1 /* Copyright 2000-2004 The Apache Software Foundation
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 /* The purpose of this file is to store the code that MOST mpm's will need
17 * this does not mean a function only goes into this file if every MPM needs
18 * it. It means that if a function is needed by more than one MPM, and
19 * future maintenance would be served by making the code common, then the
20 * function belongs here.
22 * This is going in src/main because it is not platform specific, it is
23 * specific to multi-process servers, but NOT to Unix. Which is why it
24 * does not belong in src/os/unix
27 #ifndef APACHE_MPM_COMMON_H
28 #define APACHE_MPM_COMMON_H
30 #include "ap_config.h"
32 #if APR_HAVE_NETINET_TCP_H
33 #include <netinet/tcp.h> /* for TCP_NODELAY */
43 * @package Multi-Processing Modules functions
46 /* The maximum length of the queue of pending connections, as defined
47 * by listen(2). Under some systems, it should be increased if you
48 * are experiencing a heavy TCP SYN flood attack.
50 * It defaults to 511 instead of 512 because some systems store it
51 * as an 8-bit datatype; 512 truncated to 8-bits is 0, while 511 is
54 #ifndef DEFAULT_LISTENBACKLOG
55 #define DEFAULT_LISTENBACKLOG 511
59 * Make sure all child processes that have been spawned by the parent process
60 * have died. This includes process registered as "other_children".
61 * @warning This is only defined if the MPM defines
62 * MPM_NEEDS_RECLAIM_CHILD_PROCESS
63 * @param terminate Either 1 or 0. If 1, send the child processes SIGTERM
64 * each time through the loop. If 0, give the process time to die
65 * on its own before signalling it.
66 * @tip This function requires that some macros are defined by the MPM: <pre>
67 * MPM_CHILD_PID -- Get the pid from the specified spot in the scoreboard
68 * MPM_NOTE_CHILD_KILLED -- Note the child died in the scoreboard
71 #ifdef AP_MPM_WANT_RECLAIM_CHILD_PROCESSES
72 void ap_reclaim_child_processes(int terminate);
76 * Determine if any child process has died. If no child process died, then
77 * this process sleeps for the amount of time specified by the MPM defined
78 * macro SCOREBOARD_MAINTENANCE_INTERVAL.
79 * @param status The return code if a process has died
80 * @param ret The process id of the process that died
81 * @param p The pool to allocate out of
83 #ifdef AP_MPM_WANT_WAIT_OR_TIMEOUT
84 void ap_wait_or_timeout(apr_exit_why_e *status, int *exitcode, apr_proc_t *ret,
89 * Log why a child died to the error log, if the child died without the
90 * parent signalling it.
91 * @param pid The child that has died
92 * @param status The status returned from ap_wait_or_timeout
93 * @return 0 on success, APEXIT_CHILDFATAL if MPM should terminate
95 #ifdef AP_MPM_WANT_PROCESS_CHILD_STATUS
96 int ap_process_child_status(apr_proc_t *pid, apr_exit_why_e why, int status);
99 #if defined(TCP_NODELAY) && !defined(MPE) && !defined(TPF)
101 * Turn off the nagle algorithm for the specified socket. The nagle algorithm
102 * says that we should delay sending partial packets in the hopes of getting
103 * more data. There are bad interactions between persistent connections and
104 * Nagle's algorithm that have severe performance penalties.
105 * @param s The socket to disable nagle for.
107 void ap_sock_disable_nagle(apr_socket_t *s);
109 #define ap_sock_disable_nagle(s) /* NOOP */
114 * Convert a username to a numeric ID
115 * @param name The name to convert
116 * @return The user id corresponding to a name
117 * @deffunc uid_t ap_uname2id(const char *name)
119 AP_DECLARE(uid_t) ap_uname2id(const char *name);
124 * Convert a group name to a numeric ID
125 * @param name The name to convert
126 * @return The group id corresponding to a name
127 * @deffunc gid_t ap_gname2id(const char *name)
129 AP_DECLARE(gid_t) ap_gname2id(const char *name);
132 #define AP_MPM_HARD_LIMITS_FILE APACHE_MPM_DIR "/mpm_default.h"
134 #ifdef AP_MPM_USES_POD
136 typedef struct ap_pod_t ap_pod_t;
145 * Open the pipe-of-death. The pipe of death is used to tell all child
146 * processes that it is time to die gracefully.
