Watching for tornadoes tonite

[apache] / server / mpm / winnt / mpm_winnt.c

/* ====================================================================
 * 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
 *    the documentation and/or other materials provided with the
 *    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
 * <http://www.apache.org/>.
 *
 * 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 
#include "apr_portable.h"
#include "httpd.h" 
#include "http_main.h" 
#include "http_log.h" 
#include "http_config.h"        /* for read_config */ 
#include "http_core.h"          /* for get_remote_host */ 
#include "http_connection.h"
#include "ap_mpm.h"
#include "ap_config.h"
#include "ap_listen.h"
#include "mpm_default.h"
#include "service.h"
#include "iol_socket.h"
#include "winnt.h"


/*
 * Definitions of WINNT MPM specific config globals
 */

static char *ap_pid_fname = NULL;
static int ap_threads_per_child = 0;
static int workers_may_exit = 0;
static int max_requests_per_child = 0;
static HANDLE shutdown_event;   /* used to signal shutdown to parent */
static HANDLE restart_event;    /* used to signal a restart to parent */

static struct fd_set listenfds;
static int num_listenfds = 0;
static SOCKET listenmaxfd = INVALID_SOCKET;

static ap_pool_t *pconf;                /* Pool for config stuff */

static char ap_coredump_dir[MAX_STRING_LEN];

static server_rec *server_conf;
static HANDLE AcceptExCompPort = NULL;

static int one_process = 0;

static OSVERSIONINFO osver; /* VER_PLATFORM_WIN32_NT */

int ap_max_requests_per_child=0;
int ap_daemons_to_start=0;

static event *exit_event;
ap_lock_t *start_mutex;
int my_pid;
int parent_pid;

static ap_status_t socket_cleanup(void *sock)
{
    ap_socket_t *thesocket = sock;
    SOCKET sd;
    if (ap_get_os_sock(&sd, thesocket) == APR_SUCCESS) {
        closesocket(sd);
    }
    return APR_SUCCESS;
}

/* A bunch or routines from os/win32/multithread.c that need to be merged into APR
 * or thrown out entirely...
 */


typedef void semaphore;
typedef void event;

static semaphore *
create_semaphore(int initial)
{
    return(CreateSemaphore(NULL, initial, 1000000, NULL));
}

static void acquire_semaphore(semaphore *semaphore_id)
{
    int rv;
    
    rv = WaitForSingleObject(semaphore_id, INFINITE);
    
    return;
}

static int release_semaphore(semaphore *semaphore_id)
{
    return(ReleaseSemaphore(semaphore_id, 1, NULL));
}

static void destroy_semaphore(semaphore *semaphore_id)
{
    CloseHandle(semaphore_id);
}


/* To share the semaphores with other processes, we need a NULL ACL
 * Code from MS KB Q106387
 */
static PSECURITY_ATTRIBUTES GetNullACL()
{
    PSECURITY_DESCRIPTOR pSD;
    PSECURITY_ATTRIBUTES sa;

    sa  = (PSECURITY_ATTRIBUTES) LocalAlloc(LPTR, sizeof(SECURITY_ATTRIBUTES));
    pSD = (PSECURITY_DESCRIPTOR) LocalAlloc(LPTR,
                                            SECURITY_DESCRIPTOR_MIN_LENGTH);
    if (pSD == NULL || sa == NULL) {
        return NULL;
    }
    if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)
        || GetLastError()) {
        LocalFree( pSD );
        LocalFree( sa );
        return NULL;
    }
    if (!SetSecurityDescriptorDacl(pSD, TRUE, (PACL) NULL, FALSE)
        || GetLastError()) {
        LocalFree( pSD );
        LocalFree( sa );
        return NULL;
    }
    sa->nLength = sizeof(sa);
    sa->lpSecurityDescriptor = pSD;
    sa->bInheritHandle = TRUE;
    return sa;
}

static void CleanNullACL( void *sa ) {
    if( sa ) {
        LocalFree( ((PSECURITY_ATTRIBUTES)sa)->lpSecurityDescriptor);
        LocalFree( sa );
    }
}

/*
 * The Win32 call WaitForMultipleObjects will only allow you to wait for 
 * a maximum of MAXIMUM_WAIT_OBJECTS (current 64).  Since the threading 
 * model in the multithreaded version of apache wants to use this call, 
 * we are restricted to a maximum of 64 threads.  This is a simplistic 
 * routine that will increase this size.
 */
static DWORD wait_for_many_objects(DWORD nCount, CONST HANDLE *lpHandles, 
                                   DWORD dwSeconds)
{
    time_t tStopTime;
    DWORD dwRet = WAIT_TIMEOUT;
    DWORD dwIndex=0;
    BOOL bFirst = TRUE;
  
    tStopTime = time(NULL) + dwSeconds;
  
    do {
        if (!bFirst)
            Sleep(1000);
        else
            bFirst = FALSE;
          
        for (dwIndex = 0; dwIndex * MAXIMUM_WAIT_OBJECTS < nCount; dwIndex++) {
            dwRet = WaitForMultipleObjects( 
                min(MAXIMUM_WAIT_OBJECTS, nCount - (dwIndex * MAXIMUM_WAIT_OBJECTS)),
                lpHandles + (dwIndex * MAXIMUM_WAIT_OBJECTS), 
                0, 0);
                                           
            if (dwRet != WAIT_TIMEOUT) {                                          
              break;
            }
        }
    } while((time(NULL) < tStopTime) && (dwRet == WAIT_TIMEOUT));
    
    return dwRet;
}

/*
 * Signalling Apache on NT.
 *
 * Under Unix, Apache can be told to shutdown or restart by sending various
 * signals (HUP, USR, TERM). On NT we don't have easy access to signals, so
 * we use "events" instead. The parent apache process goes into a loop
 * where it waits forever for a set of events. Two of those events are
 * called
 *
 *    apPID_shutdown
 *    apPID_restart
 *
 * (where PID is the PID of the apache parent process). When one of these
 * is signalled, the Apache parent performs the appropriate action. The events
 * can become signalled through internal Apache methods (e.g. if the child
 * finds a fatal error and needs to kill its parent), via the service
 * control manager (the control thread will signal the shutdown event when
 * requested to stop the Apache service), from the -k Apache command line,
 * or from any external program which finds the Apache PID from the
 * httpd.pid file.
 *
 * The signal_parent() function, below, is used to signal one of these events.
 * It can be called by any child or parent process, since it does not
 * rely on global variables.
 *
 * On entry, type gives the event to signal. 0 means shutdown, 1 means 
 * graceful restart.
 */
static void signal_parent(int type)
{
    HANDLE e;
    char *signal_name;
    extern char signal_shutdown_name[];
    extern char signal_restart_name[];

    /* after updating the shutdown_pending or restart flags, we need
     * to wake up the parent process so it can see the changes. The
     * parent will normally be waiting for either a child process
     * to die, or for a signal on the "spache-signal" event. So set the
     * "apache-signal" event here.
     */
    if (one_process) {
        return;
    }

    switch(type) {
    case 0: signal_name = signal_shutdown_name; break;
    case 1: signal_name = signal_restart_name; break;
    default: return;
    }
    e = OpenEvent(EVENT_ALL_ACCESS, FALSE, signal_name);
    if (!e) {
        /* Um, problem, can't signal the parent, which means we can't
         * signal ourselves to die. Ignore for now...
         */
        ap_log_error(APLOG_MARK, APLOG_EMERG, GetLastError(), server_conf,
                     "OpenEvent on %s event", signal_name);
        return;
    }
    if (SetEvent(e) == 0) {
        /* Same problem as above */
        ap_log_error(APLOG_MARK, APLOG_EMERG, GetLastError(), server_conf,
                     "SetEvent on %s event", signal_name);
        CloseHandle(e);
        return;
    }
    CloseHandle(e);
}
static int volatile is_graceful = 0;
API_EXPORT(int) ap_graceful_stop_signalled(void)
{
    return is_graceful;
}
void ap_start_shutdown(void)
{
    signal_parent(0);
}
/*
 * Initialise the signal names, in the global variables signal_name_prefix, 
 * signal_restart_name and signal_shutdown_name.
 */

