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1//
2// new_handler.cpp
3//
4// Copyright (c) Microsoft Corporation. All rights reserved.
5//
6// Implementation of the new handler and related functions..
7//
8#include <corecrt_internal.h>
9#include <new.h>
10
11// The global new handler. This pointer should only be accessed via the
12// functions defined in this source file.
13static __crt_state_management::dual_state_global<_PNH> __acrt_new_handler;
14
15
16
17// Initializes the new handler to the encoded nullptr value.
18extern "C" void __cdecl __acrt_initialize_new_handler(void* const encoded_null)
19{
20 __acrt_new_handler.initialize(reinterpret_cast<_PNH>(encoded_null));
21}
22
23// Sets the new handler to the new new handler and returns the old handler.
24_PNH __cdecl _set_new_handler(_PNH new_handler)
25{
26 _PNH result = nullptr;
27
28 __acrt_lock(__acrt_heap_lock);
29 __try
30 {
31 result = __crt_fast_decode_pointer(__acrt_new_handler.value());
32 __acrt_new_handler.value() = __crt_fast_encode_pointer(new_handler);
33 }
34 __finally
35 {
36 __acrt_unlock(__acrt_heap_lock);
37 }
38 __endtry
39
40 return result;
41}
42
43// Sets the new handler to nullptr and returns the old handler. The argument
44// must be zero. This overload is used to enable a caller to pass nullptr.
45_PNH __cdecl _set_new_handler(int const new_handler)
46{
47 // This is referenced only in the Debug CRT build
48 UNREFERENCED_PARAMETER(new_handler);
49
50 _ASSERTE(new_handler == 0);
51
52 return _set_new_handler(__crt_fast_encode_pointer(nullptr));
53}
54
55// Gets the current new handler.
56_PNH __cdecl _query_new_handler()
57{
58 _PNH result = nullptr;
59
60 __acrt_lock(__acrt_heap_lock);
61 __try
62 {
63 result = __crt_fast_decode_pointer(__acrt_new_handler.value());
64 }
65 __finally
66 {
67 __acrt_unlock(__acrt_heap_lock);
68 }
69 __endtry
70
71 return result;
72}
73
74// Calls the currently registered new handler with the provided size. If the
75// new handler succeeds, this function returns 1. This function returns 0 on
76// failure. The new handler may throw std::bad_alloc.
77extern "C" int __cdecl _callnewh(size_t const size)
78{
79 _PNH const pnh = _query_new_handler();
80
81 if (pnh == nullptr || (*pnh)(size) == 0)
82 return 0;
83
84 return 1;
85}