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DEFINITIONS
This source file includes following definitions.
- mpm_recycle_completion_context
- mpm_get_completion_context
- mpm_post_completion_context
- find_ready_listener
- add_job
- remove_job
- win9x_accept
- win9x_get_connection
- winnt_accept
- winnt_get_connection
- worker_main
- cleanup_thread
- create_listener_thread
- child_main
/* 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.
*/
#ifdef WIN32
#define CORE_PRIVATE
#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 "apr_portable.h"
#include "apr_thread_proc.h"
#include "apr_getopt.h"
#include "apr_strings.h"
#include "apr_lib.h"
#include "apr_shm.h"
#include "apr_thread_mutex.h"
#include "ap_mpm.h"
#include "ap_config.h"
#include "ap_listen.h"
#include "mpm_default.h"
#include "mpm_winnt.h"
#include "mpm_common.h"
#include <malloc.h>
#include "apr_atomic.h"
/* shared with mpm_winnt.c */
extern DWORD my_pid;
/* used by parent to signal the child to start and exit */
/* shared with mpm_winnt.c, but should be private to child.c */
apr_proc_mutex_t *start_mutex;
HANDLE exit_event;
/* child_main() should never need to modify is_graceful!?! */
extern int volatile is_graceful;
/* Queue for managing the passing of COMP_CONTEXTs between
* the accept and worker threads.
*/
static apr_pool_t *pchild;
static int shutdown_in_progress = 0;
static int workers_may_exit = 0;
static unsigned int g_blocked_threads = 0;
static HANDLE max_requests_per_child_event;
static apr_thread_mutex_t *child_lock;
static apr_thread_mutex_t *qlock;
static PCOMP_CONTEXT qhead = NULL;
static PCOMP_CONTEXT qtail = NULL;
static int num_completion_contexts = 0;
static int max_num_completion_contexts = 0;
static HANDLE ThreadDispatchIOCP = NULL;
static HANDLE qwait_event = NULL;
void mpm_recycle_completion_context(PCOMP_CONTEXT context)
{
/* Recycle the completion context.
* - clear the ptrans pool
* - put the context on the queue to be consumed by the accept thread
* Note:
* context->accept_socket may be in a disconnected but reusable
* state so -don't- close it.
*/
if (context) {
apr_pool_clear(context->ptrans);
context->ba = apr_bucket_alloc_create(context->ptrans);
context->next = NULL;
ResetEvent(context->Overlapped.hEvent);
apr_thread_mutex_lock(qlock);
if (qtail) {
qtail->next = context;
} else {
qhead = context;
SetEvent(qwait_event);
}
qtail = context;
apr_thread_mutex_unlock(qlock);
}
}
PCOMP_CONTEXT mpm_get_completion_context(void)
{
apr_status_t rv;
PCOMP_CONTEXT context = NULL;
while (1) {
/* Grab a context off the queue */
apr_thread_mutex_lock(qlock);
if (qhead) {
context = qhead;
qhead = qhead->next;
if (!qhead)
qtail = NULL;
} else {
ResetEvent(qwait_event);
}
apr_thread_mutex_unlock(qlock);
if (!context) {
/* We failed to grab a context off the queue, consider allocating
* a new one out of the child pool. There may be up to
* (ap_threads_per_child + num_listeners) contexts in the system
* at once.
*/
if (num_completion_contexts >= max_num_completion_contexts) {
/* All workers are busy, need to wait for one */
static int reported = 0;
if (!reported) {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf,
"Server ran out of threads to serve requests. Consider "
"raising the ThreadsPerChild setting");
reported = 1;
}
/* Wait for a worker to free a context. Once per second, give
* the caller a chance to check for shutdown. If the wait
* succeeds, get the context off the queue. It must be available,
* since there's only one consumer.
*/
rv = WaitForSingleObject(qwait_event, 1000);
if (rv == WAIT_OBJECT_0)
continue;
else /* Hopefully, WAIT_TIMEOUT */
return NULL;
} else {
/* Allocate another context.
* Note:
* Multiple failures in the next two steps will cause the pchild pool
* to 'leak' storage. I don't think this is worth fixing...
