1 // Copyright (c) 2009 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 // When possible, we implement allocator functions on top of the basic 6 // low-level functions malloc() and free(). This way, including a new 7 // allocator is as simple as providing just a small interface. 8 // 9 // As such, this file should not contain any allocator-specific code. 10 11 // Implement a C++ style allocation, which always calls the new_handler 12 // on failure. 13 inline void* generic_cpp_alloc(size_t size, bool nothrow) { 14 void* ptr; 15 for (;;) { 16 ptr = malloc(size); 17 if (ptr) 18 return ptr; 19 if (!call_new_handler(nothrow)) 20 break; 21 } 22 return ptr; 23 } 24 25 extern "C++" { 26 27 void* __cdecl operator new(size_t size) { 28 return generic_cpp_alloc(size, false); 29 } 30 31 void operator delete(void* p) __THROW { 32 free(p); 33 } 34 35 void* operator new[](size_t size) { 36 return generic_cpp_alloc(size, false); 37 } 38 39 void operator delete[](void* p) __THROW { 40 free(p); 41 } 42 43 void* operator new(size_t size, const std::nothrow_t& nt) __THROW { 44 return generic_cpp_alloc(size, true); 45 } 46 47 void* operator new[](size_t size, const std::nothrow_t& nt) __THROW { 48 return generic_cpp_alloc(size, true); 49 } 50 51 // This function behaves similarly to MSVC's _set_new_mode. 52 // If flag is 0 (default), calls to malloc will behave normally. 53 // If flag is 1, calls to malloc will behave like calls to new, 54 // and the std_new_handler will be invoked on failure. 55 // Returns the previous mode. 56 int _set_new_mode(int flag) __THROW { 57 int old_mode = new_mode; 58 new_mode = flag; 59 return old_mode; 60 } 61 62 } // extern "C++" 63 64 extern "C" { 65 66 void* calloc(size_t n, size_t elem_size) __THROW { 67 // Overflow check 68 const size_t size = n * elem_size; 69 if (elem_size != 0 && size / elem_size != n) return NULL; 70 71 void* result = malloc(size); 72 if (result != NULL) { 73 memset(result, 0, size); 74 } 75 return result; 76 } 77 78 void cfree(void* p) __THROW { 79 free(p); 80 } 81 82 #ifdef WIN32 83 84 void* _recalloc(void* p, size_t n, size_t elem_size) { 85 if (!p) 86 return calloc(n, elem_size); 87 88 // This API is a bit odd. 89 // Note: recalloc only guarantees zeroed memory when p is NULL. 90 // Generally, calls to malloc() have padding. So a request 91 // to malloc N bytes actually malloc's N+x bytes. Later, if 92 // that buffer is passed to recalloc, we don't know what N 93 // was anymore. We only know what N+x is. As such, there is 94 // no way to know what to zero out. 95 const size_t size = n * elem_size; 96 if (elem_size != 0 && size / elem_size != n) return NULL; 97 return realloc(p, size); 98 } 99 100 void* _calloc_impl(size_t n, size_t size) { 101 return calloc(n, size); 102 } 103 104 #ifndef NDEBUG 105 #undef malloc 106 #undef free 107 #undef calloc 108 int _CrtDbgReport(int, const char*, int, const char*, const char*, ...) { 109 return 0; 110 } 111 112 int _CrtDbgReportW(int, const wchar_t*, int, const wchar_t*, 113 const wchar_t*, ...) { 114 return 0; 115 } 116 117 int _CrtSetReportMode(int, int) { 118 return 0; 119 } 120 121 void* _malloc_dbg(size_t size, int , const char*, int) { 122 return malloc(size); 123 } 124 125 void _free_dbg(void* ptr, int) { 126 free(ptr); 127 } 128 129 void* _calloc_dbg(size_t n, size_t size, int, const char*, int) { 130 return calloc(n, size); 131 } 132 #endif // NDEBUG 133 134 #endif // WIN32 135 136 } // extern C 137 138
