// static
void LLThread::yield()
{
#if LL_LINUX || LL_SOLARIS
sched_yield(); // annoyingly, apr_thread_yield is a noop on linux...
#else
apr_thread_yield();
#endif
}
/* Called by a thread to indicate it has completed a block operation and is
* thus able to particpate in a GC run again. Note that this case needs some
* special handling if it comes out of this mode when a GC run is taking place. */
void MVM_gc_mark_thread_unblocked(MVMThreadContext *tc) {
/* Try to set it from unable to running. */
while (apr_atomic_cas32(&tc->gc_status, MVMGCStatus_NONE,
MVMGCStatus_UNABLE) != MVMGCStatus_UNABLE) {
/* We can't, presumably because a GC run is going on. We should wait
* for that to finish before we go on, but without chewing CPU. */
apr_thread_yield();
}
}
/*
* This function checks the scoreboard, which is updated concurrently in the parent process,
* right after the fork. So here we loop waiting when everything is ready.
*/
static int get_slot(void)
{
apr_proc_t proc;
proc.pid = getpid();
int slot = find_child_by_pid(&proc);
while (slot == -1) {
apr_thread_yield();
slot = find_child_by_pid(&proc);
}
return slot;
}
static APR_INLINE void busyloop_read32(tbox_t *tbox)
{
apr_uint32_t val;
do {
val = apr_atomic_read32(tbox->mem);
if (val != tbox->preval)
apr_thread_yield();
else
break;
} while (1);
}
static void busyloop_cas32(tbox_t *tbox)
{
apr_uint32_t val;
do {
do {
val = apr_atomic_cas32(tbox->mem, tbox->postval, tbox->preval);
if (val != tbox->preval)
apr_thread_yield();
else
break;
} while (1);
} while (--tbox->loop);
}
static void sig_term(int sig)
{
if (shutdown_pending == 1) {
/* Um, is this _probably_ not an error, if the user has
* tried to do a shutdown twice quickly, so we won't
* worry about reporting it.
*/
return;
}
shutdown_pending = 1;
DBPRINT0 ("waiting for threads\n");
while (wait_to_finish) {
apr_thread_yield();
}
DBPRINT0 ("goodbye\n");
}
static int make_child(server_rec *s, int slot)
{
int tid;
int err=0;
NXContext_t ctx;
if (slot + 1 > ap_max_workers_limit) {
ap_max_workers_limit = slot + 1;
}
ap_update_child_status_from_indexes(0, slot, WORKER_STARTING,
(request_rec *) NULL);
if (ctx = NXContextAlloc((void (*)(void *)) worker_main, (void*)slot, NX_PRIO_MED, ap_thread_stacksize, NX_CTX_NORMAL, &err)) {
char threadName[32];
sprintf (threadName, "Apache_Worker %d", slot);
NXContextSetName(ctx, threadName);
err = NXThreadCreate(ctx, NX_THR_BIND_CONTEXT, &tid);
if (err) {
NXContextFree (ctx);
}
}
if (err) {
/* create thread didn't succeed. Fix the scoreboard or else
* it will say SERVER_STARTING forever and ever
*/
ap_update_child_status_from_indexes(0, slot, WORKER_DEAD,
(request_rec *) NULL);
/* In case system resources are maxxed out, we don't want
Apache running away with the CPU trying to fork over and
over and over again. */
apr_thread_yield();
return -1;
}
ap_scoreboard_image->servers[0][slot].tid = tid;
return 0;
}
static int netware_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
{
apr_status_t status=0;
pconf = _pconf;
ap_server_conf = s;
if (setup_listeners(s)) {
ap_log_error(APLOG_MARK, APLOG_ALERT, status, s, APLOGNO(00223)
"no listening sockets available, shutting down");
return !OK;
}
restart_pending = shutdown_pending = 0;
worker_thread_count = 0;
if (!is_graceful) {
if (ap_run_pre_mpm(s->process->pool, SB_NOT_SHARED) != OK) {
return !OK;
}
}
/* Only set slot 0 since that is all NetWare will ever have. */
