teach TSAN about SkSpinlock, SkRefCnt, and SkOnce

include/core/SkOnce.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkOnce_DEFINED
 #define SkOnce_DEFINED
 
@@ skipping 36 matching lines @@
 //  ----------------------  Implementation details below here. -----------------------------
 
 // This is POD and must be zero-initialized.
 struct SkSpinlock {
     void acquire() {
         SkASSERT(shouldBeZero == 0);
         // No memory barrier needed, but sk_atomic_cas gives us at least release anyway.
         while (!sk_atomic_cas(&thisIsPrivate, 0, 1)) {
             // spin
         }
+        SK_ANNOTATE_RWLOCK_ACQUIRED(this, true);
     }
 
     void release() {
         SkASSERT(shouldBeZero == 0);
+        SK_ANNOTATE_RWLOCK_RELEASED(this, true);
         // This requires a release memory barrier before storing, which sk_atomic_cas guarantees.
         SkAssertResult(sk_atomic_cas(&thisIsPrivate, 1, 0));
     }
 
     int32_t thisIsPrivate;
     SkDEBUGCODE(int32_t shouldBeZero;)
 };
 
 struct SkOnceFlag {
     bool done;
@@ skipping 67 matching lines @@
         // done before here---in particular, those done by calling f(arg)---are observable
         // before the writes after the line, *done = true.
         //
         // In version control terms this is like saying, "check in the work up
         // to and including f(arg), then check in *done=true as a subsequent change".
         //
         // We'll use this in the fast path to make sure f(arg)'s effects are
         // observable whenever we observe *done == true.
         release_barrier();
         *done = true;
+        SK_ANNOTATE_HAPPENS_BEFORE(done);
     }
 }
 
 // This is our fast path, called all the time.  We do really want it to be inlined.
 template <typename Lock, typename Func, typename Arg>
 inline void SkOnce(bool* done, Lock* lock, Func f, Arg arg, void(*atExit)()) {
     if (!SK_ANNOTATE_UNPROTECTED_READ(*done)) {
         sk_once_slow(done, lock, f, arg, atExit);
     }
     // Also known as a load-load/load-store barrier, this acquire barrier makes
     // sure that anything we read from memory---in particular, memory written by
     // calling f(arg)---is at least as current as the value we read from once->done.
     //
     // In version control terms, this is a lot like saying "sync up to the
     // commit where we wrote once->done = true".
     //
     // The release barrier in sk_once_slow guaranteed that once->done = true
     // happens after f(arg), so by syncing to once->done = true here we're
     // forcing ourselves to also wait until the effects of f(arg) are readble.
     acquire_barrier();
+    SK_ANNOTATE_HAPPENS_AFTER(done);
 }
 
 template <typename Func, typename Arg>
 inline void SkOnce(SkOnceFlag* once, Func f, Arg arg, void(*atExit)()) {
     return SkOnce(&once->done, &once->lock, f, arg, atExit);
 }
 
 #undef SK_ANNOTATE_BENIGN_RACE
 
 #endif  // SkOnce_DEFINED