*/
apr_allocator_t *allocator;
apr_thread_mutex_lock(child_lock);
context = (PCOMP_CONTEXT) apr_pcalloc(pchild, sizeof(COMP_CONTEXT));
context->Overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (context->Overlapped.hEvent == NULL) {
/* Hopefully this is a temporary condition ... */
ap_log_error(APLOG_MARK,APLOG_WARNING, apr_get_os_error(), ap_server_conf,
"mpm_get_completion_context: CreateEvent failed.");
apr_thread_mutex_unlock(child_lock);
return NULL;
}
/* Create the tranaction pool */
apr_allocator_create(&allocator);
apr_allocator_max_free_set(allocator, ap_max_mem_free);
rv = apr_pool_create_ex(&context->ptrans, pchild, NULL, allocator);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK,APLOG_WARNING, rv, ap_server_conf,
"mpm_get_completion_context: Failed to create the transaction pool.");
CloseHandle(context->Overlapped.hEvent);
apr_thread_mutex_unlock(child_lock);
return NULL;
}
apr_allocator_owner_set(allocator, context->ptrans);
apr_pool_tag(context->ptrans, "transaction");
context->accept_socket = INVALID_SOCKET;
context->ba = apr_bucket_alloc_create(context->ptrans);
apr_atomic_inc32(&num_completion_contexts);
apr_thread_mutex_unlock(child_lock);
break;
}
} else {
/* Got a context from the queue */
break;
}
}
return context;
}
apr_status_t mpm_post_completion_context(PCOMP_CONTEXT context,
io_state_e state)
{
LPOVERLAPPED pOverlapped;
if (context)
pOverlapped = &context->Overlapped;
else
pOverlapped = NULL;
PostQueuedCompletionStatus(ThreadDispatchIOCP, 0, state, pOverlapped);
return APR_SUCCESS;
}
/*
* find_ready_listener()
* Only used by Win9* and should go away when the win9*_accept() function is
* reimplemented using apr_poll().
*/
static ap_listen_rec *head_listener;
static APR_INLINE ap_listen_rec *find_ready_listener(fd_set * main_fds)
{
ap_listen_rec *lr;
SOCKET nsd;
lr = head_listener;
do {
apr_os_sock_get(&nsd, lr->sd);
if (FD_ISSET(nsd, main_fds)) {
head_listener = lr->next;
if (!head_listener) {
head_listener = ap_listeners;
}
return lr;
}
lr = lr->next;
if (!lr) {
lr = ap_listeners;
}
} while (lr != head_listener);
return NULL;
}
/* 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_accept()
* 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.
* win9x_get_connection()
* Calls remove_job() to pull a job from the accept queue. All the worker
* threads block on remove_job.
*/
typedef struct joblist_s {
struct joblist_s *next;
SOCKET sock;
} joblist;
typedef struct globals_s {
HANDLE jobsemaphore;
joblist *jobhead;
joblist *jobtail;
apr_thread_mutex_t *jobmutex;
int jobcount;
} globals;
globals allowed_globals = {NULL, NULL, NULL, NULL, 0};
#define MAX_SELECT_ERRORS 100
static void add_job(SOCKET sock)
{
joblist *new_job;
new_job = (joblist *) malloc(sizeof(joblist));
if (new_job == NULL) {
ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
"Ouch! Out of memory in add_job()!");
return;
}
new_job->next = NULL;
new_job->sock = sock;
apr_thread_mutex_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++;
ReleaseSemaphore(allowed_globals.jobsemaphore, 1, NULL);
apr_thread_mutex_unlock(allowed_globals.jobmutex);
}
static SOCKET remove_job(void)
{
joblist *job;
SOCKET sock;
WaitForSingleObject(allowed_globals.jobsemaphore, INFINITE);
apr_thread_mutex_lock(allowed_globals.jobmutex);
if (shutdown_in_progress && !allowed_globals.jobhead) {
apr_thread_mutex_unlock(allowed_globals.jobmutex);
return (INVALID_SOCKET);
}
job = allowed_globals.jobhead;
ap_assert(job);
allowed_globals.jobhead = job->next;
if (allowed_globals.jobhead == NULL)
allowed_globals.jobtail = NULL;
apr_thread_mutex_unlock(allowed_globals.jobmutex);
sock = job->sock;
free(job);
return (sock);
}
static unsigned int __stdcall win9x_accept(void * dummy)
{
struct timeval tv;
fd_set main_fds;
int wait_time = 1;
SOCKET csd;
SOCKET nsd = INVALID_SOCKET;
int count_select_errors = 0;
int rc;
int clen;
ap_listen_rec *lr;
struct fd_set listenfds;
#if APR_HAVE_IPV6
