Annotation of win32/apache13/src/include/ap_alloc.h, revision 1.1.1.1

1.1       parser      1: /* ====================================================================
                      2:  * Copyright (c) 1995-1999 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: void ap_cleanup_alloc(void);
                     96: API_EXPORT(pool *) ap_make_sub_pool(pool *);   /* All pools are subpools of permanent_pool */
                     97: API_EXPORT(void) ap_destroy_pool(pool *);
                     98: 
                     99: /* pools have nested lifetimes -- sub_pools are destroyed when the
                    100:  * parent pool is cleared.  We allow certain liberties with operations
                    101:  * on things such as tables (and on other structures in a more general
                    102:  * sense) where we allow the caller to insert values into a table which
                    103:  * were not allocated from the table's pool.  The table's data will
                    104:  * remain valid as long as all the pools from which its values are
                    105:  * allocated remain valid.
                    106:  *
                    107:  * For example, if B is a sub pool of A, and you build a table T in
                    108:  * pool B, then it's safe to insert data allocated in A or B into T
                    109:  * (because B lives at most as long as A does, and T is destroyed when
                    110:  * B is cleared/destroyed).  On the other hand, if S is a table in
                    111:  * pool A, it is safe to insert data allocated in A into S, but it
                    112:  * is *not safe* to insert data allocated from B into S... because
                    113:  * B can be cleared/destroyed before A is (which would leave dangling
                    114:  * pointers in T's data structures).
                    115:  *
                    116:  * In general we say that it is safe to insert data into a table T
                    117:  * if the data is allocated in any ancestor of T's pool.  This is the
                    118:  * basis on which the POOL_DEBUG code works -- it tests these ancestor
                    119:  * relationships for all data inserted into tables.  POOL_DEBUG also
                    120:  * provides tools (ap_find_pool, and ap_pool_is_ancestor) for other
                    121:  * folks to implement similar restrictions for their own data
                    122:  * structures.
                    123:  *
                    124:  * However, sometimes this ancestor requirement is inconvenient --
                    125:  * sometimes we're forced to create a sub pool (such as through
                    126:  * ap_sub_req_lookup_uri), and the sub pool is guaranteed to have
                    127:  * the same lifetime as the parent pool.  This is a guarantee implemented
                    128:  * by the *caller*, not by the pool code.  That is, the caller guarantees
                    129:  * they won't destroy the sub pool individually prior to destroying the
                    130:  * parent pool.
                    131:  *
                    132:  * In this case the caller must call ap_pool_join() to indicate this
                    133:  * guarantee to the POOL_DEBUG code.  There are a few examples spread
                    134:  * through the standard modules.
                    135:  */
                    136: #ifndef POOL_DEBUG
                    137: #ifdef ap_pool_join
                    138: #undef ap_pool_join
                    139: #endif
                    140: #define ap_pool_join(a,b)
                    141: #else
                    142: API_EXPORT(void) ap_pool_join(pool *p, pool *sub);
                    143: API_EXPORT(pool *) ap_find_pool(const void *ts);
                    144: API_EXPORT(int) ap_pool_is_ancestor(pool *a, pool *b);
                    145: #endif
                    146: 
                    147: /* Clearing out EVERYTHING in an pool... destroys any sub-pools */
                    148: 
                    149: API_EXPORT(void) ap_clear_pool(struct pool *);
                    150: 
                    151: /* Preparing for exec() --- close files, etc., but *don't* flush I/O
                    152:  * buffers, *don't* wait for subprocesses, and *don't* free any memory.
                    153:  */
                    154: 
                    155: API_EXPORT(void) ap_cleanup_for_exec(void);
                    156: 
                    157: /* routines to allocate memory from an pool... */
                    158: 
                    159: API_EXPORT(void *) ap_palloc(struct pool *, int nbytes);
                    160: API_EXPORT(void *) ap_pcalloc(struct pool *, int nbytes);
                    161: API_EXPORT(char *) ap_pstrdup(struct pool *, const char *s);
                    162: /* make a nul terminated copy of the n characters starting with s */
                    163: API_EXPORT(char *) ap_pstrndup(struct pool *, const char *s, int n);
                    164: API_EXPORT_NONSTD(char *) ap_pstrcat(struct pool *,...);       /* all '...' must be char* */
                    165: API_EXPORT_NONSTD(char *) ap_psprintf(struct pool *, const char *fmt, ...)