ap_scoreboard_image->parent[0].pid = getpid();
ap_run_child_status(ap_server_conf,
ap_scoreboard_image->parent[0].pid,
ap_my_generation,
0,
MPM_CHILD_STARTED);
set_signals();
apr_pool_create(&pmain, pconf);
ap_run_child_init(pmain, ap_server_conf);
if (ap_threads_max_free < ap_threads_min_free + 1) /* Don't thrash... */
ap_threads_max_free = ap_threads_min_free + 1;
request_count = 0;
startup_workers(ap_threads_to_start);
/* Allow the Apache screen to be closed normally on exit() only if it
has not been explicitly forced to close on exit(). (ie. the -E flag
was specified at startup) */
if (hold_screen_on_exit > 0) {
hold_screen_on_exit = 0;
}
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00224)
"%s configured -- resuming normal operations",
ap_get_server_description());
ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, APLOGNO(00225)
"Server built: %s", ap_get_server_built());
ap_log_command_line(plog, s);
ap_log_common(s);
show_server_data();
mpm_state = AP_MPMQ_RUNNING;
while (!restart_pending && !shutdown_pending) {
perform_idle_server_maintenance(pconf);
if (show_settings)
display_settings();
apr_thread_yield();
apr_sleep(SCOREBOARD_MAINTENANCE_INTERVAL);
}
mpm_state = AP_MPMQ_STOPPING;
ap_run_child_status(ap_server_conf,
ap_scoreboard_image->parent[0].pid,
ap_my_generation,
0,
MPM_CHILD_EXITED);
/* Shutdown the listen sockets so that we don't get stuck in a blocking call.
shutdown_listeners();*/
if (shutdown_pending) { /* Got an unload from the console */
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00226)
"caught SIGTERM, shutting down");
while (worker_thread_count > 0) {
printf ("\rShutdown pending. Waiting for %lu thread(s) to terminate...",
worker_thread_count);
apr_thread_yield();
}
mpm_main_cleanup();
return DONE;
}
else { /* the only other way out is a restart */
/* advance to the next generation */
/* XXX: we really need to make sure this new generation number isn't in
* use by any of the children.
*/
++ap_my_generation;
ap_scoreboard_image->global->running_generation = ap_my_generation;
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00227)
"Graceful restart requested, doing restart");
/* Wait for all of the threads to terminate before initiating the restart */
while (worker_thread_count > 0) {
printf ("\rRestart pending. Waiting for %lu thread(s) to terminate...",
worker_thread_count);
apr_thread_yield();
}
printf ("\nRestarting...\n");
}
mpm_main_cleanup();
return OK;
}
/*static */
void worker_main(void *arg)
{
ap_listen_rec *lr, *first_lr, *last_lr = NULL;
apr_pool_t *ptrans;
apr_allocator_t *allocator;
apr_bucket_alloc_t *bucket_alloc;
conn_rec *current_conn;
apr_status_t stat = APR_EINIT;
ap_sb_handle_t *sbh;
apr_thread_t *thd = NULL;
apr_os_thread_t osthd;
int my_worker_num = (int)arg;
apr_socket_t *csd = NULL;
int requests_this_child = 0;
apr_socket_t *sd = NULL;
fd_set main_fds;
int sockdes;
int srv;
struct timeval tv;
int wouldblock_retry;
osthd = apr_os_thread_current();
apr_os_thread_put(&thd, &osthd, pmain);
tv.tv_sec = 1;
tv.tv_usec = 0;
apr_allocator_create(&allocator);
apr_allocator_max_free_set(allocator, ap_max_mem_free);
apr_pool_create_ex(&ptrans, pmain, NULL, allocator);
apr_allocator_owner_set(allocator, ptrans);
apr_pool_tag(ptrans, "transaction");
bucket_alloc = apr_bucket_alloc_create_ex(allocator);
atomic_inc (&worker_thread_count);
while (!die_now) {
/*
* (Re)initialize this child to a pre-connection state.
