1/* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "apr.h" 18#include "apr_portable.h" 19#include "apr_strings.h" 20#include "apr_thread_proc.h" 21#include "apr_signal.h" 22 23#define APR_WANT_STDIO 24#define APR_WANT_STRFUNC 25#include "apr_want.h" 26 27#if APR_HAVE_UNISTD_H 28#include <unistd.h> 29#endif 30#if APR_HAVE_SYS_TYPES_H 31#include <sys/types.h> 32#endif 33 34#include "ap_config.h" 35#include "httpd.h" 36#include "mpm_default.h" 37#include "http_main.h" 38#include "http_log.h" 39#include "http_config.h" 40#include "http_core.h" /* for get_remote_host */ 41#include "http_connection.h" 42#include "scoreboard.h" 43#include "ap_mpm.h" 44#include "util_mutex.h" 45#include "unixd.h" 46#include "mpm_common.h" 47#include "ap_listen.h" 48#include "ap_mmn.h" 49#include "apr_poll.h" 50 51#ifdef HAVE_TIME_H 52#include <time.h> 53#endif 54#ifdef HAVE_SYS_PROCESSOR_H 55#include <sys/processor.h> /* for bindprocessor() */ 56#endif 57 58#include <signal.h> 59#include <sys/times.h> 60 61/* Limit on the total --- clients will be locked out if more servers than 62 * this are needed. It is intended solely to keep the server from crashing 63 * when things get out of hand. 64 * 65 * We keep a hard maximum number of servers, for two reasons --- first off, 66 * in case something goes seriously wrong, we want to stop the fork bomb 67 * short of actually crashing the machine we're running on by filling some 68 * kernel table. Secondly, it keeps the size of the scoreboard file small 69 * enough that we can read the whole thing without worrying too much about 70 * the overhead. 71 */ 72#ifndef DEFAULT_SERVER_LIMIT 73#define DEFAULT_SERVER_LIMIT 256 74#endif 75 76/* Admin can't tune ServerLimit beyond MAX_SERVER_LIMIT. We want 77 * some sort of compile-time limit to help catch typos. 78 */ 79#ifndef MAX_SERVER_LIMIT 80#define MAX_SERVER_LIMIT 200000 81#endif 82 83#ifndef HARD_THREAD_LIMIT 84#define HARD_THREAD_LIMIT 1 85#endif 86 87/* config globals */ 88 89static apr_proc_mutex_t *accept_mutex; 90static int ap_daemons_to_start=0; 91static int ap_daemons_min_free=0; 92static int ap_daemons_max_free=0; 93static int ap_daemons_limit=0; /* MaxRequestWorkers */ 94static int server_limit = 0; 95static int mpm_state = AP_MPMQ_STARTING; 96static ap_pod_t *pod; 97 98/* data retained by prefork across load/unload of the module 99 * allocated on first call to pre-config hook; located on 100 * subsequent calls to pre-config hook 101 */ 102typedef struct prefork_retained_data { 103 int first_server_limit; 104 int module_loads; 105 ap_generation_t my_generation; 106 int volatile is_graceful; /* set from signal handler */ 107 int maxclients_reported; 108 /* 109 * The max child slot ever assigned, preserved across restarts. Necessary 110 * to deal with MaxRequestWorkers changes across AP_SIG_GRACEFUL restarts. We 111 * use this value to optimize routines that have to scan the entire scoreboard. 112 */ 113 int max_daemons_limit; 114 /* 115 * idle_spawn_rate is the number of children that will be spawned on the 116 * next maintenance cycle if there aren't enough idle servers. It is 117 * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by 118 * without the need to spawn. 119 */ 120 int idle_spawn_rate; 121#ifndef MAX_SPAWN_RATE 122#define MAX_SPAWN_RATE (32) 123#endif 124 int hold_off_on_exponential_spawning; 125} prefork_retained_data; 126static prefork_retained_data *retained; 127 128#define MPM_CHILD_PID(i) (ap_scoreboard_image->parent[i].pid) 129 130/* one_process --- debugging mode variable; can be set from the command line 131 * with the -X flag. If set, this gets you the child_main loop running 132 * in the process which originally started up (no detach, no make_child), 133 * which is a pretty nice debugging environment. (You'll get a SIGHUP 134 * early in standalone_main; just continue through. This is the server 135 * trying to kill off any child processes which it might have lying 136 * around --- Apache doesn't keep track of their pids, it just sends 137 * SIGHUP to the process group, ignoring it in the root process. 138 * Continue through and you'll be fine.). 139 */ 140 141static int one_process = 0; 142 143static apr_pool_t *pconf; /* Pool for config stuff */ 144static apr_pool_t *pchild; /* Pool for httpd child stuff */ 145 146static pid_t ap_my_pid; /* it seems silly to call getpid all the time */ 147static pid_t parent_pid; 148static int my_child_num; 149 150#ifdef GPROF 151/* 152 * change directory for gprof to plop the gmon.out file 153 * configure in httpd.conf: 154 * GprofDir $RuntimeDir/ -> $ServerRoot/$RuntimeDir/gmon.out 155 * GprofDir $RuntimeDir/% -> $ServerRoot/$RuntimeDir/gprof.$pid/gmon.out 156 */ 157static void chdir_for_gprof(void) 158{ 159 core_server_config *sconf = 160 ap_get_core_module_config(ap_server_conf->module_config); 161 char *dir = sconf->gprof_dir; 162 const char *use_dir; 163 164 if(dir) { 165 apr_status_t res; 166 char *buf = NULL ; 167 int len = strlen(sconf->gprof_dir) - 1; 168 if(*(dir + len) == '%') { 169 dir[len] = '\0'; 170 buf = ap_append_pid(pconf, dir, "gprof."); 171 } 172 use_dir = ap_server_root_relative(pconf, buf ? buf : dir); 173 res = apr_dir_make(use_dir, 174 APR_UREAD | APR_UWRITE | APR_UEXECUTE | 175 APR_GREAD | APR_GEXECUTE | 176 APR_WREAD | APR_WEXECUTE, pconf); 177 if(res != APR_SUCCESS && !APR_STATUS_IS_EEXIST(res)) { 178 ap_log_error(APLOG_MARK, APLOG_ERR, res, ap_server_conf, APLOGNO(00142) 179 "gprof: error creating directory %s", dir); 180 } 181 } 182 else { 183 use_dir = ap_runtime_dir_relative(pconf, ""); 184 } 185 186 chdir(use_dir); 187} 188#else 189#define chdir_for_gprof() 190#endif 191 192static void prefork_note_child_killed(int childnum, pid_t pid, 193 ap_generation_t gen) 194{ 195 AP_DEBUG_ASSERT(childnum != -1); /* no scoreboard squatting with this MPM */ 196 ap_run_child_status(ap_server_conf, 197 ap_scoreboard_image->parent[childnum].pid, 198 ap_scoreboard_image->parent[childnum].generation, 199 childnum, MPM_CHILD_EXITED); 200 ap_scoreboard_image->parent[childnum].pid = 0; 201} 202 203static void prefork_note_child_started(int slot, pid_t pid) 204{ 205 ap_scoreboard_image->parent[slot].pid = pid; 206 