4 * Citadel "system dependent" stuff.
5 * See COPYING for copyright information.
7 * Here's where we have the Citadel thread implimentation
14 #include <sys/types.h>
16 #include <sys/socket.h>
21 #if TIME_WITH_SYS_TIME
22 # include <sys/time.h>
26 # include <sys/time.h>
32 #include <libcitadel.h>
35 #include "ctdl_module.h"
36 #include "modules_init.h"
37 #include "housekeeping.h"
39 #include "citserver.h"
40 #include "sysdep_decls.h"
44 * define this to use the new worker_thread method of handling connections
49 * New thread interface.
50 * To create a thread you must call one of the create thread functions.
51 * You must pass it the address of (a pointer to a CtdlThreadNode initialised to NULL) like this
52 * struct CtdlThreadNode *node = NULL;
54 * If the thread is created *node will point to the thread control structure for the created thread.
55 * If the thread creation fails *node remains NULL
56 * Do not free the memory pointed to by *node, it doesn't belong to you.
57 * This new interface duplicates much of the eCrash stuff. We should go for closer integration since that would
58 * remove the need for the calls to eCrashRegisterThread and friends
61 static int next_tid = 3; /* offset LWPID to PID */
62 static int num_threads = 0; /* Current number of threads */
63 static int num_workers = 0; /* Current number of worker threads */
64 long statcount = 0; /* are we doing a stats check? */
65 static long stats_done = 0;
67 CtdlThreadNode *CtdlThreadList = NULL;
68 CtdlThreadNode *CtdlThreadSchedList = NULL;
70 static CtdlThreadNode *GC_thread = NULL;
71 static char *CtdlThreadStates[CTDL_THREAD_LAST_STATE];
72 double CtdlThreadLoadAvg = 0;
73 double CtdlThreadWorkerAvg = 0;
74 citthread_key_t ThreadKey;
76 citthread_mutex_t Critters[MAX_SEMAPHORES]; /* Things needing locking */
80 void InitialiseSemaphores(void)
84 /* Set up a bunch of semaphores to be used for critical sections */
85 for (i=0; i<MAX_SEMAPHORES; ++i) {
86 citthread_mutex_init(&Critters[i], NULL);
94 * Obtain a semaphore lock to begin a critical section.
95 * but only if no one else has one
97 int try_critical_section(int which_one)
99 /* For all types of critical sections except those listed here,
100 * ensure nobody ever tries to do a critical section within a
101 * transaction; this could lead to deadlock.
103 if ( (which_one != S_FLOORCACHE)
104 #ifdef DEBUG_MEMORY_LEAKS
105 && (which_one != S_DEBUGMEMLEAKS)
107 && (which_one != S_RPLIST)
111 return (citthread_mutex_trylock(&Critters[which_one]));
116 * Obtain a semaphore lock to begin a critical section.
118 void begin_critical_section(int which_one)
120 /* CtdlLogPrintf(CTDL_DEBUG, "begin_critical_section(%d)\n", which_one); */
122 /* For all types of critical sections except those listed here,
123 * ensure nobody ever tries to do a critical section within a
124 * transaction; this could lead to deadlock.
126 if ( (which_one != S_FLOORCACHE)
127 #ifdef DEBUG_MEMORY_LEAKS
128 && (which_one != S_DEBUGMEMLEAKS)
130 && (which_one != S_RPLIST)
134 citthread_mutex_lock(&Critters[which_one]);
138 * Release a semaphore lock to end a critical section.
140 void end_critical_section(int which_one)
142 citthread_mutex_unlock(&Critters[which_one]);
147 * A function to destroy the TSD
149 static void ctdl_thread_internal_dest_tsd(void *arg)
159 * A function to initialise the thread TSD
161 void ctdl_thread_internal_init_tsd(void)
165 if ((ret = citthread_key_create(&ThreadKey, ctdl_thread_internal_dest_tsd))) {
166 CtdlLogPrintf(CTDL_EMERG, "citthread_key_create: %s\n", strerror(ret));
172 * Ensure that we have a key for thread-specific data.