struct sockaddr_in6 sa_client;
#else
struct sockaddr_in sa_client;
#endif
/* Setup the listeners
* ToDo: Use apr_poll()
*/
FD_ZERO(&listenfds);
for (lr = ap_listeners; lr; lr = lr->next) {
if (lr->sd != NULL) {
apr_os_sock_get(&nsd, lr->sd);
FD_SET(nsd, &listenfds);
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"Child %d: Listening on port %d.", my_pid, lr->bind_addr->port);
}
}
head_listener = ap_listeners;
while (!shutdown_in_progress) {
tv.tv_sec = wait_time;
tv.tv_usec = 0;
memcpy(&main_fds, &listenfds, sizeof(fd_set));
/* First parameter of select() is ignored on Windows */
rc = select(0, &main_fds, NULL, NULL, &tv);
if (rc == 0 || (rc == SOCKET_ERROR && APR_STATUS_IS_EINTR(apr_get_netos_error()))) {
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, apr_get_netos_error(), ap_server_conf,
"select failed with error %d", apr_get_netos_error());
count_select_errors++;
if (count_select_errors > MAX_SELECT_ERRORS) {
shutdown_in_progress = 1;
ap_log_error(APLOG_MARK, APLOG_ERR, apr_get_netos_error(), ap_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 */
apr_os_sock_get(&nsd, lr->sd);
}
}
do {
clen = sizeof(sa_client);
csd = accept(nsd, (struct sockaddr *) &sa_client, &clen);
} while (csd < 0 && APR_STATUS_IS_EINTR(apr_get_netos_error()));
if (csd < 0) {
if (APR_STATUS_IS_ECONNABORTED(apr_get_netos_error())) {
ap_log_error(APLOG_MARK, APLOG_ERR, apr_get_netos_error(), ap_server_conf,
"accept: (client socket)");
}
}
else {
add_job(csd);
}
}
SetEvent(exit_event);
return 0;
}
static PCOMP_CONTEXT win9x_get_connection(PCOMP_CONTEXT context)
{
apr_os_sock_info_t sockinfo;
int len, salen;
#if APR_HAVE_IPV6
salen = sizeof(struct sockaddr_in6);
#else
salen = sizeof(struct sockaddr_in);
#endif
if (context == NULL) {
/* allocate the completion context and the transaction pool */
apr_allocator_t *allocator;
apr_thread_mutex_lock(child_lock);
context = apr_pcalloc(pchild, sizeof(COMP_CONTEXT));
apr_allocator_create(&allocator);
apr_allocator_max_free_set(allocator, ap_max_mem_free);
apr_pool_create_ex(&context->ptrans, pchild, NULL, allocator);
apr_allocator_owner_set(allocator, context->ptrans);
apr_pool_tag(context->ptrans, "transaction");
apr_thread_mutex_unlock(child_lock);
}
while (1) {
apr_pool_clear(context->ptrans);
context->ba = apr_bucket_alloc_create(context->ptrans);
context->accept_socket = remove_job();
if (context->accept_socket == INVALID_SOCKET) {
return NULL;
}
len = salen;
context->sa_server = apr_palloc(context->ptrans, len);
if (getsockname(context->accept_socket,
context->sa_server, &len)== SOCKET_ERROR) {
ap_log_error(APLOG_MARK, APLOG_WARNING, apr_get_netos_error(), ap_server_conf,
"getsockname failed");
continue;
}
len = salen;
context->sa_client = apr_palloc(context->ptrans, len);
if ((getpeername(context->accept_socket,
context->sa_client, &len)) == SOCKET_ERROR) {
ap_log_error(APLOG_MARK, APLOG_WARNING, apr_get_netos_error(), ap_server_conf,
"getpeername failed");
memset(&context->sa_client, '\0', sizeof(context->sa_client));
}
sockinfo.os_sock = &context->accept_socket;
sockinfo.local = context->sa_server;
sockinfo.remote = context->sa_client;
sockinfo.family = context->sa_server->sa_family;
sockinfo.type = SOCK_STREAM;
apr_os_sock_make(&context->sock, &sockinfo, context->ptrans);
return context;
}
}
/* Windows NT/2000 specific code...
* Accept processing for on Windows NT uses a producer/consumer queue
* model. An accept thread accepts connections off the network then issues
* PostQueuedCompletionStatus() to awake a thread blocked on the ThreadDispatch
* IOCompletionPort.
*
* winnt_accept()
* One or more accept threads run in this function, each of which accepts
* connections off the network and calls PostQueuedCompletionStatus() to
* queue an io completion packet to the ThreadDispatch IOCompletionPort.
* winnt_get_connection()
* Worker threads block on the ThreadDispatch IOCompletionPort awaiting
* connections to service.