ap_run_child_status(ap_server_conf, 207 ap_scoreboard_image->parent[slot].pid, 208 retained->my_generation, slot, MPM_CHILD_STARTED); 209} 210 211/* a clean exit from a child with proper cleanup */ 212static void clean_child_exit(int code) __attribute__ ((noreturn)); 213static void clean_child_exit(int code) 214{ 215 mpm_state = AP_MPMQ_STOPPING; 216 217 if (pchild) { 218 apr_pool_destroy(pchild); 219 } 220 221 if (one_process) { 222 prefork_note_child_killed(/* slot */ 0, 0, 0); 223 } 224 225 ap_mpm_pod_close(pod); 226 chdir_for_gprof(); 227 exit(code); 228} 229 230static void accept_mutex_on(void) 231{ 232 apr_status_t rv = apr_proc_mutex_lock(accept_mutex); 233 if (rv != APR_SUCCESS) { 234 const char *msg = "couldn't grab the accept mutex"; 235 236 if (retained->my_generation != 237 ap_scoreboard_image->global->running_generation) { 238 ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, ap_server_conf, APLOGNO(00143) "%s", msg); 239 clean_child_exit(0); 240 } 241 else { 242 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(00144) "%s", msg); 243 exit(APEXIT_CHILDFATAL); 244 } 245 } 246} 247 248static void accept_mutex_off(void) 249{ 250 apr_status_t rv = apr_proc_mutex_unlock(accept_mutex); 251 if (rv != APR_SUCCESS) { 252 const char *msg = "couldn't release the accept mutex"; 253 254 if (retained->my_generation != 255 ap_scoreboard_image->global->running_generation) { 256 ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, ap_server_conf, APLOGNO(00145) "%s", msg); 257 /* don't exit here... we have a connection to 258 * process, after which point we'll see that the 259 * generation changed and we'll exit cleanly 260 */ 261 } 262 else { 263 ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf, APLOGNO(00146) "%s", msg); 264 exit(APEXIT_CHILDFATAL); 265 } 266 } 267} 268 269/* On some architectures it's safe to do unserialized accept()s in the single 270 * Listen case. But it's never safe to do it in the case where there's 271 * multiple Listen statements. Define SINGLE_LISTEN_UNSERIALIZED_ACCEPT 272 * when it's safe in the single Listen case. 273 */ 274#ifdef SINGLE_LISTEN_UNSERIALIZED_ACCEPT 275#define SAFE_ACCEPT(stmt) do {if (ap_listeners->next) {stmt;}} while(0) 276#else 277#define SAFE_ACCEPT(stmt) do {stmt;} while(0) 278#endif 279 280static int prefork_query(int query_code, int *result, apr_status_t *rv) 281{ 282 *rv = APR_SUCCESS; 283 switch(query_code){ 284 case AP_MPMQ_MAX_DAEMON_USED: 285 *result = ap_daemons_limit; 286 break; 287 case AP_MPMQ_IS_THREADED: 288 *result = AP_MPMQ_NOT_SUPPORTED; 289 break; 290 case AP_MPMQ_IS_FORKED: 291 *result = AP_MPMQ_DYNAMIC; 292 break; 293 case AP_MPMQ_HARD_LIMIT_DAEMONS: 294 *result = server_limit; 295 break; 296 case AP_MPMQ_HARD_LIMIT_THREADS: 297 *result = HARD_THREAD_LIMIT; 298 break; 299 case AP_MPMQ_MAX_THREADS: 300 *result = 1; 301 break; 302 case AP_MPMQ_MIN_SPARE_DAEMONS: 303 *result = ap_daemons_min_free; 304 break; 305 case AP_MPMQ_MIN_SPARE_THREADS: 306 *result = 0; 307 break; 308 case AP_MPMQ_MAX_SPARE_DAEMONS: 309 *result = ap_daemons_max_free; 310 break; 311 case AP_MPMQ_MAX_SPARE_THREADS: 312 *result = 0; 313 break; 314 case AP_MPMQ_MAX_REQUESTS_DAEMON: 315 *result = ap_max_requests_per_child; 316 break; 317 case AP_MPMQ_MAX_DAEMONS: 318 *result = ap_daemons_limit; 319 break; 320 case AP_MPMQ_MPM_STATE: 321 *result = mpm_state; 322 break; 323 case AP_MPMQ_GENERATION: 324 *result = retained->my_generation; 325 break; 326 default: 327 *rv = APR_ENOTIMPL; 328 break; 329 } 330 return OK; 331} 332 333static const char *prefork_get_name(void) 334{ 335 return "prefork"; 336} 337 338/***************************************************************** 339 * Connection structures and accounting... 340 */ 341 342static void just_die(int sig) 343{ 344 clean_child_exit(0); 345} 346 347/* volatile because they're updated from a signal handler */ 348static int volatile shutdown_pending; 349static int volatile restart_pending; 350static int volatile die_now = 0; 351 352static void stop_listening(int sig) 353{ 354 mpm_state = AP_MPMQ_STOPPING; 355 ap_close_listeners(); 356 357 /* For a graceful stop, we want the child to exit when done */ 358 die_now = 1; 359} 360 361static void sig_term(int sig) 362{ 363 if (shutdown_pending == 1) { 364 /* Um, is this _probably_ not an error, if the user has 365 * tried to do a shutdown twice quickly, so we won't 366 * worry about reporting it. 367 */ 368 return; 369 } 370 mpm_state = AP_MPMQ_STOPPING; 371 shutdown_pending = 1; 372 retained->is_graceful = (sig == AP_SIG_GRACEFUL_STOP); 373} 374 375/* restart() is the signal handler for SIGHUP and AP_SIG_GRACEFUL 376 * in the parent process, unless running in ONE_PROCESS mode 377 */ 378static void restart(int sig) 379{ 380 if (restart_pending == 1) { 381 /* Probably not an error - don't bother reporting it */ 382 return; 383 } 384 mpm_state = AP_MPMQ_STOPPING; 385 restart_pending = 1; 386 retained->is_graceful = (sig == AP_SIG_GRACEFUL); 387} 388 389static void set_signals(void) 390{ 391#ifndef NO_USE_SIGACTION 392 struct sigaction sa; 393#endif 394 395 if (!one_process) { 396 ap_fatal_signal_setup(ap_server_conf, pconf); 397 } 398 399#ifndef NO_USE_SIGACTION 400 sigemptyset(&sa.sa_mask); 401 sa.sa_flags = 0; 402 403 sa.sa_handler = sig_term; 404 if (sigaction(SIGTERM, &sa, NULL) < 0) 405 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00147) "sigaction(SIGTERM)"); 406#ifdef AP_SIG_GRACEFUL_STOP 407 if (sigaction(AP_SIG_GRACEFUL_STOP, &sa, NULL) < 0) 408 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00148) 409 "sigaction(" AP_SIG_GRACEFUL_STOP_STRING ")"); 410#endif 411#ifdef SIGINT 412 if (sigaction(SIGINT, &sa, NULL) < 0) 413 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00149) "sigaction(SIGINT)"); 414#endif 415#ifdef SIGXCPU 416 sa.sa_handler = SIG_DFL; 417 if (sigaction(SIGXCPU, &sa, NULL) < 0) 418 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00150) "sigaction(SIGXCPU)"); 419#endif 420#ifdef SIGXFSZ 421 /* For systems following the LFS standard, ignoring SIGXFSZ allows 422 * a write() beyond the 2GB limit to fail gracefully with E2BIG 423 * rather than terminate the process. */ 424 sa.sa_handler = SIG_IGN; 425 if (sigaction(SIGXFSZ, &sa, NULL) < 0) 426 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00151) "sigaction(SIGXFSZ)"); 427#endif 428#ifdef SIGPIPE 429 sa.sa_handler = SIG_IGN; 430 if (sigaction(SIGPIPE, &sa, NULL) < 0) 431 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00152) "sigaction(SIGPIPE)"); 432#endif 433 434 /* we want to ignore HUPs and AP_SIG_GRACEFUL while we're busy 435 * processing one 436 */ 437 sigaddset(&sa.sa_mask, SIGHUP); 438 sigaddset(&sa.sa_mask, AP_SIG_GRACEFUL); 439 sa.sa_handler = restart; 440 if (sigaction(SIGHUP, &sa, NULL) < 0) 441 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00153) "sigaction(SIGHUP)"); 442 if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0) 443 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00154) "sigaction(" AP_SIG_GRACEFUL_STRING ")"); 444#else 445 if (!one_process) { 446#ifdef SIGXCPU 447 apr_signal(SIGXCPU, SIG_DFL); 448#endif /* SIGXCPU */ 449#ifdef SIGXFSZ 450 apr_signal(SIGXFSZ, SIG_IGN); 451#endif /* SIGXFSZ */ 452 } 453 454 apr_signal(SIGTERM, sig_term); 455#ifdef SIGHUP 456 apr_signal(SIGHUP, restart); 457#endif /* SIGHUP */ 458#ifdef AP_SIG_GRACEFUL 459 apr_signal(AP_SIG_GRACEFUL, restart); 460#endif /* AP_SIG_GRACEFUL */ 461#ifdef AP_SIG_GRACEFUL_STOP 462 apr_signal(AP_SIG_GRACEFUL_STOP, sig_term); 463#endif /* AP_SIG_GRACEFUL */ 464#ifdef SIGPIPE 465 apr_signal(SIGPIPE, SIG_IGN); 466#endif /* SIGPIPE */ 467 468#endif 469} 470 471/***************************************************************** 472 * Child process main loop. 473 * The following vars are static to avoid getting clobbered by longjmp(); 474 * they are really private to child_main. 475 */ 476 477static int requests_this_child; 478static int num_listensocks = 0; 479 480static void child_main(int child_num_arg) 481{ 482#if APR_HAS_THREADS 483 apr_thread_t *thd = NULL; 484 apr_os_thread_t osthd; 485#endif 486 apr_pool_t *ptrans; 487 apr_allocator_t *allocator; 488 apr_status_t status; 489 int i; 490 ap_listen_rec *lr; 491 apr_pollset_t *pollset; 492 ap_sb_handle_t *sbh; 493 apr_bucket_alloc_t *bucket_alloc; 494 int last_poll_idx = 0; 495 const char *lockfile; 496 497 mpm_state = AP_MPMQ_STARTING; /* for benefit of any hooks that run as this 498 * child initializes 499 */ 500 501 my_child_num = child_num_arg; 502 ap_my_pid = getpid(); 503 requests_this_child = 0; 504 505 ap_fatal_signal_child_setup(ap_server_conf); 506 507 /* Get a sub context for global allocations in this child, so that 508 * we can have cleanups occur when the child exits. 509 */ 510 apr_allocator_create(&allocator); 511 apr_allocator_max_free_set(allocator, ap_max_mem_free); 512 apr_pool_create_ex(&pchild, pconf, NULL, allocator); 513 apr_allocator_owner_set(allocator, pchild); 514 apr_pool_tag(pchild, "pchild"); 515 516#if APR_HAS_THREADS 517 osthd = apr_os_thread_current(); 518 apr_os_thread_put(&thd, &osthd, pchild); 519#endif 520 521 apr_pool_create(&ptrans, pchild); 522 apr_pool_tag(ptrans, "transaction"); 523 524 /* needs to be done before we switch UIDs so we have permissions */ 525 ap_reopen_scoreboard(pchild, NULL, 0); 526 lockfile = apr_proc_mutex_lockfile(accept_mutex); 527 status = apr_proc_mutex_child_init(&accept_mutex, 528 lockfile, 529 pchild); 530 if (status != APR_SUCCESS) { 531 ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(00155) 532 "Couldn't initialize cross-process lock in child " 533 "(%s) (%s)", 534 lockfile ? lockfile : "none", 535 apr_proc_mutex_name(accept_mutex)); 536 clean_child_exit(APEXIT_CHILDFATAL); 537 } 538 539 if (ap_run_drop_privileges(pchild, ap_server_conf)) { 540 clean_child_exit(APEXIT_CHILDFATAL); 541 } 542 543 ap_run_child_init(pchild, ap_server_conf); 544 545 ap_create_sb_handle(&sbh, pchild, my_child_num, 0); 546 547 (void) ap_update_child_status(sbh, SERVER_READY, (request_rec *) NULL); 548 549 /* Set up the pollfd array */ 550 status = apr_pollset_create(&pollset, num_listensocks, pchild, 0); 551 if (status != APR_SUCCESS) { 552 ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(00156) 553 "Couldn't create pollset in child; check system or user limits"); 554 clean_child_exit(APEXIT_CHILDSICK); /* assume temporary resource issue */ 555 } 556 557 for (lr = ap_listeners, i = num_listensocks; i--; lr = lr->next) { 558 apr_pollfd_t pfd = { 0 }; 559 560 pfd.desc_type = APR_POLL_SOCKET; 561 pfd.desc.s = lr->sd; 562 pfd.reqevents = APR_POLLIN; 563 pfd.client_data = lr; 564 565 status = apr_pollset_add(pollset, &pfd); 566 if (status != APR_SUCCESS) { 567 /* If the child processed a SIGWINCH before setting up the 568 * pollset, this error path is expected and harmless, 569 * since the listener fd was already closed; so don't 570 * pollute the logs in that case. */ 571 if (!die_now) { 572 ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(00157) 573 "Couldn't add listener to pollset; check system or user limits"); 574 clean_child_exit(APEXIT_CHILDSICK); 575 } 576 clean_child_exit(0); 577 } 578 579 lr->accept_func = ap_unixd_accept; 580 } 581 582 mpm_state = AP_MPMQ_RUNNING; 583 584 bucket_alloc = apr_bucket_alloc_create(pchild); 585 586 /* die_now is set when AP_SIG_GRACEFUL is received in the child; 587 * shutdown_pending is set when SIGTERM is received when running 588 * in single process mode. */ 589 while (!die_now && !shutdown_pending) { 590 conn_rec *current_conn; 591 void *csd; 592 593 /* 594 * (Re)initialize this child to a pre-connection state. 595 */ 596 597 apr_pool_clear(ptrans); 598 599 if ((ap_max_requests_per_child > 0 600 && requests_this_child++ >= ap_max_requests_per_child)) { 601 clean_child_exit(0); 602 } 603 604 (void) ap_update_child_status(sbh, SERVER_READY, (request_rec *) NULL); 605 606 /* 607 * Wait for an acceptable connection to arrive. 