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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 /* Multi-process, multi-threaded MPM for OS/2
20 * - a main, parent process
21 * - a small, static number of child processes
23 * The parent process's job is to manage the child processes. This involves
24 * spawning children as required to ensure there are always ap_daemons_to_start
25 * processes accepting connections.
27 * Each child process consists of a a pool of worker threads and a
28 * main thread that accepts connections & passes them to the workers via
29 * a work queue. The worker thread pool is dynamic, managed by a maintanence
30 * thread so that the number of idle threads is kept between
31 * min_spare_threads & max_spare_threads.
37 - Enforce MaxClients somehow
42 #define INCL_DOSERRORS
44 #include "ap_config.h"
46 #include "mpm_default.h"
47 #include "http_main.h"
49 #include "http_config.h"
50 #include "http_core.h" /* for get_remote_host */
51 #include "http_connection.h"
54 #include "ap_listen.h"
55 #include "apr_portable.h"
56 #include "mpm_common.h"
57 #include "apr_strings.h"
61 /* We don't need many processes,
62 * they're only for redundancy in the event of a crash
64 #define HARD_SERVER_LIMIT 10
66 /* Limit on the total number of threads per process
68 #ifndef HARD_THREAD_LIMIT
69 #define HARD_THREAD_LIMIT 256
72 server_rec *ap_server_conf;
73 static apr_pool_t *pconf = NULL; /* Pool for config stuff */
74 static const char *ap_pid_fname=NULL;
77 static int one_process = 0;
78 static int ap_daemons_to_start = 0;
79 static int ap_thread_limit = 0;
80 static int ap_max_requests_per_child = 0;
81 int ap_min_spare_threads = 0;
82 int ap_max_spare_threads = 0;
84 /* Keep track of a few interesting statistics */
85 int ap_max_daemons_limit = -1;
87 /* volatile just in case */
88 static int volatile shutdown_pending;
89 static int volatile restart_pending;
90 static int volatile is_graceful = 0;
91 ap_generation_t volatile ap_my_generation=0; /* Used by the scoreboard */
92 static int is_parent_process=TRUE;
93 HMTX ap_mpm_accept_mutex = 0;
95 /* An array of these is stored in a shared memory area for passing
96 * sockets from the parent to child processes
99 struct sockaddr_in name;
100 apr_os_sock_t listen_fd;
105 listen_socket_t listeners[1];
108 static char master_main();
109 static void spawn_child(int slot);
110 void ap_mpm_child_main(apr_pool_t *pconf);
111 static void set_signals();
114 int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s )
116 char *listener_shm_name;
117 parent_info_t *parent_info;
123 DosSetMaxFH(ap_thread_limit * 2);
124 listener_shm_name = apr_psprintf(pconf, "/sharemem/httpd/parent_info.%d", getppid());
125 rc = DosGetNamedSharedMem((PPVOID)&parent_info, listener_shm_name, PAG_READ);
126 is_parent_process = rc != 0;
127 ap_scoreboard_fname = apr_psprintf(pconf, "/sharemem/httpd/scoreboard.%d", is_parent_process ? getpid() : getppid());
132 int num_listeners = 0;
134 ap_mpm_accept_mutex = parent_info->accept_mutex;
136 /* Set up a default listener if necessary */
137 if (ap_listeners == NULL) {
138 ap_listen_rec *lr = apr_pcalloc(s->process->pool, sizeof(ap_listen_rec));
140 apr_sockaddr_info_get(&lr->bind_addr, "0.0.0.0", APR_UNSPEC,
141 DEFAULT_HTTP_PORT, 0, s->process->pool);
142 apr_socket_create(&lr->sd, lr->bind_addr->family,
143 SOCK_STREAM, s->process->pool);
146 for (lr = ap_listeners; lr; lr = lr->next) {
148 apr_os_sock_put(&lr->sd, &parent_info->listeners[num_listeners].listen_fd, pconf);
149 apr_socket_addr_get(&sa, APR_LOCAL, lr->sd);
153 DosFreeMem(parent_info);
156 ap_mpm_child_main(pconf);
164 is_parent_process = TRUE;
166 if (ap_setup_listeners(ap_server_conf) < 1) {
167 ap_log_error(APLOG_MARK, APLOG_ALERT, 0, s,
168 "no listening sockets available, shutting down");
172 ap_log_pid(pconf, ap_pid_fname);
174 restart = master_main();
176 ap_scoreboard_image->global->running_generation = ap_my_generation;
179 const char *pidfile = ap_server_root_relative(pconf, ap_pid_fname);
181 if (pidfile != NULL && remove(pidfile) == 0) {
182 ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS,
183 ap_server_conf, "removed PID file %s (pid=%d)",
187 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
188 "caught SIGTERM, shutting down");
191 } /* Parent process */
193 return 0; /* Restart */
198 /* Main processing of the parent process
199 * returns TRUE if restarting
201 static char master_main()