*/
#define MAX_ACCEPTEX_ERR_COUNT 100
static unsigned int __stdcall winnt_accept(void *lr_)
{
ap_listen_rec *lr = (ap_listen_rec *)lr_;
apr_os_sock_info_t sockinfo;
PCOMP_CONTEXT context = NULL;
DWORD BytesRead;
SOCKET nlsd;
int rv, err_count = 0;
#if APR_HAVE_IPV6
SOCKADDR_STORAGE ss_listen;
int namelen = sizeof(ss_listen);
#endif
apr_os_sock_get(&nlsd, lr->sd);
#if APR_HAVE_IPV6
if (getsockname(nlsd, (struct sockaddr *)&ss_listen, &namelen) == SOCKET_ERROR) {
ap_log_error(APLOG_MARK,APLOG_ERR, apr_get_netos_error(), ap_server_conf,
"winnt_accept: getsockname error on listening socket, is IPv6 available?");
return 1;
}
#endif
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
"Child %d: Starting thread to listen on port %d.", my_pid, lr->bind_addr->port);
while (!shutdown_in_progress) {
if (!context) {
context = mpm_get_completion_context();
if (!context) {
/* Temporary resource constraint? */
Sleep(0);
continue;
}
}
/* Create and initialize the accept socket */
#if APR_HAVE_IPV6
if (context->accept_socket == INVALID_SOCKET) {
context->accept_socket = socket(ss_listen.ss_family, SOCK_STREAM, IPPROTO_TCP);
context->socket_family = ss_listen.ss_family;
}
else if (context->socket_family != ss_listen.ss_family) {
closesocket(context->accept_socket);
context->accept_socket = socket(ss_listen.ss_family, SOCK_STREAM, IPPROTO_TCP);
context->socket_family = ss_listen.ss_family;
}
if (context->accept_socket == INVALID_SOCKET) {
ap_log_error(APLOG_MARK,APLOG_WARNING, apr_get_netos_error(), ap_server_conf,
"winnt_accept: Failed to allocate an accept socket. "
"Temporary resource constraint? Try again.");
Sleep(100);
continue;
}
#else
if (context->accept_socket == INVALID_SOCKET) {
context->accept_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (context->accept_socket == INVALID_SOCKET) {
/* Another temporary condition? */
ap_log_error(APLOG_MARK,APLOG_WARNING, apr_get_netos_error(), ap_server_conf,
"winnt_accept: Failed to allocate an accept socket. "
"Temporary resource constraint? Try again.");
Sleep(100);
continue;
}
}
#endif
/* AcceptEx on the completion context. The completion context will be
* signaled when a connection is accepted.
*/
if (!AcceptEx(nlsd, context->accept_socket,
context->buff,
0,
PADDED_ADDR_SIZE,
PADDED_ADDR_SIZE,
&BytesRead,
&context->Overlapped)) {
rv = apr_get_netos_error();
if ((rv == APR_FROM_OS_ERROR(WSAEINVAL)) ||
(rv == APR_FROM_OS_ERROR(WSAENOTSOCK))) {
/* We can get here when:
* 1) the client disconnects early
* 2) TransmitFile does not properly recycle the accept socket (typically
* because the client disconnected)
* 3) there is VPN or Firewall software installed with buggy AcceptEx implementation
* 4) the webserver is using a dynamic address that has changed
*/
++err_count;
closesocket(context->accept_socket);
context->accept_socket = INVALID_SOCKET;
if (err_count > MAX_ACCEPTEX_ERR_COUNT) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
"Child %d: Encountered too many errors accepting client connections. "
"Possible causes: dynamic address renewal, or incompatible VPN or firewall software. "
"Try using the Win32DisableAcceptEx directive.", my_pid);
err_count = 0;
}
continue;
}
else if ((rv != APR_FROM_OS_ERROR(ERROR_IO_PENDING)) &&
(rv != APR_FROM_OS_ERROR(WSA_IO_PENDING))) {
++err_count;
if (err_count > MAX_ACCEPTEX_ERR_COUNT) {
ap_log_error(APLOG_MARK,APLOG_ERR, rv, ap_server_conf,
"Child %d: Encountered too many errors accepting client connections. "
"Possible causes: Unknown. "
"Try using the Win32DisableAcceptEx directive.", my_pid);
err_count = 0;
}
closesocket(context->accept_socket);
context->accept_socket = INVALID_SOCKET;
continue;
}
err_count = 0;
/* Wait for pending i/o.
* Wake up once per second to check for shutdown .
