base/allocator/allocator_extension.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H_
   6 #define BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H_
   7
   8 #include <stddef.h> // for size_t
   9
  10 #include "base/allocator/allocator_extension_thunks.h"
  11 #include "base/base_export.h"
  12 #include "build/build_config.h"
  13
  14 namespace base {
  15 namespace allocator {
  16
  17 // Request the allocator to report value of its waste memory size.
  18 // Waste size corresponds to memory that has been allocated from the OS but
  19 // not passed up to the application. It e.g. includes memory retained by free
  20 // lists, internal data, chunks padding, etc.
  21 //
  22 // |size| pointer to the returned value, must be not NULL.
  23 // Returns true if the value has been returned, false otherwise.
  24 BASE_EXPORT bool GetAllocatorWasteSize(size_t* size);
  25
  26 // Request that the allocator print a human-readable description of the current
  27 // state of the allocator into a null-terminated string in the memory segment
  28 // buffer[0,buffer_length-1].
  29 //
  30 // |buffer| must point to a valid piece of memory
  31 // |buffer_length| must be > 0.
  32 BASE_EXPORT void GetStats(char* buffer, int buffer_length);
  33
  34 // Request that the allocator release any free memory it knows about to the
  35 // system.
  36 BASE_EXPORT void ReleaseFreeMemory();
  37
  38
  39 // These settings allow specifying a callback used to implement the allocator
  40 // extension functions.  These are optional, but if set they must only be set
  41 // once.  These will typically called in an allocator-specific initialization
  42 // routine.
  43 //
  44 // No threading promises are made.  The caller is responsible for making sure
  45 // these pointers are set before any other threads attempt to call the above
  46 // functions.
  47 BASE_EXPORT void SetGetAllocatorWasteSizeFunction(
  48     thunks::GetAllocatorWasteSizeFunction get_allocator_waste_size_function);
  49
  50 BASE_EXPORT void SetGetStatsFunction(
  51     thunks::GetStatsFunction get_stats_function);
  52
  53 BASE_EXPORT void SetReleaseFreeMemoryFunction(
  54     thunks::ReleaseFreeMemoryFunction release_free_memory_function);
  55
  56 }  // namespace allocator
  57 }  // namespace base
  58
  59 #endif  // BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H_