174 * This should be called immediately after startup by any thread
177 void CtdlThreadAllocTSD(void)
181 if (citthread_getspecific(ThreadKey) != NULL)
184 tsd = malloc(sizeof(ThreadTSD));
188 memset(tsd->cursors, 0, sizeof tsd->cursors);
191 citthread_setspecific(ThreadKey, tsd);
195 void ctdl_thread_internal_free_tsd(void)
197 ctdl_thread_internal_dest_tsd(citthread_getspecific(ThreadKey));
198 citthread_setspecific(ThreadKey, NULL);
202 void ctdl_thread_internal_cleanup(void)
205 CtdlThreadNode *this_thread, *that_thread;
207 for (i=0; i<CTDL_THREAD_LAST_STATE; i++)
209 free (CtdlThreadStates[i]);
212 /* Clean up the scheduled thread list */
213 this_thread = CtdlThreadSchedList;
216 that_thread = this_thread;
217 this_thread = this_thread->next;
218 citthread_mutex_destroy(&that_thread->ThreadMutex);
219 citthread_cond_destroy(&that_thread->ThreadCond);
220 citthread_mutex_destroy(&that_thread->SleepMutex);
221 citthread_cond_destroy(&that_thread->SleepCond);
222 citthread_attr_destroy(&that_thread->attr);
225 ctdl_thread_internal_free_tsd();
228 void ctdl_thread_internal_init(void)
230 CtdlThreadNode *this_thread;
233 CtdlThreadStates[CTDL_THREAD_INVALID] = strdup ("Invalid Thread");
234 CtdlThreadStates[CTDL_THREAD_VALID] = strdup("Valid Thread");
235 CtdlThreadStates[CTDL_THREAD_CREATE] = strdup("Thread being Created");
236 CtdlThreadStates[CTDL_THREAD_CANCELLED] = strdup("Thread Cancelled");
237 CtdlThreadStates[CTDL_THREAD_EXITED] = strdup("Thread Exited");
238 CtdlThreadStates[CTDL_THREAD_STOPPING] = strdup("Thread Stopping");
239 CtdlThreadStates[CTDL_THREAD_STOP_REQ] = strdup("Thread Stop Requested");
240 CtdlThreadStates[CTDL_THREAD_SLEEPING] = strdup("Thread Sleeping");
241 CtdlThreadStates[CTDL_THREAD_RUNNING] = strdup("Thread Running");
242 CtdlThreadStates[CTDL_THREAD_BLOCKED] = strdup("Thread Blocked");
244 /* Get ourself a thread entry */
245 this_thread = malloc(sizeof(CtdlThreadNode));
246 if (this_thread == NULL) {
247 CtdlLogPrintf(CTDL_EMERG, "Thread system, can't allocate CtdlThreadNode, exiting\n");
250 // Ensuring this is zero'd means we make sure the thread doesn't start doing its thing until we are ready.
251 memset (this_thread, 0, sizeof(CtdlThreadNode));
253 citthread_mutex_init (&(this_thread->ThreadMutex), NULL);
254 citthread_cond_init (&(this_thread->ThreadCond), NULL);
255 citthread_mutex_init (&(this_thread->SleepMutex), NULL);
256 citthread_cond_init (&(this_thread->SleepCond), NULL);
258 /* We are garbage collector so create us as running */
259 this_thread->state = CTDL_THREAD_RUNNING;
261 if ((ret = citthread_attr_init(&this_thread->attr))) {
262 CtdlLogPrintf(CTDL_EMERG, "Thread system, citthread_attr_init: %s\n", strerror(ret));
267 this_thread->name = "Garbage Collection Thread";
269 this_thread->tid = citthread_self();
270 GC_thread = this_thread;
273 num_threads++; // Increase the count of threads in the system.
275 this_thread->next = CtdlThreadList;
276 CtdlThreadList = this_thread;
277 if (this_thread->next)
278 this_thread->next->prev = this_thread;
279 /* Set up start times */
280 gettimeofday(&this_thread->start_time, NULL); /* Time this thread started */
281 memcpy(&this_thread->last_state_change, &this_thread->start_time, sizeof (struct timeval)); /* Changed state so mark it. */
286 * A function to update a threads load averages
288 void ctdl_thread_internal_update_avgs(CtdlThreadNode *this_thread)
290 struct timeval now, result;
291 double last_duration;
293 gettimeofday(&now, NULL);
294 timersub(&now, &(this_thread->last_state_change), &result);
295 /* I don't think these mutex's are needed here */
296 citthread_mutex_lock(&this_thread->ThreadMutex);
297 // result now has a timeval for the time we spent in the last state since we last updated
298 last_duration = (double)result.tv_sec + ((double)result.tv_usec / (double) 1000000);
299 if (this_thread->state == CTDL_THREAD_SLEEPING)
300 this_thread->avg_sleeping += last_duration;
301 if (this_thread->state == CTDL_THREAD_RUNNING)
302 this_thread->avg_running += last_duration;
303 if (this_thread->state == CTDL_THREAD_BLOCKED)
304 this_thread->avg_blocked += last_duration;
305 memcpy (&this_thread->last_state_change, &now, sizeof (struct timeval));
306 citthread_mutex_unlock(&this_thread->ThreadMutex);
310 * A function to chenge the state of a thread
312 void ctdl_thread_internal_change_state (CtdlThreadNode *this_thread, enum CtdlThreadState new_state)
315 * Wether we change state or not we need update the load values
317 ctdl_thread_internal_update_avgs(this_thread);
318 /* This mutex not needed here? */
319 citthread_mutex_lock(&this_thread->ThreadMutex); /* To prevent race condition of a sleeping thread */
320 if ((new_state == CTDL_THREAD_STOP_REQ) && (this_thread->state > CTDL_THREAD_STOP_REQ))
321 this_thread->state = new_state;
322 if (((new_state == CTDL_THREAD_SLEEPING) || (new_state == CTDL_THREAD_BLOCKED)) && (this_thread->state == CTDL_THREAD_RUNNING))
323 this_thread->state = new_state;
324 if ((new_state == CTDL_THREAD_RUNNING) && ((this_thread->state == CTDL_THREAD_SLEEPING) || (this_thread->state == CTDL_THREAD_BLOCKED)))
325 this_thread->state = new_state;
326 citthread_mutex_unlock(&this_thread->ThreadMutex);
331 * A function to tell all threads to exit
333 void CtdlThreadStopAll(void)
335 /* First run any registered shutdown hooks. This probably doesn't belong here. */
336 PerformSessionHooks(EVT_SHUTDOWN);
338 //FIXME: The signalling of the condition should not be in the critical_section
339 // We need to build a list of threads we are going to signal and then signal them afterwards
341 CtdlThreadNode *this_thread;
343 begin_critical_section(S_THREAD_LIST);
344 this_thread = CtdlThreadList;
345 // Ask the GC thread to stop first so everything knows we are shutting down.
