src/afsweb/apache_includes/1.3.1/alloc.h

   1 /* ====================================================================
   2  * Copyright (c) 1995-1998 The Apache Group.  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
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the Apache Group
  19  *    for use in the Apache HTTP server project (http://www.apache.org/)."
  20  *
  21  * 4. The names "Apache Server" and "Apache Group" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    apache@apache.org.
  25  *
  26  * 5. Products derived from this software may not be called "Apache"
  27  *    nor may "Apache" appear in their names without prior written
  28  *    permission of the Apache Group.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the Apache Group
  33  *    for use in the Apache HTTP server project (http://www.apache.org/)."
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  * ====================================================================
  48  *
  49  * This software consists of voluntary contributions made by many
  50  * individuals on behalf of the Apache Group and was originally based
  51  * on public domain software written at the National Center for
  52  * Supercomputing Applications, University of Illinois, Urbana-Champaign.
  53  * For more information on the Apache Group and the Apache HTTP server
  54  * project, please see <http://www.apache.org/>.
  55  *
  56  */
  57
  58 #ifndef APACHE_ALLOC_H
  59 #define APACHE_ALLOC_H
  60
  61 #ifdef __cplusplus
  62 extern "C" {
  63 #endif
  64
  65 /*
  66  * Resource allocation routines...
  67  *
  68  * designed so that we don't have to keep track of EVERYTHING so that
  69  * it can be explicitly freed later (a fundamentally unsound strategy ---
  70  * particularly in the presence of die()).
  71  *
  72  * Instead, we maintain pools, and allocate items (both memory and I/O
  73  * handlers) from the pools --- currently there are two, one for per
  74  * transaction info, and one for config info.  When a transaction is over,
  75  * we can delete everything in the per-transaction pool without fear, and
  76  * without thinking too hard about it either.
  77  *
  78  * rst
  79  */
  80
  81 /* Arenas for configuration info and transaction info
  82  * --- actual layout of the pool structure is private to
  83  * alloc.c.
  84  */
  85
  86     /* Need declaration of DIR on Win32 */
  87 #ifdef WIN32
  88 #include "os/win32/readdir.h"
  89 #endif
  90
  91     typedef struct pool pool;
  92     typedef struct pool ap_pool;
  93
  94     pool *ap_init_alloc(void);  /* Set up everything */
  95       API_EXPORT(pool *) ap_make_sub_pool(pool *);      /* All pools are subpools of permanent_pool */
  96       API_EXPORT(void) ap_destroy_pool(pool *);
  97
  98 /* used to guarantee to the pool debugging code that the sub pool will not be
  99  * destroyed before the parent pool
 100  */
 101 #ifndef POOL_DEBUG
 102 #ifdef ap_pool_join
 103 #undef ap_pool_join
 104 #endif
 105 #define ap_pool_join(a,b)
 106 #else
 107       API_EXPORT(void) ap_pool_join(pool * p, pool * sub);
 108       API_EXPORT(pool *) ap_find_pool(const void *ts);
 109       API_EXPORT(int) ap_pool_is_ancestor(pool * a, pool * b);
 110 #endif
 111
 112 /* Clearing out EVERYTHING in an pool... destroys any sub-pools */
 113
 114       API_EXPORT(void) ap_clear_pool(struct pool *);
 115
 116 /* Preparing for exec() --- close files, etc., but *don't* flush I/O
 117  * buffers, *don't* wait for subprocesses, and *don't* free any memory.
 118  */
 119
 120       API_EXPORT(void) ap_cleanup_for_exec(void);
 121
 122 /* routines to allocate memory from an pool... */
 123
 124       API_EXPORT(void *) ap_palloc(struct pool *, int nbytes);
 125       API_EXPORT(void *) ap_pcalloc(struct pool *, int nbytes);
 126       API_EXPORT(char *) ap_pstrdup(struct pool *, const char *s);
 127 /* make a nul terminated copy of the n characters starting with s */
 128       API_EXPORT(char *) ap_pstrndup(struct pool *, const char *s, int n);
 129       API_EXPORT_NONSTD(char *) ap_pstrcat(struct pool *, ...); /* all '...' must be char* */
 130       API_EXPORT_NONSTD(char *) ap_psprintf(struct pool *, const char *fmt,
 131                                             ...)
 132         __attribute__ ((format(printf, 2, 3)));
 133       API_EXPORT(char *) ap_pvsprintf(struct pool *, const char *fmt,
 134                                       va_list);
 135
 136 /* array and alist management... keeping lists of things.
 137  * Common enough to want common support code ...
