spmt_os2.c revision 587c6c9b6f22f1de04168d9d3e11332d2ab39e39
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
#define CORE_PRIVATE
#define INCL_DOS
#define INCL_DOSERRORS
#include "ap_config.h"
#include "httpd.h"
#include "mpm_default.h"
#include "http_main.h"
#include "http_log.h"
#include "http_config.h"
#include "http_core.h" /* for get_remote_host */
#include "http_connection.h"
#include "mpm.h"
#include "ap_mpm.h"
#include "ap_listen.h"
#include "apr_portable.h"
#include "mpm_common.h"
#include "apr_strings.h"
#include <os2.h>
#include <stdlib.h>
#include <process.h>
#include <time.h>
#include <io.h>
/* config globals */
static int ap_max_requests_per_child=0;
static char *ap_pid_fname=NULL;
static int ap_daemons_to_start=0;
static int ap_daemons_min_free=0;
static int ap_daemons_max_free=0;
static int ap_daemons_limit=0;
/*
* The max child slot ever assigned, preserved across restarts. Necessary
* to deal with MaxClients changes across SIGUSR1 restarts. We use this
* value to optimize routines that have to scan the entire scoreboard.
*/
static int max_daemons_limit = -1;
char ap_coredump_dir[MAX_STRING_LEN];
/* *Non*-shared http_main globals... */
/* one_process --- debugging mode variable; can be set from the command line
* with the -X flag. If set, this gets you the child_main loop running
* in the process which originally started up (no detach, no make_child),
* which is a pretty nice debugging environment. (You'll get a SIGHUP
* early in standalone_main; just continue through. This is the server
* trying to kill off any child processes which it might have lying
* around --- Apache doesn't keep track of their pids, it just sends
* SIGHUP to the process group, ignoring it in the root process.
* Continue through and you'll be fine.).
*/
static int one_process = 0;
struct thread_globals {
int thread_num;
int usr1_just_die;
};
struct thread_control_t {
char deferred_die;
/* a clean exit from a child with proper cleanup */
static void clean_child_exit(int code)
{
if (THREAD_GLOBAL(pchild)) {
}
_endthread();
}
{
return apr_lock_release(accept_mutex);
}
/*
* Initialize mutex lock.
* Done by each child at it's birth
*/
static void accept_mutex_child_init(apr_pool_t *p)
{
}
/*
* Initialize mutex lock.
* Must be safe to call this on a restart.
*/
static void accept_mutex_init(apr_pool_t *p)
{
if (rc != APR_SUCCESS) {
"Error creating accept lock. Exiting!");
}
}
static void accept_mutex_on(void)
{
if (rc != APR_SUCCESS) {
"Error getting accept lock. Exiting!");
}
}
static void accept_mutex_off(void)
{
if (rc != APR_SUCCESS) {
"Error freeing accept lock. Exiting!");
}
}
/* On some architectures it's safe to do unserialized accept()s in the single
* Listen case. But it's never safe to do it in the case where there's
* multiple Listen statements. Define SINGLE_LISTEN_UNSERIALIZED_ACCEPT
* when it's safe in the single Listen case.
*/
#else
#endif
AP_DECLARE(int) ap_get_max_daemons(void)
{
return max_daemons_limit;
}
static int find_thread_by_tid(int tid)
{
int i;
for (i = 0; i < max_daemons_limit; ++i)
return i;
return -1;
}
/* Finally, this routine is used by the caretaker thread to wait for
* a while...
*/
/* number of calls to wait_or_timeout between writable probes */
#ifndef INTERVAL_OF_WRITABLE_PROBES
#define INTERVAL_OF_WRITABLE_PROBES 10
#endif
static int wait_or_timeout_counter;
{
int ret;
#endif
}
tid = 0;
if (ret == 0) {
ap_assert( thread_num > 0 );
return tid;
}
return -1;
}
/* handle all varieties of core dumping signals */
static void sig_coredump(int sig)
{
/* At this point we've got sig blocked, because we're still inside
* the signal handler. When we leave the signal handler it will
* be unblocked, and we'll take the signal... and coredump or whatever
* is appropriate for this particular Unix. In addition the parent
* will see the real signal we received -- whereas if we called
* abort() here, the parent would only see SIGABRT.
*/
}
/*****************************************************************
* Connection structures and accounting...
*/
{
clean_child_exit(0);
}
static void usr1_handler(int sig)
{
if (THREAD_GLOBAL(usr1_just_die)) {
}
}
/* volatile just in case */
static int volatile shutdown_pending;
static int volatile restart_pending;
static int volatile is_graceful;
{
if (shutdown_pending == 1) {
/* Um, is this _probably_ not an error, if the user has
* tried to do a shutdown twice quickly, so we won't
* worry about reporting it.