* XXX: We should be waiting on exit_event instead of polling
*/
while (1) {
rv = WaitForSingleObject(context->Overlapped.hEvent, 1000);
if (rv == WAIT_OBJECT_0) {
if (context->accept_socket == INVALID_SOCKET) {
/* socket already closed */
break;
}
if (!GetOverlappedResult((HANDLE)context->accept_socket,
&context->Overlapped,
&BytesRead, FALSE)) {
ap_log_error(APLOG_MARK, APLOG_WARNING,
apr_get_os_error(), ap_server_conf,
"winnt_accept: Asynchronous AcceptEx failed.");
closesocket(context->accept_socket);
context->accept_socket = INVALID_SOCKET;
}
break;
}
/* WAIT_TIMEOUT */
if (shutdown_in_progress) {
closesocket(context->accept_socket);
context->accept_socket = INVALID_SOCKET;
break;
}
}
if (context->accept_socket == INVALID_SOCKET) {
continue;
}
}
err_count = 0;
/* Inherit the listen socket settings. Required for
* shutdown() to work
*/
if (setsockopt(context->accept_socket, SOL_SOCKET,
SO_UPDATE_ACCEPT_CONTEXT, (char *)&nlsd,
sizeof(nlsd))) {
ap_log_error(APLOG_MARK, APLOG_WARNING, apr_get_netos_error(), ap_server_conf,
"setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed.");
/* Not a failure condition. Keep running. */
}
/* Get the local & remote address */
GetAcceptExSockaddrs(context->buff,
0,
PADDED_ADDR_SIZE,
PADDED_ADDR_SIZE,
&context->sa_server,
&context->sa_server_len,
&context->sa_client,
&context->sa_client_len);
sockinfo.os_sock = &context->accept_socket;
sockinfo.local = context->sa_server;
sockinfo.remote = context->sa_client;
sockinfo.family = context->sa_server->sa_family;
sockinfo.type = SOCK_STREAM;
apr_os_sock_make(&context->sock, &sockinfo, context->ptrans);
/* When a connection is received, send an io completion notification to
* the ThreadDispatchIOCP. This function could be replaced by
* mpm_post_completion_context(), but why do an extra function call...
*/
PostQueuedCompletionStatus(ThreadDispatchIOCP, 0, IOCP_CONNECTION_ACCEPTED,
&context->Overlapped);
context = NULL;
}
if (!shutdown_in_progress) {
/* Yow, hit an irrecoverable error! Tell the child to die. */
SetEvent(exit_event);
}
ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS, ap_server_conf,
"Child %d: Accept thread exiting.", my_pid);
return 0;
}
static PCOMP_CONTEXT winnt_get_connection(PCOMP_CONTEXT context)
{
int rc;
DWORD BytesRead;
LPOVERLAPPED pol;
#ifdef _WIN64
ULONG_PTR CompKey;
#else
DWORD CompKey;
#endif
mpm_recycle_completion_context(context);
apr_atomic_inc32(&g_blocked_threads);
while (1) {
if (workers_may_exit) {
apr_atomic_dec32(&g_blocked_threads);
return NULL;
}
rc = GetQueuedCompletionStatus(ThreadDispatchIOCP, &BytesRead, &CompKey,
&pol, INFINITE);
if (!rc) {
rc = apr_get_os_error();
ap_log_error(APLOG_MARK,APLOG_DEBUG, rc, ap_server_conf,
"Child %d: GetQueuedComplationStatus returned %d", my_pid, rc);
continue;
}
switch (CompKey) {
case IOCP_CONNECTION_ACCEPTED:
context = CONTAINING_RECORD(pol, COMP_CONTEXT, Overlapped);
break;
case IOCP_SHUTDOWN:
apr_atomic_dec32(&g_blocked_threads);
return NULL;
default:
apr_atomic_dec32(&g_blocked_threads);
return NULL;
}
break;
}
apr_atomic_dec32(&g_blocked_threads);
return context;
}
/*
* worker_main()
* Main entry point for the worker threads. Worker threads block in
* win*_get_connection() awaiting a connection to service.
*/
static unsigned int __stdcall worker_main(void *thread_num_val)
{
static int requests_this_child = 0;
PCOMP_CONTEXT context = NULL;
int thread_num = (int)thread_num_val;
ap_sb_handle_t *sbh;
while (1) {
conn_rec *c;
apr_int32_t disconnected;
ap_update_child_status_from_indexes(0, thread_num, SERVER_READY, NULL);
/* Grab a connection off the network */
if (use_acceptex) {
context = winnt_get_connection(context);
}
else {
context = win9x_get_connection(context);
}
if (!context) {
/* Time for the thread to exit */
break;
}
/* Have we hit MaxRequestPerChild connections? */
if (ap_max_requests_per_child) {
requests_this_child++;
if (requests_this_child > ap_max_requests_per_child) {
SetEvent(max_requests_per_child_event);
}
}
ap_create_sb_handle(&sbh, context->ptrans, 0, thread_num);
c = ap_run_create_connection(context->ptrans, ap_server_conf,
context->sock, thread_num, sbh,
context->ba);
if (c) {
ap_process_connection(c, context->sock);
apr_socket_opt_get(context->sock, APR_SO_DISCONNECTED,
&disconnected);
if (!disconnected) {
context->accept_socket = INVALID_SOCKET;
ap_lingering_close(c);
}
else if (!use_acceptex) {
/* If the socket is disconnected but we are not using acceptex,
* we cannot reuse the socket. Disconnected sockets are removed
* from the apr_socket_t struct by apr_sendfile() to prevent the
* socket descriptor from being inadvertently closed by a call
* to apr_socket_close(), so close it directly.