 138  */
 139
 140     typedef struct {
 141         ap_pool *pool;
 142         int elt_size;
 143         int nelts;
 144         int nalloc;
 145         char *elts;
 146     } array_header;
 147
 148       API_EXPORT(array_header *) ap_make_array(pool * p, int nelts,
 149                                                int elt_size);
 150       API_EXPORT(void *) ap_push_array(array_header *);
 151       API_EXPORT(void) ap_array_cat(array_header * dst,
 152                                     const array_header * src);
 153       API_EXPORT(array_header *) ap_append_arrays(pool *,
 154                                                   const array_header *,
 155                                                   const array_header *);
 156
 157 /* copy_array copies the *entire* array.  copy_array_hdr just copies
 158  * the header, and arranges for the elements to be copied if (and only
 159  * if) the code subsequently does a push or arraycat.
 160  */
 161
 162       API_EXPORT(array_header *) ap_copy_array(pool * p,
 163                                                const array_header * src);
 164       API_EXPORT(array_header *) ap_copy_array_hdr(pool * p,
 165                                                    const array_header * src);
 166
 167
 168 /* Tables.  Implemented alist style, for now, though we try to keep
 169  * it so that imposing a hash table structure on top in the future
 170  * wouldn't be *too* hard...
 171  *
 172  * Note that key comparisons for these are case-insensitive, largely
 173  * because that's what's appropriate and convenient everywhere they're
 174  * currently being used...
 175  */
 176
 177     typedef struct table table;
 178
 179     typedef struct {
 180         char *key;              /* maybe NULL in future;
 181                                  * check when iterating thru table_elts
 182                                  */
 183         char *val;
 184     } table_entry;
 185
 186       API_EXPORT(table *) ap_make_table(pool * p, int nelts);
 187       API_EXPORT(table *) ap_copy_table(pool * p, const table *);
 188       API_EXPORT(void) ap_clear_table(table *);
 189       API_EXPORT(const char *) ap_table_get(const table *, const char *);
 190       API_EXPORT(void) ap_table_set(table *, const char *name,
 191                                     const char *val);
 192       API_EXPORT(void) ap_table_setn(table *, const char *name,
 193                                      const char *val);
 194       API_EXPORT(void) ap_table_merge(table *, const char *name,
 195                                       const char *more_val);
 196       API_EXPORT(void) ap_table_mergen(table *, const char *name,
 197                                        const char *more_val);
 198       API_EXPORT(void) ap_table_unset(table *, const char *key);
 199       API_EXPORT(void) ap_table_add(table *, const char *name,
 200                                     const char *val);
 201       API_EXPORT(void) ap_table_addn(table *, const char *name,
 202                                      const char *val);
 203       API_EXPORT(void)
 204       ap_table_do(int (*comp) (void *, const char *, const char *), void *rec,
 205                   const table * t, ...);
 206
 207       API_EXPORT(table *) ap_overlay_tables(pool * p, const table * overlay,
 208                                             const table * base);
 209
 210 /* XXX: these know about the definition of struct table in alloc.c.  That
 211  * definition is not here because it is supposed to be private, and by not
 212  * placing it here we are able to get compile-time diagnostics from modules
 213  * written which assume that a table is the same as an array_header. -djg
 214  */
 215 #define ap_table_elts(t) ((array_header *)(t))
 216 #define ap_is_empty_table(t) (((t) == NULL)||(((array_header *)(t))->nelts == 0))
 217
 218 /* routines to remember allocation of other sorts of things...
 219  * generic interface first.  Note that we want to have two separate
 220  * cleanup functions in the general case, one for exec() preparation,
 221  * to keep CGI scripts and the like from inheriting access to things
 222  * they shouldn't be able to touch, and one for actually cleaning up,
 223  * when the actual server process wants to get rid of the thing,
 224  * whatever it is.
 225  *
 226  * kill_cleanup disarms a cleanup, presumably because the resource in
 227  * question has been closed, freed, or whatever, and it's scarce
 228  * enough to want to reclaim (e.g., descriptors).  It arranges for the
 229  * resource not to be cleaned up a second time (it might have been
 230  * reallocated).  run_cleanup does the same, but runs it first.
 231  *
 232  * Cleanups are identified for purposes of finding & running them off by the
 233  * plain_cleanup and data, which should presumably be unique.
 234  *
 235  * NB any code which invokes register_cleanup or kill_cleanup directly
 236  * is a critical section which should be guarded by block_alarms() and
 237  * unblock_alarms() below...
 238  */
 239
 240       API_EXPORT(void) ap_register_cleanup(pool * p, void *data,
 241                                            void (*plain_cleanup) (void *),
 242                                            void (*child_cleanup) (void *));
 243
 244       API_EXPORT(void) ap_kill_cleanup(pool * p, void *data,
 245                                        void (*plain_cleanup) (void *));
 246       API_EXPORT(void) ap_run_cleanup(pool * p, void *data,
 247                                       void (*cleanup) (void *));
 248
 249 /* A "do-nothing" cleanup, for register_cleanup; it's faster to do
 250  * things this way than to test for NULL. */
 251       API_EXPORT_NONSTD(void) ap_null_cleanup(void *data);
 252
 253 /* The time between when a resource is actually allocated, and when it
 254  * its cleanup is registered is a critical section, during which the
 255  * resource could leak if we got interrupted or timed out.  So, anything
 256  * which registers cleanups should bracket resource allocation and the
 257  * cleanup registry with these.  (This is done internally by run_cleanup).