346 GC_thread->state = CTDL_THREAD_STOP_REQ;
349 if (!citthread_equal(this_thread->tid, GC_thread->tid))
350 citthread_kill(this_thread->tid, SIGHUP);
352 ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_STOP_REQ);
353 citthread_cond_signal(&this_thread->ThreadCond);
354 citthread_cond_signal(&this_thread->SleepCond);
355 this_thread->stop_ticker = time(NULL);
356 CtdlLogPrintf(CTDL_DEBUG, "Thread system stopping thread \"%s\" (0x%08lx).\n",
357 this_thread->name, this_thread->tid);
358 this_thread = this_thread->next;
360 end_critical_section(S_THREAD_LIST);
365 * A function to wake up all sleeping threads
367 void CtdlThreadWakeAll(void)
369 CtdlThreadNode *this_thread;
371 CtdlLogPrintf(CTDL_DEBUG, "Thread system waking all threads.\n");
373 begin_critical_section(S_THREAD_LIST);
374 this_thread = CtdlThreadList;
377 if (!this_thread->thread_func)
379 citthread_cond_signal(&this_thread->ThreadCond);
380 citthread_cond_signal(&this_thread->SleepCond);
382 this_thread = this_thread->next;
384 end_critical_section(S_THREAD_LIST);
389 * A function to return the number of threads running in the system
391 int CtdlThreadGetCount(void)
396 int CtdlThreadGetWorkers(void)
401 double CtdlThreadGetWorkerAvg(void)
405 begin_critical_section(S_THREAD_LIST);
406 ret = CtdlThreadWorkerAvg;
407 end_critical_section(S_THREAD_LIST);
411 double CtdlThreadGetLoadAvg(void)
413 double load_avg[3] = {0.0, 0.0, 0.0};
418 /* Borrowed this straight from procps */
419 smp_num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
420 if(smp_num_cpus<1) smp_num_cpus=1; /* SPARC glibc is buggy */
422 #ifdef HAVE_GETLOADAVG
423 ret = getloadavg(load_avg, 3);
427 return load_avg[0] / smp_num_cpus;
429 * This old chunk of code return a value that indicated the load on citserver
430 * This value could easily reach 100 % even when citserver was doing very little and
431 * hence the machine has much more spare capacity.
432 * Because this value was used to determine if the machine was under heavy load conditions
433 * from other processes in the system then citserver could be strangled un-necesarily
434 * What we are actually trying to achieve is to strangle citserver if the machine is heavily loaded.
435 * So we have changed this.
437 begin_critical_section(S_THREAD_LIST);
438 ret = CtdlThreadLoadAvg;
439 end_critical_section(S_THREAD_LIST);
448 * A function to rename a thread
449 * Returns a const char *
451 const char *CtdlThreadName(const char *name)
453 const char *old_name;
457 CtdlLogPrintf(CTDL_WARNING, "Thread system WARNING. Attempt to CtdlThreadRename() a non thread. %s\n", name);
468 * A function to force a thread to exit
470 void CtdlThreadCancel(CtdlThreadNode *thread)
472 CtdlThreadNode *this_thread;
477 this_thread = thread;
480 CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC. Attempt to CtdlThreadCancel() a non thread.\n");
485 if (!this_thread->thread_func)
487 CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC. Attempt to CtdlThreadCancel() the garbage collector.\n");
492 ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_CANCELLED);
493 citthread_cancel(this_thread->tid);
498 * A function for a thread to check if it has been asked to stop
500 int CtdlThreadCheckStop(void)
506 CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, CtdlThreadCheckStop() called by a non thread.\n");
515 CtdlLogPrintf(CTDL_DEBUG, "Thread \"%s\" caught signal %d.\n", CT->name, CT->signal);
516 if (CT->signal == SIGHUP)
517 CT->state = CTDL_THREAD_STOP_REQ;
520 if(state == CTDL_THREAD_STOP_REQ)
522 CT->state = CTDL_THREAD_STOPPING;
525 else if((state < CTDL_THREAD_STOP_REQ) && (state > CTDL_THREAD_CREATE))
534 * A function to ask a thread to exit
535 * The thread must call CtdlThreadCheckStop() periodically to determine if it should exit
537 void CtdlThreadStop(CtdlThreadNode *thread)
539 CtdlThreadNode *this_thread;
544 this_thread = thread;
547 if (!(this_thread->thread_func))
548 return; // Don't stop garbage collector
550 if (!citthread_equal(this_thread->tid, GC_thread->tid))
551 citthread_kill(this_thread->tid, SIGHUP);
553 ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_STOP_REQ);
554 citthread_cond_signal(&this_thread->ThreadCond);
555 citthread_cond_signal(&this_thread->SleepCond);
556 this_thread->stop_ticker = time(NULL);
560 * So we now have a sleep command that works with threads but it is in seconds
562 void CtdlThreadSleep(int secs)
564 struct timespec wake_time;
565 struct timeval time_now;
570 CtdlLogPrintf(CTDL_WARNING, "CtdlThreadSleep() called by something that is not a thread. Should we die?\n");
574 memset (&wake_time, 0, sizeof(struct timespec));