608 */ 609 610 /* Lock around "accept", if necessary */ 611 SAFE_ACCEPT(accept_mutex_on()); 612 613 if (num_listensocks == 1) { 614 /* There is only one listener record, so refer to that one. */ 615 lr = ap_listeners; 616 } 617 else { 618 /* multiple listening sockets - need to poll */ 619 for (;;) { 620 apr_int32_t numdesc; 621 const apr_pollfd_t *pdesc; 622 623 /* check for termination first so we don't sleep for a while in 624 * poll if already signalled 625 */ 626 if (die_now /* in graceful stop/restart */ 627 || (one_process && shutdown_pending)) { 628 SAFE_ACCEPT(accept_mutex_off()); 629 clean_child_exit(0); 630 } 631 632 /* timeout == 10 seconds to avoid a hang at graceful restart/stop 633 * caused by the closing of sockets by the signal handler 634 */ 635 status = apr_pollset_poll(pollset, apr_time_from_sec(10), 636 &numdesc, &pdesc); 637 if (status != APR_SUCCESS) { 638 if (APR_STATUS_IS_TIMEUP(status) || 639 APR_STATUS_IS_EINTR(status)) { 640 continue; 641 } 642 /* Single Unix documents select as returning errnos 643 * EBADF, EINTR, and EINVAL... and in none of those 644 * cases does it make sense to continue. In fact 645 * on Linux 2.0.x we seem to end up with EFAULT 646 * occasionally, and we'd loop forever due to it. 647 */ 648 ap_log_error(APLOG_MARK, APLOG_ERR, status, 649 ap_server_conf, APLOGNO(00158) "apr_pollset_poll: (listen)"); 650 SAFE_ACCEPT(accept_mutex_off()); 651 clean_child_exit(APEXIT_CHILDSICK); 652 } 653 654 /* We can always use pdesc[0], but sockets at position N 655 * could end up completely starved of attention in a very 656 * busy server. Therefore, we round-robin across the 657 * returned set of descriptors. While it is possible that 658 * the returned set of descriptors might flip around and 659 * continue to starve some sockets, we happen to know the 660 * internal pollset implementation retains ordering 661 * stability of the sockets. Thus, the round-robin should 662 * ensure that a socket will eventually be serviced. 663 */ 664 if (last_poll_idx >= numdesc) 665 last_poll_idx = 0; 666 667 /* Grab a listener record from the client_data of the poll 668 * descriptor, and advance our saved index to round-robin 669 * the next fetch. 670 * 671 * ### hmm... this descriptor might have POLLERR rather 672 * ### than POLLIN 673 */ 674 lr = pdesc[last_poll_idx++].client_data; 675 goto got_fd; 676 } 677 } 678 got_fd: 679 /* if we accept() something we don't want to die, so we have to 680 * defer the exit 681 */ 682 status = lr->accept_func(&csd, lr, ptrans); 683 684 SAFE_ACCEPT(accept_mutex_off()); /* unlock after "accept" */ 685 686 if (status == APR_EGENERAL) { 687 /* resource shortage or should-not-occur occured */ 688 clean_child_exit(APEXIT_CHILDSICK); 689 } 690 else if (status != APR_SUCCESS) { 691 continue; 692 } 693 694 /* 695 * We now have a connection, so set it up with the appropriate 696 * socket options, file descriptors, and read/write buffers. 697 */ 698 699 current_conn = ap_run_create_connection(ptrans, ap_server_conf, csd, my_child_num, sbh, bucket_alloc); 700 if (current_conn) { 701#if APR_HAS_THREADS 702 current_conn->current_thread = thd; 703#endif 704 ap_process_connection(current_conn, csd); 705 ap_lingering_close(current_conn); 706 } 707 708 /* Check the pod and the generation number after processing a 709 * connection so that we'll go away if a graceful restart occurred 710 * while we were processing the connection or we are the lucky 711 * idle server process that gets to die. 712 */ 713 if (ap_mpm_pod_check(pod) == APR_SUCCESS) { /* selected as idle? */ 714 die_now = 1; 715 } 716 else if (retained->my_generation != 717 ap_scoreboard_image->global->running_generation) { /* restart? */ 718 /* yeah, this could be non-graceful restart, in which case the 719 * parent will kill us soon enough, but why bother checking? 720 */ 721 die_now = 1; 722 } 723 } 724 apr_pool_clear(ptrans); /* kludge to avoid crash in APR reslist cleanup code */ 725 clean_child_exit(0); 726} 727 728 729static int make_child(server_rec *s, int slot) 730{ 731 int pid; 732 733 if (slot + 1 > retained->max_daemons_limit) { 734 retained->max_daemons_limit = slot + 1; 735 } 736 737 if (one_process) { 738 apr_signal(SIGHUP, sig_term); 739 /* Don't catch AP_SIG_GRACEFUL in ONE_PROCESS mode :) */ 740 apr_signal(SIGINT, sig_term); 741#ifdef SIGQUIT 742 apr_signal(SIGQUIT, SIG_DFL); 743#endif 744 apr_signal(SIGTERM, sig_term); 745 prefork_note_child_started(slot, getpid()); 746 child_main(slot); 747 /* NOTREACHED */ 748 } 749 750 (void) ap_update_child_status_from_indexes(slot, 0, SERVER_STARTING, 751 (request_rec *) NULL); 752 753 754#ifdef _OSD_POSIX 755 /* BS2000 requires a "special" version of fork() before a setuid() call */ 756 if ((pid = os_fork(ap_unixd_config.user_name)) == -1) { 757#else 758 if ((pid = fork()) == -1) { 759#endif 760 ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, APLOGNO(00159) "fork: Unable to fork new process"); 761 762 /* fork didn't succeed. Fix the scoreboard or else 763 * it will say SERVER_STARTING forever and ever 764 */ 765 (void) ap_update_child_status_from_indexes(slot, 0, SERVER_DEAD, 766 (request_rec *) NULL); 767 768 /* In case system resources are maxxed out, we don't want 769 * Apache running away with the CPU trying to fork over and 770 * over and over again. 771 */ 772 sleep(10); 773 774 return -1; 775 } 776 777 if (!pid) { 778#ifdef HAVE_BINDPROCESSOR 779 /* by default AIX binds to a single processor 780 * this bit unbinds children which will then bind to another cpu 781 */ 782 int status = bindprocessor(BINDPROCESS, (int)getpid(), 783 PROCESSOR_CLASS_ANY); 784 if (status != OK) { 785 ap_log_error(APLOG_MARK, APLOG_DEBUG, errno, 786 ap_server_conf, APLOGNO(00160) "processor unbind failed"); 787 } 788#endif 789 RAISE_SIGSTOP(MAKE_CHILD); 790 AP_MONCONTROL(1); 791 /* Disable the parent's signal handlers and set up proper handling in 792 * the child. 793 */ 794 apr_signal(SIGHUP, just_die); 795 apr_signal(SIGTERM, just_die); 796 /* The child process just closes listeners on AP_SIG_GRACEFUL. 797 * The pod is used for signalling the graceful restart. 