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      1 /*
      2  * Copyright (C) 2011 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Neither the name of Google Inc. nor the names of its
     11  * contributors may be used to endorse or promote products derived from
     12  * this software without specific prior written permission.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     15  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     16  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     17  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     18  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     19  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     20  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #ifndef WTF_DynamicAnnotations_h
     28 #define WTF_DynamicAnnotations_h
     29 
     30 /* This file defines dynamic annotations for use with dynamic analysis
     31  * tool such as ThreadSanitizer, Valgrind, etc.
     32  *
     33  * Dynamic annotation is a source code annotation that affects
     34  * the generated code (that is, the annotation is not a comment).
     35  * Each such annotation is attached to a particular
     36  * instruction and/or to a particular object (address) in the program.
     37  *
     38  * By using dynamic annotations a developer can give more details to the dynamic
     39  * analysis tool to improve its precision.
     40  *
     41  * In C/C++ program the annotations are represented as C macros.
     42  * With the default build flags, these macros are empty, hence don't affect
     43  * performance of a compiled binary.
     44  * If dynamic annotations are enabled, they just call no-op functions.
     45  * The dynamic analysis tools can intercept these functions and replace them
     46  * with their own implementations.
     47  *
     48  * See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations for more information.
     49  */
     50 
     51 #include "wtf/WTFExport.h"
     52 
     53 #if USE(DYNAMIC_ANNOTATIONS)
     54 /* Tell data race detector that we're not interested in reports on the given address range. */
     55 #define WTF_ANNOTATE_BENIGN_RACE_SIZED(address, size, description) WTFAnnotateBenignRaceSized(__FILE__, __LINE__, address, size, description)
     56 #define WTF_ANNOTATE_BENIGN_RACE(pointer, description) WTFAnnotateBenignRaceSized(__FILE__, __LINE__, pointer, sizeof(*(pointer)), description)
     57 
     58 /* Annotations for user-defined synchronization mechanisms.
     59  * These annotations can be used to define happens-before arcs in user-defined
     60  * synchronization mechanisms: the race detector will infer an arc from
     61  * the former to the latter when they share the same argument pointer.
     62  *
     63  * The most common case requiring annotations is atomic reference counting:
     64  * bool deref() {
     65  *     ANNOTATE_HAPPENS_BEFORE(&m_refCount);
     66  *     if (!atomicDecrement(&m_refCount)) {
     67  *         // m_refCount is now 0
     68  *         ANNOTATE_HAPPENS_AFTER(&m_refCount);
     69  *         // "return true; happens-after each atomicDecrement of m_refCount"
     70  *         return true;
     71  *     }
     72  *     return false;
     73  * }
     74  */
     75 #define WTF_ANNOTATE_HAPPENS_BEFORE(address) WTFAnnotateHappensBefore(__FILE__, __LINE__, address)
     76 #define WTF_ANNOTATE_HAPPENS_AFTER(address) WTFAnnotateHappensAfter(__FILE__, __LINE__, address)
     77 
     78 #ifdef __cplusplus
     79 extern "C" {
     80 #endif
     81 /* Don't use these directly, use the above macros instead. */
     82 WTF_EXPORT void WTFAnnotateBenignRaceSized(const char* file, int line, const volatile void* memory, long size, const char* description);
     83 WTF_EXPORT void WTFAnnotateHappensBefore(const char* file, int line, const volatile void* address);
     84 WTF_EXPORT void WTFAnnotateHappensAfter(const char* file, int line, const volatile void* address);
     85 #ifdef __cplusplus
     86 } // extern "C"
     87 #endif
     88 
     89 #else // USE(DYNAMIC_ANNOTATIONS)
     90 /* These macros are empty when dynamic annotations are not enabled so you can
     91  * use them without affecting the performance of release binaries. */
     92 #define WTF_ANNOTATE_BENIGN_RACE_SIZED(address, size, description)
     93 #define WTF_ANNOTATE_BENIGN_RACE(pointer, description)
     94 #define WTF_ANNOTATE_HAPPENS_BEFORE(address)
     95 #define WTF_ANNOTATE_HAPPENS_AFTER(address)
     96 #endif // USE(DYNAMIC_ANNOTATIONS)
     97 
     98 #endif // WTF_DynamicAnnotations_h
     99