 258  *
 259  * NB they are actually implemented in http_main.c, since they are bound
 260  * up with timeout handling in general...
 261  */
 262
 263       API_EXPORT(void) ap_block_alarms(void);
 264       API_EXPORT(void) ap_unblock_alarms(void);
 265
 266 /* Common cases which want utility support..
 267  * the note_cleanups_for_foo routines are for
 268  */
 269
 270       API_EXPORT(FILE *) ap_pfopen(struct pool *, const char *name,
 271                                    const char *fmode);
 272       API_EXPORT(FILE *) ap_pfdopen(struct pool *, int fd, const char *fmode);
 273       API_EXPORT(int) ap_popenf(struct pool *, const char *name, int flg,
 274                                 int mode);
 275
 276       API_EXPORT(void) ap_note_cleanups_for_file(pool *, FILE *);
 277       API_EXPORT(void) ap_note_cleanups_for_fd(pool *, int);
 278 #ifdef WIN32
 279       API_EXPORT(void) ap_note_cleanups_for_h(pool *, HANDLE);
 280 #endif
 281       API_EXPORT(void) ap_kill_cleanups_for_fd(pool * p, int fd);
 282
 283       API_EXPORT(void) ap_note_cleanups_for_socket(pool *, int);
 284       API_EXPORT(void) ap_kill_cleanups_for_socket(pool * p, int sock);
 285       API_EXPORT(int) ap_psocket(pool * p, int, int, int);
 286       API_EXPORT(int) ap_pclosesocket(pool * a, int sock);
 287
 288       API_EXPORT(regex_t *) ap_pregcomp(pool * p, const char *pattern,
 289                                         int cflags);
 290       API_EXPORT(void) ap_pregfree(pool * p, regex_t * reg);
 291
 292 /* routines to note closes... file descriptors are constrained enough
 293  * on some systems that we want to support this.
 294  */
 295
 296       API_EXPORT(int) ap_pfclose(struct pool *, FILE *);
 297       API_EXPORT(int) ap_pclosef(struct pool *, int fd);
 298 #ifdef WIN32
 299       API_EXPORT(int) ap_pcloseh(struct pool *, HANDLE hDevice);
 300 #endif
 301
 302 /* routines to deal with directories */
 303       API_EXPORT(DIR *) ap_popendir(pool * p, const char *name);
 304       API_EXPORT(void) ap_pclosedir(pool * p, DIR * d);
 305
 306 /* ... even child processes (which we may want to wait for,
 307  * or to kill outright, on unexpected termination).
 308  *
 309  * ap_spawn_child is a utility routine which handles an awful lot of
 310  * the rigamarole associated with spawning a child --- it arranges
 311  * for pipes to the child's stdin and stdout, if desired (if not,
 312  * set the associated args to NULL).  It takes as args a function
 313  * to call in the child, and an argument to be passed to the function.
 314  */
 315
 316     enum kill_conditions {
 317         kill_never,             /* process is never sent any signals */
 318         kill_always,            /* process is sent SIGKILL on pool cleanup */
 319         kill_after_timeout,     /* SIGTERM, wait 3 seconds, SIGKILL */
 320         just_wait,              /* wait forever for the process to complete */
 321         kill_only_once          /* send SIGTERM and then wait */
 322     };
 323
 324     typedef struct child_info child_info;
 325       API_EXPORT(void) ap_note_subprocess(pool * a, int pid,
 326                                           enum kill_conditions how);
 327       API_EXPORT(int) ap_spawn_child(pool *, int (*)(void *, child_info *),
 328                                      void *, enum kill_conditions,
 329                                      FILE ** pipe_in, FILE ** pipe_out,
 330                                      FILE ** pipe_err);
 331
 332 /* magic numbers --- min free bytes to consider a free pool block useable,
 333  * and the min amount to allocate if we have to go to malloc() */
 334
 335 #ifndef BLOCK_MINFREE
 336 #define BLOCK_MINFREE 4096
 337 #endif
 338 #ifndef BLOCK_MINALLOC
 339 #define BLOCK_MINALLOC 8192
 340 #endif
 341
 342 /* Finally, some accounting */
 343
 344       API_EXPORT(long) ap_bytes_in_pool(pool * p);
 345       API_EXPORT(long) ap_bytes_in_free_blocks(void);
 346
 347 #ifdef __cplusplus
 348 }
 349 #endif
 350 #endif                          /* !APACHE_ALLOC_H */