798 */ 799 apr_signal(AP_SIG_GRACEFUL, stop_listening); 800 child_main(slot); 801 } 802 803 prefork_note_child_started(slot, pid); 804 805 return 0; 806} 807 808 809/* start up a bunch of children */ 810static void startup_children(int number_to_start) 811{ 812 int i; 813 814 for (i = 0; number_to_start && i < ap_daemons_limit; ++i) { 815 if (ap_scoreboard_image->servers[i][0].status != SERVER_DEAD) { 816 continue; 817 } 818 if (make_child(ap_server_conf, i) < 0) { 819 break; 820 } 821 --number_to_start; 822 } 823} 824 825static void perform_idle_server_maintenance(apr_pool_t *p) 826{ 827 int i; 828 int idle_count; 829 worker_score *ws; 830 int free_length; 831 int free_slots[MAX_SPAWN_RATE]; 832 int last_non_dead; 833 int total_non_dead; 834 835 /* initialize the free_list */ 836 free_length = 0; 837 838 idle_count = 0; 839 last_non_dead = -1; 840 total_non_dead = 0; 841 842 for (i = 0; i < ap_daemons_limit; ++i) { 843 int status; 844 845 if (i >= retained->max_daemons_limit && free_length == retained->idle_spawn_rate) 846 break; 847 ws = &ap_scoreboard_image->servers[i][0]; 848 status = ws->status; 849 if (status == SERVER_DEAD) { 850 /* try to keep children numbers as low as possible */ 851 if (free_length < retained->idle_spawn_rate) { 852 free_slots[free_length] = i; 853 ++free_length; 854 } 855 } 856 else { 857 /* We consider a starting server as idle because we started it 858 * at least a cycle ago, and if it still hasn't finished starting 859 * then we're just going to swamp things worse by forking more. 860 * So we hopefully won't need to fork more if we count it. 861 * This depends on the ordering of SERVER_READY and SERVER_STARTING. 862 */ 863 if (status <= SERVER_READY) { 864 ++ idle_count; 865 } 866 867 ++total_non_dead; 868 last_non_dead = i; 869 } 870 } 871 retained->max_daemons_limit = last_non_dead + 1; 872 if (idle_count > ap_daemons_max_free) { 873 /* kill off one child... we use the pod because that'll cause it to 874 * shut down gracefully, in case it happened to pick up a request 875 * while we were counting 876 */ 877 ap_mpm_pod_signal(pod); 878 retained->idle_spawn_rate = 1; 879 } 880 else if (idle_count < ap_daemons_min_free) { 881 /* terminate the free list */ 882 if (free_length == 0) { 883 /* only report this condition once */ 884 if (!retained->maxclients_reported) { 885 ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(00161) 886 "server reached MaxRequestWorkers setting, consider" 887 " raising the MaxRequestWorkers setting"); 888 retained->maxclients_reported = 1; 889 } 890 retained->idle_spawn_rate = 1; 891 } 892 else { 893 if (retained->idle_spawn_rate >= 8) { 894 ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, APLOGNO(00162) 895 "server seems busy, (you may need " 896 "to increase StartServers, or Min/MaxSpareServers), " 897 "spawning %d children, there are %d idle, and " 898 "%d total children", retained->idle_spawn_rate, 899 idle_count, total_non_dead); 900 } 901 for (i = 0; i < free_length; ++i) { 902 make_child(ap_server_conf, free_slots[i]); 903 } 904 /* the next time around we want to spawn twice as many if this 905 * wasn't good enough, but not if we've just done a graceful 906 */ 907 if (retained->hold_off_on_exponential_spawning) { 908 --retained->hold_off_on_exponential_spawning; 909 } 910 else if (retained->idle_spawn_rate < MAX_SPAWN_RATE) { 911 retained->idle_spawn_rate *= 2; 912 } 913 } 914 } 915 else { 916 retained->idle_spawn_rate = 1; 917 } 918} 919 920/***************************************************************** 921 * Executive routines. 922 */ 923 924static int prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 925{ 926 int index; 927 int remaining_children_to_start; 928 apr_status_t rv; 929 930 ap_log_pid(pconf, ap_pid_fname); 931 932 /* Initialize cross-process accept lock */ 933 rv = ap_proc_mutex_create(&accept_mutex, NULL, AP_ACCEPT_MUTEX_TYPE, NULL, 934 s, _pconf, 0); 935 if (rv != APR_SUCCESS) { 936 mpm_state = AP_MPMQ_STOPPING; 937 return DONE; 938 } 939 940 if (!retained->is_graceful) { 941 if (ap_run_pre_mpm(s->process->pool, SB_SHARED) != OK) { 942 mpm_state = AP_MPMQ_STOPPING; 943 return DONE; 944 } 945 /* fix the generation number in the global score; we just got a new, 946 * cleared scoreboard 947 */ 948 ap_scoreboard_image->global->running_generation = retained->my_generation; 949 } 950 951 restart_pending = shutdown_pending = 0; 952 set_signals(); 953 954 if (one_process) { 955 AP_MONCONTROL(1); 956 make_child(ap_server_conf, 0); 957 /* NOTREACHED */ 958 } 959 else { 960 if (ap_daemons_max_free < ap_daemons_min_free + 1) /* Don't thrash... */ 961 ap_daemons_max_free = ap_daemons_min_free + 1; 962 963 /* If we're doing a graceful_restart then we're going to see a lot 964 * of children exiting immediately when we get into the main loop 965 * below (because we just sent them AP_SIG_GRACEFUL). This happens pretty 966 * rapidly... and for each one that exits we'll start a new one until 967 * we reach at least daemons_min_free. But we may be permitted to 968 * start more than that, so we'll just keep track of how many we're 969 * supposed to start up without the 1 second penalty between each fork. 970 */ 971 remaining_children_to_start = ap_daemons_to_start; 972 if (remaining_children_to_start > ap_daemons_limit) { 973 remaining_children_to_start = ap_daemons_limit; 974 } 975 if (!retained->is_graceful) { 976 startup_children(remaining_children_to_start); 977 remaining_children_to_start = 0; 978 } 979 else { 980 /* give the system some time to recover before kicking into 981 * exponential mode 982 */ 983 retained->hold_off_on_exponential_spawning = 10; 984 } 985 986 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00163) 987 "%s configured -- resuming normal operations", 988 ap_get_server_description()); 989 ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, APLOGNO(00164) 990 "Server built: %s", ap_get_server_built()); 991 ap_log_command_line(plog, s); 992 ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(00165) 993 "Accept mutex: %s (default: %s)", 994 apr_proc_mutex_name(accept_mutex), 995 apr_proc_mutex_defname()); 996 997 mpm_state = AP_MPMQ_RUNNING; 998 999 while (!restart_pending && !shutdown_pending) { 1000 int child_slot; 1001 apr_exit_why_e exitwhy; 1002 int status, processed_status; 1003 /* this is a memory leak, but I'll fix it later. */ 1004 apr_proc_t pid; 1005 1006 ap_wait_or_timeout(&exitwhy, &status, &pid, pconf, ap_server_conf); 1007 1008 /* XXX: if it takes longer than 1 second for all our children 1009 * to start up and get into IDLE state then we may spawn an 1010 * extra child 1011 */ 1012 if (pid.pid != -1) { 1013 processed_status = ap_process_child_status(&pid, exitwhy, status); 1014 child_slot = ap_find_child_by_pid(&pid); 1015 if (processed_status == APEXIT_CHILDFATAL) { 1016 /* fix race condition found in PR 39311 1017 * A child created at the same time as a graceful happens 1018 * can find the lock missing and create a fatal error. 