575 gettimeofday(&time_now, NULL);
576 wake_time.tv_sec = time_now.tv_sec + secs;
577 wake_time.tv_nsec = time_now.tv_usec * 10;
579 ctdl_thread_internal_change_state (CT, CTDL_THREAD_SLEEPING);
581 citthread_mutex_lock(&CT->ThreadMutex); /* Prevent something asking us to awaken before we've gone to sleep */
582 citthread_cond_timedwait(&CT->SleepCond, &CT->ThreadMutex, &wake_time);
583 citthread_mutex_unlock(&CT->ThreadMutex);
585 ctdl_thread_internal_change_state (CT, CTDL_THREAD_RUNNING);
590 * Routine to clean up our thread function on exit
592 static void ctdl_internal_thread_cleanup(void *arg)
595 * In here we were called by the current thread because it is exiting
596 * NB. WE ARE THE CURRENT THREAD
600 const char *name = CT->name;
601 const pid_t tid = CT->tid;
603 CtdlLogPrintf(CTDL_NOTICE, "Thread \"%s\" (0x%08lx) exited.\n", name, tid);
607 CtdlLogPrintf(CTDL_NOTICE, "some ((unknown ? ? ?) Thread exited.\n");
610 #ifdef HAVE_BACKTRACE
611 /// eCrash_UnregisterThread();
614 citthread_mutex_lock(&CT->ThreadMutex);
615 CT->state = CTDL_THREAD_EXITED; // needs to be last thing else house keeping will unlink us too early
616 citthread_mutex_unlock(&CT->ThreadMutex);
620 * A quick function to show the load averages
622 void ctdl_thread_internal_calc_loadavg(void)
624 CtdlThreadNode *that_thread;
625 double load_avg, worker_avg;
628 that_thread = CtdlThreadList;
633 /* Update load averages */
634 ctdl_thread_internal_update_avgs(that_thread);
635 citthread_mutex_lock(&that_thread->ThreadMutex);
636 that_thread->load_avg = (that_thread->avg_sleeping + that_thread->avg_running) / (that_thread->avg_sleeping + that_thread->avg_running + that_thread->avg_blocked) * 100;
637 that_thread->avg_sleeping /= 2;
638 that_thread->avg_running /= 2;
639 that_thread->avg_blocked /= 2;
640 load_avg += that_thread->load_avg;
641 if (that_thread->flags & CTDLTHREAD_WORKER)
643 worker_avg += that_thread->load_avg;
646 #ifdef WITH_THREADLOG
647 CtdlLogPrintf(CTDL_DEBUG, "CtdlThread, \"%s\" (%lu) \"%s\" %.2f %.2f %.2f %.2f\n",
650 CtdlThreadStates[that_thread->state],
651 that_thread->avg_sleeping,
652 that_thread->avg_running,
653 that_thread->avg_blocked,
654 that_thread->load_avg);
656 citthread_mutex_unlock(&that_thread->ThreadMutex);
657 that_thread = that_thread->next;
659 CtdlThreadLoadAvg = load_avg/num_threads;
660 CtdlThreadWorkerAvg = worker_avg/workers;
661 #ifdef WITH_THREADLOG
662 CtdlLogPrintf(CTDL_INFO, "System load average %.2f, workers averag %.2f, threads %d, workers %d, sessions %d\n", CtdlThreadGetLoadAvg(), CtdlThreadWorkerAvg, num_threads, num_workers, num_sessions);
668 * Garbage collection routine.
669 * Gets called by main() in a loop to clean up the thread list periodically.
671 void CtdlThreadGC (void)
673 CtdlThreadNode *this_thread, *that_thread;
674 int workers = 0, sys_workers;
677 begin_critical_section(S_THREAD_LIST);
679 /* Handle exiting of garbage collector thread */
681 CtdlThreadList->state = CTDL_THREAD_EXITED;
683 #ifdef WITH_THREADLOG
684 CtdlLogPrintf(CTDL_DEBUG, "Thread system running garbage collection.\n");
687 * Woke up to do garbage collection
689 this_thread = CtdlThreadList;
692 that_thread = this_thread;
693 this_thread = this_thread->next;
695 if ((that_thread->state == CTDL_THREAD_STOP_REQ || that_thread->state == CTDL_THREAD_STOPPING)
696 && (!citthread_equal(that_thread->tid, citthread_self())))
697 CtdlLogPrintf(CTDL_DEBUG, "Waiting for thread %s (0x%08lx) to exit.\n", that_thread->name, that_thread->tid);
701 * Catch the situation where a worker was asked to stop but couldn't and we are not
704 that_thread->stop_ticker = 0;
707 if (that_thread->stop_ticker + 5 == time(NULL))
709 CtdlLogPrintf(CTDL_DEBUG, "Thread System: The thread \"%s\" (0x%08lx) failed to self terminate within 5 ticks. It would be cancelled now.\n", that_thread->name, that_thread->tid);
710 if ((that_thread->flags & CTDLTHREAD_WORKER) == 0)
711 CtdlLogPrintf(CTDL_INFO, "Thread System: A non worker thread would have been canceled this may cause message loss.\n");
712 // that_thread->state = CTDL_THREAD_CANCELLED;
713 that_thread->stop_ticker++;
714 // citthread_cancel(that_thread->tid);
718 /* Do we need to clean up this thread? */
719 if ((that_thread->state != CTDL_THREAD_EXITED) && (that_thread->state != CTDL_THREAD_CANCELLED))
721 if(that_thread->flags & CTDLTHREAD_WORKER)
722 workers++; /* Sanity check on number of worker threads */
726 if (citthread_equal(that_thread->tid, citthread_self()) && that_thread->thread_func)
728 end_critical_section(S_THREAD_LIST);
729 CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, a thread is trying to clean up after itself.\n");