                    166:     __attribute__((format(printf,2,3)));
                    167: API_EXPORT(char *) ap_pvsprintf(struct pool *, const char *fmt, va_list);
                    168: 
                    169: /* array and alist management... keeping lists of things.
                    170:  * Common enough to want common support code ...
                    171:  */
                    172: 
                    173: typedef struct {
                    174:     ap_pool *pool;
                    175:     int elt_size;
                    176:     int nelts;
                    177:     int nalloc;
                    178:     char *elts;
                    179: } array_header;
                    180: 
                    181: API_EXPORT(array_header *) ap_make_array(pool *p, int nelts, int elt_size);
                    182: API_EXPORT(void *) ap_push_array(array_header *);
                    183: API_EXPORT(void) ap_array_cat(array_header *dst, const array_header *src);
                    184: API_EXPORT(array_header *) ap_append_arrays(pool *, const array_header *,
                    185:                                         const array_header *);
                    186: 
                    187: /* ap_array_pstrcat generates a new string from the pool containing
                    188:  * the concatenated sequence of substrings referenced as elements within
                    189:  * the array.  The string will be empty if all substrings are empty or null,
                    190:  * or if there are no elements in the array.
                    191:  * If sep is non-NUL, it will be inserted between elements as a separator.
                    192:  */
                    193: API_EXPORT(char *) ap_array_pstrcat(pool *p, const array_header *arr,
                    194:                                     const char sep);
                    195: 
                    196: /* copy_array copies the *entire* array.  copy_array_hdr just copies
                    197:  * the header, and arranges for the elements to be copied if (and only
                    198:  * if) the code subsequently does a push or arraycat.
                    199:  */
                    200: 
                    201: API_EXPORT(array_header *) ap_copy_array(pool *p, const array_header *src);
                    202: API_EXPORT(array_header *) ap_copy_array_hdr(pool *p, const array_header *src);
                    203: 
                    204: 
                    205: /* Tables.  Implemented alist style, for now, though we try to keep
                    206:  * it so that imposing a hash table structure on top in the future
                    207:  * wouldn't be *too* hard...
                    208:  *
                    209:  * Note that key comparisons for these are case-insensitive, largely
                    210:  * because that's what's appropriate and convenient everywhere they're
                    211:  * currently being used...
                    212:  */
                    213: 
                    214: typedef struct table table;
                    215: 
                    216: typedef struct {
                    217:     char *key;         /* maybe NULL in future;
                    218:                         * check when iterating thru table_elts
                    219:                         */
                    220:     char *val;
                    221: } table_entry;
                    222: 
                    223: API_EXPORT(table *) ap_make_table(pool *p, int nelts);
                    224: API_EXPORT(table *) ap_copy_table(pool *p, const table *);
                    225: API_EXPORT(void) ap_clear_table(table *);
                    226: API_EXPORT(const char *) ap_table_get(const table *, const char *);
                    227: API_EXPORT(void) ap_table_set(table *, const char *name, const char *val);
                    228: API_EXPORT(void) ap_table_setn(table *, const char *name, const char *val);
                    229: API_EXPORT(void) ap_table_merge(table *, const char *name, const char *more_val);
                    230: API_EXPORT(void) ap_table_mergen(table *, const char *name, const char *more_val);
                    231: API_EXPORT(void) ap_table_unset(table *, const char *key);
                    232: API_EXPORT(void) ap_table_add(table *, const char *name, const char *val);
                    233: API_EXPORT(void) ap_table_addn(table *, const char *name, const char *val);
                    234: API_EXPORT(void) ap_table_do(int (*comp) (void *, const char *, const char *), void *rec,
                    235:                          const table *t,...);
                    236: 
                    237: API_EXPORT(table *) ap_overlay_tables(pool *p, const table *overlay, const table *base);
                    238: 
                    239: /* Conceptually, ap_overlap_tables does this:
                    240: 
                    241:     array_header *barr = ap_table_elts(b);
                    242:     table_entry *belt = (table_entry *)barr->elts;
                    243:     int i;
                    244: 
                    245:     for (i = 0; i < barr->nelts; ++i) {
                    246:        if (flags & AP_OVERLAP_TABLES_MERGE) {
                    247:            ap_table_mergen(a, belt[i].key, belt[i].val);
                    248:        }
                    249:        else {
                    250:            ap_table_setn(a, belt[i].key, belt[i].val);
                    251:        }
                    252:     }
                    253: 
                    254:     Except that it is more efficient (less space and cpu-time) especially
                    255:     when b has many elements.
