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author | aaron <> | 1999-11-09 22:12:36 +0000 |
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committer | aaron <> | 1999-11-09 22:12:36 +0000 |
commit | 804f568be8b94c5d121b519265452c56bd2efb50 (patch) | |
tree | 8e8983be58be19c795441fe752c4a3b616216b09 /src/lib/libc/stdlib/malloc.3 | |
parent | 5d55745080b705a4223d109d1dbbd95cf1072a73 (diff) | |
download | openbsd-804f568be8b94c5d121b519265452c56bd2efb50.tar.gz openbsd-804f568be8b94c5d121b519265452c56bd2efb50.tar.bz2 openbsd-804f568be8b94c5d121b519265452c56bd2efb50.zip |
Merge calloc(3) man page into malloc.3; as suggested by millert@
Diffstat (limited to 'src/lib/libc/stdlib/malloc.3')
-rw-r--r-- | src/lib/libc/stdlib/malloc.3 | 57 |
1 files changed, 39 insertions, 18 deletions
diff --git a/src/lib/libc/stdlib/malloc.3 b/src/lib/libc/stdlib/malloc.3 index e7c237c63a..c9c87cf420 100644 --- a/src/lib/libc/stdlib/malloc.3 +++ b/src/lib/libc/stdlib/malloc.3 | |||
@@ -33,31 +33,30 @@ | |||
33 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | 33 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
34 | .\" SUCH DAMAGE. | 34 | .\" SUCH DAMAGE. |
35 | .\" | 35 | .\" |
36 | .\" $OpenBSD: malloc.3,v 1.15 1999/06/29 18:36:21 aaron Exp $ | 36 | .\" $OpenBSD: malloc.3,v 1.16 1999/11/09 22:12:36 aaron Exp $ |
37 | .\" | 37 | .\" |
38 | .Dd August 27, 1996 | 38 | .Dd August 27, 1996 |
39 | .Dt MALLOC 3 | 39 | .Dt MALLOC 3 |
40 | .Os | 40 | .Os |
41 | .Sh NAME | 41 | .Sh NAME |
42 | .Nm malloc , | 42 | .Nm malloc , |
43 | .Nd general memory allocation function | 43 | .Nm calloc , |
44 | .Pp | 44 | .Nm realloc , |
45 | .Nm free , | 45 | .Nm free , |
46 | .Nm cfree | 46 | .Nm cfree |
47 | .Nd free up memory allocated with malloc, calloc or realloc | 47 | .Nd memory allocation and deallocation |
48 | .Pp | ||
49 | .Nm realloc | ||
50 | .Nd reallocation of memory function | ||
51 | .Sh SYNOPSIS | 48 | .Sh SYNOPSIS |
52 | .Fd #include <stdlib.h> | 49 | .Fd #include <stdlib.h> |
53 | .Ft void * | 50 | .Ft void * |
54 | .Fn malloc "size_t size" | 51 | .Fn malloc "size_t size" |
52 | .Ft void * | ||
53 | .Fn calloc "size_t nmemb" "size_t size" | ||
54 | .Ft void * | ||
55 | .Fn realloc "void *ptr" "size_t size" | ||
55 | .Ft void | 56 | .Ft void |
56 | .Fn free "void *ptr" | 57 | .Fn free "void *ptr" |
57 | .Ft void | 58 | .Ft void |
58 | .Fn cfree "void *ptr" | 59 | .Fn cfree "void *ptr" |
59 | .Ft void * | ||
60 | .Fn realloc "void *ptr" "size_t size" | ||
61 | .Ft char * | 60 | .Ft char * |
62 | .Va malloc_options | 61 | .Va malloc_options |
63 | .Sh DESCRIPTION | 62 | .Sh DESCRIPTION |
@@ -80,6 +79,14 @@ or larger, the memory returned will be page-aligned. | |||
80 | Allocation of a zero size object returns a pointer to a zero size object. | 79 | Allocation of a zero size object returns a pointer to a zero size object. |
81 | .Pp | 80 | .Pp |
82 | The | 81 | The |
82 | .Fn calloc | ||
83 | function allocates space for an array of | ||
84 | .Fa nmemb | ||
85 | objects, each of whose size is | ||
86 | .Fa size . | ||
87 | The space is initialized to all bits zero. | ||
88 | .Pp | ||
89 | The | ||
83 | .Fn free | 90 | .Fn free |
84 | function causes the space pointed to by | 91 | function causes the space pointed to by |
85 | .Fa ptr | 92 | .Fa ptr |
@@ -231,13 +238,17 @@ See above. | |||
231 | .Sh RETURN VALUES | 238 | .Sh RETURN VALUES |
232 | The | 239 | The |
233 | .Fn malloc | 240 | .Fn malloc |
234 | function returns | 241 | and |
242 | .Fn calloc | ||
243 | functions return | ||
235 | a pointer to the allocated space if successful; otherwise | 244 | a pointer to the allocated space if successful; otherwise |