*/
closesocket(context->accept_socket);
context->accept_socket = INVALID_SOCKET;
}
}
else {
/* ap_run_create_connection closes the socket on failure */
context->accept_socket = INVALID_SOCKET;
}
}
ap_update_child_status_from_indexes(0, thread_num, SERVER_DEAD,
(request_rec *) NULL);
return 0;
}
static void cleanup_thread(HANDLE *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()
* Entry point for the main control thread for the child process.
* This thread creates the accept thread, worker threads and
* monitors the child process for maintenance and shutdown
* events.
*/
static void create_listener_thread()
{
int tid;
int num_listeners = 0;
if (!use_acceptex) {
_beginthreadex(NULL, 0, win9x_accept,
NULL, 0, &tid);
} else {
/* Start an accept thread per listener
* XXX: Why would we have a NULL sd in our listeners?
*/
ap_listen_rec *lr;
/* Number of completion_contexts allowed in the system is
* (ap_threads_per_child + num_listeners). We need the additional
* completion contexts to prevent server hangs when ThreadsPerChild
* is configured to something less than or equal to the number
* of listeners. This is not a usual case, but people have
* encountered it.
* */
for (lr = ap_listeners; lr ; lr = lr->next) {
num_listeners++;
}
max_num_completion_contexts = ap_threads_per_child + num_listeners;
/* Now start a thread per listener */
for (lr = ap_listeners; lr; lr = lr->next) {
if (lr->sd != NULL) {
_beginthreadex(NULL, 1000, winnt_accept,
(void *) lr, 0, &tid);
}
}
}
}
void child_main(apr_pool_t *pconf)
{
apr_status_t status;
apr_hash_t *ht;
ap_listen_rec *lr;
HANDLE child_events[2];
HANDLE *child_handles;
int listener_started = 0;
int threads_created = 0;
int watch_thread;
int time_remains;
int cld;
int tid;
int rv;
int i;
apr_pool_create(&pchild, pconf);
apr_pool_tag(pchild, "pchild");
ap_run_child_init(pchild, ap_server_conf);
ht = apr_hash_make(pchild);
/* Initialize the child_events */
max_requests_per_child_event = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!max_requests_per_child_event) {
ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
"Child %d: Failed to create a max_requests event.", my_pid);
exit(APEXIT_CHILDINIT);
}
child_events[0] = exit_event;
child_events[1] = max_requests_per_child_event;
allowed_globals.jobsemaphore = CreateSemaphore(NULL, 0, 1000000, NULL);
apr_thread_mutex_create(&allowed_globals.jobmutex,
APR_THREAD_MUTEX_DEFAULT, 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 = apr_proc_mutex_lock(start_mutex);
if (status != APR_SUCCESS) {
ap_log_error(APLOG_MARK,APLOG_ERR, status, ap_server_conf,
"Child %d: Failed to acquire the start_mutex. Process will exit.", my_pid);
exit(APEXIT_CHILDINIT);
}
ap_log_error(APLOG_MARK,APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
"Child %d: Acquired the start mutex.", my_pid);
/*
* Create the worker thread dispatch IOCompletionPort
* on Windows NT/2000
*/
if (use_acceptex) {
/* Create the worker thread dispatch IOCP */
ThreadDispatchIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE,
NULL,
0,
0); /* CONCURRENT ACTIVE THREADS */
apr_thread_mutex_create(&qlock, APR_THREAD_MUTEX_DEFAULT, pchild);
qwait_event = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!qwait_event) {
ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
"Child %d: Failed to create a qwait event.", my_pid);
exit(APEXIT_CHILDINIT);
}
}
/*
* Create the pool of worker threads
*/
ap_log_error(APLOG_MARK,APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
"Child %d: Starting %d worker threads.", my_pid, ap_threads_per_child);
child_handles = (HANDLE) apr_pcalloc(pchild, ap_threads_per_child * sizeof(HANDLE));
apr_thread_mutex_create(&child_lock, APR_THREAD_MUTEX_DEFAULT, pchild);
while (1) {
for (i = 0; i < ap_threads_per_child; i++) {
int *score_idx;
int status = ap_scoreboard_image->servers[0][i].status;
if (status != SERVER_GRACEFUL && status != SERVER_DEAD) {
continue;
}
ap_update_child_status_from_indexes(0, i, SERVER_STARTING, NULL);
child_handles[i] = (HANDLE) _beginthreadex(NULL, (unsigned)ap_thread_stacksize,
worker_main, (void *) i, 0, &tid);
if (child_handles[i] == 0) {
ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
"Child %d: _beginthreadex failed. Unable to create all worker threads. "
"Created %d of the %d threads requested with the ThreadsPerChild configuration directive.",
my_pid, threads_created, ap_threads_per_child);
ap_signal_parent(SIGNAL_PARENT_SHUTDOWN);
goto shutdown;
}
threads_created++;
/* Save the score board index in ht keyed to the thread handle. We need this
* when cleaning up threads down below...