*/
current_conn = NULL;
apr_pool_clear(ptrans);
if ((ap_max_requests_per_child > 0
&& requests_this_child++ >= ap_max_requests_per_child)) {
DBPRINT1 ("\n**Thread slot %d is shutting down", my_worker_num);
clean_child_exit(0, my_worker_num, ptrans, bucket_alloc);
}
ap_update_child_status_from_indexes(0, my_worker_num, WORKER_READY,
(request_rec *) NULL);
/*
* Wait for an acceptable connection to arrive.
*/
for (;;) {
if (shutdown_pending || restart_pending || (ap_scoreboard_image->servers[0][my_worker_num].status == WORKER_IDLE_KILL)) {
DBPRINT1 ("\nThread slot %d is shutting down\n", my_worker_num);
clean_child_exit(0, my_worker_num, ptrans, bucket_alloc);
}
/* Check the listen queue on all sockets for requests */
memcpy(&main_fds, &listenfds, sizeof(fd_set));
srv = select(listenmaxfd + 1, &main_fds, NULL, NULL, &tv);
if (srv <= 0) {
if (srv < 0) {
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(00217)
"select() failed on listen socket");
apr_thread_yield();
}
continue;
}
/* remember the last_lr we searched last time around so that
we don't end up starving any particular listening socket */
if (last_lr == NULL) {
lr = ap_listeners;
}
else {
lr = last_lr->next;
if (!lr)
lr = ap_listeners;
}
first_lr = lr;
do {
apr_os_sock_get(&sockdes, lr->sd);
if (FD_ISSET(sockdes, &main_fds))
goto got_listener;
lr = lr->next;
if (!lr)
lr = ap_listeners;
} while (lr != first_lr);
/* if we get here, something unexpected happened. Go back
into the select state and try again.
*/
continue;
got_listener:
last_lr = lr;
sd = lr->sd;
wouldblock_retry = MAX_WB_RETRIES;
while (wouldblock_retry) {
if ((stat = apr_socket_accept(&csd, sd, ptrans)) == APR_SUCCESS) {
break;
}
else {
/* if the error is a wouldblock then maybe we were too
quick try to pull the next request from the listen
queue. Try a few more times then return to our idle
listen state. */
if (!APR_STATUS_IS_EAGAIN(stat)) {
break;
}
if (wouldblock_retry--) {
apr_thread_yield();
}
}
}
/* If we got a new socket, set it to non-blocking mode and process
it. Otherwise handle the error. */
if (stat == APR_SUCCESS) {
apr_socket_opt_set(csd, APR_SO_NONBLOCK, 0);
#ifdef DBINFO_ON
if (wouldblock_retry < MAX_WB_RETRIES) {
retry_success++;
avg_retries += (MAX_WB_RETRIES-wouldblock_retry);
}
#endif
break; /* We have a socket ready for reading */
}
else {
#ifdef DBINFO_ON
if (APR_STATUS_IS_EAGAIN(stat)) {
would_block++;
retry_fail++;
}
else if (
#else
if (APR_STATUS_IS_EAGAIN(stat) ||
#endif
APR_STATUS_IS_ECONNRESET(stat) ||
APR_STATUS_IS_ETIMEDOUT(stat) ||
APR_STATUS_IS_EHOSTUNREACH(stat) ||
APR_STATUS_IS_ENETUNREACH(stat)) {
;
}
#ifdef USE_WINSOCK
else if (APR_STATUS_IS_ENETDOWN(stat)) {
/*
* When the network layer has been shut down, there
* is not much use in simply exiting: the parent
* would simply re-create us (and we'd fail again).
* Use the CHILDFATAL code to tear the server down.
* @@@ Martin's idea for possible improvement:
* A different approach would be to define
* a new APEXIT_NETDOWN exit code, the reception
* of which would make the parent shutdown all
* children, then idle-loop until it detected that
* the network is up again, and restart the children.
* Ben Hyde noted that temporary ENETDOWN situations
* occur in mobile IP.