#define MAX_SIGNAL_NAME 30  /* Long enough for apPID_shutdown, where PID is an int */
char signal_name_prefix[MAX_SIGNAL_NAME];
char signal_restart_name[MAX_SIGNAL_NAME]; 
char signal_shutdown_name[MAX_SIGNAL_NAME];
static void setup_signal_names(char *prefix)
{
    ap_snprintf(signal_name_prefix, sizeof(signal_name_prefix), prefix);    
    ap_snprintf(signal_shutdown_name, sizeof(signal_shutdown_name), 
        "%s_shutdown", signal_name_prefix);    
    ap_snprintf(signal_restart_name, sizeof(signal_restart_name), 
        "%s_restart", signal_name_prefix);    
}

/*
 * Routines that deal with sockets, some are WIN32 specific...
 */
static int s_iInitCount = 0;
static int AMCSocketInitialize(void)
{
    int iVersionRequested;
    WSADATA wsaData;
    int err;

    if (s_iInitCount > 0) {
        s_iInitCount++;
        return (0);
    }
    else if (s_iInitCount < 0)
        return (s_iInitCount);

    /* s_iInitCount == 0. Do the initailization */
    iVersionRequested = MAKEWORD(2, 0);
    err = WSAStartup((WORD) iVersionRequested, &wsaData);
    if (err) {
        s_iInitCount = -1;
        return (s_iInitCount);
    }
    if (LOBYTE(wsaData.wVersion) != 1 ||
        HIBYTE(wsaData.wVersion) != 1) {
        s_iInitCount = -2;
        WSACleanup();
        return (s_iInitCount);
    }

    s_iInitCount++;
    return (s_iInitCount);

}
static void AMCSocketCleanup(void)
{
    if (--s_iInitCount == 0)
        WSACleanup();
    return;
}

static void sock_disable_nagle(int s) 
{
    /* The Nagle algorithm says that we should delay sending partial
     * packets in hopes of getting more data.  We don't want to do
     * this; we are not telnet.  There are bad interactions between
     * persistent connections and Nagle's algorithm that have very severe
     * performance penalties.  (Failing to disable Nagle is not much of a
     * problem with simple HTTP.)
     *
     * In spite of these problems, failure here is not a shooting offense.
     */
    int just_say_no = 1;

    if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (char *) &just_say_no,
                   sizeof(int)) < 0) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, APR_SUCCESS, server_conf,
                    "setsockopt: (TCP_NODELAY)");
    }
}

/*
 * Routines to deal with managing the list of listening sockets.
 */
static ap_listen_rec *head_listener;
static ap_inline ap_listen_rec *find_ready_listener(fd_set * main_fds)
{
    ap_listen_rec *lr;
    SOCKET nsd;

    for (lr = head_listener; lr ; lr = lr->next) {
        ap_get_os_sock(&nsd, lr->sd);
        if (FD_ISSET(nsd, main_fds)) {
            head_listener = lr->next;
            if (head_listener == NULL)
                head_listener = ap_listeners;

            return (lr);
        }
    }
    return NULL;
}
static int setup_listeners(server_rec *s)
{
    ap_listen_rec *lr;
    int num_listeners = 0;
    SOCKET nsd;

    /* Setup the listeners */
    FD_ZERO(&listenfds);

    if (ap_listen_open(s->process, s->port)) {
       return 0;
    }
    for (lr = ap_listeners; lr; lr = lr->next) {
        num_listeners++;
        if (lr->sd != NULL) {
            ap_get_os_sock(&nsd, lr->sd);
            FD_SET(nsd, &listenfds);
            if (listenmaxfd == INVALID_SOCKET || nsd > listenmaxfd) {
                listenmaxfd = nsd;
            }
        }
        lr->count = 0;
    }

    head_listener = ap_listeners;

    return num_listeners;
}

static int setup_inherited_listeners(server_rec *s)
{
    WSAPROTOCOL_INFO WSAProtocolInfo;
    HANDLE pipe;
    ap_listen_rec *lr;
    DWORD BytesRead;
    int num_listeners = 0;
    SOCKET nsd;

    /* Setup the listeners */
    FD_ZERO(&listenfds);

    /* Set up a default listener if necessary */

    if (ap_listeners == NULL) {
        ap_listen_rec *lr;
        lr = ap_palloc(s->process->pool, sizeof(ap_listen_rec));
        if (!lr)
            return 0;
        lr->sd = NULL;
        lr->next = ap_listeners;
        ap_listeners = lr;
    }

    /* Open the pipe to the parent process to receive the inherited socket
     * data. The sockets have been set to listening in the parent process.
     */
    pipe = GetStdHandle(STD_INPUT_HANDLE);
    for (lr = ap_listeners; lr; lr = lr->next) {
        if (!ReadFile(pipe, &WSAProtocolInfo, sizeof(WSAPROTOCOL_INFO), 
                      &BytesRead, (LPOVERLAPPED) NULL)) {
            ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                         "setup_inherited_listeners: Unable to read socket data from parent");
            signal_parent(0);   /* tell parent to die */
            exit(1);
        }
        ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, APR_SUCCESS, server_conf,
                     "Child %d: setup_inherited_listener() read = %d bytes of WSAProtocolInfo.", my_pid);
        nsd = WSASocket(FROM_PROTOCOL_INFO, FROM_PROTOCOL_INFO, FROM_PROTOCOL_INFO,
                        &WSAProtocolInfo, 0, 0);
        if (nsd == INVALID_SOCKET) {
            ap_log_error(APLOG_MARK, APLOG_CRIT, WSAGetLastError(), server_conf,
                         "Child %d: setup_inherited_listeners(), WSASocket failed to open the inherited socket.", my_pid);
            signal_parent(0);   /* tell parent to die */
            exit(1);
        }
        if (nsd >= 0) {
            FD_SET(nsd, &listenfds);
            if (listenmaxfd == INVALID_SOCKET || nsd > listenmaxfd) {
                listenmaxfd = nsd;
            }
        }
//        ap_register_cleanup(p, (void *)lr->sd, socket_cleanup, ap_null_cleanup);
        ap_put_os_sock(&lr->sd, &nsd, pconf);
        lr->count = 0;
    }
    /* Now, read the AcceptExCompPort from the parent */
    ReadFile(pipe, &AcceptExCompPort, sizeof(AcceptExCompPort), &BytesRead, (LPOVERLAPPED) NULL);
    CloseHandle(pipe);

    for (lr = ap_listeners; lr; lr = lr->next) {
        num_listeners++;
    }

    head_listener = ap_listeners;
    return num_listeners;
}

static void bind_listeners_to_completion_port()
{
    /* Associate the open listeners with the completion port.
     * Bypass the operation for Windows 95/98
     */
    ap_listen_rec *lr;

    if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS) {
        for (lr = ap_listeners; lr; lr = lr->next) {
            int nsd;
            ap_get_os_sock(&nsd,lr->sd);
            CreateIoCompletionPort((HANDLE) nsd, AcceptExCompPort, 0, 0);
        }
    }
}