203 server_rec *s = ap_server_conf;
205 parent_info_t *parent_info;
206 char *listener_shm_name;
207 int listener_num, num_listeners, slot;
210 printf("%s \n", ap_get_server_version());
213 if (ap_setup_listeners(ap_server_conf) < 1) {
214 ap_log_error(APLOG_MARK, APLOG_ALERT, 0, s,
215 "no listening sockets available, shutting down");
219 /* Allocate a shared memory block for the array of listeners */
220 for (num_listeners = 0, lr = ap_listeners; lr; lr = lr->next) {
224 listener_shm_name = apr_psprintf(pconf, "/sharemem/httpd/parent_info.%d", getpid());
225 rc = DosAllocSharedMem((PPVOID)&parent_info, listener_shm_name,
226 sizeof(parent_info_t) + num_listeners * sizeof(listen_socket_t),
227 PAG_READ|PAG_WRITE|PAG_COMMIT);
230 ap_log_error(APLOG_MARK, APLOG_ALERT, APR_FROM_OS_ERROR(rc), s,
231 "failure allocating shared memory, shutting down");
235 /* Store the listener sockets in the shared memory area for our children to see */
236 for (listener_num = 0, lr = ap_listeners; lr; lr = lr->next, listener_num++) {
237 apr_os_sock_get(&parent_info->listeners[listener_num].listen_fd, lr->sd);
240 /* Create mutex to prevent multiple child processes from detecting
241 * a connection with apr_poll()
244 rc = DosCreateMutexSem(NULL, &ap_mpm_accept_mutex, DC_SEM_SHARED, FALSE);
247 ap_log_error(APLOG_MARK, APLOG_ALERT, APR_FROM_OS_ERROR(rc), s,
248 "failure creating accept mutex, shutting down");
252 parent_info->accept_mutex = ap_mpm_accept_mutex;
254 /* Allocate shared memory for scoreboard */
255 if (ap_scoreboard_image == NULL) {
257 rc = DosAllocSharedMem(&sb_mem, ap_scoreboard_fname,
258 ap_calc_scoreboard_size(),
259 PAG_COMMIT|PAG_READ|PAG_WRITE);
262 ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
263 "unable to allocate shared memory for scoreboard , exiting");
267 ap_init_scoreboard(sb_mem);
270 ap_scoreboard_image->global->restart_time = apr_time_now();
271 ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
272 "%s configured -- resuming normal operations",
273 ap_get_server_version());
274 ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf,
275 "Server built: %s", ap_get_server_built());
276 #ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH
277 ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
278 "AcceptMutex: %s (default: %s)",
279 apr_proc_mutex_name(accept_mutex),
280 apr_proc_mutex_defname());
283 ap_scoreboard_image->parent[0].pid = getpid();
284 ap_mpm_child_main(pconf);
288 while (!restart_pending && !shutdown_pending) {
291 int active_children = 0;
293 /* Count number of active children */
294 for (slot=0; slot < HARD_SERVER_LIMIT; slot++) {
295 active_children += ap_scoreboard_image->parent[slot].pid != 0 &&
296 !ap_scoreboard_image->parent[slot].quiescing;
299 /* Spawn children if needed */
300 for (slot=0; slot < HARD_SERVER_LIMIT && active_children < ap_daemons_to_start; slot++) {
301 if (ap_scoreboard_image->parent[slot].pid == 0) {
307 rc = DosWaitChild(DCWA_PROCESSTREE, DCWW_NOWAIT, &proc_rc, &child_pid, 0);
310 /* A child has terminated, remove its scoreboard entry & terminate if necessary */
311 for (slot=0; ap_scoreboard_image->parent[slot].pid != child_pid && slot < HARD_SERVER_LIMIT; slot++);
313 if (slot < HARD_SERVER_LIMIT) {
314 ap_scoreboard_image->parent[slot].pid = 0;
315 ap_scoreboard_image->parent[slot].quiescing = 0;
317 if (proc_rc.codeTerminate == TC_EXIT) {
318 /* Child terminated normally, check its exit code and
319 * terminate server if child indicates a fatal error
321 if (proc_rc.codeResult == APEXIT_CHILDFATAL)
325 } else if (rc == ERROR_CHILD_NOT_COMPLETE) {
326 /* No child exited, lets sleep for a while.... */
327 apr_sleep(SCOREBOARD_MAINTENANCE_INTERVAL);
331 /* Signal children to shut down, either gracefully or immediately */
332 for (slot=0; slot<HARD_SERVER_LIMIT; slot++) {
333 kill(ap_scoreboard_image->parent[slot].pid, is_graceful ? SIGHUP : SIGTERM);
336 DosFreeMem(parent_info);
337 return restart_pending;
342 static void spawn_child(int slot)
346 char fail_module[100];
347 char progname[CCHMAXPATH];
351 ap_scoreboard_image->parent[slot].generation = ap_my_generation;
352 DosGetInfoBlocks(&ptib, &ppib);
353 DosQueryModuleName(ppib->pib_hmte, sizeof(progname), progname);
354 rc = DosExecPgm(fail_module, sizeof(fail_module), EXEC_ASYNCRESULT,
355 ppib->pib_pchcmd, NULL, &proc_rc, progname);
358 ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
359 "error spawning child, slot %d", slot);