*/
ap_log_error(APLOG_MARK, APLOG_EMERG, stat, ap_server_conf, APLOGNO(00218)
"apr_socket_accept: giving up.");
clean_child_exit(APEXIT_CHILDFATAL, my_worker_num, ptrans,
bucket_alloc);
}
#endif
else {
ap_log_error(APLOG_MARK, APLOG_ERR, stat, ap_server_conf, APLOGNO(00219)
"apr_socket_accept: (client socket)");
clean_child_exit(1, my_worker_num, ptrans, bucket_alloc);
}
}
}
ap_create_sb_handle(&sbh, ptrans, 0, my_worker_num);
/*
* We now have a connection, so set it up with the appropriate
* socket options, file descriptors, and read/write buffers.
*/
current_conn = ap_run_create_connection(ptrans, ap_server_conf, csd,
my_worker_num, sbh,
bucket_alloc);
if (current_conn) {
current_conn->current_thread = thd;
ap_process_connection(current_conn, csd);
ap_lingering_close(current_conn);
}
request_count++;
}
clean_child_exit(0, my_worker_num, ptrans, bucket_alloc);
}
/**
* Yield the processor.
*
* @return none
*/
void VMCALL hythread_yield() {
apr_thread_yield();
}
/* This is called when the allocator finds it has run out of memory and wants
* to trigger a GC run. In this case, it's possible (probable, really) that it
* will need to do that triggering, notifying other running threads that the
* time has come to GC. */
void MVM_gc_enter_from_allocator(MVMThreadContext *tc) {
GCORCH_LOG(tc, "Thread %d run %d : Entered from allocate\n");
/* Try to start the GC run. */
if (MVM_trycas(&tc->instance->gc_start, 0, 1)) {
MVMThread *last_starter = NULL;
MVMuint32 num_threads = 0;
/* We are the winner of the GC starting race. This gives us some
* extra responsibilities as well as doing the usual things.
* First, increment GC sequence number. */
tc->instance->gc_seq_number++;
GCORCH_LOG(tc, "Thread %d run %d : GC thread elected coordinator: starting gc seq %d\n", tc->instance->gc_seq_number);
/* Ensure our stolen list is empty. */
tc->gc_work_count = 0;
/* need to wait for other threads to reset their gc_status. */
while (tc->instance->gc_ack)
apr_thread_yield();
add_work(tc, tc);
/* grab our child */
signal_child(tc);
do {
if (tc->instance->threads && tc->instance->threads != last_starter) {
MVMThread *head;
MVMuint32 add;
while (!MVM_trycas(&tc->instance->threads, (head = tc->instance->threads), NULL));
add = signal_all_but(tc, head, last_starter);
last_starter = head;
if (add) {
GCORCH_LOG(tc, "Thread %d run %d : Found %d other threads\n", add);
MVM_atomic_add(&tc->instance->gc_start, add);
num_threads += add;
}
}
} while (tc->instance->gc_start > 1);
if (!MVM_trycas(&tc->instance->threads, NULL, last_starter))
MVM_panic(MVM_exitcode_gcorch, "threads list corrupted\n");
if (tc->instance->gc_finish != 0)
MVM_panic(MVM_exitcode_gcorch, "finish votes was %d\n", tc->instance->gc_finish);
tc->instance->gc_ack = tc->instance->gc_finish = num_threads + 1;
GCORCH_LOG(tc, "Thread %d run %d : finish votes is %d\n", (int)tc->instance->gc_finish);
/* signal to the rest to start */
if (MVM_atomic_decr(&tc->instance->gc_start) != 1)
MVM_panic(MVM_exitcode_gcorch, "start votes was %d\n", tc->instance->gc_finish);
run_gc(tc, MVMGCWhatToDo_All);
}
else {
/* Another thread beat us to starting the GC sync process. Thus, act as
* if we were interrupted to GC. */
GCORCH_LOG(tc, "Thread %d run %d : Lost coordinator election\n");
MVM_gc_enter_from_interrupt(tc);
}
}
