Make xmalloc and xrealloc thread-safe
[git/git.git] / wrapper.c
1 /*
2 * Various trivial helper wrappers around standard functions
3 */
4 #include "cache.h"
5
6 static void try_to_free_builtin(size_t size)
7 {
8 release_pack_memory(size, -1);
9 }
10
11 static void (*try_to_free_routine)(size_t size) = try_to_free_builtin;
12
13 void set_try_to_free_routine(void (*routine)(size_t))
14 {
15 try_to_free_routine = (routine) ? routine : try_to_free_builtin;
16 }
17
18 char *xstrdup(const char *str)
19 {
20 char *ret = strdup(str);
21 if (!ret) {
22 try_to_free_routine(strlen(str) + 1);
23 ret = strdup(str);
24 if (!ret)
25 die("Out of memory, strdup failed");
26 }
27 return ret;
28 }
29
30 void *xmalloc(size_t size)
31 {
32 void *ret = malloc(size);
33 if (!ret && !size)
34 ret = malloc(1);
35 if (!ret) {
36 try_to_free_routine(size);
37 ret = malloc(size);
38 if (!ret && !size)
39 ret = malloc(1);
40 if (!ret)
41 die("Out of memory, malloc failed");
42 }
43 #ifdef XMALLOC_POISON
44 memset(ret, 0xA5, size);
45 #endif
46 return ret;
47 }
48
49 void *xmallocz(size_t size)
50 {
51 void *ret;
52 if (size + 1 < size)
53 die("Data too large to fit into virtual memory space.");
54 ret = xmalloc(size + 1);
55 ((char*)ret)[size] = 0;
56 return ret;
57 }
58
59 /*
60 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
61 * "data" to the allocated memory, zero terminates the allocated memory,
62 * and returns a pointer to the allocated memory. If the allocation fails,
63 * the program dies.
64 */
65 void *xmemdupz(const void *data, size_t len)
66 {
67 return memcpy(xmallocz(len), data, len);
68 }
69
70 char *xstrndup(const char *str, size_t len)
71 {
72 char *p = memchr(str, '\0', len);
73 return xmemdupz(str, p ? p - str : len);
74 }
75
76 void *xrealloc(void *ptr, size_t size)
77 {
78 void *ret = realloc(ptr, size);
79 if (!ret && !size)
80 ret = realloc(ptr, 1);
81 if (!ret) {
82 try_to_free_routine(size);
83 ret = realloc(ptr, size);
84 if (!ret && !size)
85 ret = realloc(ptr, 1);
86 if (!ret)
87 die("Out of memory, realloc failed");
88 }
89 return ret;
90 }
91
92 void *xcalloc(size_t nmemb, size_t size)
93 {
94 void *ret = calloc(nmemb, size);
95 if (!ret && (!nmemb || !size))
96 ret = calloc(1, 1);
97 if (!ret) {
98 try_to_free_routine(nmemb * size);
99 ret = calloc(nmemb, size);
100 if (!ret && (!nmemb || !size))
101 ret = calloc(1, 1);
102 if (!ret)
103 die("Out of memory, calloc failed");
104 }
105 return ret;
106 }
107
108 void *xmmap(void *start, size_t length,
109 int prot, int flags, int fd, off_t offset)
110 {
111 void *ret = mmap(start, length, prot, flags, fd, offset);
112 if (ret == MAP_FAILED) {
113 if (!length)
114 return NULL;
115 release_pack_memory(length, fd);
116 ret = mmap(start, length, prot, flags, fd, offset);
117 if (ret == MAP_FAILED)
118 die_errno("Out of memory? mmap failed");
119 }
120 return ret;
121 }
122
123 /*
124 * xread() is the same a read(), but it automatically restarts read()
125 * operations with a recoverable error (EAGAIN and EINTR). xread()
126 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
127 */
128 ssize_t xread(int fd, void *buf, size_t len)
129 {
130 ssize_t nr;
131 while (1) {
132 nr = read(fd, buf, len);
133 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
134 continue;
135 return nr;
136 }
137 }
138
139 /*
140 * xwrite() is the same a write(), but it automatically restarts write()
141 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
142 * GUARANTEE that "len" bytes is written even if the operation is successful.
