Make leak counters thread-safe and turn them on by default for Debug

Make leak counters implemented with SK_DECLARE_INST_COUNT thread-safe.
Enable the leak counting for Debug builds when Skia is built as a
static library. Having SK_DECLARE_INST_COUNT without
SK_DEFINE_INST_COUNT relies on static variables in member functions
declared in the header files. These might be duplicated in the clients
of the library when Skia is built as a dynamic library, producing
incorrect operation.

Protect the instance counter initialization step (initStep) by
using SkOnce.

Makes SkOnce.h part of the public API, since SkInstCnt is public.

Protect the per-class child list shared variable with a per-class mutex.

Changes the behavior in the way that if the child list has been
"cleaned up", it will still try to create subsequent child lists.

BUG=skia:1219
R=robertphillips@google.com, mtklein@google.com, bsalomon@google.com, bungeman@google.com, djsollen@google.com

Author: kkinnunen@nvidia.com

Review URL: https://codereview.chromium.org/99483003

git-svn-id: http://skia.googlecode.com/svn/trunk@13120 2bbb7eff-a529-9590-31e7-b0007b416f81

diff --git a/gm/colormatrix.cpp b/gm/colormatrix.cpp
index 9ab6563..2f98693 100644 (file)
--- a/gm/colormatrix.cpp
+++ b/gm/colormatrix.cpp
@@ -12,9 +12,9 @@
 #define WIDTH 500
 #define HEIGHT 500
 
-class SkOnce {
+class SkDoOnce {
 public:
-    SkOnce() : fOnce(false) {};
+    SkDoOnce() : fOnce(false) {};
 
     bool once() const {
         if (fOnce) {
@@ -39,7 +39,7 @@ static void setArray(SkPaint* paint, const SkScalar array[]) {
 namespace skiagm {
 
 class ColorMatrixGM : public GM {
-    SkOnce fOnce;
+    SkDoOnce fOnce;
     void init() {
         if (fOnce.once()) {
             fSolidBitmap = this->createSolidBitmap(64, 64);

diff --git a/gm/convexpaths.cpp b/gm/convexpaths.cpp
index 8eb4cba..91afbfe 100644 (file)
--- a/gm/convexpaths.cpp
+++ b/gm/convexpaths.cpp
@@ -9,9 +9,9 @@
 #include "SkRandom.h"
 #include "SkTArray.h"
 
-class SkOnce : SkNoncopyable {
+class SkDoOnce : SkNoncopyable {
 public:
-    SkOnce() { fDidOnce = false; }
+    SkDoOnce() { fDidOnce = false; }
 
     bool needToDo() const { return !fDidOnce; }
     bool alreadyDone() const { return fDidOnce; }
@@ -27,7 +27,7 @@ private:
 namespace skiagm {
 
 class ConvexPathsGM : public GM {
-    SkOnce fOnce;
+    SkDoOnce fOnce;
 public:
     ConvexPathsGM() {
         this->setBGColor(0xFF000000);

diff --git a/gyp/core.gypi b/gyp/core.gypi
index 56ea42a..55447fe 100644 (file)
--- a/gyp/core.gypi
+++ b/gyp/core.gypi
@@ -114,7 +114,6 @@
         '<(skia_src_path)/core/SkMessageBus.h',
         '<(skia_src_path)/core/SkMetaData.cpp',
         '<(skia_src_path)/core/SkMipMap.cpp',
-        '<(skia_src_path)/core/SkOnce.h',
         '<(skia_src_path)/core/SkOrderedReadBuffer.cpp',
         '<(skia_src_path)/core/SkOrderedWriteBuffer.cpp',
         '<(skia_src_path)/core/SkPackBits.cpp',
@@ -256,6 +255,7 @@
         '<(skia_include_path)/core/SkMath.h',
         '<(skia_include_path)/core/SkMatrix.h',
         '<(skia_include_path)/core/SkMetaData.h',
+        '<(skia_include_path)/core/SkOnce.h',
         '<(skia_include_path)/core/SkOSFile.h',
         '<(skia_include_path)/core/SkPackBits.h',
         '<(skia_include_path)/core/SkPaint.h',

diff --git a/include/core/SkInstCnt.h b/include/core/SkInstCnt.h
index 89bbfa1..7e5b454 100644 (file)
--- a/include/core/SkInstCnt.h
+++ b/include/core/SkInstCnt.h
@@ -20,9 +20,16 @@
 #include "SkTypes.h"
 