734 if (num_threads <= 0)
736 end_critical_section(S_THREAD_LIST);
737 CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, num_threads <= 0 and trying to do Garbage Collection.\n");
742 if(that_thread->flags & CTDLTHREAD_WORKER)
743 num_workers--; /* This is a wroker thread so reduce the count. */
745 /* If we are unlinking the list head then the next becomes the list head */
746 if(that_thread->prev)
747 that_thread->prev->next = that_thread->next;
749 CtdlThreadList = that_thread->next;
750 if(that_thread->next)
751 that_thread->next->prev = that_thread->prev;
753 citthread_cond_signal(&that_thread->ThreadCond);
754 citthread_cond_signal(&that_thread->SleepCond); // Make sure this thread is awake
755 citthread_mutex_lock(&that_thread->ThreadMutex); // Make sure it has done what its doing
756 citthread_mutex_unlock(&that_thread->ThreadMutex);
758 * Join on the thread to do clean up and prevent memory leaks
759 * Also makes sure the thread has cleaned up after itself before we remove it from the list
760 * We can join on the garbage collector thread the join should just return EDEADLCK
762 ret = citthread_join (that_thread->tid, NULL);
764 CtdlLogPrintf(CTDL_DEBUG, "Garbage collection on own thread.\n");
765 else if (ret == EINVAL)
766 CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, that thread already joined on.\n");
767 else if (ret == ESRCH)
768 CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, no thread to join on.\n");
770 CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, citthread_join returned an unknown error(%d).\n", ret);
772 * Now we own that thread entry
774 CtdlLogPrintf(CTDL_INFO, "Garbage Collection for thread \"%s\" (0x%08lx).\n",
775 that_thread->name, that_thread->tid);
776 citthread_mutex_destroy(&that_thread->ThreadMutex);
777 citthread_cond_destroy(&that_thread->ThreadCond);
778 citthread_mutex_destroy(&that_thread->SleepMutex);
779 citthread_cond_destroy(&that_thread->SleepCond);
780 citthread_attr_destroy(&that_thread->attr);
783 sys_workers = num_workers;
784 end_critical_section(S_THREAD_LIST);
786 /* Sanity check number of worker threads */
787 if (workers != sys_workers)
789 CtdlLogPrintf(CTDL_EMERG,
790 "Thread system PANIC, discrepancy in number of worker threads. Counted %d, should be %d.\n",
801 * Runtime function for a Citadel Thread.
802 * This initialises the threads environment and then calls the user supplied thread function
803 * Note that this is the REAL thread function and wraps the users thread function.
805 static void *ctdl_internal_thread_func (void *arg)
807 CtdlThreadNode *this_thread;
810 /* lock and unlock the thread list.
811 * This causes this thread to wait until all its creation stuff has finished before it
812 * can continue its execution.
814 begin_critical_section(S_THREAD_LIST);
815 this_thread = (CtdlThreadNode *) arg;
816 gettimeofday(&this_thread->start_time, NULL); /* Time this thread started */
818 // Register the cleanup function to take care of when we exit.
819 citthread_cleanup_push(ctdl_internal_thread_cleanup, NULL);
820 // Get our thread data structure
821 CtdlThreadAllocTSD();
823 this_thread->pid = getpid();
824 memcpy(&this_thread->last_state_change, &this_thread->start_time, sizeof (struct timeval)); /* Changed state so mark it. */
825 /* Only change to running state if we weren't asked to stop during the create cycle
826 * Other wise there is a window to allow this threads creation to continue to full grown and
827 * therby prevent a shutdown of the server.
829 if (!CtdlThreadCheckStop())
831 citthread_mutex_lock(&this_thread->ThreadMutex);
832 this_thread->state = CTDL_THREAD_RUNNING;
833 citthread_mutex_unlock(&this_thread->ThreadMutex);
835 end_critical_section(S_THREAD_LIST);
837 // Register for tracing
838 #ifdef HAVE_BACKTRACE
839 /// eCrash_RegisterThread(this_thread->name, 0);
842 // Tell the world we are here
843 CtdlLogPrintf(CTDL_NOTICE, "Created a new thread \"%s\" (0x%08lx).\n",
844 this_thread->name, this_thread->tid);
847 * run the thread to do the work but only if we haven't been asked to stop
849 if (!CtdlThreadCheckStop())
850 ret = (this_thread->thread_func)(this_thread->user_args);
853 * Our thread is exiting either because it wanted to end or because the server is stopping
854 * We need to clean up
856 citthread_cleanup_pop(1); // Execute our cleanup routine and remove it
865 * Function to initialise an empty thread structure
867 CtdlThreadNode *ctdl_internal_init_thread_struct(CtdlThreadNode *this_thread, long flags)
871 // Ensuring this is zero'd means we make sure the thread doesn't start doing its thing until we are ready.
