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 #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
  25 namespace 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.
  33 BASE_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.
  37 BASE_EXPORT void EnableTerminationOnHeapCorruption();
  38
  39 // Turns on process termination if memory runs out.
  40 BASE_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.
  45 BASE_EXPORT HMODULE GetModuleFromAddress(void* address);
  46 #endif
  47
  48 #if defined(OS_LINUX) || defined(OS_ANDROID)
  49 BASE_EXPORT extern size_t g_oom_size;
  50
  51 // The maximum allowed value for the OOM score.
  52 const 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.
  61 BASE_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.
  74 BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedMalloc(size_t size,
  75                                                     void** result);
  76 BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedCalloc(size_t num_items,
  77                                                     size_t size,
  78                                                     void** result);
  79
  80 }  // namespace base
  81
  82 #endif  // BASE_PROCESS_MEMORY_H_