1019 * It is not fatal for the last generation to be in this state. 1020 */ 1021 if (child_slot < 0 1022 || ap_get_scoreboard_process(child_slot)->generation 1023 == retained->my_generation) { 1024 mpm_state = AP_MPMQ_STOPPING; 1025 return DONE; 1026 } 1027 else { 1028 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf, APLOGNO(00166) 1029 "Ignoring fatal error in child of previous " 1030 "generation (pid %ld).", 1031 (long)pid.pid); 1032 } 1033 } 1034 1035 /* non-fatal death... note that it's gone in the scoreboard. */ 1036 if (child_slot >= 0) { 1037 (void) ap_update_child_status_from_indexes(child_slot, 0, SERVER_DEAD, 1038 (request_rec *) NULL); 1039 prefork_note_child_killed(child_slot, 0, 0); 1040 if (processed_status == APEXIT_CHILDSICK) { 1041 /* child detected a resource shortage (E[NM]FILE, ENOBUFS, etc) 1042 * cut the fork rate to the minimum 1043 */ 1044 retained->idle_spawn_rate = 1; 1045 } 1046 else if (remaining_children_to_start 1047 && child_slot < ap_daemons_limit) { 1048 /* we're still doing a 1-for-1 replacement of dead 1049 * children with new children 1050 */ 1051 make_child(ap_server_conf, child_slot); 1052 --remaining_children_to_start; 1053 } 1054#if APR_HAS_OTHER_CHILD 1055 } 1056 else if (apr_proc_other_child_alert(&pid, APR_OC_REASON_DEATH, status) == APR_SUCCESS) { 1057 /* handled */ 1058#endif 1059 } 1060 else if (retained->is_graceful) { 1061 /* Great, we've probably just lost a slot in the 1062 * scoreboard. Somehow we don't know about this 1063 * child. 1064 */ 1065 ap_log_error(APLOG_MARK, APLOG_WARNING, 1066 0, ap_server_conf, APLOGNO(00167) 1067 "long lost child came home! (pid %ld)", (long)pid.pid); 1068 } 1069 /* Don't perform idle maintenance when a child dies, 1070 * only do it when there's a timeout. Remember only a 1071 * finite number of children can die, and it's pretty 1072 * pathological for a lot to die suddenly. 1073 */ 1074 continue; 1075 } 1076 else if (remaining_children_to_start) { 1077 /* we hit a 1 second timeout in which none of the previous 1078 * generation of children needed to be reaped... so assume 1079 * they're all done, and pick up the slack if any is left. 1080 */ 1081 startup_children(remaining_children_to_start); 1082 remaining_children_to_start = 0; 1083 /* In any event we really shouldn't do the code below because 1084 * few of the servers we just started are in the IDLE state 1085 * yet, so we'd mistakenly create an extra server. 1086 */ 1087 continue; 1088 } 1089 1090 perform_idle_server_maintenance(pconf); 1091 } 1092 } /* one_process */ 1093 1094 mpm_state = AP_MPMQ_STOPPING; 1095 1096 if (shutdown_pending && !retained->is_graceful) { 1097 /* Time to shut down: 1098 * Kill child processes, tell them to call child_exit, etc... 1099 */ 1100 if (ap_unixd_killpg(getpgrp(), SIGTERM) < 0) { 1101 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00168) "killpg SIGTERM"); 1102 } 1103 ap_reclaim_child_processes(1, /* Start with SIGTERM */ 1104 prefork_note_child_killed); 1105 1106 /* cleanup pid file on normal shutdown */ 1107 ap_remove_pid(pconf, ap_pid_fname); 1108 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00169) 1109 "caught SIGTERM, shutting down"); 1110 1111 return DONE; 1112 } else if (shutdown_pending) { 1113 /* Time to perform a graceful shut down: 1114 * Reap the inactive children, and ask the active ones 1115 * to close their listeners, then wait until they are 1116 * all done to exit. 1117 */ 1118 int active_children; 1119 apr_time_t cutoff = 0; 1120 1121 /* Stop listening */ 1122 ap_close_listeners(); 1123 1124 /* kill off the idle ones */ 1125 ap_mpm_pod_killpg(pod, retained->max_daemons_limit); 1126 1127 /* Send SIGUSR1 to the active children */ 1128 active_children = 0; 1129 for (index = 0; index < ap_daemons_limit; ++index) { 1130 if (ap_scoreboard_image->servers[index][0].status != SERVER_DEAD) { 1131 /* Ask each child to close its listeners. */ 1132 ap_mpm_safe_kill(MPM_CHILD_PID(index), AP_SIG_GRACEFUL); 1133 active_children++; 1134 } 1135 } 1136 1137 /* Allow each child which actually finished to exit */ 1138 ap_relieve_child_processes(prefork_note_child_killed); 1139 1140 /* cleanup pid file */ 1141 ap_remove_pid(pconf, ap_pid_fname); 1142 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00170) 1143 "caught " AP_SIG_GRACEFUL_STOP_STRING ", shutting down gracefully"); 1144 1145 if (ap_graceful_shutdown_timeout) { 1146 cutoff = apr_time_now() + 1147 apr_time_from_sec(ap_graceful_shutdown_timeout); 1148 } 1149 1150 /* Don't really exit until each child has finished */ 1151 shutdown_pending = 0; 1152 do { 1153 /* Pause for a second */ 1154 sleep(1); 1155 1156 /* Relieve any children which have now exited */ 1157 ap_relieve_child_processes(prefork_note_child_killed); 1158 1159 active_children = 0; 1160 for (index = 0; index < ap_daemons_limit; ++index) { 1161 if (ap_mpm_safe_kill(MPM_CHILD_PID(index), 0) == APR_SUCCESS) { 1162 active_children = 1; 1163 /* Having just one child is enough to stay around */ 1164 break; 1165 } 1166 } 1167 } while (!shutdown_pending && active_children && 1168 (!ap_graceful_shutdown_timeout || apr_time_now() < cutoff)); 1169 1170 /* We might be here because we received SIGTERM, either 1171 * way, try and make sure that all of our processes are 1172 * really dead. 1173 */ 1174 ap_unixd_killpg(getpgrp(), SIGTERM); 1175 1176 return DONE; 1177 } 1178 1179 /* we've been told to restart */ 1180 apr_signal(SIGHUP, SIG_IGN); 1181 apr_signal(AP_SIG_GRACEFUL, SIG_IGN); 1182 if (one_process) { 1183 /* not worth thinking about */ 1184 return DONE; 1185 } 1186 1187 /* advance to the next generation */ 1188 /* XXX: we really need to make sure this new generation number isn't in 1189 * use by any of the children. 