Cycles: Use lock in the memory statistics

CPU rendering is allowed to allocate memory from multiple threads,
which means statistics need to be avare of this.

3 files changed, 39 insertions, 4 deletions

diff --git a/intern/cycles/util/CMakeLists.txt b/intern/cycles/util/CMakeLists.txt
index 295ebd24a5c..a07deb68b15 100644
--- a/intern/cycles/util/CMakeLists.txt
+++ b/intern/cycles/util/CMakeLists.txt
@@ -30,6 +30,7 @@ endif()
 set(SRC_HEADERS
 	util_algorithm.h
 	util_args.h
+	util_atomic.h
 	util_boundbox.h
 	util_cache.h
 	util_debug.h
diff --git a/intern/cycles/util/util_atomic.h b/intern/cycles/util/util_atomic.h
new file mode 100644
index 00000000000..1bbb0a86e23
--- /dev/null
+++ b/intern/cycles/util/util_atomic.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2014 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+#ifndef __UTIL_ATOMIC_H__
+#define __UTIL_ATOMIC_H__
+
+/* Using atomic ops header from Blender. */
+#include "atomic_ops.h"
+
+ATOMIC_INLINE void atomic_update_max_z(size_t *maximum_value, size_t value)
+{
+	size_t prev_value = *maximum_value;
+	while (prev_value < value) {
+		if (atomic_cas_z(maximum_value, prev_value, value) != prev_value) {
+			break;
+		}
+	}
+}
+
+#endif /* __UTIL_ATOMIC_H__ */
diff --git a/intern/cycles/util/util_stats.h b/intern/cycles/util/util_stats.h
index 8758b823084..fe6c162366e 100644
--- a/intern/cycles/util/util_stats.h
+++ b/intern/cycles/util/util_stats.h
@@ -17,6 +17,8 @@
 #ifndef __UTIL_STATS_H__
 #define __UTIL_STATS_H__
 
+#include "util_atomic.h"
+
 CCL_NAMESPACE_BEGIN
 
 class Stats {
@@ -24,14 +26,13 @@ public:
 	Stats() : mem_used(0), mem_peak(0) {}
 
 	void mem_alloc(size_t size) {
-		mem_used += size;
-		if(mem_used > mem_peak)
-			mem_peak = mem_used;
+		atomic_add_z(&mem_used, size);
+		atomic_update_max_z(&mem_peak, mem_used);
 	}
 
 	void mem_free(size_t size) {
 		assert(mem_used >= size);
-		mem_used -= size;
+		atomic_sub_z(&mem_used, size);
 	}
 
 	size_t mem_used;