                    256: 
                    257:     Notice the assumptions on the keys and values in b -- they must be
                    258:     in an ancestor of a's pool.  In practice b and a are usually from
                    259:     the same pool.
                    260: */
                    261: #define AP_OVERLAP_TABLES_SET  (0)
                    262: #define AP_OVERLAP_TABLES_MERGE        (1)
                    263: API_EXPORT(void) ap_overlap_tables(table *a, const table *b, unsigned flags);
                    264: 
                    265: /* XXX: these know about the definition of struct table in alloc.c.  That
                    266:  * definition is not here because it is supposed to be private, and by not
                    267:  * placing it here we are able to get compile-time diagnostics from modules
                    268:  * written which assume that a table is the same as an array_header. -djg
                    269:  */
                    270: #define ap_table_elts(t) ((array_header *)(t))
                    271: #define ap_is_empty_table(t) (((t) == NULL)||(((array_header *)(t))->nelts == 0))
                    272: 
                    273: /* routines to remember allocation of other sorts of things...
                    274:  * generic interface first.  Note that we want to have two separate
                    275:  * cleanup functions in the general case, one for exec() preparation,
                    276:  * to keep CGI scripts and the like from inheriting access to things
                    277:  * they shouldn't be able to touch, and one for actually cleaning up,
                    278:  * when the actual server process wants to get rid of the thing,
                    279:  * whatever it is.  
                    280:  *
                    281:  * kill_cleanup disarms a cleanup, presumably because the resource in
                    282:  * question has been closed, freed, or whatever, and it's scarce
                    283:  * enough to want to reclaim (e.g., descriptors).  It arranges for the
                    284:  * resource not to be cleaned up a second time (it might have been
                    285:  * reallocated).  run_cleanup does the same, but runs it first.
                    286:  *
                    287:  * Cleanups are identified for purposes of finding & running them off by the
                    288:  * plain_cleanup and data, which should presumably be unique.
                    289:  *
                    290:  * NB any code which invokes register_cleanup or kill_cleanup directly
                    291:  * is a critical section which should be guarded by block_alarms() and
                    292:  * unblock_alarms() below...
                    293:  */
                    294: 
                    295: API_EXPORT(void) ap_register_cleanup(pool *p, void *data,
                    296:                                  void (*plain_cleanup) (void *),
                    297:                                  void (*child_cleanup) (void *));
                    298: 
                    299: API_EXPORT(void) ap_kill_cleanup(pool *p, void *data, void (*plain_cleanup) (void *));
                    300: API_EXPORT(void) ap_run_cleanup(pool *p, void *data, void (*cleanup) (void *));
                    301: 
                    302: /* A "do-nothing" cleanup, for register_cleanup; it's faster to do
                    303:  * things this way than to test for NULL. */
                    304: API_EXPORT_NONSTD(void) ap_null_cleanup(void *data);
                    305: 
                    306: /* The time between when a resource is actually allocated, and when it
                    307:  * its cleanup is registered is a critical section, during which the
                    308:  * resource could leak if we got interrupted or timed out.  So, anything
                    309:  * which registers cleanups should bracket resource allocation and the
                    310:  * cleanup registry with these.  (This is done internally by run_cleanup).
                    311:  *
                    312:  * NB they are actually implemented in http_main.c, since they are bound
                    313:  * up with timeout handling in general...
                    314:  */
                    315: 
                    316: #ifdef TPF
                    317: #define ap_block_alarms() (0)
                    318: #define ap_unblock_alarms() (0)
                    319: #else
                    320: API_EXPORT(void) ap_block_alarms(void);
                    321: API_EXPORT(void) ap_unblock_alarms(void);
                    322: #endif /* TPF */
                    323: 
                    324: /* Common cases which want utility support..
