memory.cc revision 232950 
1/*
2 * Copyright 2010-2011 PathScale, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright notice,
8 *    this list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 *    this list of conditions and the following disclaimer in the documentation
12 *    and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
15 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
16 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27/**
28 * memory.cc - Contains stub definition of C++ new/delete operators.
29 *
30 * These definitions are intended to be used for testing and are weak symbols
31 * to allow them to be replaced by definitions from a STL implementation.
32 * These versions simply wrap malloc() and free(), they do not provide a
33 * C++-specific allocator.
34 */
35
36#include <stddef.h>
37#include <stdlib.h>
38#include "stdexcept.h"
39
40#ifndef __has_builtin
41#define __has_builtin(x) 0
42#endif
43
44#if !__has_builtin(__sync_swap)
45#define __sync_swap __sync_lock_test_and_set
46#endif
47
48namespace std
49{
50	struct nothrow_t {};
51}
52
53
54/// The type of the function called when allocation fails.
55typedef void (*new_handler)();
56/**
57 * The function to call when allocation fails.  By default, there is no
58 * handler and a bad allocation exception is thrown if an allocation fails.
59 */
60static new_handler new_handl;
61
62namespace std
63{
64	/**
65	 * Sets a function to be called when there is a failure in new.
66	 */
67	__attribute__((weak))
68	new_handler set_new_handler(new_handler handler)
69	{
70		return __sync_swap(&new_handl, handler);
71	}
72}
73
74
75__attribute__((weak))
76void* operator new(size_t size)
77{
78	void * mem = malloc(size);
79	while (0 == mem)
80	{
81		if (0 != new_handl)
82		{
83			new_handl();
84		}
85		else
86		{
87			throw std::bad_alloc();
88		}
89		mem = malloc(size);
90	}
91
92	return mem;
93}
94
95__attribute__((weak))
96void* operator new(size_t size, const std::nothrow_t &) throw()
97{
98	void *mem = malloc(size);
99	while (0 == mem)
100	{
101		if (0 != new_handl)
102		{
103			try
104			{
105				new_handl();
106			}
107			catch (...)
108			{
109				// nothrow operator new should return NULL in case of
110				// std::bad_alloc exception in new handler
111				return NULL;
112			}
113		}
114		else
115		{
116			return NULL;
117		}
118		mem = malloc(size);
119	}
120
121	return mem;
122}
123
124
125__attribute__((weak))
126void operator delete(void * ptr)
127{
128	free(ptr);
129}
130
131
132__attribute__((weak))
133void * operator new[](size_t size)
134{
135	return ::operator new(size);
136}
137
138
139__attribute__((weak))
140void operator delete[](void * ptr) throw()
141{
142	::operator delete(ptr);
143}
144
145
146