*/
return;
}
shutdown_pending = 1;
}
{
if (restart_pending == 1) {
/* Probably not an error - don't bother reporting it */
return;
}
restart_pending = 1;
}
static void set_signals(void)
{
#ifndef NO_USE_SIGACTION
if (!one_process) {
#if defined(SA_ONESHOT)
#elif defined(SA_RESETHAND)
#endif
#ifdef SIGBUS
#endif
#ifdef SIGABORT
#endif
#ifdef SIGABRT
#endif
#ifdef SIGILL
#endif
}
#ifdef SIGINT
#endif
#ifdef SIGXCPU
#endif
#ifdef SIGXFSZ
#endif
#ifdef SIGPIPE
#endif
/* we want to ignore HUPs and USR1 while we're busy processing one */
#else
if (!one_process) {
#ifdef SIGBUS
#endif /* SIGBUS */
#ifdef SIGABORT
#endif /* SIGABORT */
#ifdef SIGABRT
#endif /* SIGABRT */
#ifdef SIGILL
#endif /* SIGILL */
#ifdef SIGXCPU
#endif /* SIGXCPU */
#ifdef SIGXFSZ
#endif /* SIGXFSZ */
}
#ifdef SIGHUP
#endif /* SIGHUP */
#ifdef SIGUSR1
#endif /* SIGUSR1 */
#ifdef SIGPIPE
#endif /* SIGPIPE */
#endif
}
/*****************************************************************
* Child process main loop.
*/
{
r->connection->keepalive = 0;
}
int ap_graceful_stop_signalled(void)
{
ap_scoreboard_image->global.running_generation != thread_control[THREAD_GLOBAL(thread_num)].generation) {
return 1;
}
return 0;
}
int ap_stop_signalled(void)
{
if (shutdown_pending || restart_pending ||
ap_scoreboard_image->global.running_generation != thread_control[THREAD_GLOBAL(thread_num)].generation) {
return 1;
}
return 0;
}
{
int numfds = 0;
numfds++;
}
}
return 0;
}
static void thread_main(void *thread_num_arg)
{
int requests_this_child = 0;
/* Disable the restart signal handlers and enable the just_die stuff.
* Note that since restart() just notes that a restart has been
* requested there's no race condition here.
*/
set_signals(); /* signals aren't inherrited by child threads */
/* Get a sub pool for global allocations in this child, so that
* we can have cleanups occur when the child exits.
*/
clean_child_exit(1);
}
/* needs to be done before we switch UIDs so we have permissions */
while (!ap_stop_signalled()) {
int srv;
/* Prepare to receive a SIGUSR1 due to graceful restart so that
* we can exit cleanly.
*/
/*
* (Re)initialize this child to a pre-connection state.
*/
current_conn = NULL;
if ((ap_max_requests_per_child > 0
&& requests_this_child++ >= ap_max_requests_per_child)) {
clean_child_exit(0);
}
/*
* Wait for an acceptable connection to arrive.
*/
/* Lock around "accept", if necessary */
if (ap_stop_signalled()) {
clean_child_exit(0);
}
for (;;) {
if (ap_listeners->next) {
/* more than one socket */
if (srv != APR_SUCCESS) {
/* Single Unix documents select as returning errnos
* EBADF, EINTR, and EINVAL... and in none of those
* cases does it make sense to continue. In fact
* on Linux 2.0.x we seem to end up with EFAULT
* occasionally, and we'd loop forever due to it.
*/
clean_child_exit(1);
}
/* we remember the last_lr we searched last time around so that
we don't end up starving any particular listening socket */
}
do {
if (!lr) {
lr = ap_listeners;
}
if (event == APR_POLLIN) {
break;
}
continue;
}
}
else {
/* only one socket, just pretend we did the other stuff */
}
/* if we accept() something we don't want to die, so we have to
* defer the exit
*/
THREAD_GLOBAL(usr1_just_die) = 0;
if (APR_STATUS_IS_SUCCESS(rv)) {
break; /* We have a socket ready for reading */
}
else if (APR_STATUS_IS_ECONNABORTED(rv)
|| APR_STATUS_IS_ENETUNREACH(rv)) {
/* Our old behaviour here was to continue after accept()
* errors. But this leads us into lots of troubles
* because most of the errors are quite fatal. For
* example, EMFILE can be caused by slow descriptor
* leaks (say in a 3rd party module, or libc). It's
* foolish for us to continue after an EMFILE. We also
* seem to tickle kernel bugs on some platforms which
* lead to never-ending loops here. So it seems best
* to just exit in most cases.