                    325:  * the note_cleanups_for_foo routines are for 
                    326:  */
                    327: 
                    328: API_EXPORT(FILE *) ap_pfopen(struct pool *, const char *name, const char *fmode);
                    329: API_EXPORT(FILE *) ap_pfdopen(struct pool *, int fd, const char *fmode);
                    330: API_EXPORT(int) ap_popenf(struct pool *, const char *name, int flg, int mode);
                    331: 
                    332: API_EXPORT(void) ap_note_cleanups_for_file(pool *, FILE *);
                    333: API_EXPORT(void) ap_note_cleanups_for_fd(pool *, int);
                    334: #ifdef WIN32
                    335: API_EXPORT(void) ap_note_cleanups_for_h(pool *, HANDLE);
                    336: #endif
                    337: API_EXPORT(void) ap_kill_cleanups_for_fd(pool *p, int fd);
                    338: 
                    339: API_EXPORT(void) ap_note_cleanups_for_socket(pool *, int);
                    340: API_EXPORT(void) ap_kill_cleanups_for_socket(pool *p, int sock);
                    341: API_EXPORT(int) ap_psocket(pool *p, int, int, int);
                    342: API_EXPORT(int) ap_pclosesocket(pool *a, int sock);
                    343: 
                    344: API_EXPORT(regex_t *) ap_pregcomp(pool *p, const char *pattern, int cflags);
                    345: API_EXPORT(void) ap_pregfree(pool *p, regex_t * reg);
                    346: 
                    347: /* routines to note closes... file descriptors are constrained enough
                    348:  * on some systems that we want to support this.
                    349:  */
                    350: 
                    351: API_EXPORT(int) ap_pfclose(struct pool *, FILE *);
                    352: API_EXPORT(int) ap_pclosef(struct pool *, int fd);
                    353: #ifdef WIN32
                    354: API_EXPORT(int) ap_pcloseh(struct pool *, HANDLE hDevice);
                    355: #endif
                    356: 
                    357: /* routines to deal with directories */
                    358: API_EXPORT(DIR *) ap_popendir(pool *p, const char *name);
                    359: API_EXPORT(void) ap_pclosedir(pool *p, DIR * d);
                    360: 
                    361: /* ... even child processes (which we may want to wait for,
                    362:  * or to kill outright, on unexpected termination).
                    363:  *
                    364:  * ap_spawn_child is a utility routine which handles an awful lot of
                    365:  * the rigamarole associated with spawning a child --- it arranges
                    366:  * for pipes to the child's stdin and stdout, if desired (if not,
                    367:  * set the associated args to NULL).  It takes as args a function
                    368:  * to call in the child, and an argument to be passed to the function.
                    369:  */
                    370: 
                    371: enum kill_conditions {
                    372:     kill_never,                        /* process is never sent any signals */
                    373:     kill_always,               /* process is sent SIGKILL on pool cleanup */
                    374:     kill_after_timeout,                /* SIGTERM, wait 3 seconds, SIGKILL */
                    375:     just_wait,                 /* wait forever for the process to complete */
                    376:     kill_only_once             /* send SIGTERM and then wait */
                    377: };
                    378: 
                    379: typedef struct child_info child_info;
                    380: API_EXPORT(void) ap_note_subprocess(pool *a, pid_t pid,
                    381:                                    enum kill_conditions how);
                    382: API_EXPORT(int) ap_spawn_child(pool *, int (*)(void *, child_info *),
                    383:                                   void *, enum kill_conditions,
                    384:                                   FILE **pipe_in, FILE **pipe_out,
                    385:                                   FILE **pipe_err);
                    386: 
                    387: /* magic numbers --- min free bytes to consider a free pool block useable,
                    388:  * and the min amount to allocate if we have to go to malloc() */
                    389: 
                    390: #ifndef BLOCK_MINFREE
                    391: #define BLOCK_MINFREE 4096
                    392: #endif
                    393: #ifndef BLOCK_MINALLOC
                    394: #define BLOCK_MINALLOC 8192
                    395: #endif
                    396: 
                    397: /* Finally, some accounting */
                    398: 
                    399: API_EXPORT(long) ap_bytes_in_pool(pool *p);
                    400: API_EXPORT(long) ap_bytes_in_free_blocks(void);
                    401: 
                    402: #ifdef __cplusplus
                    403: }
                    404: #endif
                    405: 
                    406: #endif /* !APACHE_ALLOC_H */

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