base/process/memory.h

   1 // Copyright (c) 2013 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_PROCESS_MEMORY_H_
   6 #define BASE_PROCESS_MEMORY_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/basictypes.h"
  10 #include "base/process/process_handle.h"
  11 #include "build/build_config.h"
  12
  13 #if defined(OS_WIN)
  14 #include <windows.h>
  15 #endif
  16
  17 namespace base {
  18
  19 // Enables low fragmentation heap (LFH) for every heaps of this process. This
  20 // won't have any effect on heaps created after this function call. It will not
  21 // modify data allocated in the heaps before calling this function. So it is
  22 // better to call this function early in initialization and again before
  23 // entering the main loop.
  24 // Note: Returns true on Windows 2000 without doing anything.
  25 BASE_EXPORT bool EnableLowFragmentationHeap();
  26
  27 // Enables 'terminate on heap corruption' flag. Helps protect against heap
  28 // overflow. Has no effect if the OS doesn't provide the necessary facility.
  29 BASE_EXPORT void EnableTerminationOnHeapCorruption();
  30
  31 // Turns on process termination if memory runs out.
  32 BASE_EXPORT void EnableTerminationOnOutOfMemory();
  33
  34 #if defined(OS_WIN)
  35 // Returns the module handle to which an address belongs. The reference count
  36 // of the module is not incremented.
  37 BASE_EXPORT HMODULE GetModuleFromAddress(void* address);
  38 #endif
  39
  40 #if defined(OS_LINUX) || defined(OS_ANDROID)
  41 BASE_EXPORT extern size_t g_oom_size;
  42
  43 // The maximum allowed value for the OOM score.
  44 const int kMaxOomScore = 1000;
  45
  46 // This adjusts /proc/<pid>/oom_score_adj so the Linux OOM killer will
  47 // prefer to kill certain process types over others. The range for the
  48 // adjustment is [-1000, 1000], with [0, 1000] being user accessible.
  49 // If the Linux system doesn't support the newer oom_score_adj range
  50 // of [0, 1000], then we revert to using the older oom_adj, and
  51 // translate the given value into [0, 15].  Some aliasing of values
  52 // may occur in that case, of course.
  53 BASE_EXPORT bool AdjustOOMScore(ProcessId process, int score);
  54 #endif
  55
  56 #if defined(OS_MACOSX)
  57 // Very large images or svg canvases can cause huge mallocs.  Skia
  58 // does tricks on tcmalloc-based systems to allow malloc to fail with
  59 // a NULL rather than hit the oom crasher.  This replicates that for
  60 // OSX.
  61 //
  62 // IF YOU USE THIS WITHOUT CONSULTING YOUR FRIENDLY OSX DEVELOPER,
  63 // YOUR CODE IS LIKELY TO BE REVERTED.  THANK YOU.
  64 BASE_EXPORT void* UncheckedMalloc(size_t size);
  65 BASE_EXPORT void* UncheckedCalloc(size_t num_items, size_t size);
  66 #endif  // defined(OS_MACOSX)
  67
  68 }  // namespace base
  69
  70 #endif  // BASE_PROCESS_MEMORY_H_