Make leak counters thread-safe

include/core/SkInstCnt.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkInstCnt_DEFINED
 #define SkInstCnt_DEFINED
 
 /*
  * The instance counting system consists of three macros that create the
  * instance counting machinery. A class is added to the system by adding:
  *   SK_DECLARE_INST_COUNT at the top of its declaration for derived classes
  *   SK_DECLARE_INST_COUNT_ROOT at the top of its declaration for a root class
  * At the end of an application a call to all the "root" objects'
  * CheckInstanceCount methods should be made
  */
 #include "SkTypes.h"
 
 #if SK_ENABLE_INST_COUNT
 #include "SkTArray.h"
 #include "SkThread_platform.h"
 
 extern bool gPrintInstCount;
 
+SkBaseMutex& SkGetInstCntAddInstChildMutex();
+
 // The non-root classes just register themselves with their parent
 #define SK_DECLARE_INST_COUNT(className)                                    \
     SK_DECLARE_INST_COUNT_INTERNAL(className,                               \
                                    INHERITED::AddInstChild(CheckInstanceCount);)
 
 // The root classes registers a function to print out the memory stats when
 // the app ends
 #define SK_DECLARE_INST_COUNT_ROOT(className)                               \
     SK_DECLARE_INST_COUNT_INTERNAL(className, atexit(exitPrint);)
 
 #define SK_DECLARE_INST_COUNT_INTERNAL(className, initStep)                 \
     class SkInstanceCountHelper {                                           \
     public:                                                                 \
         typedef int (*PFCheckInstCnt)(int level, bool cleanUp);             \
         SkInstanceCountHelper() {                                           \
-            static bool gInited;                                            \
-            if (!gInited) {                                                 \
-                initStep                                                    \
-                GetChildren() = new SkTArray<PFCheckInstCnt>;               \
-                gInited = true;                                             \
+            if (0 == sk_atomic_inc(GetInstanceCountPtr())) {                \
+                sk_membar_aquire__after_atomic_dec();                       \
+                static bool gInited;                                        \

[bsalomon, 2013/12/04 15:04:19]

Perhaps we should use SK_DECLARE_STATIC_ONCE()/SkOnce() here.

[bungeman-skia, 2013/12/04 15:24:45]

Seconded.

[Kimmo Kinnunen, 2013/12/05 08:03:23]

Done.

+                if (!gInited) {                                             \
+                    initStep                                                \
+                    gInited = true;                                         \
+                }                                                           \
             }                                                               \
-            sk_atomic_inc(GetInstanceCountPtr());                           \
         }                                                                   \
                                                                             \
         SkInstanceCountHelper(const SkInstanceCountHelper&) {               \
             sk_atomic_inc(GetInstanceCountPtr());                           \
         }                                                                   \
                                                                             \
         ~SkInstanceCountHelper() {                                          \
             sk_atomic_dec(GetInstanceCountPtr());                           \
         }                                                                   \
                                                                             \
@@ skipping 38 matching lines @@
             SkDebugf("%*c Leaked ???: %d\n", 4*(level + 1), ' ', count);    \
         }                                                                   \
         if (cleanUp) {                                                      \
             delete children;                                                \
             SkInstanceCountHelper::GetChildren() = NULL;                    \
         }                                                                   \
         return GetInstanceCount();                                          \
     }                                                                       \
                                                                             \
     static void AddInstChild(int (*childCheckInstCnt)(int, bool)) {         \
-        if (CheckInstanceCount != childCheckInstCnt &&                      \
-            NULL != SkInstanceCountHelper::GetChildren()) {                 \
+        if (CheckInstanceCount != childCheckInstCnt) {                      \
+            SkAutoMutexAcquire ama(SkGetInstCntAddInstChildMutex());        \
+            if (NULL == SkInstanceCountHelper::GetChildren()) {             \

[robertphillips, 2013/12/04 14:01:22]

Why not use PFCheckInstCnt here?

[Kimmo Kinnunen, 2013/12/05 08:03:23]

I was confused with the previous need for separate _TEMPLATE macro, eg. I
assumed typename wouldn't work for non-templated classes. You're right, it
works. 
Done.

+                SkInstanceCountHelper::GetChildren() = new SkTArray<int (*)(int, bool)>; \
+            }                                                               \
             SkInstanceCountHelper::GetChildren()->push_back(childCheckInstCnt); \
         }                                                                   \
     }
 
 #else
 // Typically SK_ENABLE_INST_COUNT=0. Make sure the class declares public typedef INHERITED by
 // causing a compile-time error if the typedef is missing. This way SK_ENABLE_INST_COUNT=1 stays
 // compiling.
 #define SK_DECLARE_INST_COUNT(className) static void AddInstChild() { INHERITED::AddInstChild(); }
 #define SK_DECLARE_INST_COUNT_ROOT(className) static void AddInstChild() { }
 #endif
 
 // Following are deprecated. They are defined only for backwards API compatibility.
 #define SK_DECLARE_INST_COUNT_TEMPLATE(className) SK_DECLARE_INST_COUNT(className)
 #define SK_DEFINE_INST_COUNT(className)
 #define SK_DEFINE_INST_COUNT_TEMPLATE(templateInfo, className)
 
 #endif // SkInstCnt_DEFINED