Clean up SkOnce:

  1 Remove atExit feature: clients can do it just as well as SkOnce can.
  2 Remove support for functors: no one but the unit test did that.
  3 Remove support for unused non-static SkOnceFlag (no SK_ONCE_INIT).
  4 Add SkOnce variants for no-arg functions so we're not forced to pass dummy values all the time.
  5 Merge SkSpinlock and SkOnceFlag, making all members private.
  6 More notes about memory barriers, adding an acquire load after acquiring the spinlock.

BUG=skia:
R=bungeman@google.com, mtklein@google.com, reed@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/302083003

4 files changed, 21 insertions, 22 deletions

diff --git a/src/ports/SkGlobalInitialization_chromium.cpp b/src/ports/SkGlobalInitialization_chromium.cpp
index 37e5450e19..f42b272f18 100644
--- a/src/ports/SkGlobalInitialization_chromium.cpp
+++ b/src/ports/SkGlobalInitialization_chromium.cpp
@@ -62,7 +62,7 @@
 #include "SkMatrixImageFilter.h"
 #include "SkXfermodeImageFilter.h"
 
-static void InitializeFlattenables(int*) {
+static void InitializeFlattenables() {
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkAvoidXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBicubicImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBitmapProcShader)
@@ -122,7 +122,6 @@ static void InitializeFlattenables(int*) {
 }
 
 void SkFlattenable::InitializeFlattenablesIfNeeded() {
-    int dummy;
     SK_DECLARE_STATIC_ONCE(once);
-    SkOnce(&once, InitializeFlattenables, &dummy);
+    SkOnce(&once, InitializeFlattenables);
 }
diff --git a/src/ports/SkGlobalInitialization_default.cpp b/src/ports/SkGlobalInitialization_default.cpp
index 949decd018..ce42ca5aad 100644
--- a/src/ports/SkGlobalInitialization_default.cpp
+++ b/src/ports/SkGlobalInitialization_default.cpp
@@ -62,7 +62,7 @@
 #include "SkMatrixImageFilter.h"
 #include "SkXfermodeImageFilter.h"
 
-static void InitializeFlattenables(int*) {
+static void InitializeFlattenables() {
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkAvoidXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBicubicImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBitmapProcShader)
@@ -123,7 +123,6 @@ static void InitializeFlattenables(int*) {
 }
 
 void SkFlattenable::InitializeFlattenablesIfNeeded() {
-    int dummy;
     SK_DECLARE_STATIC_ONCE(once);
-    SkOnce(&once, InitializeFlattenables, &dummy);
+    SkOnce(&once, InitializeFlattenables);
 }
diff --git a/src/utils/SkEventTracer.cpp b/src/utils/SkEventTracer.cpp
index 529fca3519..65e8372395 100644
--- a/src/utils/SkEventTracer.cpp
+++ b/src/utils/SkEventTracer.cpp
@@ -36,25 +36,24 @@ class SkDefaultEventTracer: public SkEventTracer {
     };
 };
 
-SkEventTracer *SkEventTracer::gInstance;
+SkEventTracer* SkEventTracer::gInstance;
 
-static void intialiize_default_tracer(void *current_instance) {
+static void cleanup_tracer() {
+    // calling SetInstance will delete the existing instance.
+    SkEventTracer::SetInstance(NULL);
+}
+
+static void intialize_default_tracer(SkEventTracer* current_instance) {
     if (NULL == current_instance) {
         SkEventTracer::SetInstance(SkNEW(SkDefaultEventTracer));
     }
+    atexit(cleanup_tracer);
 }
 
-static void cleanup_tracer() {
-    // calling SetInstance will delete the existing instance.
-    SkEventTracer::SetInstance(NULL);
-}
 
 SkEventTracer* SkEventTracer::GetInstance() {
     SK_DECLARE_STATIC_ONCE(once);
-    SkOnce(&once,
-           intialiize_default_tracer,
-           SkEventTracer::gInstance,
-           cleanup_tracer);
+    SkOnce(&once, intialize_default_tracer, SkEventTracer::gInstance);
     SkASSERT(NULL != SkEventTracer::gInstance);
     return SkEventTracer::gInstance;
 }
diff --git a/src/utils/win/SkDWrite.cpp b/src/utils/win/SkDWrite.cpp
index 16e8ddc4d0..87826b5194 100644
--- a/src/utils/win/SkDWrite.cpp
+++ b/src/utils/win/SkDWrite.cpp
@@ -14,6 +14,12 @@
 
 static IDWriteFactory* gDWriteFactory = NULL;
 
+static void release_dwrite_factory() {
+    if (gDWriteFactory) {
+        gDWriteFactory->Release();
+    }
+}
+
 static void create_dwrite_factory(IDWriteFactory** factory) {
     typedef decltype(DWriteCreateFactory)* DWriteCreateFactoryProc;
     DWriteCreateFactoryProc dWriteCreateFactoryProc = reinterpret_cast<DWriteCreateFactoryProc>(
@@ -31,17 +37,13 @@ static void create_dwrite_factory(IDWriteFactory** factory) {
                                  __uuidof(IDWriteFactory),
                                  reinterpret_cast<IUnknown**>(factory)),
          "Could not create DirectWrite factory.");
+    atexit(release_dwrite_factory);
 }
 
-static void release_dwrite_factory() {
-    if (gDWriteFactory) {
-        gDWriteFactory->Release();
-    }
-}
 
 IDWriteFactory* sk_get_dwrite_factory() {
     SK_DECLARE_STATIC_ONCE(once);
-    SkOnce(&once, create_dwrite_factory, &gDWriteFactory, release_dwrite_factory);
+    SkOnce(&once, create_dwrite_factory, &gDWriteFactory);
 
     return gDWriteFactory;
 }