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 <stddef.h> 9 10 #include "base/base_export.h" 11 #include "base/process/process_handle.h" 12 #include "build/build_config.h" 13 14 #ifdef PVALLOC_AVAILABLE 15 // Build config explicitly tells us whether or not pvalloc is available. 16 #elif defined(LIBC_GLIBC) && !defined(USE_TCMALLOC) 17 #define PVALLOC_AVAILABLE 1 18 #else 19 #define PVALLOC_AVAILABLE 0 20 #endif 21 22 namespace base { 23 24 // Enables 'terminate on heap corruption' flag. Helps protect against heap 25 // overflow. Has no effect if the OS doesn't provide the necessary facility. 26 BASE_EXPORT void EnableTerminationOnHeapCorruption(); 27 28 // Turns on process termination if memory runs out. 29 BASE_EXPORT void EnableTerminationOnOutOfMemory(); 30 31 // Terminates process. Should be called only for out of memory errors. 32 // Crash reporting classifies such crashes as OOM. 33 BASE_EXPORT void TerminateBecauseOutOfMemory(size_t size); 34 35 #if defined(OS_LINUX) || defined(OS_ANDROID) || defined(OS_AIX) 36 BASE_EXPORT extern size_t g_oom_size; 37 38 // The maximum allowed value for the OOM score. 39 const int kMaxOomScore = 1000; 40 41 // This adjusts /proc/<pid>/oom_score_adj so the Linux OOM killer will 42 // prefer to kill certain process types over others. The range for the 43 // adjustment is [-1000, 1000], with [0, 1000] being user accessible. 44 // If the Linux system doesn't support the newer oom_score_adj range 45 // of [0, 1000], then we revert to using the older oom_adj, and 46 // translate the given value into [0, 15]. Some aliasing of values 47 // may occur in that case, of course. 48 BASE_EXPORT bool AdjustOOMScore(ProcessId process, int score); 49 #endif 50 51 #if defined(OS_WIN) 52 namespace win { 53 54 // Custom Windows exception code chosen to indicate an out of memory error. 55 // See https://msdn.microsoft.com/en-us/library/het71c37.aspx. 56 // "To make sure that you do not define a code that conflicts with an existing 57 // exception code" ... "The resulting error code should therefore have the 58 // highest four bits set to hexadecimal E." 59 // 0xe0000008 was chosen arbitrarily, as 0x00000008 is ERROR_NOT_ENOUGH_MEMORY. 60 const DWORD kOomExceptionCode = 0xe0000008; 61 62 } // namespace win 63 #endif 64 65 // Special allocator functions for callers that want to check for OOM. 66 // These will not abort if the allocation fails even if 67 // EnableTerminationOnOutOfMemory has been called. 68 // This can be useful for huge and/or unpredictable size memory allocations. 69 // Please only use this if you really handle the case when the allocation 70 // fails. Doing otherwise would risk security. 71 // These functions may still crash on OOM when running under memory tools, 72 // specifically ASan and other sanitizers. 73 // Return value tells whether the allocation succeeded. If it fails |result| is 74 // set to NULL, otherwise it holds the memory address. 75 BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedMalloc(size_t size, 76 void** result); 77 BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedCalloc(size_t num_items, 78 size_t size, 79 void** result); 80 81 } // namespace base 82 83 #endif // BASE_PROCESS_MEMORY_H_ 84