*/
/* Linux generates most of these, other tcp
* stacks (i.e. bsd) tend to hide them behind
* getsockopt() interfaces. They occur when
* the net goes sour or the client disconnects
* after the three-way handshake has been done
* in the kernel but before userland has picked
* up the socket.
*/
break;
}
else if (APR_STATUS_IS_EINTR(rv)) {
/* We only get hit by an EINTR if the parent is
* killing us off
*/
clean_child_exit(0);
}
else {
"accept: (client socket)");
clean_child_exit(1);
}
if (ap_stop_signalled()) {
clean_child_exit(0);
}
}
/* We've got a socket, let's at least process one request off the
* socket before we accept a graceful restart request. We set
* the signal to ignore because we don't want to disturb any
* third party code.
*/
/*
* We now have a connection, so set it up with the appropriate
*/
(request_rec *) NULL);
if (current_conn) {
}
}
clean_child_exit(0);
}
{
}
if (one_process) {
#ifdef SIGQUIT
#endif
thread_main((void *)slot);
}
ap_log_error(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, s, "_beginthread: Unable to create new thread");
/* _beginthread didn't succeed. Fix the scoreboard or else
* it will say SERVER_STARTING forever and ever
*/
/* In case system resources are maxxed out, we don't want
Apache running away with the CPU trying to _beginthread over and
over and over again. */
sleep(10);
return -1;
}
thread_control[THREAD_GLOBAL(thread_num)].generation = ap_scoreboard_image->global.running_generation;
return 0;
}
/* start up a bunch of children */
static void startup_children(int number_to_start)
{
int i;
for (i = 0; number_to_start && i < ap_daemons_limit; ++i) {
continue;
}
if (make_child(ap_server_conf, i) < 0) {
break;
}
}
}
/*
* idle_spawn_rate is the number of children that will be spawned on the
* next maintenance cycle if there aren't enough idle servers. It is
* doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by
* without the need to spawn.
*/
static int idle_spawn_rate = 1;
#ifndef MAX_SPAWN_RATE
#define MAX_SPAWN_RATE (32)
#endif
static int hold_off_on_exponential_spawning;
static void perform_idle_server_maintenance(void)
{
int i;
int to_kill;
int idle_count;
int free_length;
int free_slots[MAX_SPAWN_RATE];
int last_non_dead;
int total_non_dead;
/* initialize the free_list */
free_length = 0;
to_kill = -1;
idle_count = 0;
last_non_dead = -1;
total_non_dead = 0;
for (i = 0; i < ap_daemons_limit; ++i) {
int status;
break;
if (status == SERVER_DEAD) {
/* try to keep children numbers as low as possible */
if (free_length < idle_spawn_rate) {
free_slots[free_length] = i;
++free_length;
}
}
else {
/* We consider a starting server as idle because we started it
* at least a cycle ago, and if it still hasn't finished starting
* then we're just going to swamp things worse by forking more.
* So we hopefully won't need to fork more if we count it.
* This depends on the ordering of SERVER_READY and SERVER_STARTING.
*/
if (status <= SERVER_READY) {
++ idle_count;
/* always kill the highest numbered child if we have to...
* no really well thought out reason ... other than observing
* the server behaviour under linux where lower numbered children
* tend to service more hits (and hence are more likely to have
* their data in cpu caches).
*/
to_kill = i;
}
last_non_dead = i;
}
}
if (idle_count > ap_daemons_max_free) {
/* kill off one child... we use SIGUSR1 because that'll cause it to
* shut down gracefully, in case it happened to pick up a request
* while we were counting
*/
idle_spawn_rate = 1;
}
else if (idle_count < ap_daemons_min_free) {
/* terminate the free list */
if (free_length == 0) {
/* only report this condition once */
static int reported = 0;
if (!reported) {
"server reached MaxClients setting, consider"
" raising the MaxClients setting");
reported = 1;
}
idle_spawn_rate = 1;
}
else {
if (idle_spawn_rate >= 8) {
"server seems busy, (you may need "
"to increase StartServers, or Min/MaxSpareServers), "
"spawning %d children, there are %d idle, and "
"%d total children", idle_spawn_rate,
}
for (i = 0; i < free_length; ++i) {
}
/* 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
*/
}
else if (idle_spawn_rate < MAX_SPAWN_RATE) {
idle_spawn_rate *= 2;
}
}
}
else {
idle_spawn_rate = 1;
}
}
/*****************************************************************
* Executive routines.
*/
{
int i;
ap_server_conf = s;
"no listening sockets available, shutting down");
return -1;
}
if (!is_graceful) {
}
set_signals();
if (ppthread_globals == NULL) {
"Error allocating thread local storage"
"Apache is exiting!");
} else {
}
}
/* 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 SIGUSR1). 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.