147 * @param p The pool to use for allocating the pipe
149 AP_DECLARE(apr_status_t) ap_mpm_pod_open(apr_pool_t *p, ap_pod_t **pod);
152 * Check the pipe to determine if the process has been signalled to die.
154 AP_DECLARE(apr_status_t) ap_mpm_pod_check(ap_pod_t *pod);
157 * Close the pipe-of-death
159 AP_DECLARE(apr_status_t) ap_mpm_pod_close(ap_pod_t *pod);
162 * Write data to the pipe-of-death, signalling that one child process
164 * @param p The pool to use when allocating any required structures.
166 AP_DECLARE(apr_status_t) ap_mpm_pod_signal(ap_pod_t *pod);
169 * Write data to the pipe-of-death, signalling that all child process
171 * @param p The pool to use when allocating any required structures.
172 * @param num The number of child processes to kill
174 AP_DECLARE(void) ap_mpm_pod_killpg(ap_pod_t *pod, int num);
178 * These data members are common to all mpms. Each new mpm
179 * should either use the appropriate ap_mpm_set_* function
180 * in their command table or create their own for custom or
181 * OS specific needs. These should work for most.
185 * The maximum number of requests each child thread or
186 * process handles before dying off
188 #ifdef AP_MPM_WANT_SET_MAX_REQUESTS
189 extern int ap_max_requests_per_child;
190 const char *ap_mpm_set_max_requests(cmd_parms *cmd, void *dummy,
195 * The filename used to store the process id.
197 #ifdef AP_MPM_WANT_SET_PIDFILE
198 extern const char *ap_pid_fname;
199 const char *ap_mpm_set_pidfile(cmd_parms *cmd, void *dummy,
204 * The name of lockfile used when Apache needs to lock the accept() call.
206 #ifdef AP_MPM_WANT_SET_LOCKFILE
207 extern const char *ap_lock_fname;
208 const char *ap_mpm_set_lockfile(cmd_parms *cmd, void *dummy,
213 * The system mutex implementation to use for the accept mutex.
215 #ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH
216 extern apr_lockmech_e ap_accept_lock_mech;
217 extern const char ap_valid_accept_mutex_string[];
218 const char *ap_mpm_set_accept_lock_mech(cmd_parms *cmd, void *dummy,
223 * Set the scorboard file.
225 #ifdef AP_MPM_WANT_SET_SCOREBOARD
226 const char *ap_mpm_set_scoreboard(cmd_parms *cmd, void *dummy,
231 * The directory that the server changes directory to dump core.
233 #ifdef AP_MPM_WANT_SET_COREDUMPDIR
234 extern char ap_coredump_dir[MAX_STRING_LEN];
235 extern int ap_coredumpdir_configured;
236 const char *ap_mpm_set_coredumpdir(cmd_parms *cmd, void *dummy,
240 #ifdef AP_MPM_WANT_SIGNAL_SERVER
241 int ap_signal_server(int *, apr_pool_t *);
242 void ap_mpm_rewrite_args(process_rec *);
245 #ifdef AP_MPM_WANT_SET_MAX_MEM_FREE
246 extern apr_uint32_t ap_max_mem_free;
247 extern const char *ap_mpm_set_max_mem_free(cmd_parms *cmd, void *dummy,
251 #ifdef AP_MPM_WANT_SET_STACKSIZE
252 extern apr_size_t ap_thread_stacksize;
253 extern const char *ap_mpm_set_thread_stacksize(cmd_parms *cmd, void *dummy,
257 #ifdef AP_MPM_WANT_FATAL_SIGNAL_HANDLER
258 extern apr_status_t ap_fatal_signal_setup(server_rec *s, apr_pool_t *pconf);
259 extern apr_status_t ap_fatal_signal_child_setup(server_rec *s);
262 #if AP_ENABLE_EXCEPTION_HOOK
263 extern const char *ap_mpm_set_exception_hook(cmd_parms *cmd, void *dummy,
271 #endif /* !APACHE_MPM_COMMON_H */