/**********************************************************************
 * Multithreaded implementation
 *
 * This code is fairly specific to Win32.
 *
 * The model used to handle requests is a set of threads. One "main"
 * thread listens for new requests. When something becomes
 * available, it does a select and places the newly available socket
 * onto a list of "jobs" (add_job()). Then any one of a fixed number
 * of "worker" threads takes the top job off the job list with
 * remove_job() and handles that connection to completion. After
 * the connection has finished the thread is free to take another
 * job from the job list.
 *
 * In the code, the "main" thread is running within the child_main()
 * function. The first thing this function does is create the
 * worker threads, which operate in the child_sub_main() function. The
 * main thread then goes into a loop within child_main() where they
 * do a select() on the listening sockets. The select times out once
 * per second so that the thread can check for an "exit" signal
 * from the parent process (see below). If this signal is set, the 
 * thread can exit, but only after it has accepted all incoming
 * connections already in the listen queue (since Win32 appears
 * to through away listened but unaccepted connections when a 
 * process dies).
 *
 * Because the main and worker threads exist within a single process
 * they are vulnerable to crashes or memory leaks (crashes can also
 * be caused within modules, of course). There also needs to be a 
 * mechanism to perform restarts and shutdowns. This is done by
 * creating the main & worker threads within a subprocess. A
 * main process (the "parent process") creates one (or more) 
 * processes to do the work, then the parent sits around waiting
 * for the working process to die, in which case it starts a new
 * one. The parent process also handles restarts (by creating
 * a new working process then signalling the previous working process 
 * exit ) and shutdowns (by signalling the working process to exit).
 * The parent process operates within the master_main() function. This
 * process also handles requests from the service manager (NT only).
 *
 * Signalling between the parent and working process uses a Win32
 * event. Each child has a unique name for the event, which is
 * passed to it with the -Z argument when the child is spawned. The
 * parent sets (signals) this event to tell the child to die.
 * At present all children do a graceful die - they finish all
 * current jobs _and_ empty the listen queue before they exit.
 * A non-graceful die would need a second event. The -Z argument in
 * the child is also used to create the shutdown and restart events,
 * since the prefix (apPID) contains the parent process PID.
 *
 * The code below starts with functions at the lowest level -
 * worker threads, and works up to the top level - the main()
 * function of the parent process.
 *
 * The scoreboard (in process memory) contains details of the worker
 * threads (within the active working process). There is no shared
 * "scoreboard" between processes, since only one is ever active
 * at once (or at most, two, when one has been told to shutdown but
 * is processes outstanding requests, and a new one has been started).
 * This is controlled by a "start_mutex" which ensures only one working
 * process is active at once.
 **********************************************************************/


/*
 * Definition of jobs, shared by main and worker threads.
 */

typedef struct joblist_s {
    struct joblist_s *next;
    int sock;
} joblist;

/*
 * Globals common to main and worker threads. This structure is not
 * used by the parent process.
 */

typedef struct globals_s {
    semaphore *jobsemaphore;
    joblist *jobhead;
    joblist *jobtail;
    ap_lock_t *jobmutex;
    int jobcount;
} globals;

globals allowed_globals =
{NULL, NULL, NULL, NULL, 0};
#define MAX_SELECT_ERRORS 100
#define PADDED_ADDR_SIZE sizeof(SOCKADDR_IN)+16

/* Windows 9x specific code...
 * Accept processing for on Windows 95/98 uses a producer/consumer queue 
 * model. A single thread accepts connections and queues the accepted socket 
 * to the accept queue for consumption by a pool of worker threads.
 *
 * win9x_get_connection()
 *    Calls remove_job() to pull a job from the accept queue. All the worker 
 *    threads block on remove_job.
 * accept_and_queue_connections()
 *    The accept threads runs this function, which accepts connections off 
 *    the network and calls add_job() to queue jobs to the accept_queue.
 * add_job()/remove_job()
 *    Add or remove an accepted socket from the list of sockets 
 *    connected to clients. allowed_globals.jobmutex protects
 *    against multiple concurrent access to the linked list of jobs.
 */
static void add_job(int sock)
{
    joblist *new_job;

    new_job = (joblist *) malloc(sizeof(joblist));
    if (new_job == NULL) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, 
                     "Ouch!  Out of memory in add_job()!");
        return;
    }
    new_job->next = NULL;
    new_job->sock = sock;

    ap_lock(allowed_globals.jobmutex);

    if (allowed_globals.jobtail != NULL)
        allowed_globals.jobtail->next = new_job;
    allowed_globals.jobtail = new_job;
    if (!allowed_globals.jobhead)
        allowed_globals.jobhead = new_job;
    allowed_globals.jobcount++;
    release_semaphore(allowed_globals.jobsemaphore);

    ap_unlock(allowed_globals.jobmutex);
}

static int remove_job(void)
{
    joblist *job;
    int sock;

    acquire_semaphore(allowed_globals.jobsemaphore);
    ap_lock(allowed_globals.jobmutex);

    if (workers_may_exit && !allowed_globals.jobhead) {
        ap_unlock(allowed_globals.jobmutex);
        return (-1);
    }
    job = allowed_globals.jobhead;
    ap_assert(job);
    allowed_globals.jobhead = job->next;
    if (allowed_globals.jobhead == NULL)
        allowed_globals.jobtail = NULL;
    ap_unlock(allowed_globals.jobmutex);
    sock = job->sock;
    free(job);

    return (sock);
}

static void accept_and_queue_connections(void * dummy)
{
    int requests_this_child = 0;
    struct timeval tv;
    fd_set main_fds;
    int wait_time = 1;
    int csd;
    int nsd = INVALID_SOCKET;
    struct sockaddr_in sa_client;
    int count_select_errors = 0;
    int rc;
    int clen;

    while (!workers_may_exit) {
        if (ap_max_requests_per_child && (requests_this_child > ap_max_requests_per_child)) {
            break;
        }

        tv.tv_sec = wait_time;
        tv.tv_usec = 0;
        memcpy(&main_fds, &listenfds, sizeof(fd_set));

//      rc = ap_select(listenmaxfd + 1, &main_fds, NULL, NULL, &tv);
        rc = select(listenmaxfd + 1, &main_fds, NULL, NULL, &tv);

        if (rc == 0 || (rc == SOCKET_ERROR && h_errno == WSAEINTR)) {
            count_select_errors = 0;    /* reset count of errors */            
            continue;
        }
        else if (rc == SOCKET_ERROR) {
            /* A "real" error occurred, log it and increment the count of
             * select errors. This count is used to ensure we don't go into
             * a busy loop of continuous errors.
             */
            ap_log_error(APLOG_MARK, APLOG_INFO, h_errno, server_conf, 
                         "select failed with errno %d", h_errno);
            count_select_errors++;
            if (count_select_errors > MAX_SELECT_ERRORS) {
                workers_may_exit = 1;
                ap_log_error(APLOG_MARK, APLOG_ERR, h_errno, server_conf,
                             "Too many errors in select loop. Child process exiting.");
                break;
            }
        } else {
            ap_listen_rec *lr;

            lr = find_ready_listener(&main_fds);
            if (lr != NULL) {
                /* fetch the native socket descriptor */
                ap_get_os_sock(&nsd, lr->sd);
            }
        }

        do {
            clen = sizeof(sa_client);
            csd = accept(nsd, (struct sockaddr *) &sa_client, &clen);
            if (csd == INVALID_SOCKET) {
                csd = -1;
            }
        } while (csd < 0 && h_errno == WSAEINTR);

        if (csd < 0) {
            if (h_errno != WSAECONNABORTED) {
                ap_log_error(APLOG_MARK, APLOG_ERR, h_errno, server_conf,
                            "accept: (client socket)");
            }
        }
        else {
            add_job(csd);
            requests_this_child++;
        }
    }
    SetEvent(exit_event);
}
static PCOMP_CONTEXT win9x_get_connection(PCOMP_CONTEXT context)
{
    int len;

    if (context == NULL) {
        /* allocate the completion context and the transaction pool */
        context = ap_pcalloc(pconf, sizeof(COMP_CONTEXT));
        if (!context) {
            ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                         "win9x_get_connection: ap_pcalloc() failed. Process will exit.");
            return NULL;
        }
        ap_create_pool(&context->ptrans, pconf);
    }
    

    while (1) {
        ap_clear_pool(context->ptrans);        
        context->accept_socket = remove_job();
        if (context->accept_socket == -1) {
            return NULL;
        }
        //ap_note_cleanups_for_socket(ptrans, csd);
        len = sizeof(struct sockaddr);
        context->sa_server = ap_palloc(context->ptrans, len);
        if (getsockname(context->accept_socket, 
                        context->sa_server, &len)== SOCKET_ERROR) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, WSAGetLastError(), server_conf, 
                         "getsockname failed");
            continue;
        }
        len = sizeof(struct sockaddr);
        context->sa_client = ap_palloc(context->ptrans, len);
        if ((getpeername(context->accept_socket,
                         context->sa_client, &len)) == SOCKET_ERROR) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, h_errno, server_conf, 
                         "getpeername failed with error %d\n", WSAGetLastError());
            memset(&context->sa_client, '\0', sizeof(context->sa_client));
        }

        context->conn_io = ap_bcreate(context->ptrans, B_RDWR);

