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// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_PROCESS_MEMORY_H_
#define BASE_PROCESS_MEMORY_H_
#include <stddef.h>
#include "base/base_export.h"
#include "base/process/process_handle.h"
#include "build/build_config.h"
namespace base {
// Enables 'terminate on heap corruption' flag. Helps protect against heap
// overflow. Has no effect if the OS doesn't provide the necessary facility.
BASE_EXPORT void EnableTerminationOnHeapCorruption();
// Turns on process termination if memory runs out.
BASE_EXPORT void EnableTerminationOnOutOfMemory();
// Terminates process. Should be called only for out of memory errors.
// Crash reporting classifies such crashes as OOM.
BASE_EXPORT void TerminateBecauseOutOfMemory(size_t size);
#if defined(OS_LINUX) || defined(OS_ANDROID) || defined(OS_AIX)
BASE_EXPORT extern size_t g_oom_size;
// The maximum allowed value for the OOM score.
const int kMaxOomScore = 1000;
// This adjusts /proc/<pid>/oom_score_adj so the Linux OOM killer will
// prefer to kill certain process types over others. The range for the
// adjustment is [-1000, 1000], with [0, 1000] being user accessible.
// If the Linux system doesn't support the newer oom_score_adj range
// of [0, 1000], then we revert to using the older oom_adj, and
// translate the given value into [0, 15]. Some aliasing of values
// may occur in that case, of course.
BASE_EXPORT bool AdjustOOMScore(ProcessId process, int score);
#endif
namespace internal {
// Returns true if address-space was released. Some configurations reserve part
// of the process address-space for special allocations (e.g. WASM).
bool ReleaseAddressSpaceReservation();
} // namespace internal
#if defined(OS_WIN)
namespace win {
// Custom Windows exception code chosen to indicate an out of memory error.
// See https://msdn.microsoft.com/en-us/library/het71c37.aspx.
// "To make sure that you do not define a code that conflicts with an existing
// exception code" ... "The resulting error code should therefore have the
// highest four bits set to hexadecimal E."
// 0xe0000008 was chosen arbitrarily, as 0x00000008 is ERROR_NOT_ENOUGH_MEMORY.
const DWORD kOomExceptionCode = 0xe0000008;
} // namespace win
#endif
namespace internal {
// Handles out of memory, with the failed allocation |size|, or 0 when it is not
// known.
BASE_EXPORT void OnNoMemoryInternal(size_t size);
} // namespace internal
// Special allocator functions for callers that want to check for OOM.
// These will not abort if the allocation fails even if
// EnableTerminationOnOutOfMemory has been called.
// This can be useful for huge and/or unpredictable size memory allocations.
// Please only use this if you really handle the case when the allocation
// fails. Doing otherwise would risk security.
// These functions may still crash on OOM when running under memory tools,
// specifically ASan and other sanitizers.
// Return value tells whether the allocation succeeded. If it fails |result| is
// set to NULL, otherwise it holds the memory address.
BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedMalloc(size_t size,
void** result);
BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedCalloc(size_t num_items,
size_t size,
void** result);
} // namespace base
#endif // BASE_PROCESS_MEMORY_H_