memory.h revision effb81e5f8246d0db0270817048dc992db66e9fb 
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#ifdef PVALLOC_AVAILABLE
18// Build config explicitly tells us whether or not pvalloc is available.
19#elif defined(LIBC_GLIBC) && !defined(USE_TCMALLOC)
20#define PVALLOC_AVAILABLE 1
21#else
22#define PVALLOC_AVAILABLE 0
23#endif
24
25namespace base {
26
27// Enables low fragmentation heap (LFH) for every heaps of this process. This
28// won't have any effect on heaps created after this function call. It will not
29// modify data allocated in the heaps before calling this function. So it is
30// better to call this function early in initialization and again before
31// entering the main loop.
32// Note: Returns true on Windows 2000 without doing anything.
33BASE_EXPORT bool EnableLowFragmentationHeap();
34
35// Enables 'terminate on heap corruption' flag. Helps protect against heap
36// overflow. Has no effect if the OS doesn't provide the necessary facility.
37BASE_EXPORT void EnableTerminationOnHeapCorruption();
38
39// Turns on process termination if memory runs out.
40BASE_EXPORT void EnableTerminationOnOutOfMemory();
41
42#if defined(OS_WIN)
43// Returns the module handle to which an address belongs. The reference count
44// of the module is not incremented.
45BASE_EXPORT HMODULE GetModuleFromAddress(void* address);
46#endif
47
48#if defined(OS_LINUX) || defined(OS_ANDROID)
49BASE_EXPORT extern size_t g_oom_size;
50
51// The maximum allowed value for the OOM score.
52const int kMaxOomScore = 1000;
53
54// This adjusts /proc/<pid>/oom_score_adj so the Linux OOM killer will
55// prefer to kill certain process types over others. The range for the
56// adjustment is [-1000, 1000], with [0, 1000] being user accessible.
57// If the Linux system doesn't support the newer oom_score_adj range
58// of [0, 1000], then we revert to using the older oom_adj, and
59// translate the given value into [0, 15].  Some aliasing of values
60// may occur in that case, of course.
61BASE_EXPORT bool AdjustOOMScore(ProcessId process, int score);
62#endif
63
64// Special allocator functions for callers that want to check for OOM.
65// These will not abort if the allocation fails even if
66// EnableTerminationOnOutOfMemory has been called.
67// This can be useful for huge and/or unpredictable size memory allocations.
68// Please only use this if you really handle the case when the allocation
69// fails. Doing otherwise would risk security.
70// These functions may still crash on OOM when running under memory tools,
71// specifically ASan and other sanitizers.
72// Return value tells whether the allocation succeeded. If it fails |result| is
73// set to NULL, otherwise it holds the memory address.
74BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedMalloc(size_t size,
75                                                    void** result);
76BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedCalloc(size_t num_items,
77                                                    size_t size,
78                                                    void** result);
79
80// TODO(b.kelemen): make Skia use the new interface and remove these.
81#if defined(OS_MACOSX)
82BASE_EXPORT void* UncheckedMalloc(size_t size);
83BASE_EXPORT void* UncheckedCalloc(size_t num_items, size_t size);
84#endif
85
86}  // namespace base
87
88#endif  // BASE_PROCESS_MEMORY_H_
89