memory.h revision 7dbb3d5cf0c15f500944d211057644d6a2f37371 
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/basictypes.h"
9#include "base/base_export.h"
10#include "base/process.h"
11#include "build/build_config.h"
12
13#if defined(OS_WIN)
14#include <windows.h>
15#endif
16
17namespace 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.
25BASE_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.
29BASE_EXPORT void EnableTerminationOnHeapCorruption();
30
31// Turns on process termination if memory runs out.
32BASE_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.
37BASE_EXPORT HMODULE GetModuleFromAddress(void* address);
38#endif
39
40#if defined(OS_LINUX) || defined(OS_ANDROID)
41BASE_EXPORT extern size_t g_oom_size;
42
43// The maximum allowed value for the OOM score.
44const 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.
53BASE_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.
64BASE_EXPORT void* UncheckedMalloc(size_t size);
65#endif  // defined(OS_MACOSX)
66
67}  // namespace base
68
69#endif  // BASE_PROCESS_MEMORY_H_
70