*/
apr_thread_mutex_lock(child_lock);
score_idx = apr_pcalloc(pchild, sizeof(int));
*score_idx = i;
apr_hash_set(ht, &child_handles[i], sizeof(HANDLE), score_idx);
apr_thread_mutex_unlock(child_lock);
}
/* Start the listener only when workers are available */
if (!listener_started && threads_created) {
create_listener_thread();
listener_started = 1;
winnt_mpm_state = AP_MPMQ_RUNNING;
}
if (threads_created == ap_threads_per_child) {
break;
}
/* Check to see if the child has been told to exit */
if (WaitForSingleObject(exit_event, 0) != WAIT_TIMEOUT) {
break;
}
/* wait for previous generation to clean up an entry in the scoreboard */
apr_sleep(1 * APR_USEC_PER_SEC);
}
/* Wait for one of three events:
* exit_event:
* The exit_event is signaled by the parent process to notify
* the child that it is time to exit.
*
* max_requests_per_child_event:
* This event is signaled by the worker threads to indicate that
* the process has handled MaxRequestsPerChild connections.
*
* TIMEOUT:
* To do periodic maintenance on the server (check for thread exits,
* number of completion contexts, etc.)
*
* XXX: thread exits *aren't* being checked.
*
* XXX: other_child - we need the process handles to the other children
* in order to map them to apr_proc_other_child_read (which is not
* named well, it's more like a_p_o_c_died.)
*
* XXX: however - if we get a_p_o_c handle inheritance working, and
* the parent process creates other children and passes the pipes
* to our worker processes, then we have no business doing such
* things in the child_main loop, but should happen in master_main.
*/
while (1) {
#if !APR_HAS_OTHER_CHILD
rv = WaitForMultipleObjects(2, (HANDLE *) child_events, FALSE, INFINITE);
cld = rv - WAIT_OBJECT_0;
#else
rv = WaitForMultipleObjects(2, (HANDLE *) child_events, FALSE, 1000);
cld = rv - WAIT_OBJECT_0;
if (rv == WAIT_TIMEOUT) {
apr_proc_other_child_refresh_all(APR_OC_REASON_RUNNING);
}
else
#endif
if (rv == WAIT_FAILED) {
/* Something serious is wrong */
ap_log_error(APLOG_MARK, APLOG_CRIT, apr_get_os_error(), ap_server_conf,
"Child %d: WAIT_FAILED -- shutting down server", my_pid);
break;
}
else if (cld == 0) {
/* Exit event was signaled */
ap_log_error(APLOG_MARK, APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
"Child %d: Exit event signaled. Child process is ending.", my_pid);
break;
}
else {
/* MaxRequestsPerChild event set by the worker threads.
* Signal the parent to restart
*/
ap_log_error(APLOG_MARK, APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
"Child %d: Process exiting because it reached "
"MaxRequestsPerChild. Signaling the parent to "
"restart a new child process.", my_pid);
ap_signal_parent(SIGNAL_PARENT_RESTART);
break;
}
}
/*
* Time to shutdown the child process
*/
shutdown:
winnt_mpm_state = AP_MPMQ_STOPPING;
/* Setting is_graceful will cause threads handling keep-alive connections
* to close the connection after handling the current request.
*/
is_graceful = 1;
/* Close the listening sockets. Note, we must close the listeners
* before closing any accept sockets pending in AcceptEx to prevent
* memory leaks in the kernel.
*/
for (lr = ap_listeners; lr ; lr = lr->next) {
apr_socket_close(lr->sd);
}
/* Shutdown listener threads and pending AcceptEx socksts
* but allow the worker threads to continue consuming from
* the queue of accepted connections.