        /* do we NEED_DUPPED_CSD ?? */
        
        return context;
    }
}

/* 
 * Windows 2000/NT specific code...
 * create_acceptex_context()
 * reset_acceptex_context()
 * drain_acceptex_complport()
 * winnt_get_connection()
 *
 * TODO: Insert a discussion of 'completion contexts' and what these function do here...
 */
static void drain_acceptex_complport(HANDLE hComplPort, BOOLEAN bCleanUp) 
{
    LPOVERLAPPED pol;
    PCOMP_CONTEXT context;
    int rc;
    DWORD BytesRead;
    DWORD CompKey;
    int lastError;

    while (1) {
        context = NULL;
        rc = GetQueuedCompletionStatus(hComplPort, &BytesRead, &CompKey,
                                       &pol, 1000);
        if (!rc) {
            lastError = GetLastError();
            if (lastError == ERROR_OPERATION_ABORTED) {
                ap_log_error(APLOG_MARK,APLOG_INFO,lastError, server_conf,
                             "Child: %d - Draining a packet off the completion port.", my_pid);
                continue;
            }
            break;
        }
        ap_log_error(APLOG_MARK,APLOG_INFO,APR_SUCCESS, server_conf,
                     "Child: %d - Nuking an active connection. context = %x", my_pid, context);
        context = (PCOMP_CONTEXT) pol;
        if (context && bCleanUp) {
            /* It is only valid to clean-up in the process that initiated the I/O */
            closesocket(context->accept_socket);
            CloseHandle(context->Overlapped.hEvent);
        }
    }
}
static int create_acceptex_context(ap_pool_t *_pconf, ap_listen_rec *lr) 
{
    PCOMP_CONTEXT context;
    DWORD BytesRead;
    SOCKET nsd;
    int lasterror;
    
    /* allocate the completion context */
    context = ap_pcalloc(_pconf, sizeof(COMP_CONTEXT));
    if (!context) {
        ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                     "create_acceptex_context: ap_pcalloc() failed. Process will exit.");
        return -1;
    }

    /* initialize the completion context */
    context->lr = lr;
    context->Overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); 
    if (context->Overlapped.hEvent == NULL) {
        ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                     "create_acceptex_context: CreateEvent() failed. Process will exit.");
        return -1;
    }
    context->accept_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (context->accept_socket == INVALID_SOCKET) {
        ap_log_error(APLOG_MARK,APLOG_ERR, WSAGetLastError(), server_conf,
                     "create_acceptex_context: socket() failed. Process will exit.");
        return -1;
    }
    ap_create_pool(&context->ptrans, _pconf);
    context->conn_io = ap_bcreate(context->ptrans, B_RDWR);
    context->recv_buf = context->conn_io->inbase;
    context->recv_buf_size = context->conn_io->bufsiz - 2*PADDED_ADDR_SIZE;
    ap_get_os_sock(&nsd, context->lr->sd);

    /* AcceptEx on the completion context. The completion context will be signaled
     * when a connection is accepted. */
    if (!AcceptEx(nsd, context->accept_socket,
                  context->recv_buf, 
                  0, //context->recv_buf_size,
                  PADDED_ADDR_SIZE, PADDED_ADDR_SIZE,
                  &BytesRead,
                  (LPOVERLAPPED) context)) {
        lasterror = WSAGetLastError();
        if (lasterror != ERROR_IO_PENDING) {
            ap_log_error(APLOG_MARK,APLOG_ERR, WSAGetLastError(), server_conf,
                         "create_acceptex_context: AcceptEx failed. Process will exit.");
            return -1;
        }
        
        /* SO_UPDATE_ACCEPT_CONTEXT is a Microsoft-ism which is required
         * if you want to use more than several key socket calls on a
         * socket initialized via AcceptEx().  In particular, it is
         * required for shutdown() to work.
         */

        if (setsockopt(context->accept_socket, SOL_SOCKET,
                       SO_UPDATE_ACCEPT_CONTEXT, (char *)&nsd,
                       sizeof(nsd))) {
            ap_log_error(APLOG_MARK, APLOG_ERR, WSAGetLastError(), server_conf,
                         "setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed.");
        }

    }
    lr->count++;

    return 0;
}
static ap_inline int reset_acceptex_context(PCOMP_CONTEXT context) 
{
    DWORD BytesRead;
    SOCKET nsd;
    int lasterror;

    context->lr->count++;

    if (context->accept_socket == -1)
        context->accept_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    if (context->accept_socket == INVALID_SOCKET) {
        ap_log_error(APLOG_MARK,APLOG_ERR, WSAGetLastError(), server_conf,
                     "reset_acceptex_context: socket() failed. Process will exit.");
        return -1;
    }

    ap_clear_pool(context->ptrans);
    context->sock = NULL;
    context->conn_io = ap_bcreate(context->ptrans, B_RDWR);
    context->recv_buf = context->conn_io->inbase;
    context->recv_buf_size = context->conn_io->bufsiz - 2*PADDED_ADDR_SIZE;
    ap_get_os_sock(&nsd, context->lr->sd);

    if (!AcceptEx(nsd, context->accept_socket, 
                  context->recv_buf, 
                  0, //context->recv_buf_size,
                  PADDED_ADDR_SIZE, PADDED_ADDR_SIZE,
                  &BytesRead, (LPOVERLAPPED) context)) {
        lasterror = WSAGetLastError();
        if (lasterror != ERROR_IO_PENDING) {
            ap_log_error(APLOG_MARK,APLOG_ERR, WSAGetLastError(), server_conf,
                         "reset_acceptex_context: AcceptEx failed. Leaving the process running.");
            return -1;
        }
        
        /* SO_UPDATE_ACCEPT_CONTEXT is a Microsoft-ism which is required
         * if you want to use more than several key socket calls on a
         * socket initialized via AcceptEx().  In particular, it is
         * required for shutdown() to work.
         */

        if (setsockopt(context->accept_socket, SOL_SOCKET,
                       SO_UPDATE_ACCEPT_CONTEXT, (char *)&nsd,
                       sizeof(nsd))) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, WSAGetLastError(),
                         server_conf,
                         "setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed.");
        }
    }

    return 0;
}
static PCOMP_CONTEXT winnt_get_connection(PCOMP_CONTEXT context)
{
    int requests_this_child = 0;
    int rc;
    LPOVERLAPPED pol;
    DWORD CompKey;
    DWORD BytesRead;

    if (context != NULL) {
        /* If child shutdown has been signaled, clean-up the completion context */
        if (workers_may_exit) {
            CloseHandle(context->Overlapped.hEvent);
            /* destroy pool */
        }
        else {
            context->accept_socket = -1; /* Don't reuse the accept_socket */
            if (reset_acceptex_context(context) == -1) {
                if (context->accept_socket != -1)
                    closesocket(context->accept_socket);
                CloseHandle(context->Overlapped.hEvent);
                return NULL;
            }
        }
    }

    while (1) {
        rc = GetQueuedCompletionStatus(AcceptExCompPort,
                                       &BytesRead,
                                       &CompKey,
                                       &pol,
                                       INFINITE);
        if (!rc) {
            ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                         "Child: %d - GetQueuedCompletionStatus() failed", my_pid);
            continue;
        }
        break;
    }
    context = (PCOMP_CONTEXT) pol;
    if (CompKey == 999) {
        return NULL;
    }