872 memset (this_thread, 0, sizeof(CtdlThreadNode));
874 /* Create the mutex's early so we can use them */
875 citthread_mutex_init (&(this_thread->ThreadMutex), NULL);
876 citthread_cond_init (&(this_thread->ThreadCond), NULL);
877 citthread_mutex_init (&(this_thread->SleepMutex), NULL);
878 citthread_cond_init (&(this_thread->SleepCond), NULL);
880 this_thread->state = CTDL_THREAD_CREATE;
882 if ((ret = citthread_attr_init(&this_thread->attr))) {
883 citthread_mutex_unlock(&this_thread->ThreadMutex);
884 citthread_mutex_destroy(&(this_thread->ThreadMutex));
885 citthread_cond_destroy(&(this_thread->ThreadCond));
886 citthread_mutex_destroy(&(this_thread->SleepMutex));
887 citthread_cond_destroy(&(this_thread->SleepCond));
888 CtdlLogPrintf(CTDL_EMERG, "Thread system, citthread_attr_init: %s\n", strerror(ret));
893 /* Our per-thread stacks need to be bigger than the default size,
894 * otherwise the MIME parser crashes on FreeBSD, and the IMAP service
895 * crashes on 64-bit Linux.
897 if (flags & CTDLTHREAD_BIGSTACK)
899 #ifdef WITH_THREADLOG
900 CtdlLogPrintf(CTDL_INFO, "Thread system. Creating BIG STACK thread.\n");
902 if ((ret = citthread_attr_setstacksize(&this_thread->attr, THREADSTACKSIZE))) {
903 citthread_mutex_unlock(&this_thread->ThreadMutex);
904 citthread_mutex_destroy(&(this_thread->ThreadMutex));
905 citthread_cond_destroy(&(this_thread->ThreadCond));
906 citthread_mutex_destroy(&(this_thread->SleepMutex));
907 citthread_cond_destroy(&(this_thread->SleepCond));
908 citthread_attr_destroy(&this_thread->attr);
909 CtdlLogPrintf(CTDL_EMERG, "Thread system, citthread_attr_setstacksize: %s\n",
916 /* Set this new thread with an avg_blocked of 2. We do this so that its creation affects the
917 * load average for the system. If we don't do this then we create a mass of threads at the same time
918 * because the creation didn't affect the load average.
920 this_thread->avg_blocked = 2;
922 return (this_thread);
929 * Internal function to create a thread.
931 CtdlThreadNode *ctdl_internal_create_thread(char *name, long flags, void *(*thread_func) (void *arg), void *args)
934 CtdlThreadNode *this_thread;
936 if (num_threads >= 32767)
938 CtdlLogPrintf(CTDL_EMERG, "Thread system. Thread list full.\n");
942 this_thread = malloc(sizeof(CtdlThreadNode));
943 if (this_thread == NULL) {
944 CtdlLogPrintf(CTDL_EMERG, "Thread system, can't allocate CtdlThreadNode, exiting\n");
948 /* Initialise the thread structure */
949 if (ctdl_internal_init_thread_struct(this_thread, flags) == NULL)
952 CtdlLogPrintf(CTDL_EMERG, "Thread system, can't initialise CtdlThreadNode, exiting\n");
956 * If we got here we are going to create the thread so we must initilise the structure
957 * first because most implimentations of threading can't create it in a stopped state
958 * and it might want to do things with its structure that aren't initialised otherwise.
962 this_thread->name = name;
966 this_thread->name = "Un-named Thread";
969 this_thread->flags = flags;
970 this_thread->thread_func = thread_func;
971 this_thread->user_args = args;
973 begin_critical_section(S_THREAD_LIST);
975 * We pass this_thread into the thread as its args so that it can find out information
976 * about itself and it has a bit of storage space for itself, not to mention that the REAL
977 * thread function needs to finish off the setup of the structure
979 if ((ret = citthread_create(&this_thread->tid, &this_thread->attr, ctdl_internal_thread_func, this_thread) != 0))
981 end_critical_section(S_THREAD_LIST);
982 CtdlLogPrintf(CTDL_ALERT, "Thread system, Can't create thread: %s\n",
984 citthread_mutex_unlock(&this_thread->ThreadMutex);
985 citthread_mutex_destroy(&(this_thread->ThreadMutex));
986 citthread_cond_destroy(&(this_thread->ThreadCond));
987 citthread_mutex_destroy(&(this_thread->SleepMutex));
988 citthread_cond_destroy(&(this_thread->SleepCond));
989 citthread_attr_destroy(&this_thread->attr);
993 this_thread->reltid = next_tid;
995 num_threads++; // Increase the count of threads in the system.
996 if(this_thread->flags & CTDLTHREAD_WORKER)
999 this_thread->next = CtdlThreadList;
1000 CtdlThreadList = this_thread;
1001 if (this_thread->next)
1002 this_thread->next->prev = this_thread;
1003 ctdl_thread_internal_calc_loadavg();
1005 end_critical_section(S_THREAD_LIST);
1011 * Wrapper function to create a thread
1012 * ensures the critical section and other protections are in place.
1013 * char *name = name to give to thread, if NULL, use generic name
1014 * int flags = flags to determine type of thread and standard facilities
1016 CtdlThreadNode *CtdlThreadCreate(char *name, long flags, void *(*thread_func) (void *arg), void *args)
1018 CtdlThreadNode *ret = NULL;
1020 ret = ctdl_internal_create_thread(name, flags, thread_func, args);
1027 * Internal function to schedule a thread.
