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1 /* | 1 /* |
2 * Copyright 2014 Google Inc. | 2 * Copyright 2014 Google Inc. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license that can be | 4 * Use of this source code is governed by a BSD-style license that can be |
5 * found in the LICENSE file. | 5 * found in the LICENSE file. |
6 */ | 6 */ |
7 | 7 |
8 #ifndef SkDynamicAnnotations_DEFINED | 8 #ifndef SkDynamicAnnotations_DEFINED |
9 #define SkDynamicAnnotations_DEFINED | 9 #define SkDynamicAnnotations_DEFINED |
10 | 10 |
11 // This file contains macros used to send out-of-band signals to dynamic instrum
entation systems, | 11 // This file contains macros used to send out-of-band signals to dynamic instrum
entation systems, |
12 // namely thread sanitizer. This is a cut-down version of the full dynamic_anno
tations library with | 12 // namely thread sanitizer. This is a cut-down version of the full dynamic_anno
tations library with |
13 // only the features used by Skia. | 13 // only the features used by Skia. |
14 | 14 |
15 // We check the same define to know to enable the annotations, but prefix all ou
r macros with SK_. | 15 // We check the same define to know to enable the annotations, but prefix all ou
r macros with SK_. |
16 #if DYNAMIC_ANNOTATIONS_ENABLED | 16 #if DYNAMIC_ANNOTATIONS_ENABLED |
17 | 17 |
18 extern "C" { | 18 extern "C" { |
19 // TSAN provides these hooks. | 19 // TSAN provides these hooks. |
20 void AnnotateIgnoreReadsBegin(const char* file, int line); | 20 void AnnotateIgnoreReadsBegin(const char* file, int line); |
21 void AnnotateIgnoreReadsEnd(const char* file, int line); | 21 void AnnotateIgnoreReadsEnd(const char* file, int line); |
22 void AnnotateHappensBefore(const char* file, int line, const volatile void* ptr)
; | |
23 void AnnotateHappensAfter(const char* file, int line, const volatile void* ptr); | |
24 void AnnotateRWLockAcquired(const char* file, int line, const volatile void* loc
k, long is_w); | |
25 void AnnotateRWLockReleased(const char* file, int line, const volatile void* loc
k, long is_w); | |
26 } // extern "C" | 22 } // extern "C" |
27 | 23 |
28 // SK_ANNOTATE_UNPROTECTED_READ can wrap any variable read to tell TSAN to ignor
e that it appears to | 24 // SK_ANNOTATE_UNPROTECTED_READ can wrap any variable read to tell TSAN to ignor
e that it appears to |
29 // be a racy read. This should be used only when we can make an external guaran
tee that though this | 25 // be a racy read. This should be used only when we can make an external guaran
tee that though this |
30 // particular read is racy, it is being used as part of a mechanism which is thr
ead safe. Examples: | 26 // particular read is racy, it is being used as part of a mechanism which is thr
ead safe. Examples: |
31 // - the first check in double-checked locking; | 27 // - the first check in double-checked locking; |
32 // - checking if a ref count is equal to 1. | 28 // - checking if a ref count is equal to 1. |
33 // Note that in both these cases, we must still add terrifyingly subtle memory b
arriers to provide | 29 // Note that in both these cases, we must still add terrifyingly subtle memory b
arriers to provide |
34 // that overall thread safety guarantee. Using this macro to shut TSAN up witho
ut providing such an | 30 // that overall thread safety guarantee. Using this macro to shut TSAN up witho
ut providing such an |
35 // external guarantee is pretty much never correct. | 31 // external guarantee is pretty much never correct. |
36 template <typename T> | 32 template <typename T> |
37 inline T SK_ANNOTATE_UNPROTECTED_READ(const volatile T& x) { | 33 inline T SK_ANNOTATE_UNPROTECTED_READ(const volatile T& x) { |
38 AnnotateIgnoreReadsBegin(__FILE__, __LINE__); | 34 AnnotateIgnoreReadsBegin(__FILE__, __LINE__); |
39 T read = x; | 35 T read = x; |
40 AnnotateIgnoreReadsEnd(__FILE__, __LINE__); | 36 AnnotateIgnoreReadsEnd(__FILE__, __LINE__); |
41 return read; | 37 return read; |
42 } | 38 } |
43 | 39 |
44 #define SK_ANNOTATE_HAPPENS_BEFORE(obj) AnnotateHappensBefore(__FILE__, __LINE__
, obj) | |
45 #define SK_ANNOTATE_HAPPENS_AFTER(obj) AnnotateHappensAfter(__FILE__, __LINE__,
obj) | |
46 | |
47 #define SK_ANNOTATE_RWLOCK_ACQUIRED(lock, w) AnnotateRWLockAcquired(__FILE__, __
LINE__, lock, w) | |
48 #define SK_ANNOTATE_RWLOCK_RELEASED(lock, w) AnnotateRWLockReleased(__FILE__, __
LINE__, lock, w) | |
49 | |
50 #else // !DYNAMIC_ANNOTATIONS_ENABLED | 40 #else // !DYNAMIC_ANNOTATIONS_ENABLED |
51 | 41 |
52 #define SK_ANNOTATE_UNPROTECTED_READ(x) (x) | 42 #define SK_ANNOTATE_UNPROTECTED_READ(x) (x) |
53 #define SK_ANNOTATE_HAPPENS_BEFORE(obj) | |
54 #define SK_ANNOTATE_HAPPENS_AFTER(obj) | |
55 #define SK_ANNOTATE_RWLOCK_ACQUIRED(lock, w) | |
56 #define SK_ANNOTATE_RWLOCK_RELEASED(lock, w) | |
57 | 43 |
58 #endif | 44 #endif |
59 | 45 |
60 #endif//SkDynamicAnnotations_DEFINED | 46 #endif//SkDynamicAnnotations_DEFINED |
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