    /* Each listener needs at least 1 context available to receive connections on.
     * Create additional listener contexts if needed. 
     */
    ap_lock(allowed_globals.jobmutex);
    context->lr->count--;
    if ((context->lr->count < 2) && !workers_may_exit) {
        if (create_acceptex_context(pconf, context->lr) == -1) {
            ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                         "Unable to create an AcceptEx completion context -- process will exit");
            signal_parent(0);
            return NULL;
        }
    }
    ap_unlock(allowed_globals.jobmutex);

    /* Received a connection */
    context->conn_io->incnt = BytesRead;
    GetAcceptExSockaddrs(context->recv_buf, 
                         0, //context->recv_buf_size,
                         PADDED_ADDR_SIZE,
                         PADDED_ADDR_SIZE,
                         &context->sa_server,
                         &context->sa_server_len,
                         &context->sa_client,
                         &context->sa_client_len);

    return context;

}
/*
 * worker_main() - this is the main loop for the worker threads
 *
 * Windows 95/98
 * Each thread runs within this function. They wait within remove_job()
 * for a job to become available, then handle all the requests on that
 * connection until it is closed, then return to remove_job().
 *
 * The worker thread will exit when it removes a job which contains
 * socket number -1. This provides a graceful thread exit, since
 * it will never exit during a connection.
 *
 * This code in this function is basically equivalent to the child_main()
 * from the multi-process (Unix) environment, except that we
 *
 *  - do not call child_init_modules (child init API phase)
 *  - block in remove_job, and when unblocked we have an already
 *    accepted socket, instead of blocking on a mutex or select().
 */

static void worker_main(int child_num)
{
    static BOOLEAN bListenersStarted = FALSE;
    PCOMP_CONTEXT context = NULL;

    if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS) {
        /* Windows NT/2000: Create AcceptEx completion contexts for each of the
         * listeners
         */
        ap_lock(allowed_globals.jobmutex);
        if (!bListenersStarted) {
            ap_listen_rec *lr;
            int i;
            bListenersStarted = TRUE;
            for (lr = ap_listeners; lr != NULL; lr = lr->next) {
                for(i=0; i<2; i++) {
                    if (lr->count < 2)
                        if (create_acceptex_context(pconf, lr) == -1) {
                            ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                                         "Unable to create an AcceptEx completion context -- process will exit");
                            signal_parent(0);   /* tell parent to die */
                        }
                }
            }
        }
        ap_unlock(allowed_globals.jobmutex);
    }

    while (1) {
        conn_rec *current_conn;
        ap_iol *iol;

        /* Grab a connection off the network */
        if (osver.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) {
            context = win9x_get_connection(context);
        }
        else {
            context = winnt_get_connection(context);
        }

        if (!context)
            break;
        sock_disable_nagle(context->accept_socket);
        ap_put_os_sock(&context->sock, &context->accept_socket, context->ptrans);
        ap_register_cleanup(context->ptrans, context->sock, socket_cleanup, ap_null_cleanup);
        iol = win32_attach_socket(context->ptrans, context->sock);
        if (iol == NULL) {
            ap_log_error(APLOG_MARK, APLOG_ERR, APR_ENOMEM, server_conf,
                         "worker_main: attach_socket() failed. Continuing...");
            closesocket(context->accept_socket);
            continue;
        }
        ap_bpush_iol(context->conn_io, iol);
        current_conn = ap_new_connection(context->ptrans, server_conf, context->conn_io,
                                         (struct sockaddr_in *) context->sa_client,
                                         (struct sockaddr_in *) context->sa_server,
                                         child_num);

        ap_process_connection(current_conn);
    }
#if 0
    ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS, server_conf,
                 "child_main: Setting exit_event");
    SetEvent(exit_event);
#endif
    /* TODO: Add code to clean-up completion contexts here */
}

static void cleanup_thread(thread **handles, int *thread_cnt, int thread_to_clean)
{
    int i;

    CloseHandle(handles[thread_to_clean]);
    for (i = thread_to_clean; i < ((*thread_cnt) - 1); i++)
        handles[i] = handles[i + 1];
    (*thread_cnt)--;
}



/*
 * child_main() is main loop for the child process. The loop in
 * this function becomes the controlling thread for the actually working
 * threads (which run in a loop in child_sub_main()).
 * Globals Used:
 *  exit_event, start_mutex, ap_threads_per_child, server_conf,
 *  h_errno defined to WSAGetLastError in winsock2.h,
 */
static void child_main()
{
    char* exit_event_name;
    int nthreads = ap_threads_per_child;
    int thread_id;
    thread **child_handles;
    int rv;
    ap_status_t status;
    time_t end_time;
    int i;
    ap_pool_t *pchild;

    /* This is the child process or we are running in single process
     * mode.
     */

    exit_event_name = ap_psprintf(pconf, "apC%d", my_pid);
    setup_signal_names(ap_psprintf(pconf,"ap%d", parent_pid));

    if (one_process) {
        /* Single process mode */
        ap_create_lock(&start_mutex,APR_MUTEX, APR_CROSS_PROCESS,signal_name_prefix,pconf);
        exit_event = CreateEvent(NULL, TRUE, FALSE, exit_event_name);

        setup_listeners(server_conf);
        bind_listeners_to_completion_port();
    }
    else {
        /* Child process mode */
        ap_child_init_lock(&start_mutex, signal_name_prefix, pconf);
        exit_event = OpenEvent(EVENT_ALL_ACCESS, FALSE, exit_event_name);
        ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS, server_conf,
                     "Child %d: exit_event_name = %s", my_pid, exit_event_name);

        setup_inherited_listeners(server_conf);
    }
    ap_assert(start_mutex);
    ap_assert(exit_event);

    ap_create_pool(&pchild, pconf);


    if (listenmaxfd == INVALID_SOCKET) {
        /* No sockets were made, better log something and exit */
        ap_log_error(APLOG_MARK, APLOG_CRIT, h_errno, NULL,
                     "No sockets were created for listening");
        signal_parent(0);       /* tell parent to die */
        ap_destroy_pool(pchild);
        exit(0);
    }

    allowed_globals.jobsemaphore = create_semaphore(0);
    ap_create_lock(&allowed_globals.jobmutex, APR_MUTEX, APR_INTRAPROCESS, NULL, pchild);

    /*
     * Wait until we have permission to start accepting connections.
     * start_mutex is used to ensure that only one child ever
     * goes into the listen/accept loop at once.
     */
    status = ap_lock(start_mutex);
    if (status != APR_SUCCESS) {
        ap_log_error(APLOG_MARK,APLOG_ERR, status, server_conf,
                     "Child %d: Failed to acquire the start_mutex. Process will exit.", my_pid);
        signal_parent(0);       /* tell parent to die */
        ap_destroy_pool(pchild);
        exit(0);
    }
    ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf, "Child %d: Acquired the start mutex", my_pid);

    /* Create the worker thread pool */
    ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf, "Child %d: Creating %d worker threads",my_pid, nthreads);
    child_handles = (thread *) alloca(nthreads * sizeof(int));
    for (i = 0; i < nthreads; i++) {
        child_handles[i] = (thread *) _beginthreadex(NULL, 0, (LPTHREAD_START_ROUTINE) worker_main,
                                                     NULL, 0, &thread_id);
    }

    if (osver.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) {
        /* Win95/98: Create the accept thread */
        _beginthreadex(NULL, 0, (LPTHREAD_START_ROUTINE) accept_and_queue_connections,
                       (void *) i, 0, &thread_id);
    }

    /* Wait for the exit event to be signaled by the parent process */
    rv = WaitForSingleObject(exit_event, INFINITE);

    ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
                 "Child %d: Exit event signaled. Child process is ending.", my_pid);
    workers_may_exit = 1;      

    /* Shutdown the worker threads */
    if (osver.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) {
        for (i = 0; i < nthreads; i++) {
            add_job(-1);
        }
    }
    else { /* Windows NT/2000 */
        /* Tell the worker threads to exit. */
        for (i=0; i < nthreads; i++) {
            if (!PostQueuedCompletionStatus(AcceptExCompPort, 0, 999, NULL)) {
                ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf, 
                             "PostQueuedCompletionStatus failed");
            }
        }
    }

    /* Wait for the worker threads to die */
    end_time = time(NULL) + 180;
    while (nthreads) {
        rv = wait_for_many_objects(nthreads, child_handles, end_time - time(NULL));
        if (rv != WAIT_TIMEOUT) {
            rv = rv - WAIT_OBJECT_0;
            ap_assert((rv >= 0) && (rv < nthreads));
            cleanup_thread(child_handles, &nthreads, rv);
            continue;
        }
        break;
    }
    for (i = 0; i < nthreads; i++) {
        TerminateThread(child_handles[i], 1);
        CloseHandle(child_handles[i]);
    }
    ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf, 
                 "Child %d: All worker threads have ended.", my_pid);

    if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS) {    
        /* All the worker threads should have exited by now, which will
         * cause any outstanding I/O on the completion port to be aborted.
         * Drain the completion port of this aborted I/O/
         */
        drain_acceptex_complport(AcceptExCompPort, TRUE);
    }

    ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf, 
                 "Child %d: Releasing the start mutex", my_pid);
    ap_unlock(start_mutex);

    /* Still need to register cleanups for the sockets */
    CloseHandle(AcceptExCompPort);
    destroy_semaphore(allowed_globals.jobsemaphore);
    ap_destroy_lock(allowed_globals.jobmutex);

    ap_destroy_pool(pchild);
    CloseHandle(exit_event);
}

/*
 * Spawn a child Apache process. The child process has the command line arguments from
 * argc and argv[], plus a -Z argument giving the name of an event. The child should
 * open and poll or wait on this event. When it is signalled, the child should die.
 * prefix is a prefix string for the event name.
 * 
 * The child_num argument on entry contains a serial number for this child (used to create
 * a unique event name). On exit, this number will have been incremented by one, ready
 * for the next call. 
 *
 * On exit, the value pointed to be *ev will contain the event created
 * to signal the new child process.
 *
 * The return value is the handle to the child process if successful, else -1. If -1 is
 * returned the error will already have been logged by ap_log_error().
 */

/**********************************************************************
 * master_main - this is the parent (main) process. We create a
 * child process to do the work, then sit around waiting for either
 * the child to exit, or a restart or exit signal. If the child dies,
 * we just respawn a new one. If we have a shutdown or graceful restart,
 * tell the child to die when it is ready. If it is a non-graceful
 * restart, force the child to die immediately.
 **********************************************************************/

#define MAX_PROCESSES 50 /* must be < MAX_WAIT_OBJECTS-1 */

static void cleanup_process(HANDLE *handles, HANDLE *events, int position, int *processes)
{
    int i;
    int handle = 0;

    CloseHandle(handles[position]);
    CloseHandle(events[position]);

    handle = (int)handles[position];

    for (i = position; i < (*processes)-1; i++) {
        handles[i] = handles[i + 1];
        events[i] = events[i + 1];
    }
    (*processes)--;
}

static int create_process(ap_pool_t *p, HANDLE *handles, HANDLE *events, int *processes)
{

    int rv;
    char buf[1024];
    char *pCommand;
    int i;
    STARTUPINFO si;           /* Filled in prior to call to CreateProcess */
    PROCESS_INFORMATION pi;   /* filled in on call to CreateProces */

    ap_listen_rec *lr;
    DWORD BytesWritten;
    HANDLE hPipeRead = NULL;
    HANDLE hPipeWrite = NULL;
    SECURITY_ATTRIBUTES sa = {0};  

    sa.nLength = sizeof(sa);
    sa.bInheritHandle = TRUE;
    sa.lpSecurityDescriptor = NULL;

    /* Build the command line. Should look something like this:
     * C:/apache/bin/apache.exe -f ap_server_confname 
     * First, get the path to the executable...
     */
    rv = GetModuleFileName(NULL, buf, sizeof(buf));
    if (rv == sizeof(buf)) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, ERROR_BAD_PATHNAME, server_conf,
                     "Parent: Path to Apache process too long");
        return -1;
    } else if (rv == 0) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                     "Parent: GetModuleFileName() returned NULL for current process.");
        return -1;
    }

    /* Build the command line */
    pCommand = ap_psprintf(p, "\"%s\"", buf);  
    for (i = 1; i < server_conf->process->argc; i++) {
        pCommand = ap_pstrcat(p, pCommand, " \"", server_conf->process->argv[i], "\"", NULL);
    }

    /* Create a pipe to send socket info to the child */
    if (!CreatePipe(&hPipeRead, &hPipeWrite, &sa, 0)) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                     "Parent: Unable to create pipe to child process.\n");
        return -1;
    }

    SetEnvironmentVariable("AP_PARENT_PID",ap_psprintf(p,"%d",parent_pid));

    /* Give the read end of the pipe (hPipeRead) to the child as stdin. The 
     * parent will write the socket data to the child on this pipe.
     */
    memset(&si, 0, sizeof(si));
    memset(&pi, 0, sizeof(pi));
    si.cb = sizeof(si);
    si.dwFlags     = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
    si.wShowWindow = SW_HIDE;
    si.hStdInput   = hPipeRead;

    if (!CreateProcess(NULL, pCommand, NULL, NULL, 
                       TRUE,               /* Inherit handles */
                       CREATE_SUSPENDED,   /* Creation flags */
                       NULL,               /* Environment block */
                       NULL,
                       &si, &pi)) {
        ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                     "Parent: Not able to create the child process.");
        /*
         * We must close the handles to the new process and its main thread
         * to prevent handle and memory leaks.
         */ 
        CloseHandle(pi.hProcess);
        CloseHandle(pi.hThread);
        return -1;
    }
    else {
        HANDLE kill_event;
        LPWSAPROTOCOL_INFO  lpWSAProtocolInfo;
        HANDLE hDupedCompPort;

        ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS, server_conf,
                     "Parent: Created child process %d", pi.dwProcessId);

        SetEnvironmentVariable("AP_PARENT_PID",NULL);

        /* Create the exit_event, apCchild_pid */
        sa.nLength = sizeof(sa);
        sa.bInheritHandle = TRUE;
        sa.lpSecurityDescriptor = NULL;        
        kill_event = CreateEvent(&sa, TRUE, FALSE, ap_psprintf(pconf,"apC%d", pi.dwProcessId));
        if (!kill_event) {
            ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                         "Parent: Could not create exit event for child process");
            CloseHandle(pi.hProcess);
            CloseHandle(pi.hThread);
            return -1;
        }
        
        /* Assume the child process lives. Update the process and event tables */
        handles[*processes] = pi.hProcess;
        events[*processes] = kill_event;
        (*processes)++;

        /* We never store the thread's handle, so close it now. */
        ResumeThread(pi.hThread);
        CloseHandle(pi.hThread);