236 | a null pointer is returned. | 245 | a null pointer is returned. |
237 | .Pp | 246 | .Pp |
238 | The | 247 | The |
239 | .Fn free | 248 | .Fn free |
240 | function returns no value. | 249 | and |
250 | .Fn cfree | ||
251 | functions return no value. | ||
241 | .Pp | 252 | .Pp |
242 | The | 253 | The |
243 | .Fn realloc | 254 | .Fn realloc |
@@ -286,14 +297,16 @@ A pointer to a free chunk is attempted freed again. | |||
286 | .Pp | 297 | .Pp |
287 | ``junk pointer, too high to make sense.'' | 298 | ``junk pointer, too high to make sense.'' |
288 | The pointer doesn't make sense. It's above the area of memory that | 299 | The pointer doesn't make sense. It's above the area of memory that |
289 | malloc knows something about. | 300 | .Fn malloc |
301 | knows something about. | ||
290 | This could be a pointer from some | 302 | This could be a pointer from some |
291 | .Xr mmap 2 'ed | 303 | .Xr mmap 2 'ed |
292 | memory. | 304 | memory. |
293 | .Pp | 305 | .Pp |
294 | ``junk pointer, too low to make sense.'' | 306 | ``junk pointer, too low to make sense.'' |
295 | The pointer doesn't make sense. It's below the area of memory that | 307 | The pointer doesn't make sense. It's below the area of memory that |
296 | malloc knows something about. | 308 | .Fn malloc |
309 | knows something about. | ||
297 | This pointer probably came from your data or bss segments. | 310 | This pointer probably came from your data or bss segments. |
298 | .Pp | 311 | .Pp |
299 | ``malloc() has never been called.'' | 312 | ``malloc() has never been called.'' |
@@ -304,7 +317,9 @@ realloc'ed. | |||
304 | The pointer passed to free or realloc has been modified. | 317 | The pointer passed to free or realloc has been modified. |
305 | .Pp | 318 | .Pp |
306 | ``pointer to wrong page.'' | 319 | ``pointer to wrong page.'' |
307 | The pointer that malloc is trying to free is not pointing to | 320 | The pointer that |
321 | .Fn malloc | ||
322 | is trying to free is not pointing to | ||
308 | a sensible page. | 323 | a sensible page. |
309 | .Pp | 324 | .Pp |
310 | ``recursive call.'' | 325 | ``recursive call.'' |
@@ -338,14 +353,20 @@ The | |||
338 | function conforms to | 353 | function conforms to |
339 | .St -ansiC . | 354 | .St -ansiC . |
340 | .Sh HISTORY | 355 | .Sh HISTORY |
341 | The present implementation of malloc started out as a filesystem on a drum | 356 | The present implementation of |
342 | attached to a 20bit binary challenged computer built with discrete germanium | 357 | .Fn malloc |
358 | started out as a filesystem on a drum | ||
359 | attached to a 20-bit binary challenged computer built with discrete germanium | ||
343 | transistors, and it has since graduated to handle primary storage rather than | 360 | transistors, and it has since graduated to handle primary storage rather than |
344 | secondary. | 361 | secondary. |
345 | .Pp | 362 | .Pp |
346 | The main difference from other malloc implementations are believed to be that | 363 | The main difference from other |
364 | .Fn malloc | ||
365 | implementations are believed to be that | ||
347 | the free pages are not accessed until allocated. | 366 | the free pages are not accessed until allocated. |
348 | Most malloc implementations will store a data structure containing a, | 367 | Most |
368 | .Fn malloc | ||
369 | implementations will store a data structure containing a, | ||
349 | possibly double-, linked list in the free chunks of memory, used to tie | 370 | possibly double-, linked list in the free chunks of memory, used to tie |
350 | all the free memory together. | 371 | all the free memory together. |
351 | That is a quite suboptimal thing to do. | 372 | That is a quite suboptimal thing to do. |