*/
}
if (!is_graceful) {
}
else {
/* give the system some time to recover before kicking into
* exponential mode */
}
"%s configured -- resuming normal operations",
"Server built: %s", ap_get_server_built());
restart_pending = shutdown_pending = 0;
while (!restart_pending && !shutdown_pending) {
int thread_slot;
/* XXX: if it takes longer than 1 second for all our children
* to start up and get into IDLE state then we may spawn an
* extra child
*/
if (tid >= 0) {
/* non-fatal death... note that it's gone in the scoreboard. */
if (thread_slot >= 0) {
(request_rec *) NULL);
&& thread_slot < ap_daemons_limit) {
/* we're still doing a 1-for-1 replacement of dead
* children with new children
*/
}
/* TODO: this won't work, we waited on a thread not a process
}
else if (reap_other_child(pid, status) == 0) {
*/
#endif
}
else if (is_graceful) {
/* Great, we've probably just lost a slot in the
* scoreboard. Somehow we don't know about this
* child.
*/
"long lost child came home! (tid %d)", tid);
}
/* 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.
*/
continue;
}
else if (remaining_children_to_start) {
/* 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.
*/
continue;
}
}
if (shutdown_pending) {
/* Time to gracefully shut down */
int slot;
DosSleep(0);
}
/* Kill off running threads */
if (rc == 0) {
if (rc) {
"error %lu waiting for thread to terminate", rc);
}
} else {
"error %lu killing thread", rc);
}
}
}
}
/* cleanup pid file on normal shutdown */
"removed PID file %s (pid=%ld)",
"caught SIGTERM, shutting down");
return 1;
}
/* we've been told to restart */
if (one_process) {
/* not worth thinking about */
return 1;
}
/* advance to the next generation */
/* XXX: we really need to make sure this new generation number isn't in
* use by any of the children.
*/
if (is_graceful) {
"SIGUSR1 received. Doing graceful restart");
/* kill off the idle ones */
for (i = 0; i < ap_daemons_limit; ++i) {
}
/* This is mostly for debugging... so that we know what is still
* gracefully dealing with existing request. But we can't really
* do it if we're in a SCOREBOARD_FILE because it'll cause
* corruption too easily.
*/
for (i = 0; i < ap_daemons_limit; ++i) {
}
}
}
else {
/* Kill 'em off */
for (i = 0; i < ap_daemons_limit; ++i) {
}
"SIGHUP received. Attempting to restart");
}
return 0;
}
{
is_graceful = 0;
ap_extended_status = 0;
}
static void spmt_os2_hooks(apr_pool_t *p)
{
/* TODO: set one_process properly */ one_process = 0;
}
{
return err;
}
return "PidFile directive not allowed in <VirtualHost>";
}
ap_pid_fname = arg;
return NULL;
}
{
return err;
}
return NULL;
}
{
return err;
}
if (ap_daemons_min_free <= 0) {
"WARNING: detected MinSpareServers set to non-positive.");
"Resetting to 1 to avoid almost certain Apache failure.");
"Please read the documentation.");
ap_daemons_min_free = 1;
}
return NULL;
}
{
return err;
}
return NULL;
}
{
return err;
}
if (ap_daemons_limit > HARD_THREAD_LIMIT) {
"WARNING: MaxClients of %d exceeds compile time limit "
" lowering MaxClients to %d. To increase, please "
"see the", HARD_THREAD_LIMIT);
" HARD_THREAD_LIMIT define in %s.",
}
else if (ap_daemons_limit < 1) {
"WARNING: Require MaxClients > 0, setting to 1");
ap_daemons_limit = 1;
}
return NULL;
}
{
return err;
}
return NULL;
}
{
const char *fname;
return err;
}
" does not exist or is not a directory", NULL);
}
return NULL;
}
/* Stub functions until this MPM supports the connection status API */
const char *value)
{
/* NOP */
}
{
/* NOP */
}
static const command_rec spmt_os2_cmds[] = {
"A file for logging the server process ID"},
"Number of child processes launched at server startup" },
"Minimum number of idle children, to handle request spikes" },
"Maximum number of idle children" },
"Maximum number of children alive at the same time" },
"Maximum number of requests a particular child serves before dying." },
"The location of the directory Apache changes to before dumping core" },
{ NULL }
};
NULL, /* hook to run before apache parses args */
NULL, /* create per-directory config structure */
NULL, /* merge per-directory config structures */
NULL, /* create per-server config structure */
NULL, /* merge per-server config structures */
spmt_os2_cmds, /* command apr_table_t */
spmt_os2_hooks, /* register_hooks */
};