        /* Run the chain of open sockets. For each socket, duplicate it 
         * for the target process then send the WSAPROTOCOL_INFO 
         * (returned by dup socket) to the child */
        for (lr = ap_listeners; lr; lr = lr->next) {
            int nsd;
            lpWSAProtocolInfo = ap_pcalloc(p, sizeof(WSAPROTOCOL_INFO));
            ap_get_os_sock(&nsd,lr->sd);
            ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_INFO, APR_SUCCESS, server_conf,
                         "Parent: Duplicating socket %d and sending it to child process %d", nsd, pi.dwProcessId);
            if (WSADuplicateSocket(nsd, pi.dwProcessId,
                                   lpWSAProtocolInfo) == SOCKET_ERROR) {
                ap_log_error(APLOG_MARK, APLOG_CRIT, h_errno, server_conf,
                             "Parent: WSADuplicateSocket failed for socket %d.", lr->sd );
                return -1;
            }

            if (!WriteFile(hPipeWrite, lpWSAProtocolInfo, (DWORD) sizeof(WSAPROTOCOL_INFO),
                           &BytesWritten,
                           (LPOVERLAPPED) NULL)) {
                ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                             "Parent: Unable to write duplicated socket %d to the child.", lr->sd );
                return -1;
            }
            ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, APR_SUCCESS, server_conf,
                         "Parent: BytesWritten = %d WSAProtocolInfo = %x20", BytesWritten, *lpWSAProtocolInfo);
        }
        if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS) {
            /* Now, send the AcceptEx completion port to the child */
            if (!DuplicateHandle(GetCurrentProcess(), AcceptExCompPort, 
                                 pi.hProcess, &hDupedCompPort,  0,
                                 TRUE, DUPLICATE_SAME_ACCESS)) {
                ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                             "Parent: Unable to duplicate AcceptEx completion port. Shutting down.");
                return -1;
            }

            WriteFile(hPipeWrite, &hDupedCompPort, (DWORD) sizeof(hDupedCompPort), &BytesWritten, (LPOVERLAPPED) NULL);
        }
    }

    CloseHandle(hPipeRead);
    CloseHandle(hPipeWrite);        

    return 0;
}

static int master_main(server_rec *s, HANDLE shutdown_event, HANDLE restart_event)
{
    int remaining_children_to_start = ap_daemons_to_start;
    int i;
    int rv, cld;
    int child_num = 0;
    int restart_pending = 0;
    int shutdown_pending = 0;
    int current_live_processes = 0; /* number of child process we know about */

    HANDLE process_handles[MAX_PROCESSES];
    HANDLE process_kill_events[MAX_PROCESSES];

    setup_listeners(s);
    bind_listeners_to_completion_port();

    /* Create child process 
     * Should only be one in this version of Apache for WIN32 
     */
    service_set_status(SERVICE_START_PENDING);
    while (remaining_children_to_start--) {
        if (create_process(pconf, process_handles, process_kill_events, 
                           &current_live_processes) < 0) {
            ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
                         "master_main: create child process failed. Exiting.");
            shutdown_pending = 1;
            goto die_now;
        }
    }
    service_set_status(SERVICE_RUNNING);

    restart_pending = shutdown_pending = 0;
    
    /* Wait for shutdown or restart events or for child death */
    process_handles[current_live_processes] = shutdown_event;
    process_handles[current_live_processes+1] = restart_event;

    rv = WaitForMultipleObjects(current_live_processes+2, (HANDLE *)process_handles, 
                                FALSE, INFINITE);
    cld = rv - WAIT_OBJECT_0;
    if (rv == WAIT_FAILED) {
        /* Something serious is wrong */
        ap_log_error(APLOG_MARK,APLOG_CRIT, GetLastError(), server_conf,
                     "master_main: WaitForMultipeObjects WAIT_FAILED -- doing server shutdown");
        shutdown_pending = 1;
    }
    else if (rv == WAIT_TIMEOUT) {
        /* Hey, this cannot happen */
        ap_log_error(APLOG_MARK, APLOG_ERR, GetLastError(), s,
                     "master_main: WaitForMultipeObjects with INFINITE wait exited with WAIT_TIMEOUT");
        shutdown_pending = 1;
    }
    else if (cld == current_live_processes) {
        /* shutdown_event signalled */
        shutdown_pending = 1;
        printf("shutdown event signaled\n");
        ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, APR_SUCCESS, s, 
                     "master_main: Shutdown event signaled -- doing server shutdown.");
        if (ResetEvent(shutdown_event) == 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, GetLastError(), s,
                         "ResetEvent(shutdown_event)");
        }

    }
    else if (cld == current_live_processes+1) {
        /* restart_event signalled */
        int children_to_kill = current_live_processes;
        restart_pending = 1;
        ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, APR_SUCCESS, s, 
                     "master_main: Restart event signaled. Doing a graceful restart.");
        if (ResetEvent(restart_event) == 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, GetLastError(), s,
                         "master_main: ResetEvent(restart_event) failed.");
        }
        /* Signal each child process to die 
         * We are making a big assumption here that the child process, once signaled,
         * will REALLY go away. Since this is a restart, we do not want to hold the 
         * new child process up waiting for the old child to die. Remove the old 
         * child out of the process_handles ap_table_t and hope for the best...
         */
        for (i = 0; i < children_to_kill; i++) {
            printf("SetEvent handle = %d\n", process_kill_events[i]);
            if (SetEvent(process_kill_events[i]) == 0)
                ap_log_error(APLOG_MARK, APLOG_ERR, GetLastError(), s,
                             "master_main: SetEvent for child process in slot #%d failed", i);
            cleanup_process(process_handles, process_kill_events, i, &current_live_processes);
        }
    } 
    else {
        /* A child process must have exited because of a fatal error condition (seg fault, etc.). 
         * Remove the dead process 
         * from the process_handles and process_kill_events ap_table_t and create a new
         * child process.
         * TODO: Consider restarting the child immediately without looping through http_main
         * and without rereading the configuration. Will need this if we ever support multiple 
         * children. One option, create a parent thread which waits on child death and restarts it.
         */
        restart_pending = 1;
        ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, APR_SUCCESS, server_conf, 
                     "master_main: Child process failed. Restarting the child process.");
        ap_assert(cld < current_live_processes);
        cleanup_process(process_handles, process_kill_events, cld, &current_live_processes);
        /* APD2("main_process: child in slot %d died", rv); */
        /* restart_child(process_hancles, process_kill_events, cld, &current_live_processes); */

        /* Drain the AcceptEx completion port of any outstanding I/O pending for the dead 
         * process. */
        drain_acceptex_complport(AcceptExCompPort, FALSE);
    }

die_now:
    if (shutdown_pending) {
        int tmstart = time(NULL);
        /* Signal each child processes to die */
        for (i = 0; i < current_live_processes; i++) {
            printf("SetEvent handle = %d\n", process_kill_events[i]);
            if (SetEvent(process_kill_events[i]) == 0)
                ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                             "master_main: SetEvent for child process in slot #%d failed", i);
        }

        while (current_live_processes && ((tmstart+60) > time(NULL))) {
            rv = WaitForMultipleObjects(current_live_processes, (HANDLE *)process_handles, FALSE, 2000);
            if (rv == WAIT_TIMEOUT)
                continue;
            ap_assert(rv != WAIT_FAILED);
            cld = rv - WAIT_OBJECT_0;
            ap_assert(rv < current_live_processes);
            cleanup_process(process_handles, process_kill_events, cld, &current_live_processes);
        }
        for (i = 0; i < current_live_processes; i++) {
            ap_log_error(APLOG_MARK,APLOG_ERR|APLOG_NOERRNO, APR_SUCCESS, server_conf,
                         "forcing termination of child #%d (handle %d)", i, process_handles[i]);
            TerminateProcess((HANDLE) process_handles[i], 1);
        }
        return 0;  /* Tell the caller we do not want to restart */
    }

    return 1;      /* Tell the caller we want a restart */
}

/* 
 * winnt_pre_config() hook
 */
static void winnt_pre_config(ap_pool_t *pconf, ap_pool_t *plog, ap_pool_t *ptemp) 
{
    char *pid;

    one_process = !!getenv("ONE_PROCESS");

    osver.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    GetVersionEx(&osver);

