perchild.c revision 7b4c4bb891261e613de39a021d7554fd08132fc5
2N/A/* ==================================================================== 2N/A * The Apache Software License, Version 1.1 2N/A * Copyright (c) 2000-2001 The Apache Software Foundation. All rights 2N/A * Redistribution and use in source and binary forms, with or without 2N/A * modification, are permitted provided that the following conditions 2N/A * 1. Redistributions of source code must retain the above copyright 2N/A * notice, this list of conditions and the following disclaimer. 2N/A * 2. Redistributions in binary form must reproduce the above copyright 2N/A * notice, this list of conditions and the following disclaimer in 2N/A * the documentation and/or other materials provided with the 2N/A * 3. The end-user documentation included with the redistribution, 2N/A * if any, must include the following acknowledgment: 2790N/A * "This product includes software developed by the 2515N/A * Alternately, this acknowledgment may appear in the software itself, 2N/A * if and wherever such third-party acknowledgments normally appear. 2N/A * 4. The names "Apache" and "Apache Software Foundation" must 2N/A * not be used to endorse or promote products derived from this 2N/A * software without prior written permission. For written 2N/A * permission, please contact apache@apache.org. 2N/A * 5. Products derived from this software may not be called "Apache", 2N/A * nor may "Apache" appear in their name, without prior written 2N/A * permission of the Apache Software Foundation. 59N/A * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 2N/A * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 2N/A * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 2N/A * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 2N/A * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26N/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26N/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 2N/A * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 26N/A * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 1470N/A * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 38N/A * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 1470N/A * ==================================================================== 181N/A * This software consists of voluntary contributions made by many 26N/A * individuals on behalf of the Apache Software Foundation. For more 26N/A * information on the Apache Software Foundation, please see 26N/A * Portions of this software are based upon public domain software 26N/A * originally written at the National Center for Supercomputing Applications, 26N/A * University of Illinois, Urbana-Champaign. 1498N/A/* ### should be APR-ized */ 26N/A * Actual definitions of config globals 3109N/A/* Tables used to determine the user and group each child process should 3109N/A * run as. The hash table is used to correlate a server name with a child 3109N/A * The max child slot ever assigned, preserved across restarts. Necessary 3109N/A * to deal with NumServers changes across SIGWINCH restarts. We use this 3109N/A * value to optimize routines that have to scan the entire child table. 3109N/A * XXX - It might not be worth keeping this code in. There aren't very 1256N/A * many child processes in this MPM. 1256N/A/* *Non*-shared http_main globals... */ 255N/A/* one_process --- debugging mode variable; can be set from the command line 145N/A * with the -X flag. If set, this gets you the child_main loop running 7N/A * in the process which originally started up (no detach, no make_child), 26N/A * which is a pretty nice debugging environment. (You'll get a SIGHUP 26N/A * early in standalone_main; just continue through. This is the server 38N/A * trying to kill off any child processes which it might have lying 26N/A * around --- Apache doesn't keep track of their pids, it just sends 197N/A * SIGHUP to the process group, ignoring it in the root process. 197N/A * Continue through and you'll be fine.). 46N/Astatic unsigned int my_pid;
/* Linux getpid() doesn't work except in 2N/A main thread. Use this instead */ 1256N/A/* Keep track of the number of worker threads currently active */ 1256N/A/* Keep track of the number of idle worker threads */ 1256N/A/* Locks for accept serialization */ 1256N/A#
