mpm_netware.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * httpd.c: simple http daemon for answering WWW file requests
 *
 * 
 * 03-21-93  Rob McCool wrote original code (up to NCSA HTTPd 1.3)
 * 
 * 03-06-95  blong
 *  changed server number for child-alone processes to 0 and changed name
 *   of processes
 *
 * 03-10-95  blong
 *      Added numerous speed hacks proposed by Robert S. Thau ([e-mail]) 
 *      including set group before fork, and call gettime before to fork
 *      to set up libraries.
 *
 * 04-14-95  rst / rh
 *      Brandon's code snarfed from NCSA 1.4, but tinkered to work with the
 *      Apache server, and also to have child processes do accept() directly.
 *
 * April-July '95 rst
 *      Extensive rework for Apache.
 */

#include "apr.h"
#include "apr_portable.h"
#include "apr_strings.h"
#include "apr_thread_proc.h"
#include "apr_signal.h"
#include "apr_tables.h"
#include "apr_getopt.h"
#include "apr_thread_mutex.h"

#define APR_WANT_STDIO
#define APR_WANT_STRFUNC
#include "apr_want.h"

#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
#if APR_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#define CORE_PRIVATE

#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 "scoreboard.h"
#include "ap_mpm.h"
#include "mpm_common.h"
#include "ap_listen.h"
#include "ap_mmn.h"

#ifdef HAVE_TIME_H
#include <time.h>
#endif

#include <signal.h>

#include <netware.h>
#include <nks/netware.h>
#include <library.h>
#include <screen.h>

/* Limit on the total --- clients will be locked out if more servers than
 * this are needed.  It is intended solely to keep the server from crashing
 * when things get out of hand.
 *
 * We keep a hard maximum number of servers, for two reasons --- first off,
 * in case something goes seriously wrong, we want to stop the fork bomb
 * short of actually crashing the machine we're running on by filling some
 * kernel table.  Secondly, it keeps the size of the scoreboard file small
 * enough that we can read the whole thing without worrying too much about
 * the overhead.
 */
#ifndef HARD_SERVER_LIMIT
#define HARD_SERVER_LIMIT 1
#endif

#define WORKER_DEAD         SERVER_DEAD
#define WORKER_STARTING     SERVER_STARTING
#define WORKER_READY        SERVER_READY
#define WORKER_IDLE_KILL    SERVER_IDLE_KILL

/* config globals */

int ap_threads_per_child=0;         /* Worker threads per child */
int ap_thread_stack_size=65536;
static int ap_threads_to_start=0;
static int ap_threads_min_free=0;
static int ap_threads_max_free=0;
static int ap_threads_limit=0;
static int mpm_state = AP_MPMQ_STARTING;

/*
 * The max child slot ever assigned, preserved across restarts.  Necessary
 * to deal with MaxClients changes across SIGWINCH restarts.  We use this
 * value to optimize routines that have to scan the entire scoreboard.
 */
int ap_max_workers_limit = -1;
server_rec *ap_server_conf;

/* *Non*-shared http_main globals... */

int hold_screen_on_exit = 0; /* Indicates whether the screen should be held open */

static fd_set listenfds;
static int listenmaxfd;

static apr_pool_t *pconf;               /* Pool for config stuff */
static apr_pool_t *pmain;               /* Pool for httpd child stuff */

static pid_t ap_my_pid;  /* it seems silly to call getpid all the time */
static char *ap_my_addrspace = NULL;

static int die_now = 0;

/* Keep track of the number of worker threads currently active */
static unsigned long worker_thread_count;
static int request_count;

/*  Structure used to register/deregister a console handler with the OS */
static int InstallConsoleHandler(void);
static void RemoveConsoleHandler(void);
static int CommandLineInterpreter(scr_t screenID, const char *commandLine);
static  CommandParser_t ConsoleHandler = {0, NULL, 0};
#define HANDLEDCOMMAND  0
#define NOTMYCOMMAND    1

static int show_settings = 0;

