /* Spin Lock */
 
@@ -117,9 +121,13 @@ void BLI_spin_end(SpinLock *spin);
 typedef pthread_rwlock_t ThreadRWMutex;
 
 void BLI_rw_mutex_init(ThreadRWMutex *mutex);
+void BLI_rw_mutex_end(ThreadRWMutex *mutex);
+
+ThreadRWMutex *BLI_rw_mutex_alloc(void);
+void BLI_rw_mutex_free(ThreadRWMutex *mutex);
+
 void BLI_rw_mutex_lock(ThreadRWMutex *mutex, int mode);
 void BLI_rw_mutex_unlock(ThreadRWMutex *mutex);
-void BLI_rw_mutex_end(ThreadRWMutex *mutex);
 
 /* ThreadedWorker
  *
diff --git a/source/blender/blenlib/intern/threads.c b/source/blender/blenlib/intern/threads.c
index 1d3312fafb1..8b1ba38a35a 100644
--- a/source/blender/blenlib/intern/threads.c
+++ b/source/blender/blenlib/intern/threads.c
@@ -399,6 +399,19 @@ void BLI_mutex_end(ThreadMutex *mutex)
 	pthread_mutex_destroy(mutex);
 }
 
+ThreadMutex *BLI_mutex_alloc(void)
+{
+	ThreadMutex *mutex = MEM_callocN(sizeof(ThreadMutex), "ThreadMutex");
+	BLI_mutex_init(mutex);
+	return mutex;
+}
+
+void BLI_mutex_free(ThreadMutex *mutex)
+{
+	BLI_mutex_end(mutex);
+	MEM_freeN(mutex);
+}
+
 /* Spin Locks */
 
 void BLI_spin_init(SpinLock *spin)
@@ -464,6 +477,19 @@ void BLI_rw_mutex_end(ThreadRWMutex *mutex)
 	pthread_rwlock_destroy(mutex);
 }
 
+ThreadRWMutex *BLI_rw_mutex_alloc(void)
+{
+	ThreadRWMutex *mutex = MEM_callocN(sizeof(ThreadRWMutex), "ThreadRWMutex");
+	BLI_rw_mutex_init(mutex);
+	return mutex;
+}
+
+void BLI_rw_mutex_free(ThreadRWMutex *mutex)
+{
+	BLI_rw_mutex_end(mutex);
+	MEM_freeN(mutex);
+}
+
 /* ************************************************ */
 
 typedef struct ThreadedWorker {