1190 */ 1191 ++retained->my_generation; 1192 ap_scoreboard_image->global->running_generation = retained->my_generation; 1193 1194 if (retained->is_graceful) { 1195 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00171) 1196 "Graceful restart requested, doing restart"); 1197 1198 /* kill off the idle ones */ 1199 ap_mpm_pod_killpg(pod, retained->max_daemons_limit); 1200 1201 /* This is mostly for debugging... so that we know what is still 1202 * gracefully dealing with existing request. This will break 1203 * in a very nasty way if we ever have the scoreboard totally 1204 * file-based (no shared memory) 1205 */ 1206 for (index = 0; index < ap_daemons_limit; ++index) { 1207 if (ap_scoreboard_image->servers[index][0].status != SERVER_DEAD) { 1208 ap_scoreboard_image->servers[index][0].status = SERVER_GRACEFUL; 1209 /* Ask each child to close its listeners. 1210 * 1211 * NOTE: we use the scoreboard, because if we send SIGUSR1 1212 * to every process in the group, this may include CGI's, 1213 * piped loggers, etc. They almost certainly won't handle 1214 * it gracefully. 1215 */ 1216 ap_mpm_safe_kill(ap_scoreboard_image->parent[index].pid, AP_SIG_GRACEFUL); 1217 } 1218 } 1219 } 1220 else { 1221 /* Kill 'em off */ 1222 if (ap_unixd_killpg(getpgrp(), SIGHUP) < 0) { 1223 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00172) "killpg SIGHUP"); 1224 } 1225 ap_reclaim_child_processes(0, /* Not when just starting up */ 1226 prefork_note_child_killed); 1227 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00173) 1228 "SIGHUP received. Attempting to restart"); 1229 } 1230 1231 return OK; 1232} 1233 1234/* This really should be a post_config hook, but the error log is already 1235 * redirected by that point, so we need to do this in the open_logs phase. 1236 */ 1237static int prefork_open_logs(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) 1238{ 1239 int startup = 0; 1240 int level_flags = 0; 1241 apr_status_t rv; 1242 1243 pconf = p; 1244 1245 /* the reverse of pre_config, we want this only the first time around */ 1246 if (retained->module_loads == 1) { 1247 startup = 1; 1248 level_flags |= APLOG_STARTUP; 1249 } 1250 1251 if ((num_listensocks = ap_setup_listeners(ap_server_conf)) < 1) { 1252 ap_log_error(APLOG_MARK, APLOG_ALERT | level_flags, 0, 1253 (startup ? NULL : s), 1254 "no listening sockets available, shutting down"); 1255 return DONE; 1256 } 1257 1258 if ((rv = ap_mpm_pod_open(pconf, &pod))) { 1259 ap_log_error(APLOG_MARK, APLOG_CRIT | level_flags, rv, 1260 (startup ? NULL : s), 1261 "could not open pipe-of-death"); 1262 return DONE; 1263 } 1264 return OK; 1265} 1266 1267static int prefork_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp) 1268{ 1269 int no_detach, debug, foreground; 1270 apr_status_t rv; 1271 const char *userdata_key = "mpm_prefork_module"; 1272 1273 mpm_state = AP_MPMQ_STARTING; 1274 1275 debug = ap_exists_config_define("DEBUG"); 1276 1277 if (debug) { 1278 foreground = one_process = 1; 1279 no_detach = 0; 1280 } 1281 else 1282 { 1283 no_detach = ap_exists_config_define("NO_DETACH"); 1284 one_process = ap_exists_config_define("ONE_PROCESS"); 1285 foreground = ap_exists_config_define("FOREGROUND"); 1286 } 1287 1288 ap_mutex_register(p, AP_ACCEPT_MUTEX_TYPE, NULL, APR_LOCK_DEFAULT, 0); 1289 1290 /* sigh, want this only the second time around */ 1291 retained = ap_retained_data_get(userdata_key); 1292 if (!retained) { 1293 retained = ap_retained_data_create(userdata_key, sizeof(*retained)); 1294 retained->max_daemons_limit = -1; 1295 retained->idle_spawn_rate = 1; 1296 } 1297 ++retained->module_loads; 1298 if (retained->module_loads == 2) { 1299 if (!one_process && !foreground) { 1300 /* before we detach, setup crash handlers to log to errorlog */ 1301 ap_fatal_signal_setup(ap_server_conf, pconf); 1302 rv = apr_proc_detach(no_detach ? APR_PROC_DETACH_FOREGROUND 1303 : APR_PROC_DETACH_DAEMONIZE); 1304 if (rv != APR_SUCCESS) { 1305 ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL, APLOGNO(00174) 1306 "apr_proc_detach failed"); 1307 return HTTP_INTERNAL_SERVER_ERROR; 1308 } 1309 } 1310 } 1311 1312 parent_pid = ap_my_pid = getpid(); 1313 1314 ap_listen_pre_config(); 1315 ap_daemons_to_start = DEFAULT_START_DAEMON; 1316 ap_daemons_min_free = DEFAULT_MIN_FREE_DAEMON; 1317 ap_daemons_max_free = DEFAULT_MAX_FREE_DAEMON; 1318 server_limit = DEFAULT_SERVER_LIMIT; 1319 ap_daemons_limit = server_limit; 1320 ap_extended_status = 0; 1321 1322 return OK; 1323} 1324 1325static int prefork_check_config(apr_pool_t *p, apr_pool_t *plog, 1326 apr_pool_t *ptemp, server_rec *s) 1327{ 1328 int startup = 0; 1329 1330 /* the reverse of pre_config, we want this only the first time around */ 1331 if (retained->module_loads == 1) { 1332 startup = 1; 1333 } 1334 1335 if (server_limit > MAX_SERVER_LIMIT) { 1336 if (startup) { 1337 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00175) 1338 "WARNING: ServerLimit of %d exceeds compile-time " 1339 "limit of", server_limit); 1340 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, 1341 " %d servers, decreasing to %d.", 1342 MAX_SERVER_LIMIT, MAX_SERVER_LIMIT); 1343 } else { 1344 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00176) 1345 "ServerLimit of %d exceeds compile-time limit " 1346 "of %d, decreasing to match", 1347 server_limit, MAX_SERVER_LIMIT); 1348 } 1349 server_limit = MAX_SERVER_LIMIT; 1350 } 1351 else if (server_limit < 1) { 1352 if (startup) { 1353 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00177) 1354 "WARNING: ServerLimit of %d not allowed, " 1355 "increasing to 1.", server_limit); 1356 } else { 1357 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00178) 1358 "ServerLimit of %d not allowed, increasing to 1", 1359 server_limit); 1360 } 1361 server_limit = 1; 1362 } 1363 1364 /* you cannot change ServerLimit across a restart; ignore 1365 * any such attempts 1366 */ 1367 if (!retained->first_server_limit) { 1368 retained->first_server_limit = server_limit; 1369 } 1370 else if (server_limit != retained->first_server_limit) { 1371 /* don't need a startup console version here */ 1372 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00179) 1373 "changing ServerLimit to %d from original value of %d " 1374 "not allowed during restart", 1375 server_limit, retained->first_server_limit); 1376 server_limit = retained->first_server_limit; 1377 } 1378 1379 if (ap_daemons_limit > server_limit) { 