 #if SK_ENABLE_INST_COUNT
+// Static variables inside member functions below may be defined multiple times
+// if Skia is being used as a dynamic library. Instance counting should be on
+// only for static builds. See bug skia:2058.
+#if defined(SKIA_DLL)
+#error Instance counting works only when Skia is built as a static library.
+#endif
+
+#include "SkOnce.h"
 #include "SkTArray.h"
 #include "SkThread.h"
-
 extern bool gPrintInstCount;
 
 // The non-root classes just register themselves with their parent
@@ -38,17 +45,16 @@ extern bool gPrintInstCount;
 #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;                                             \
-            }                                                               \
+            SK_DECLARE_STATIC_ONCE(once);                                   \
+            SkOnce(&once, init, 0);                                         \
             sk_atomic_inc(GetInstanceCountPtr());                           \
         }                                                                   \
                                                                             \
+        static void init(int) {                                             \
+            initStep                                                        \
+        }                                                                   \
+                                                                            \
         SkInstanceCountHelper(const SkInstanceCountHelper&) {               \
             sk_atomic_inc(GetInstanceCountPtr());                           \
         }                                                                   \
@@ -62,11 +68,16 @@ extern bool gPrintInstCount;
             return &gInstanceCount;                                         \
         }                                                                   \
                                                                             \
-        static SkTArray<PFCheckInstCnt>*& GetChildren() {                   \
-            static SkTArray<PFCheckInstCnt>* gChildren;                     \
+        static SkTArray<int (*)(int, bool)>*& GetChildren() {               \
+            static SkTArray<int (*)(int, bool)>* gChildren;                 \
             return gChildren;                                               \
         }                                                                   \
                                                                             \
+        static SkBaseMutex& GetChildrenMutex() {                            \
+            SK_DECLARE_STATIC_MUTEX(childrenMutex);                         \
+            return childrenMutex;                                           \
+        }                                                                   \
+                                                                            \
     } fInstanceCountHelper;                                                 \
                                                                             \
     static int32_t GetInstanceCount() {                                     \
@@ -86,7 +97,7 @@ extern bool gPrintInstCount;
         if (NULL == SkInstanceCountHelper::GetChildren()) {                 \
             return GetInstanceCount();                                      \
         }                                                                   \
-        SkTArray<int (*)(int, bool)>* children =                            \
+        SkTArray<int (*)(int, bool)>* children = \
             SkInstanceCountHelper::GetChildren();                           \
         int childCount = children->count();                                 \
         int count = GetInstanceCount();                                     \
@@ -105,8 +116,12 @@ extern bool gPrintInstCount;
     }                                                                       \
                                                                             \
     static void AddInstChild(int (*childCheckInstCnt)(int, bool)) {         \
-        if (CheckInstanceCount != childCheckInstCnt &&                      \
-            NULL != SkInstanceCountHelper::GetChildren()) {                 \
+        if (CheckInstanceCount != childCheckInstCnt) {                      \
+            SkAutoMutexAcquire ama(SkInstanceCountHelper::GetChildrenMutex()); \
+            if (NULL == SkInstanceCountHelper::GetChildren()) {             \
+                SkInstanceCountHelper::GetChildren() =                      \
+                    new SkTArray<int (*)(int, bool)>;                       \
+            }                                                               \
             SkInstanceCountHelper::GetChildren()->push_back(childCheckInstCnt); \
         }                                                                   \
     }

diff --git a/src/core/SkOnce.h b/include/core/SkOnce.h
similarity index 100%
rename from src/core/SkOnce.h
rename to include/core/SkOnce.h

diff --git a/include/core/SkPostConfig.h b/include/core/SkPostConfig.h
index 2156519..dc76522 100644 (file)
--- a/include/core/SkPostConfig.h
+++ b/include/core/SkPostConfig.h
@@ -120,12 +120,12 @@
  * SK_ENABLE_INST_COUNT controlls printing how many reference counted objects
  * are still held on exit.
  * Defaults to 1 in DEBUG and 0 in RELEASE.
- * FIXME: currently always 0, since it fails if multiple threads run at once
- * (see skbug.com/1219 ).
  */
 #ifndef SK_ENABLE_INST_COUNT
 #  ifdef SK_DEBUG
-#    define SK_ENABLE_INST_COUNT 0
+// Only enabled for static builds, because instance counting relies on static
+// variables in functions defined in header files.
+#    define SK_ENABLE_INST_COUNT !defined(SKIA_DLL)
 #  else
 #    define SK_ENABLE_INST_COUNT 0
 #  endif