//#define DBINFO_ON
//#define DBPRINT_ON
#ifdef DBPRINT_ON
#define DBPRINT0(s) printf(s)
#define DBPRINT1(s,v1) printf(s,v1)
#define DBPRINT2(s,v1,v2) printf(s,v1,v2)
#else
#define DBPRINT0(s)
#define DBPRINT1(s,v1)
#define DBPRINT2(s,v1,v2)
#endif

/* volatile just in case */
static int volatile shutdown_pending;
static int volatile restart_pending;
static int volatile is_graceful;
static int volatile wait_to_finish=1;
ap_generation_t volatile ap_my_generation=0;

/* a clean exit from a child with proper cleanup */
static void clean_child_exit(int code, int worker_num, apr_pool_t *ptrans, 
                             apr_bucket_alloc_t *bucket_alloc) __attribute__ ((noreturn));
static void clean_child_exit(int code, int worker_num, apr_pool_t *ptrans, 
                             apr_bucket_alloc_t *bucket_alloc)
{
    apr_bucket_alloc_destroy(bucket_alloc);
    if (!shutdown_pending) {
        apr_pool_destroy(ptrans);
    }

    atomic_dec (&worker_thread_count);
    if (worker_num >=0)
        ap_update_child_status_from_indexes(0, worker_num, WORKER_DEAD, 
                                            (request_rec *) NULL);
    NXThreadExit((void*)&code);
}

AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
{
    switch(query_code){
        case AP_MPMQ_MAX_DAEMON_USED:
            *result = 1;
            return APR_SUCCESS;
        case AP_MPMQ_IS_THREADED:
            *result = AP_MPMQ_DYNAMIC;
            return APR_SUCCESS;
        case AP_MPMQ_IS_FORKED:
            *result = AP_MPMQ_NOT_SUPPORTED;
            return APR_SUCCESS;
        case AP_MPMQ_HARD_LIMIT_DAEMONS:
            *result = HARD_SERVER_LIMIT;
            return APR_SUCCESS;
        case AP_MPMQ_HARD_LIMIT_THREADS:
            *result = HARD_THREAD_LIMIT;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_THREADS:
            *result = ap_threads_limit;
            return APR_SUCCESS;
        case AP_MPMQ_MIN_SPARE_DAEMONS:
            *result = 0;
            return APR_SUCCESS;
        case AP_MPMQ_MIN_SPARE_THREADS:
            *result = ap_threads_min_free;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_SPARE_DAEMONS:
            *result = 0;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_SPARE_THREADS:
            *result = ap_threads_max_free;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_REQUESTS_DAEMON:
            *result = ap_max_requests_per_child;
            return APR_SUCCESS;
        case AP_MPMQ_MAX_DAEMONS:
            *result = 1;
            return APR_SUCCESS;
        case AP_MPMQ_MPM_STATE:
            *result = mpm_state;
            return APR_SUCCESS;
    }
    return APR_ENOTIMPL;
}


/*****************************************************************
 * Connection structures and accounting...
 */

static void mpm_term(void)
{
    RemoveConsoleHandler();
    wait_to_finish = 0;
    NXThreadYield();
}

static void sig_term(int sig)
{
    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;

    DBPRINT0 ("waiting for threads\n");
    while (wait_to_finish) {
        apr_thread_yield();
    }
    DBPRINT0 ("goodbye\n");
}

/* restart() is the signal handler for SIGHUP and SIGWINCH
 * in the parent process, unless running in ONE_PROCESS mode
 */
static void restart(void)
{
    if (restart_pending == 1) {
        /* Probably not an error - don't bother reporting it */
        return;
    }
    restart_pending = 1;
    is_graceful = 1;
}

static void set_signals(void)
{
    apr_signal(SIGTERM, sig_term);
    apr_signal(SIGABRT, sig_term);
}

int nlmUnloadSignaled(int wait)
{
    shutdown_pending = 1;

    if (wait) {
        while (wait_to_finish) {
            NXThreadYield();
        }
    }

    return 0;
}

/*****************************************************************
 * Child process main loop.
 * The following vars are static to avoid getting clobbered by longjmp();
 * they are really private to child_main.
 */


int ap_graceful_stop_signalled(void)
{
    /* not ever called anymore... */
    return 0;
}