1380 if (startup) { 1381 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00180) 1382 "WARNING: MaxRequestWorkers of %d exceeds ServerLimit " 1383 "value of", ap_daemons_limit); 1384 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, 1385 " %d servers, decreasing MaxRequestWorkers to %d.", 1386 server_limit, server_limit); 1387 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, 1388 " To increase, please see the ServerLimit " 1389 "directive."); 1390 } else { 1391 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00181) 1392 "MaxRequestWorkers of %d exceeds ServerLimit value " 1393 "of %d, decreasing to match", 1394 ap_daemons_limit, server_limit); 1395 } 1396 ap_daemons_limit = server_limit; 1397 } 1398 else if (ap_daemons_limit < 1) { 1399 if (startup) { 1400 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00182) 1401 "WARNING: MaxRequestWorkers of %d not allowed, " 1402 "increasing to 1.", ap_daemons_limit); 1403 } else { 1404 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00183) 1405 "MaxRequestWorkers of %d not allowed, increasing to 1", 1406 ap_daemons_limit); 1407 } 1408 ap_daemons_limit = 1; 1409 } 1410 1411 /* ap_daemons_to_start > ap_daemons_limit checked in prefork_run() */ 1412 if (ap_daemons_to_start < 0) { 1413 if (startup) { 1414 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00184) 1415 "WARNING: StartServers of %d not allowed, " 1416 "increasing to 1.", ap_daemons_to_start); 1417 } else { 1418 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00185) 1419 "StartServers of %d not allowed, increasing to 1", 1420 ap_daemons_to_start); 1421 } 1422 ap_daemons_to_start = 1; 1423 } 1424 1425 if (ap_daemons_min_free < 1) { 1426 if (startup) { 1427 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, APLOGNO(00186) 1428 "WARNING: MinSpareServers of %d not allowed, " 1429 "increasing to 1", ap_daemons_min_free); 1430 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, 1431 " to avoid almost certain server failure."); 1432 ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL, 1433 " Please read the documentation."); 1434 } else { 1435 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(00187) 1436 "MinSpareServers of %d not allowed, increasing to 1", 1437 ap_daemons_min_free); 1438 } 1439 ap_daemons_min_free = 1; 1440 } 1441 1442 /* ap_daemons_max_free < ap_daemons_min_free + 1 checked in prefork_run() */ 1443 1444 return OK; 1445} 1446 1447static void prefork_hooks(apr_pool_t *p) 1448{ 1449 /* Our open_logs hook function must run before the core's, or stderr 1450 * will be redirected to a file, and the messages won't print to the 1451 * console. 1452 */ 1453 static const char *const aszSucc[] = {"core.c", NULL}; 1454 1455 ap_hook_open_logs(prefork_open_logs, NULL, aszSucc, APR_HOOK_REALLY_FIRST); 1456 /* we need to set the MPM state before other pre-config hooks use MPM query 1457 * to retrieve it, so register as REALLY_FIRST 1458 */ 1459 ap_hook_pre_config(prefork_pre_config, NULL, NULL, APR_HOOK_REALLY_FIRST); 1460 ap_hook_check_config(prefork_check_config, NULL, NULL, APR_HOOK_MIDDLE); 1461 ap_hook_mpm(prefork_run, NULL, NULL, APR_HOOK_MIDDLE); 1462 ap_hook_mpm_query(prefork_query, NULL, NULL, APR_HOOK_MIDDLE); 1463 ap_hook_mpm_get_name(prefork_get_name, NULL, NULL, APR_HOOK_MIDDLE); 1464} 1465 1466static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy, const char *arg) 1467{ 1468 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); 1469 if (err != NULL) { 1470 return err; 1471 } 1472 1473 ap_daemons_to_start = atoi(arg); 1474 return NULL; 1475} 1476 1477static const char *set_min_free_servers(cmd_parms *cmd, void *dummy, const char *arg) 1478{ 1479 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); 1480 if (err != NULL) { 1481 return err; 1482 } 1483 1484 ap_daemons_min_free = atoi(arg); 1485 return NULL; 1486} 1487 1488static const char *set_max_free_servers(cmd_parms *cmd, void *dummy, const char *arg) 1489{ 1490 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); 1491 if (err != NULL) { 1492 return err; 1493 } 1494 1495 ap_daemons_max_free = atoi(arg); 1496 return NULL; 1497} 1498 1499static const char *set_max_clients (cmd_parms *cmd, void *dummy, const char *arg) 1500{ 1501 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); 1502 if (err != NULL) { 1503 return err; 1504 } 1505 if (!strcasecmp(cmd->cmd->name, "MaxClients")) { 1506 ap_log_error(APLOG_MARK, APLOG_INFO, 0, NULL, APLOGNO(00188) 1507 "MaxClients is deprecated, use MaxRequestWorkers " 1508 "instead."); 1509 } 1510 ap_daemons_limit = atoi(arg); 1511 return NULL; 1512} 1513 1514static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *arg) 1515{ 1516 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); 1517 if (err != NULL) { 1518 return err; 1519 } 1520 1521 server_limit = atoi(arg); 1522 return NULL; 1523} 1524 1525static const command_rec prefork_cmds[] = { 1526LISTEN_COMMANDS, 1527AP_INIT_TAKE1("StartServers", set_daemons_to_start, NULL, RSRC_CONF, 1528 "Number of child processes launched at server startup"), 1529AP_INIT_TAKE1("MinSpareServers", set_min_free_servers, NULL, RSRC_CONF, 1530 "Minimum number of idle children, to handle request spikes"), 1531AP_INIT_TAKE1("MaxSpareServers", set_max_free_servers, NULL, RSRC_CONF, 1532 "Maximum number of idle children"), 1533AP_INIT_TAKE1("MaxClients", set_max_clients, NULL, RSRC_CONF, 1534 "Deprecated name of MaxRequestWorkers"), 1535AP_INIT_TAKE1("MaxRequestWorkers", set_max_clients, NULL, RSRC_CONF, 1536 "Maximum number of children alive at the same time"), 1537AP_INIT_TAKE1("ServerLimit", set_server_limit, NULL, RSRC_CONF, 1538 "Maximum value of MaxRequestWorkers for this run of Apache"), 1539AP_GRACEFUL_SHUTDOWN_TIMEOUT_COMMAND, 1540{ NULL } 1541}; 1542 1543AP_DECLARE_MODULE(mpm_prefork) = { 1544 MPM20_MODULE_STUFF, 1545 NULL, /* hook to run before apache parses args */ 1546 NULL, /* create per-directory config structure */ 1547 NULL, /* merge per-directory config structures */ 1548 NULL, /* create per-server config structure */ 1549 NULL, /* merge per-server config structures */ 1550 prefork_cmds, /* command apr_table_t */ 1551 prefork_hooks, /* register hooks */ 1552}; 1553