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      1 /* Copyright (c) 2005, Google Inc.
      2  * 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  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  *
     30  * ---
     31  * Author: Sanjay Ghemawat
     32  *
     33  * Module for heap-profiling.
     34  *
     35  * For full(er) information, see doc/heapprofile.html
     36  *
     37  * This module can be linked into your program with
     38  * no slowdown caused by this unless you activate the profiler
     39  * using one of the following methods:
     40  *
     41  *    1. Before starting the program, set the environment variable
     42  *       "HEAPPROFILE" to be the name of the file to which the profile
     43  *       data should be written.
     44  *
     45  *    2. Programmatically, start and stop the profiler using the
     46  *       routines "HeapProfilerStart(filename)" and "HeapProfilerStop()".
     47  *
     48  */
     49 
     50 #ifndef BASE_HEAP_PROFILER_H_
     51 #define BASE_HEAP_PROFILER_H_
     52 
     53 #include <stddef.h>
     54 
     55 /* Annoying stuff for windows; makes sure clients can import these functions */
     56 #ifndef PERFTOOLS_DLL_DECL
     57 # ifdef _WIN32
     58 #   define PERFTOOLS_DLL_DECL  __declspec(dllimport)
     59 # else
     60 #   define PERFTOOLS_DLL_DECL
     61 # endif
     62 #endif
     63 
     64 // Make the linker NOT to strip functions in this file.
     65 #if defined(_WIN64)
     66 #pragma comment(linker, "/INCLUDE:HeapProfilerStart")
     67 #elif defined(_WIN32)
     68 #pragma comment(linker, "/INCLUDE:_HeapProfilerStart")
     69 #endif
     70 
     71 /* All this code should be usable from within C apps. */
     72 #ifdef __cplusplus
     73 extern "C" {
     74 #endif
     75 
     76 /* Start profiling and arrange to write profile data to file names
     77  * of the form: "prefix.0000", "prefix.0001", ...
     78  *
     79  * If |prefix| is NULL then dumps will not be written to disk. Applications
     80  * can use GetHeapProfile() to get profile data, but HeapProfilerDump() will do
     81  * nothing.
     82  */
     83 PERFTOOLS_DLL_DECL void HeapProfilerStart(const char* prefix);
     84 
     85 /* Start profiling with a callback function that returns application-generated
     86  * stacks. Profiles are not written to disk, but may be obtained via
     87  * GetHeapProfile(). The callback:
     88  * 1. May optionally skip the first |skip_count| items on the stack.
     89  * 2. Must provide a |stack| buffer of at least size 32 * sizeof(void*).
     90  * 3. Must return the number of items copied or zero.
     91  */
     92 typedef int (*StackGeneratorFunction)(int skip_count, void** stack);
     93 PERFTOOLS_DLL_DECL void HeapProfilerWithPseudoStackStart(
     94     StackGeneratorFunction callback);
     95 
     96 /* Returns non-zero if we are currently profiling the heap.  (Returns
     97  * an int rather than a bool so it's usable from C.)  This is true
     98  * between calls to HeapProfilerStart() and HeapProfilerStop(), and
     99  * also if the program has been run with HEAPPROFILER, or some other
    100  * way to turn on whole-program profiling.
    101  */
    102 int IsHeapProfilerRunning();
    103 
    104 /* Stop heap profiling.  Can be restarted again with HeapProfilerStart(),
    105  * but the currently accumulated profiling information will be cleared.
    106  */
    107 PERFTOOLS_DLL_DECL void HeapProfilerStop();
    108 
    109 /* Dump a profile now - can be used for dumping at a hopefully
    110  * quiescent state in your program, in order to more easily track down
    111  * memory leaks. Will include the reason in the logged message
    112  */
    113 PERFTOOLS_DLL_DECL void HeapProfilerDump(const char *reason);
    114 
    115 /* Generate current heap profiling information.
    116  * Returns an empty string when heap profiling is not active.
    117  * The returned pointer is a '\0'-terminated string allocated using malloc()
    118  * and should be free()-ed as soon as the caller does not need it anymore.
    119  */
    120 PERFTOOLS_DLL_DECL char* GetHeapProfile();
    121 
    122 /* Callback function for iterating through all allocated objects. Accepts
    123  * pointer to user data passed into IterateAllocatedObjects and pointer
    124  * to the object being visited.
    125  */
    126 typedef void (*AddressVisitor)(void* data, const void* ptr);
    127 
    128 /* Iterate over all live allocated objects. For each allocation the
    129  * callback will be invoked with the data argument and allocation pointer.
    130  */
    131 PERFTOOLS_DLL_DECL void IterateAllocatedObjects(AddressVisitor callback,
    132                                                 void* data);
    133 
    134 #ifdef __cplusplus
    135 }  // extern "C"
    136 #endif
    137 
    138 #endif  /* BASE_HEAP_PROFILER_H_ */
    139