#define MAX_WB_RETRIES  3
#ifdef DBINFO_ON
static int would_block = 0;
static int retry_success = 0;
static int retry_fail = 0;
static int avg_retries = 0;
#endif

/*static */
void worker_main(void *arg)
{
    ap_listen_rec *lr, *first_lr, *last_lr = NULL;
    apr_pool_t *ptrans;
    apr_pool_t *pbucket;
    apr_allocator_t *allocator;
    apr_bucket_alloc_t *bucket_alloc;
    conn_rec *current_conn;
    apr_status_t stat = APR_EINIT;
    ap_sb_handle_t *sbh;

    int my_worker_num = (int)arg;
    apr_socket_t *csd = NULL;
    int requests_this_child = 0;
    apr_socket_t *sd = NULL;
    fd_set main_fds;

    int sockdes;
    int srv;
    struct timeval tv;
    int wouldblock_retry;

    tv.tv_sec = 1;
    tv.tv_usec = 0;

    apr_allocator_create(&allocator);
    apr_allocator_max_free_set(allocator, ap_max_mem_free);

    apr_pool_create_ex(&ptrans, pmain, NULL, allocator);
    apr_allocator_owner_set(allocator, ptrans);
    apr_pool_tag(ptrans, "transaction");

    bucket_alloc = apr_bucket_alloc_create_ex(allocator);

    atomic_inc (&worker_thread_count);

    while (!die_now) {
        /*
        * (Re)initialize this child to a pre-connection state.
        */
        current_conn = NULL;
        apr_pool_clear(ptrans);

        if ((ap_max_requests_per_child > 0
            && requests_this_child++ >= ap_max_requests_per_child)) {
            DBPRINT1 ("\n**Thread slot %d is shutting down", my_worker_num);
            clean_child_exit(0, my_worker_num, ptrans, bucket_alloc);
        }

        ap_update_child_status_from_indexes(0, my_worker_num, WORKER_READY, 
                                            (request_rec *) NULL);

        /*
        * Wait for an acceptable connection to arrive.
        */

        for (;;) {
            if (shutdown_pending || restart_pending || (ap_scoreboard_image->servers[0][my_worker_num].status == WORKER_IDLE_KILL)) {
                DBPRINT1 ("\nThread slot %d is shutting down\n", my_worker_num);
                clean_child_exit(0, my_worker_num, ptrans, bucket_alloc);
            }

            /* Check the listen queue on all sockets for requests */
            memcpy(&main_fds, &listenfds, sizeof(fd_set));
            srv = select(listenmaxfd + 1, &main_fds, NULL, NULL, &tv);

            if (srv <= 0) {
                if (srv < 0) {
                    ap_log_error(APLOG_MARK, APLOG_NOTICE, WSAGetLastError(), ap_server_conf,
                        "select() failed on listen socket");
                    apr_thread_yield();
                }
                continue;
            }

            /* remember the last_lr we searched last time around so that
            we don't end up starving any particular listening socket */
            if (last_lr == NULL) {
                lr = ap_listeners;
            }
            else {
                lr = last_lr->next;
                if (!lr)
                    lr = ap_listeners;
            }
            first_lr = lr;
            do {
                apr_os_sock_get(&sockdes, lr->sd);
                if (FD_ISSET(sockdes, &main_fds))
                    goto got_listener;
                lr = lr->next;
                if (!lr)
                    lr = ap_listeners;
            } while (lr != first_lr);
            /* if we get here, something unexpected happened. Go back
            into the select state and try again.
            */
            continue;
        got_listener:
            last_lr = lr;
            sd = lr->sd;

            wouldblock_retry = MAX_WB_RETRIES;

            while (wouldblock_retry) {
                if ((stat = apr_accept(&csd, sd, ptrans)) == APR_SUCCESS) {
                    break;
                }
                else {
                    /* if the error is a wouldblock then maybe we were too
                        quick try to pull the next request from the listen 
                        queue.  Try a few more times then return to our idle