The open source OpenXR runtime
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1/* alloc.c -- Memory allocation without mmap.
2 Copyright (C) 2012-2021 Free Software Foundation, Inc.
3 Written by Ian Lance Taylor, Google.
4
5Redistribution and use in source and binary forms, with or without
6modification, are permitted provided that the following conditions are
7met:
8
9 (1) Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
11
12 (2) Redistributions in binary form must reproduce the above copyright
13 notice, this list of conditions and the following disclaimer in
14 the documentation and/or other materials provided with the
15 distribution.
16
17 (3) The name of the author may not be used to
18 endorse or promote products derived from this software without
19 specific prior written permission.
20
21THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
25INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
29STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31POSSIBILITY OF SUCH DAMAGE. */
32
33#include "config.h"
34
35#include <errno.h>
36#include <stdlib.h>
37#include <sys/types.h>
38
39#include "backtrace.hpp"
40#include "internal.hpp"
41
42#include "../common/TracyAlloc.hpp"
43
44namespace tracy
45{
46
47/* Allocation routines to use on systems that do not support anonymous
48 mmap. This implementation just uses malloc, which means that the
49 backtrace functions may not be safely invoked from a signal
50 handler. */
51
52/* Allocate memory like malloc. If ERROR_CALLBACK is NULL, don't
53 report an error. */
54
55void *
56backtrace_alloc (struct backtrace_state *state ATTRIBUTE_UNUSED,
57 size_t size, backtrace_error_callback error_callback,
58 void *data)
59{
60 void *ret;
61
62 ret = tracy_malloc (size);
63 if (ret == NULL)
64 {
65 if (error_callback)
66 error_callback (data, "malloc", errno);
67 }
68 return ret;
69}
70
71/* Free memory. */
72
73void
74backtrace_free (struct backtrace_state *state ATTRIBUTE_UNUSED,
75 void *p, size_t size ATTRIBUTE_UNUSED,
76 backtrace_error_callback error_callback ATTRIBUTE_UNUSED,
77 void *data ATTRIBUTE_UNUSED)
78{
79 tracy_free (p);
80}
81
82/* Grow VEC by SIZE bytes. */
83
84void *
85backtrace_vector_grow (struct backtrace_state *state ATTRIBUTE_UNUSED,
86 size_t size, backtrace_error_callback error_callback,
87 void *data, struct backtrace_vector *vec)
88{
89 void *ret;
90
91 if (size > vec->alc)
92 {
93 size_t alc;
94 void *base;
95
96 if (vec->size == 0)
97 alc = 32 * size;
98 else if (vec->size >= 4096)
99 alc = vec->size + 4096;
100 else
101 alc = 2 * vec->size;
102
103 if (alc < vec->size + size)
104 alc = vec->size + size;
105
106 base = tracy_realloc (vec->base, alc);
107 if (base == NULL)
108 {
109 error_callback (data, "realloc", errno);
110 return NULL;
111 }
112
113 vec->base = base;
114 vec->alc = alc - vec->size;
115 }
116
117 ret = (char *) vec->base + vec->size;
118 vec->size += size;
119 vec->alc -= size;
120 return ret;
121}
122
123/* Finish the current allocation on VEC. */
124
125void *
126backtrace_vector_finish (struct backtrace_state *state,
127 struct backtrace_vector *vec,
128 backtrace_error_callback error_callback,
129 void *data)
130{
131 void *ret;
132
133 /* With this allocator we call realloc in backtrace_vector_grow,
134 which means we can't easily reuse the memory here. So just
135 release it. */
136 if (!backtrace_vector_release (state, vec, error_callback, data))
137 return NULL;
138 ret = vec->base;
139 vec->base = NULL;
140 vec->size = 0;
141 vec->alc = 0;
142 return ret;
143}
144
145/* Release any extra space allocated for VEC. */
146
147int
148backtrace_vector_release (struct backtrace_state *state ATTRIBUTE_UNUSED,
149 struct backtrace_vector *vec,
150 backtrace_error_callback error_callback,
151 void *data)
152{
153 vec->alc = 0;
154
155 if (vec->size == 0)
156 {
157 /* As of C17, realloc with size 0 is marked as an obsolescent feature, use
158 free instead. */
159 tracy_free (vec->base);
160 vec->base = NULL;
161 return 1;
162 }
163
164 vec->base = tracy_realloc (vec->base, vec->size);
165 if (vec->base == NULL)
166 {
167 error_callback (data, "realloc", errno);
168 return 0;
169 }
170
171 return 1;
172}
173
174}