143 */
144 ssize_t xwrite(int fd, const void *buf, size_t len)
145 {
146 ssize_t nr;
147 while (1) {
148 nr = write(fd, buf, len);
149 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
150 continue;
151 return nr;
152 }
153 }
154
155 ssize_t read_in_full(int fd, void *buf, size_t count)
156 {
157 char *p = buf;
158 ssize_t total = 0;
159
160 while (count > 0) {
161 ssize_t loaded = xread(fd, p, count);
162 if (loaded <= 0)
163 return total ? total : loaded;
164 count -= loaded;
165 p += loaded;
166 total += loaded;
167 }
168
169 return total;
170 }
171
172 ssize_t write_in_full(int fd, const void *buf, size_t count)
173 {
174 const char *p = buf;
175 ssize_t total = 0;
176
177 while (count > 0) {
178 ssize_t written = xwrite(fd, p, count);
179 if (written < 0)
180 return -1;
181 if (!written) {
182 errno = ENOSPC;
183 return -1;
184 }
185 count -= written;
186 p += written;
187 total += written;
188 }
189
190 return total;
191 }
192
193 int xdup(int fd)
194 {
195 int ret = dup(fd);
196 if (ret < 0)
197 die_errno("dup failed");
198 return ret;
199 }
200
201 FILE *xfdopen(int fd, const char *mode)
202 {
203 FILE *stream = fdopen(fd, mode);
204 if (stream == NULL)
205 die_errno("Out of memory? fdopen failed");
206 return stream;
207 }
208
209 int xmkstemp(char *template)
210 {
211 int fd;
212
213 fd = mkstemp(template);
214 if (fd < 0)
215 die_errno("Unable to create temporary file");
216 return fd;
217 }
218
219 int xmkstemp_mode(char *template, int mode)
220 {
221 int fd;
222
223 fd = git_mkstemp_mode(template, mode);
224 if (fd < 0)
225 die_errno("Unable to create temporary file");
226 return fd;
227 }
228
229 /*
230 * zlib wrappers to make sure we don't silently miss errors
231 * at init time.
232 */
233 void git_inflate_init(z_streamp strm)
234 {
235 const char *err;
236
237 switch (inflateInit(strm)) {
238 case Z_OK:
239 return;
240
241 case Z_MEM_ERROR:
242 err = "out of memory";
243 break;
244 case Z_VERSION_ERROR:
245 err = "wrong version";
246 break;
247 default:
248 err = "error";
249 }
250 die("inflateInit: %s (%s)", err, strm->msg ? strm->msg : "no message");
251 }
252
253 void git_inflate_end(z_streamp strm)
254 {
255 if (inflateEnd(strm) != Z_OK)
256 error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
257 }
258
259 int git_inflate(z_streamp strm, int flush)
260 {
261 int ret = inflate(strm, flush);
262 const char *err;
263
264 switch (ret) {
265 /* Out of memory is fatal. */
266 case Z_MEM_ERROR:
267 die("inflate: out of memory");
268
269 /* Data corruption errors: we may want to recover from them (fsck) */
270 case Z_NEED_DICT:
271 err = "needs dictionary"; break;
272 case Z_DATA_ERROR:
273 err = "data stream error"; break;
274 case Z_STREAM_ERROR:
275 err = "stream consistency error"; break;
276 default:
277 err = "unknown error"; break;
278
279 /* Z_BUF_ERROR: normal, needs more space in the output buffer */
280 case Z_BUF_ERROR:
281 case Z_OK:
282 case Z_STREAM_END:
283 return ret;
284 }
285 error("inflate: %s (%s)", err, strm->msg ? strm->msg : "no message");
286 return ret;
287 }
288
289 int odb_mkstemp(char *template, size_t limit, const char *pattern)
290 {
291 int fd;
292 /*
293 * we let the umask do its job, don't try to be more
294 * restrictive except to remove write permission.
295 */
296 int mode = 0444;
297 snprintf(template, limit, "%s/%s",
298 get_object_directory(), pattern);
299 fd = git_mkstemp_mode(template, mode);
300 if (0 <= fd)
301 return fd;
302
303 /* slow path */
304 /* some mkstemp implementations erase template on failure */
305 snprintf(template, limit, "%s/%s",
306 get_object_directory(), pattern);
307 safe_create_leading_directories(template);
308 return xmkstemp_mode(template, mode);
309 }
310
311 int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
312 {
313 int fd;
314
315 snprintf(name, namesz, "%s/pack/pack-%s.keep",
316 get_object_directory(), sha1_to_hex(sha1));
317 fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
318 if (0 <= fd)
319 return fd;
320
321 /* slow path */
322 safe_create_leading_directories(name);
323 return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
324 }
325
326 int unlink_or_warn(const char *file)
327 {
328 int rc = unlink(file);
329
330 if (rc < 0) {
331 int err = errno;
332 if (ENOENT != err) {
333 warning("unable to unlink %s: %s",
334 file, strerror(errno));
335 errno = err;
336 }
337 }
338 return rc;
339 }
340