1028 * Must be called from within a S_THREAD_LIST critical section
1030 CtdlThreadNode *CtdlThreadSchedule(char *name, long flags, void *(*thread_func) (void *arg), void *args, time_t when)
1032 CtdlThreadNode *this_thread;
1034 if (num_threads >= 32767)
1036 CtdlLogPrintf(CTDL_EMERG, "Thread system. Thread list full.\n");
1040 this_thread = malloc(sizeof(CtdlThreadNode));
1041 if (this_thread == NULL) {
1042 CtdlLogPrintf(CTDL_EMERG, "Thread system, can't allocate CtdlThreadNode, exiting\n");
1045 /* Initialise the thread structure */
1046 if (ctdl_internal_init_thread_struct(this_thread, flags) == NULL)
1049 CtdlLogPrintf(CTDL_EMERG, "Thread system, can't initialise CtdlThreadNode, exiting\n");
1054 * If we got here we are going to create the thread so we must initilise the structure
1055 * first because most implimentations of threading can't create it in a stopped state
1056 * and it might want to do things with its structure that aren't initialised otherwise.
1060 this_thread->name = name;
1064 this_thread->name = "Un-named Thread";
1067 this_thread->flags = flags;
1068 this_thread->thread_func = thread_func;
1069 this_thread->user_args = args;
1072 * When to start this thread
1074 this_thread->when = when;
1076 begin_critical_section(S_SCHEDULE_LIST);
1077 this_thread->next = CtdlThreadSchedList;
1078 CtdlThreadSchedList = this_thread;
1079 if (this_thread->next)
1080 this_thread->next->prev = this_thread;
1081 end_critical_section(S_SCHEDULE_LIST);
1088 CtdlThreadNode *ctdl_thread_internal_start_scheduled (CtdlThreadNode *this_thread)
1092 begin_critical_section(S_THREAD_LIST);
1094 * We pass this_thread into the thread as its args so that it can find out information
1095 * about itself and it has a bit of storage space for itself, not to mention that the REAL
1096 * thread function needs to finish off the setup of the structure
1098 if ((ret = citthread_create(&this_thread->tid, &this_thread->attr, ctdl_internal_thread_func, this_thread) != 0))
1100 end_critical_section(S_THREAD_LIST);
1101 CtdlLogPrintf(CTDL_DEBUG, "Failed to start scheduled thread \"%s\": %s\n", this_thread->name, strerror(ret));
1102 citthread_mutex_destroy(&(this_thread->ThreadMutex));
1103 citthread_cond_destroy(&(this_thread->ThreadCond));
1104 citthread_mutex_destroy(&(this_thread->SleepMutex));
1105 citthread_cond_destroy(&(this_thread->SleepCond));
1106 citthread_attr_destroy(&this_thread->attr);
1112 num_threads++; // Increase the count of threads in the system.
1113 if(this_thread->flags & CTDLTHREAD_WORKER)
1116 this_thread->next = CtdlThreadList;
1117 CtdlThreadList = this_thread;
1118 if (this_thread->next)
1119 this_thread->next->prev = this_thread;
1121 ctdl_thread_internal_calc_loadavg();
1122 end_critical_section(S_THREAD_LIST);
1130 void ctdl_thread_internal_check_scheduled(void)
1132 CtdlThreadNode *this_thread, *that_thread;
1135 /* Don't start scheduled threads if the system wants single user mode */
1136 if (CtdlWantSingleUser())
1139 if (try_critical_section(S_SCHEDULE_LIST))
1140 return; /* If this list is locked we wait till the next chance */
1144 #ifdef WITH_THREADLOG
1145 CtdlLogPrintf(CTDL_DEBUG, "Checking for scheduled threads to start.\n");
1148 this_thread = CtdlThreadSchedList;
1151 that_thread = this_thread;
1152 this_thread = this_thread->next;
1154 if (now > that_thread->when)
1156 /* Unlink from schedule list */
1157 if (that_thread->prev)
1158 that_thread->prev->next = that_thread->next;
1160 CtdlThreadSchedList = that_thread->next;
1161 if (that_thread->next)
1162 that_thread->next->prev = that_thread->prev;
1164 that_thread->next = that_thread->prev = NULL;
1165 #ifdef WITH_THREADLOG
1166 CtdlLogPrintf(CTDL_DEBUG, "About to start scheduled thread \"%s\".\n", that_thread->name);
1168 if (CT->state > CTDL_THREAD_STOP_REQ)
1169 { /* Only start it if the system is not stopping */
1170 if (ctdl_thread_internal_start_scheduled (that_thread))
1172 #ifdef WITH_THREADLOG
1173 CtdlLogPrintf(CTDL_INFO, "Thread system, Started a scheduled thread \"%s\" (0x%08lx).\n",
1174 that_thread->name, that_thread->tid);
1179 #ifdef WITH_THREADLOG
1182 CtdlLogPrintf(CTDL_DEBUG, "Thread \"%s\" will start in %ld seconds.\n",
1183 that_thread->name, that_thread->when - time(NULL));
1187 end_critical_section(S_SCHEDULE_LIST);
1192 * A warapper function for select so we can show a thread as blocked
1194 int CtdlThreadSelect(int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
1198 ctdl_thread_internal_change_state(CT, CTDL_THREAD_BLOCKED);
1199 if (!CtdlThreadCheckStop())
1200 ret = select(n, readfds, writefds, exceptfds, timeout);
1202 * If the select returned <= 0 then it failed due to an error
1203 * or timeout so this thread could stop if asked to do so.
1204 * Anything else means it needs to continue unless the system is shutting down
1209 * The select says this thread needs to do something useful.
1210 * This thread was in an idle state so it may have been asked to stop
1211 * but if the system isn't shutting down this thread is no longer
1212 * idle and select has given it a task to do so it must not stop
1213 * In this condition we need to force it into the running state.
1214 * CtdlThreadGC will clear its ticker for us.