*/
shutdown_in_progress = 1;
Sleep(1000);
/* Tell the worker threads to exit */
workers_may_exit = 1;
/* Release the start_mutex to let the new process (in the restart
* scenario) a chance to begin accepting and servicing requests
*/
rv = apr_proc_mutex_unlock(start_mutex);
if (rv == APR_SUCCESS) {
ap_log_error(APLOG_MARK,APLOG_NOTICE, rv, ap_server_conf,
"Child %d: Released the start mutex", my_pid);
}
else {
ap_log_error(APLOG_MARK,APLOG_ERR, rv, ap_server_conf,
"Child %d: Failure releasing the start mutex", my_pid);
}
/* Shutdown the worker threads */
if (!use_acceptex) {
for (i = 0; i < threads_created; i++) {
add_job(INVALID_SOCKET);
}
}
else { /* Windows NT/2000 */
/* Post worker threads blocked on the ThreadDispatch IOCompletion port */
while (g_blocked_threads > 0) {
ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, ap_server_conf,
"Child %d: %d threads blocked on the completion port", my_pid, g_blocked_threads);
for (i=g_blocked_threads; i > 0; i--) {
PostQueuedCompletionStatus(ThreadDispatchIOCP, 0, IOCP_SHUTDOWN, NULL);
}
Sleep(1000);
}
/* Empty the accept queue of completion contexts */
apr_thread_mutex_lock(qlock);
while (qhead) {
CloseHandle(qhead->Overlapped.hEvent);
closesocket(qhead->accept_socket);
qhead = qhead->next;
}
apr_thread_mutex_unlock(qlock);
}
/* Give busy threads a chance to service their connections,
* (no more than the global server timeout period which
* we track in msec remaining).
*/
watch_thread = 0;
time_remains = (int)(ap_server_conf->timeout / APR_TIME_C(1000));
while (threads_created)
{
int nFailsafe = MAXIMUM_WAIT_OBJECTS;
DWORD dwRet;
/* Every time we roll over to wait on the first group
* of MAXIMUM_WAIT_OBJECTS threads, take a breather,
* and infrequently update the error log.
*/
if (watch_thread >= threads_created) {
if ((time_remains -= 100) < 0)
break;
/* Every 30 seconds give an update */
if ((time_remains % 30000) == 0) {
ap_log_error(APLOG_MARK, APLOG_NOTICE, APR_SUCCESS,
ap_server_conf,
"Child %d: Waiting %d more seconds "
"for %d worker threads to finish.",
my_pid, time_remains / 1000, threads_created);
}
/* We'll poll from the top, 10 times per second */
Sleep(100);
watch_thread = 0;
}
/* Fairness, on each iteration we will pick up with the thread
* after the one we just removed, even if it's a single thread.
* We don't block here.
*/
dwRet = WaitForMultipleObjects(min(threads_created - watch_thread,
MAXIMUM_WAIT_OBJECTS),
child_handles + watch_thread, 0, 0);
if (dwRet == WAIT_FAILED) {
break;
}
if (dwRet == WAIT_TIMEOUT) {
/* none ready */
watch_thread += MAXIMUM_WAIT_OBJECTS;
continue;
}
else if (dwRet >= WAIT_ABANDONED_0) {
/* We just got the ownership of the object, which
* should happen at most MAXIMUM_WAIT_OBJECTS times.
* It does NOT mean that the object is signaled.
*/
if ((nFailsafe--) < 1)
break;
}
else {
watch_thread += (dwRet - WAIT_OBJECT_0);
if (watch_thread >= threads_created)
break;
cleanup_thread(child_handles, &threads_created, watch_thread);
}
}
/* Kill remaining threads off the hard way */
if (threads_created) {
ap_log_error(APLOG_MARK,APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
"Child %d: Terminating %d threads that failed to exit.",
my_pid, threads_created);
}
for (i = 0; i < threads_created; i++) {
int *score_idx;
TerminateThread(child_handles[i], 1);
CloseHandle(child_handles[i]);
/* Reset the scoreboard entry for the thread we just whacked */
score_idx = apr_hash_get(ht, &child_handles[i], sizeof(HANDLE));
if (score_idx) {
ap_update_child_status_from_indexes(0, *score_idx,
SERVER_DEAD, NULL);
}
}
ap_log_error(APLOG_MARK,APLOG_NOTICE, APR_SUCCESS, ap_server_conf,
"Child %d: All worker threads have exited.", my_pid);
CloseHandle(allowed_globals.jobsemaphore);
apr_thread_mutex_destroy(allowed_globals.jobmutex);
apr_thread_mutex_destroy(child_lock);
if (use_acceptex) {
apr_thread_mutex_destroy(qlock);
CloseHandle(qwait_event);
}
apr_pool_destroy(pchild);
CloseHandle(exit_event);
}
#endif /* def WIN32 */