Mac TSAN support: annotate Sk[Base]Mutex as a mutex.

TSAN does not intercept Mach semaphore_t calls used to implement
SkBaseMutex's fSemaphore (its OSSemaphore field).  We can teach
it that Sk[Base]Mutex is a mutex anyway with the same annotations
we use for SkSharedMutex.

Change-Id: Ib91928bb9fcfa94f5cea985b46dea31ff2b56963
Reviewed-on: https://skia-review.googlesource.com/48580
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>

2 files changed, 88 insertions, 2 deletions

diff --git a/include/private/SkMutex.h b/include/private/SkMutex.h
index 7cfdb1132c..da9a80b00e 100644
--- a/include/private/SkMutex.h
+++ b/include/private/SkMutex.h
@@ -10,10 +10,15 @@
 
 #include "../private/SkSemaphore.h"
 #include "../private/SkThreadID.h"
+#include "SkTSAN.h"
 #include "SkTypes.h"
 
 #define SK_DECLARE_STATIC_MUTEX(name) static SkBaseMutex name;
 
+// We use ANNOTE_RWLOCK_foo() macros in here because TSAN does
+// not intercept Mach semaphore_t calls, and so on Mac can't
+// see that SkMutex is indeed a mutex.
+
 class SkBaseMutex {
 public:
     constexpr SkBaseMutex() = default;
@@ -21,10 +26,12 @@ public:
     void acquire() {
         fSemaphore.wait();
         SkDEBUGCODE(fOwner = SkGetThreadID();)
+        ANNOTATE_RWLOCK_ACQUIRED(&fSemaphore, true);
     }
 
     void release() {
         this->assertHeld();
+        ANNOTATE_RWLOCK_RELEASED(&fSemaphore, true);
         SkDEBUGCODE(fOwner = kIllegalThreadID;)
         fSemaphore.signal();
     }
@@ -40,8 +47,11 @@ protected:
 
 class SkMutex : public SkBaseMutex {
 public:
-    using SkBaseMutex::SkBaseMutex;
-    ~SkMutex() { fSemaphore.cleanup(); }
+    SkMutex() { ANNOTATE_RWLOCK_CREATE(&fSemaphore); }
+    ~SkMutex() {
+        ANNOTATE_RWLOCK_DESTROY(&fSemaphore);
+        fSemaphore.cleanup();
+    }
 };
 
 class SkAutoMutexAcquire {
diff --git a/include/private/SkTSAN.h b/include/private/SkTSAN.h
new file mode 100644
index 0000000000..52f6bad4fe
--- /dev/null
+++ b/include/private/SkTSAN.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkTSAN_DEFINED
+#define SkTSAN_DEFINED
+
+#include "SkTypes.h"
+
+#if !defined(__DYNAMIC_ANNOTATIONS_H__)
+
+    #if !defined(__has_feature)
+        #define __has_feature(x) 0
+    #endif
+
+    #if __has_feature(thread_sanitizer)
+
+        /* Report that a lock has been created at address "lock". */
+        #define ANNOTATE_RWLOCK_CREATE(lock) \
+            AnnotateRWLockCreate(__FILE__, __LINE__, lock)
+
+        /* Report that the lock at address "lock" is about to be destroyed. */
+        #define ANNOTATE_RWLOCK_DESTROY(lock) \
+            AnnotateRWLockDestroy(__FILE__, __LINE__, lock)
+
+        /* Report that the lock at address "lock" has been acquired.
+           is_w=1 for writer lock, is_w=0 for reader lock. */
+        #define ANNOTATE_RWLOCK_ACQUIRED(lock, is_w) \
+            AnnotateRWLockAcquired(__FILE__, __LINE__, lock, is_w)
+
+        /* Report that the lock at address "lock" is about to be released. */
+        #define ANNOTATE_RWLOCK_RELEASED(lock, is_w) \
+          AnnotateRWLockReleased(__FILE__, __LINE__, lock, is_w)
+
+        #if defined(DYNAMIC_ANNOTATIONS_WANT_ATTRIBUTE_WEAK)
+            #if defined(__GNUC__)
+                #define DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK __attribute__((weak))
+            #else
+                /* TODO(glider): for Windows support we may want to change this macro in order
+                   to prepend __declspec(selectany) to the annotations' declarations. */
+                #error weak annotations are not supported for your compiler
+            #endif
+        #else
+            #define DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK
+        #endif
+
+        extern "C" {
+        void AnnotateRWLockCreate(
+            const char *file, int line,
+            const volatile void *lock) DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK;
+        void AnnotateRWLockDestroy(
+            const char *file, int line,
+            const volatile void *lock) DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK;
+        void AnnotateRWLockAcquired(
+            const char *file, int line,
+            const volatile void *lock, long is_w) DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK;
+        void AnnotateRWLockReleased(
+            const char *file, int line,
+            const volatile void *lock, long is_w) DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK;
+        }
+
+    #else
+
+        #define ANNOTATE_RWLOCK_CREATE(lock)
+        #define ANNOTATE_RWLOCK_DESTROY(lock)
+        #define ANNOTATE_RWLOCK_ACQUIRED(lock, is_w)
+        #define ANNOTATE_RWLOCK_RELEASED(lock, is_w)
+
+    #endif
+
+#endif//!defined(__DYNAMIC_ANNOTATIONS_H__)
+
+#endif//SkTSAN_DEFINED