/* Copyright (c) 2005, Google Inc.
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 * modification, are permitted provided that the following conditions are
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 * 
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ---
 * Author: Sanjay Ghemawat
 *
 * Module for heap-profiling.
 *
 * For full(er) information, see doc/heapprofile.html
 *
 * This module can be linked into your program with
 * no slowdown caused by this unless you activate the profiler
 * using one of the following methods:
 *
 *    1. Before starting the program, set the environment variable
 *       "HEAPPROFILE" to be the name of the file to which the profile
 *       data should be written.
 *
 *    2. Programmatically, start and stop the profiler using the
 *       routines "HeapProfilerStart(filename)" and "HeapProfilerStop()".
 *
 */

#ifndef BASE_HEAP_PROFILER_H_
#define BASE_HEAP_PROFILER_H_

#include <stddef.h>

/* Annoying stuff for windows; makes sure clients can import these functions */
#ifndef PERFTOOLS_DLL_DECL
# ifdef _WIN32
#   define PERFTOOLS_DLL_DECL  __declspec(dllimport)
# else
#   define PERFTOOLS_DLL_DECL
# endif
#endif

// Make the linker NOT to strip functions in this file.
#if defined(_WIN64)
#pragma comment(linker, "/INCLUDE:HeapProfilerStart")
#elif defined(_WIN32)
#pragma comment(linker, "/INCLUDE:_HeapProfilerStart")
#endif

/* All this code should be usable from within C apps. */
#ifdef __cplusplus
extern "C" {
#endif

/* Start profiling and arrange to write profile data to file names
 * of the form: "prefix.0000", "prefix.0001", ...
 *
 * If |prefix| is NULL then dumps will not be written to disk. Applications
 * can use GetHeapProfile() to get profile data, but HeapProfilerDump() will do
 * nothing.
 */
PERFTOOLS_DLL_DECL void HeapProfilerStart(const char* prefix);

/* Start profiling with a callback function that returns application-generated
 * stacks. Profiles are not written to disk, but may be obtained via
 * GetHeapProfile(). The callback:
 * 1. May optionally skip the first |skip_count| items on the stack.
 * 2. Must provide a |stack| buffer of at least size 32 * sizeof(void*).
 * 3. Must return the number of items copied or zero.
 */
typedef int (*StackGeneratorFunction)(int skip_count, void** stack);
PERFTOOLS_DLL_DECL void HeapProfilerWithPseudoStackStart(
    StackGeneratorFunction callback);

/* Returns non-zero if we are currently profiling the heap.  (Returns
 * an int rather than a bool so it's usable from C.)  This is true
 * between calls to HeapProfilerStart() and HeapProfilerStop(), and
 * also if the program has been run with HEAPPROFILER, or some other
 * way to turn on whole-program profiling.
 */
int IsHeapProfilerRunning();

/* Stop heap profiling.  Can be restarted again with HeapProfilerStart(),
 * but the currently accumulated profiling information will be cleared.
 */
PERFTOOLS_DLL_DECL void HeapProfilerStop();

/* Dump a profile now - can be used for dumping at a hopefully
 * quiescent state in your program, in order to more easily track down
 * memory leaks. Will include the reason in the logged message
 */
PERFTOOLS_DLL_DECL void HeapProfilerDump(const char *reason);

/* Generate current heap profiling information.
 * Returns an empty string when heap profiling is not active.
 * The returned pointer is a '\0'-terminated string allocated using malloc()
 * and should be free()-ed as soon as the caller does not need it anymore.
 */
PERFTOOLS_DLL_DECL char* GetHeapProfile();

/* Callback function for iterating through all allocated objects. Accepts
 * pointer to user data passed into IterateAllocatedObjects and pointer
 * to the object being visited.
 */
typedef void (*AddressVisitor)(void* data, const void* ptr);

/* Iterate over all live allocated objects. For each allocation the
 * callback will be invoked with the data argument and allocation pointer.
 */
PERFTOOLS_DLL_DECL void IterateAllocatedObjects(AddressVisitor callback,
                                                void* data);

#ifdef __cplusplus
}  // extern "C"
#endif

#endif  /* BASE_HEAP_PROFILER_H_ */