teach TSAN about SkSpinlock, SkRefCnt, and SkOnce

include/core/SkDynamicAnnotations.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDynamicAnnotations_DEFINED
 #define SkDynamicAnnotations_DEFINED
 
 // This file contains macros used to send out-of-band signals to dynamic instrumentation systems,
 // namely thread sanitizer.  This is a cut-down version of the full dynamic_annotations library with
 // only the features used by Skia.
 
 // We check the same define to know to enable the annotations, but prefix all our macros with SK_.
 #if DYNAMIC_ANNOTATIONS_ENABLED
 
 extern "C" {
 // TSAN provides these hooks.
 void AnnotateIgnoreReadsBegin(const char* file, int line);
 void AnnotateIgnoreReadsEnd(const char* file, int line);
+void AnnotateHappensBefore(const char* file, int line, const volatile void* ptr);
+void AnnotateHappensAfter(const char* file, int line, const volatile void* ptr);
+void AnnotateRWLockAcquired(const char* file, int line, const volatile void* lock, long is_w);
+void AnnotateRWLockReleased(const char* file, int line, const volatile void* lock, long is_w);
 }  // extern "C"
 
 // SK_ANNOTATE_UNPROTECTED_READ can wrap any variable read to tell TSAN to ignore that it appears to
 // be a racy read.  This should be used only when we can make an external guarantee that though this
 // particular read is racy, it is being used as part of a mechanism which is thread safe.  Examples:
 //   - the first check in double-checked locking;
 //   - checking if a ref count is equal to 1.
 // Note that in both these cases, we must still add terrifyingly subtle memory barriers to provide
 // that overall thread safety guarantee.  Using this macro to shut TSAN up without providing such an
 // external guarantee is pretty much never correct.
 template <typename T>
 inline T SK_ANNOTATE_UNPROTECTED_READ(const volatile T& x) {
     AnnotateIgnoreReadsBegin(__FILE__, __LINE__);
     T read = x;
     AnnotateIgnoreReadsEnd(__FILE__, __LINE__);
     return read;
 }
 
+#define SK_ANNOTATE_HAPPENS_BEFORE(obj) AnnotateHappensBefore(__FILE__, __LINE__, obj)
+#define SK_ANNOTATE_HAPPENS_AFTER(obj)  AnnotateHappensAfter(__FILE__, __LINE__, obj)
+
+#define SK_ANNOTATE_RWLOCK_ACQUIRED(lock, w) AnnotateRWLockAcquired(__FILE__, __LINE__, lock, w)
+#define SK_ANNOTATE_RWLOCK_RELEASED(lock, w) AnnotateRWLockReleased(__FILE__, __LINE__, lock, w)
+
 #else  // !DYNAMIC_ANNOTATIONS_ENABLED
 
 #define SK_ANNOTATE_UNPROTECTED_READ(x) (x)
+#define SK_ANNOTATE_HAPPENS_BEFORE(obj)
+#define SK_ANNOTATE_HAPPENS_AFTER(obj)
+#define SK_ANNOTATE_RWLOCK_ACQUIRED(lock, w)
+#define SK_ANNOTATE_RWLOCK_RELEASED(lock, w)
 
 #endif
 
 #endif//SkDynamicAnnotations_DEFINED