endif /* NO_SERIALIZED_ACCEPT */ 3109N/A/* a clean exit from a child with proper cleanup */ 3109N/A/* handle all varieties of core dumping signals */ 3109N/A /* At this point we've got sig blocked, because we're still inside 3109N/A * the signal handler. When we leave the signal handler it will 3109N/A * be unblocked, and we'll take the signal... and coredump or whatever 3109N/A * is appropriate for this particular Unix. In addition the parent 3109N/A * will see the real signal we received -- whereas if we called 3109N/A * abort() here, the parent would only see SIGABRT. 3109N/A/***************************************************************** 3109N/A * Connection structures and accounting... 3109N/A/* we don't currently track ap_my_generation, but mod_status 3109N/A * references it so it must be defined */ 1256N/A * ap_start_shutdown() and ap_start_restart(), below, are a first stab at 1256N/A * functions to initiate shutdown or restart without relying on signals. 1256N/A * Previously this was initiated in sig_term() and restart() signal handlers, 1256N/A * e.g. on Win32, from the service manager. Now the service manager can 1256N/A * call ap_start_shutdown() or ap_start_restart() as appropiate. Note that 1256N/A * these functions can also be called by the child processes, since global 1256N/A * variables are no longer used to pass on the required action to the parent. 46N/A * These should only be called from the parent process itself, since the 46N/A * parent process will use the shutdown_pending and restart_pending variables 26N/A * to determine whether to shutdown or restart. The child process should 181N/A * call signal_parent() directly to tell the parent to die -- this will 369N/A * cause neither of those variable to be set, which the parent will 181N/A * assume means something serious is wrong (which it will be, for the 181N/A * child to force an exit) and so do an exit anyway. 99N/A /* Um, is this _probably_ not an error, if the user has 181N/A * tried to do a shutdown twice quickly, so we won't 2818N/A * worry about reporting it. 1929N/A/* do a graceful restart if graceful == 1 */ 1929N/A /* Probably not an error - don't bother reporting it */ 145N/A /* we want to ignore HUPs and WINCH while we're busy processing one */ 32N/A#
endif /* SIGABORT */ 32N/A#
endif /* SIGABRT */ /***************************************************************** * Here follows a long bunch of generic server bookkeeping stuff... /* XXX - Does this really work? - Manoj */ /***************************************************************** * Child process main loop. "new file descriptor %d is too large; you probably need " "to rebuild Apache with a larger FD_SETSIZE " /* Starts a thread as long as we're below max_threads */ "apr_thread_create: unable to create worker thread");
/* In case system resources are maxxed out, we don't want Apache running away with the CPU trying to fork over and over and over again if we exit. */ "server reached MaxThreadsPerChild setting, consider raising the" " MaxThreadsPerChild or NumServers settings");
/* Sets workers_may_exit if we received a character on the pipe_of_death */ /* It lost the lottery. It must continue to suffer * through a life of servitude. */ /* It won the lottery (or something else is very * wrong). Embrace death with open arms. */ /* idle_thread_count should be incremented before starting a worker_thread */ "apr_lock_acquire failed. Attempting to shutdown " /* apr_poll() will only return errors in catastrophic * circumstances. Let's try exiting gracefully, for now. */ /* A process got a signal on the shutdown pipe. Check if we're * the lucky process to die. */ /* This request is from another child in our current process. * We should set a flag here, and then below we will read * two bytes (the socket number and the NULL byte. /* XXX: Should we check for POLLERR? */ "apr_lock_release failed. Attempting to shutdown " "apr_lock_release failed. Attempting to shutdown " /* All the threads have exited, now finish the shutdown process * by signalling the sigwait thread */ * Note that we use the username as set in the config files, rather than * the lookup of to uid --- the same uid may have multiple passwd entries, * with different sets of groups for each. /* Get username if passed as a uid */ "getpwuid: couldn't determine user name from uid %u, " "you probably need to modify the User directive",
* Set the GID before initgroups(), since on some platforms * setgid() is known to zap the group list. "setgid: unable to set group id to Group %u",
/* Reset `groups' attributes. */ "initgroups: unable to set groups for User %s " "and Group %u",
name, (
unsigned)
gid);
/* Only try to switch if we're running as root */ "setuid: unable to change to uid: %ld",
/*stuff to do before we switch id's, so we have permissions.*/ "Couldn't initialize cross-process lock in child");
/*done with init critical section */ /* Set up the pollfd array, num_listenfds + 1 for the pipe and 1 for /* Setup worker threads */ /* We are creating worker threads right now */ /* start_thread shouldn't fail here */ "fork: Unable to fork new process");