362 if (ap_max_daemons_limit < slot) {
363 ap_max_daemons_limit = slot;
366 ap_scoreboard_image->parent[slot].pid = proc_rc.codeTerminate;
371 /* Signal handling routines */
373 static void sig_term(int sig)
375 shutdown_pending = 1;
376 signal(SIGTERM, SIG_DFL);
381 static void sig_restart(int sig)
383 if (sig == SIGUSR1) {
392 static void set_signals()
396 sigemptyset(&sa.sa_mask);
398 sa.sa_handler = sig_term;
400 if (sigaction(SIGTERM, &sa, NULL) < 0)
401 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGTERM)");
403 if (sigaction(SIGINT, &sa, NULL) < 0)
404 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGINT)");
406 sa.sa_handler = sig_restart;
408 if (sigaction(SIGHUP, &sa, NULL) < 0)
409 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
410 if (sigaction(SIGUSR1, &sa, NULL) < 0)
411 ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGUSR1)");
416 /* Enquiry functions used get MPM status info */
418 AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
420 switch (query_code) {
421 case AP_MPMQ_MAX_DAEMON_USED:
422 *result = ap_max_daemons_limit;
424 case AP_MPMQ_IS_THREADED:
425 *result = AP_MPMQ_DYNAMIC;
427 case AP_MPMQ_IS_FORKED:
428 *result = AP_MPMQ_NOT_SUPPORTED;
430 case AP_MPMQ_HARD_LIMIT_DAEMONS:
431 *result = HARD_SERVER_LIMIT;
433 case AP_MPMQ_HARD_LIMIT_THREADS:
434 *result = HARD_THREAD_LIMIT;
436 case AP_MPMQ_MIN_SPARE_DAEMONS:
439 case AP_MPMQ_MAX_SPARE_DAEMONS:
442 case AP_MPMQ_MAX_REQUESTS_DAEMON:
443 *result = ap_max_requests_per_child;
451 int ap_graceful_stop_signalled(void)
458 /* Configuration handling stuff */
460 static int mpmt_os2_pre_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp)
462 one_process = ap_exists_config_define("ONE_PROCESS") ||
463 ap_exists_config_define("DEBUG");
465 ap_listen_pre_config();
466 ap_daemons_to_start = DEFAULT_START_DAEMON;
467 ap_thread_limit = HARD_THREAD_LIMIT;
468 ap_pid_fname = DEFAULT_PIDLOG;
469 ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
470 ap_extended_status = 0;
471 ap_min_spare_threads = DEFAULT_MIN_SPARE_THREAD;
472 ap_max_spare_threads = DEFAULT_MAX_SPARE_THREAD;
473 #ifdef AP_MPM_WANT_SET_MAX_MEM_FREE
474 ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED;
482 static void mpmt_os2_hooks(apr_pool_t *p)
484 ap_hook_pre_config(mpmt_os2_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
489 static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy, const char *arg)
491 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
497 ap_daemons_to_start = atoi(arg);
503 static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
506 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
512 ap_min_spare_threads = atoi(arg);
514 if (ap_min_spare_threads <= 0) {
515 ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
516 "WARNING: detected MinSpareThreads set to non-positive.");
517 ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
518 "Resetting to 1 to avoid almost certain Apache failure.");
519 ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
520 "Please read the documentation.");
521 ap_min_spare_threads = 1;
529 static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
532 const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
538 ap_max_spare_threads = atoi(arg);
544 static const char *ignore_cmd(cmd_parms *cmd, void *dummy, const char *arg)
551 static const command_rec mpmt_os2_cmds[] = {
553 AP_INIT_TAKE1( "StartServers", set_daemons_to_start, NULL, RSRC_CONF,
554 "Number of child processes launched at server startup" ),
555 AP_INIT_TAKE1("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF,
556 "Minimum number of idle children, to handle request spikes"),
557 AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF,
558 "Maximum number of idle children"),
559 AP_INIT_TAKE1("User", ignore_cmd, NULL, RSRC_CONF,
560 "Not applicable on this platform"),
561 AP_INIT_TAKE1("Group", ignore_cmd, NULL, RSRC_CONF,
562 "Not applicable on this platform"),
563 AP_INIT_TAKE1("ScoreBoardFile", ignore_cmd, NULL, RSRC_CONF, \
564 "Not applicable on this platform"),
568 module AP_MODULE_DECLARE_DATA mpm_mpmt_os2_module = {
570 NULL, /* hook to run before apache parses args */
571 NULL, /* create per-directory config structure */
572 NULL, /* merge per-directory config structures */
573 NULL, /* create per-server config structure */
574 NULL, /* merge per-server config structures */
575 mpmt_os2_cmds, /* command apr_table_t */
576 mpmt_os2_hooks, /* register_hooks */