    /* AP_PARENT_PID is only valid in the child */
    pid = getenv("AP_PARENT_PID");
    if (pid) {
        /* This is the child */
        parent_pid = atoi(pid);
        my_pid = getpid();
    }
    else {
        /* This is the parent */
        parent_pid = my_pid = getpid();
    }

    ap_listen_pre_config();
    ap_daemons_to_start = DEFAULT_NUM_DAEMON;
    ap_threads_per_child = DEFAULT_START_THREAD;
    ap_pid_fname = DEFAULT_PIDLOG;
    max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;

    ap_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));

}

static void winnt_post_config(ap_pool_t *pconf, ap_pool_t *plog, ap_pool_t *ptemp, server_rec* server_conf)
{
    static int restart_num = 0;
    server_conf = server_conf;

    if (parent_pid == my_pid) {
        if (restart_num++ == 1) {
            /* This code should be run once in the parent and not run
             * accross a restart
             */
            PSECURITY_ATTRIBUTES sa = GetNullACL();  /* returns NULL if invalid (Win95?) */
            setup_signal_names(ap_psprintf(pconf,"ap%d", parent_pid));
            if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS) {
                /* Create the AcceptEx IoCompletionPort once in the parent.
                 * The completion port persists across restarts. 
                 */
                AcceptExCompPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE,
                                                          NULL,
                                                          0,
                                                          0); /* CONCURRENT ACTIVE THREADS */
                if (AcceptExCompPort == NULL) {
                    ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
                                 "Parent: Unable to create the AcceptExCompletionPort -- process will exit");
                    exit(1);
                }
            }

            ap_log_pid(pconf, ap_pid_fname);
            service_set_status(SERVICE_START_PENDING);

            AMCSocketInitialize();
        
            /* Create shutdown event, apPID_shutdown, where PID is the parent 
             * Apache process ID. Shutdown is signaled by 'apache -k shutdown'.
             */
            shutdown_event = CreateEvent(sa, FALSE, FALSE, signal_shutdown_name);
            if (!shutdown_event) {
                ap_log_error(APLOG_MARK, APLOG_EMERG, GetLastError(), server_conf,
                             "Parent: Cannot create shutdown event %s", signal_shutdown_name);
                CleanNullACL((void *)sa);
                exit(1);
            }

            /* Create restart event, apPID_restart, where PID is the parent 
             * Apache process ID. Restart is signaled by 'apache -k restart'.
             */
            restart_event = CreateEvent(sa, FALSE, FALSE, signal_restart_name);
            if (!restart_event) {
                CloseHandle(shutdown_event);
                ap_log_error(APLOG_MARK, APLOG_EMERG, GetLastError(), server_conf,
                             "Parent: Cannot create restart event %s", signal_restart_name);
                CleanNullACL((void *)sa);
                exit(1);
            }
            CleanNullACL((void *)sa);
            
            /* Create the start mutex, apPID, where PID is the parent Apache process ID.
             * Ths start mutex is used during a restart to prevent more than one 
             * child process from entering the accept loop at once.
             */
            ap_create_lock(&start_mutex,APR_MUTEX, APR_CROSS_PROCESS, signal_name_prefix,
                               server_conf->process->pool);
        }
    }
}

API_EXPORT(int) ap_mpm_run(ap_pool_t *_pconf, ap_pool_t *plog, server_rec *s )
{
    static int restart = 0;            /* Default is "not a restart" */

    pconf = _pconf;
    server_conf = s;

    if ((parent_pid != my_pid) || one_process) {
        /* Running as Child process or in one_process (debug) mode */
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_SUCCESS, server_conf,
                     "Child %d: Child process is running", my_pid);
        AMCSocketInitialize();
        child_main();
        AMCSocketCleanup();
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_SUCCESS, server_conf,
                     "Child %d: Child process is exiting", my_pid);        

        return 1;
    }  /* Child or single process */
    else { /* Parent process */
        restart = master_main(server_conf, shutdown_event, restart_event);

        if (!restart) {
            /* Shutting down. Clean up... */
            const char *pidfile = ap_server_root_relative (pconf, ap_pid_fname);

            if (pidfile != NULL && unlink(pidfile) == 0) {
                ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO,APR_SUCCESS,
                             server_conf, "removed PID file %s (pid=%ld)",
                             pidfile, (long)getpid());
            }
            ap_destroy_lock(start_mutex);

            CloseHandle(restart_event);
            CloseHandle(shutdown_event);
            AMCSocketCleanup();

            service_set_status(SERVICE_STOPPED);

            return 1;
        }
    }  /* Parent process */

    return 0; /* Restart */
}

static void winnt_hooks(void)
{
    one_process = 0;
    ap_hook_post_config(winnt_post_config, NULL, NULL, 0);
}

/* 
 * Command processors 
 */
static const char *set_pidfile(cmd_parms *cmd, void *dummy, char *arg) 
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    if (cmd->server->is_virtual) {
        return "PidFile directive not allowed in <VirtualHost>";
    }
    ap_pid_fname = arg;
    return NULL;
}

static const char *set_threads_per_child (cmd_parms *cmd, void *dummy, char *arg) 
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    ap_threads_per_child = atoi(arg);
    if (ap_threads_per_child > HARD_THREAD_LIMIT) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, 
                     "WARNING: ThreadsPerChild of %d exceeds compile time"
                     " limit of %d threads,", ap_threads_per_child, 
                     HARD_THREAD_LIMIT);
        ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
                     " lowering ThreadsPerChild to %d. To increase, please"
                     " see the  HARD_THREAD_LIMIT define in src/include/httpd.h.", 
                     HARD_THREAD_LIMIT);
    }
    else if (ap_threads_per_child < 1) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL, 
                     "WARNING: Require ThreadsPerChild > 0, setting to 1");
        ap_threads_per_child = 1;
    }
    return NULL;
}


static const char *set_max_requests(cmd_parms *cmd, void *dummy, char *arg) 
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    max_requests_per_child = atoi(arg);

    return NULL;
}

static const char *set_coredumpdir (cmd_parms *cmd, void *dummy, char *arg) 
{
    struct stat finfo;
    const char *fname;
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    fname = ap_server_root_relative(cmd->pool, arg);
    if ((stat(fname, &finfo) == -1) || !S_ISDIR(finfo.st_mode)) {
        return ap_pstrcat(cmd->pool, "CoreDumpDirectory ", fname, 
                          " does not exist or is not a directory", NULL);
    }
    ap_cpystrn(ap_coredump_dir, fname, sizeof(ap_coredump_dir));
    return NULL;
}

/* Stub functions until this MPM supports the connection status API */

API_EXPORT(void) ap_update_connection_status(long conn_id, const char *key, \
                                             const char *value)
{
    /* NOP */
}

API_EXPORT(void) ap_reset_connection_status(long conn_id)
{
    /* NOP */
}

API_EXPORT(ap_array_header_t *) ap_get_status_table(ap_pool_t *p)
{
    /* NOP */
    return NULL;
}

static const command_rec winnt_cmds[] = {
LISTEN_COMMANDS
{ "PidFile", set_pidfile, NULL, RSRC_CONF, TAKE1,
    "A file for logging the server process ID"},
{ "ThreadsPerChild", set_threads_per_child, NULL, RSRC_CONF, TAKE1,
  "Number of threads each child creates" },
{ "MaxRequestsPerChild", set_max_requests, NULL, RSRC_CONF, TAKE1,
  "Maximum number of requests a particular child serves before dying." },
{ "CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF, TAKE1,
  "The location of the directory Apache changes to before dumping core" },
{ NULL }
};

module MODULE_VAR_EXPORT mpm_winnt_module = {
    MPM20_MODULE_STUFF,
    winnt_pre_config,           /* hook run before configuration is read */
    NULL,                       /* create per-directory config structure */
    NULL,                       /* merge per-directory config structures */
    NULL,                       /* create per-server config structure */
    NULL,                       /* merge per-server config structures */
    winnt_cmds,                 /* command ap_table_t */
    NULL,                       /* handlers */
    winnt_hooks                 /* register_hooks */
};