/* In case system resources are maxxed out, we don't want Apache running away with the CPU trying to fork over and /* By default, AIX binds to a single processor. This bit unbinds * children which will then bind to another CPU. /* XXX - For an unthreaded server, a signal handler will be necessary apr_signal(SIGTERM, just_die); /* start up a bunch of children */ * spawn_rate is the number of children that will be spawned on the * next maintenance cycle if there aren't enough servers. It is * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by * without the need to spawn. /* initialize the free_list */ /* the next time around we want to spawn twice as many if this * wasn't good enough, but not if we've just done a graceful /* non-fatal death... note that it's gone in the child table and * clean out the status table. */ /* we're still doing a 1-for-1 replacement of dead * children with new children /* Great, we've probably just lost a slot in the * child table. Somehow we don't know about this "long lost child came home! (pid %ld)",
/* Don't perform idle maintenance when a child dies, * only do it when there's a timeout. Remember only a * finite number of children can die, and it's pretty * pathological for a lot to die suddenly. /* we hit a 1 second timeout in which none of the previous * generation of children needed to be reaped... so assume * they're all done, and pick up the slack if any is left. /* In any event we really shouldn't do the code below because * few of the servers we just started are in the IDLE state * yet, so we'd mistakenly create an extra server. "apr_file_pipe_create (pipe_of_death)");
"apr_file_pipe_timeout_set (pipe_of_death)");
/* XXX: hey, what's the right way for the mpm to indicate a fatal error? */ "no listening sockets available, shutting down");
/* Initialize cross-process accept lock */ "Couldn't create cross-process lock");
/* Initialize the child table */ /* If we're doing a graceful_restart then we're going to see a lot * of children exiting immediately when we get into the main loop * below (because we just sent them SIGWINCH). This happens pretty * rapidly... and for each one that exits we'll start a new one until * we reach at least daemons_min_free. But we may be permitted to * start more than that, so we'll just keep track of how many we're * supposed to start up without the 1 second penalty between each fork. /* give the system some time to recover before kicking into "%s configured -- resuming normal operations",
/* Time to gracefully shut down: * Kill child processes, tell them to call child_exit, etc... /* cleanup pid file on normal shutdown */ "removed PID file %s (pid=%ld)",
/* we've been told to restart */ /* not worth thinking about */ "SIGWINCH received. Doing graceful restart");
/* This is mostly for debugging... so that we know what is still * gracefully dealing with existing request. /* give the children the signal to die */ /* Kill 'em all. Since the child acts the same on the parents SIGTERM * and a SIGHUP, we may as well use the same signal, because some user * pthreads are stealing signals from us left and right. /* sigh, want this only the second time around */ /* ### this "read one line" doesn't seem right... shouldn't we be ### reading large chunks of data or something? "child, request will not be honored.");
/* This must be run absolutely first. If this request isn't for this * server then we need to forward it to the proper child. No sense * tying up this server running more post_read request hooks if it is * just going to be forwarded along. "WARNING: NumServers of %d exceeds compile time limit " " lowering NumServers to %d. To increase, please " " HARD_SERVER_LIMIT define in %s.",
"WARNING: Require NumServers > 0, setting to 1");
"WARNING: StartThreads of %d exceeds compile time" " lowering StartThreads to %d. To increase, please" " HARD_THREAD_LIMIT define in %s.",
"WARNING: Require StartThreads > 0, setting to 1");
"WARNING: detected MinSpareThreads set to non-positive.");
"Resetting to 1 to avoid almost certain Apache failure.");
"Please read the documentation.");
"WARNING: detected MinSpareThreads set higher than");
"WARNING: detected MaxThreadsPerChild set higher than");
const char *g,
const char *
num)
return "Trying to use more child ID's than NumServers. Increase " "NumServers in your config file.";
"Number of children alive at the same time"),
"Number of threads each child creates"),
"Minimum number of idle threads per child, to handle request spikes"),
"Maximum number of idle threads per child"),
"Maximum number of threads per child"),
"Specify a User and Group for a specific child process."),
"Tie a virtual host to a specific child process."),
NULL,
/* hook to run before apache parses args */ NULL,
/* create per-directory config structure */ NULL,
/* merge per-directory config structures */ NULL,
/* merge per-server config structures */