1216 * FIXME: there is still a small hole here. It is possible for the sequence of locking
1217 * to allow the state to get changed to STOP_REQ just after this code if the other thread
1218 * has decided to change the state before this lock, it there fore has to wait till the lock
1219 * completes but it will continue to change the state. We need something a bit better here.
1221 citthread_mutex_lock(&CT->ThreadMutex); /* To prevent race condition of a sleeping thread */
1222 if (GC_thread->state > CTDL_THREAD_STOP_REQ && CT->state <= CTDL_THREAD_STOP_REQ)
1224 CtdlLogPrintf(CTDL_DEBUG, "Thread %s (0x%08lx) refused stop request.\n", CT->name, CT->tid);
1225 CT->state = CTDL_THREAD_RUNNING;
1227 citthread_mutex_unlock(&CT->ThreadMutex);
1230 ctdl_thread_internal_change_state(CT, CTDL_THREAD_RUNNING);
1237 void *new_worker_thread(void *arg);
1238 extern void close_masters (void);
1241 void *simulation_worker (void*arg) {
1242 struct CitContext *this;
1244 this = CreateNewContext();
1247 this->state = CON_IDLE;
1248 dead_session_purge(1);
1249 begin_critical_section(S_SESSION_TABLE);
1251 end_critical_section(S_SESSION_TABLE);
1256 void *simulation_thread (void *arg)
1258 long stats = statcount;
1260 while(stats && !CtdlThreadCheckStop()) {
1261 CtdlThreadCreate("Connection simulation worker", CTDLTHREAD_BIGSTACK, simulation_worker, NULL);
1264 CtdlThreadStopAll();
1268 void go_threading(void)
1271 CtdlThreadNode *last_worker;
1272 struct timeval start, now, result;
1273 double last_duration;
1276 * Initialise the thread system
1278 ctdl_thread_internal_init();
1280 /* Second call to module init functions now that threading is up */
1282 initialise_modules(1);
1283 CtdlThreadCreate("select_on_master", CTDLTHREAD_BIGSTACK, select_on_master, NULL);
1286 CtdlLogPrintf(CTDL_EMERG, "Running connection simulation stats\n");
1287 gettimeofday(&start, NULL);
1288 CtdlThreadCreate("Connection simulation master", CTDLTHREAD_BIGSTACK, simulation_thread, NULL);
1293 * This thread is now used for garbage collection of other threads in the thread list
1295 CtdlLogPrintf(CTDL_INFO, "Startup thread %d becoming garbage collector,\n", citthread_self());
1298 * We do a lot of locking and unlocking of the thread list in here.
1299 * We do this so that we can repeatedly release time for other threads
1300 * that may be waiting on the thread list.
1301 * We are a low priority thread so we can afford to do this
1304 while (CtdlThreadGetCount())
1307 exit_signal = CT->signal;
1310 CtdlThreadStopAll();
1312 check_sched_shutdown();
1313 if (CT->state > CTDL_THREAD_STOP_REQ)
1315 begin_critical_section(S_THREAD_LIST);
1316 ctdl_thread_internal_calc_loadavg();
1317 end_critical_section(S_THREAD_LIST);
1319 ctdl_thread_internal_check_scheduled(); /* start scheduled threads */
1322 /* Reduce the size of the worker thread pool if necessary. */
1323 if ((CtdlThreadGetWorkers() > config.c_min_workers + 1) && (CtdlThreadWorkerAvg < 20) && (CT->state > CTDL_THREAD_STOP_REQ))
1325 /* Ask a worker thread to stop as we no longer need it */
1326 begin_critical_section(S_THREAD_LIST);
1327 last_worker = CtdlThreadList;
1330 citthread_mutex_lock(&last_worker->ThreadMutex);
1331 if (last_worker->flags & CTDLTHREAD_WORKER && (last_worker->state > CTDL_THREAD_STOPPING) && (last_worker->Context == NULL))
1333 citthread_mutex_unlock(&last_worker->ThreadMutex);
1336 citthread_mutex_unlock(&last_worker->ThreadMutex);
1337 last_worker = last_worker->next;
1339 end_critical_section(S_THREAD_LIST);
1342 #ifdef WITH_THREADLOG
1343 CtdlLogPrintf(CTDL_DEBUG, "Thread system, stopping excess worker thread \"%s\" (0x%08lx).\n",
1348 CtdlThreadStop(last_worker);
1353 * If all our workers are working hard, start some more to help out
1356 /* FIXME: come up with a better way to dynamically alter the number of threads
1357 * based on the system load
1360 if ((((CtdlThreadGetWorkers() < config.c_max_workers) && (CtdlThreadGetWorkerAvg() > 60)) || CtdlThreadGetWorkers() < config.c_min_workers) && (CT->state > CTDL_THREAD_STOP_REQ))
1362 /* Only start new threads if we are not going to overload the machine */
1363 /* Temporarily set to 10 should be enough to make sure we don't stranglew the server
1364 * at least until we make this a config option */
1365 if (CtdlThreadGetLoadAvg() < ((double)10.00)) {
1366 for (i=0; i<5 ; i++) {
1367 CtdlThreadCreate("Worker Thread",
1368 CTDLTHREAD_BIGSTACK + CTDLTHREAD_WORKER,
1375 CtdlLogPrintf (CTDL_WARNING, "Server strangled due to machine load average too high.\n");
1381 if (CtdlThreadGetCount() <= 1) // Shutting down clean up the garbage collector
1386 #ifdef THREADS_USESIGNALS
1387 if (CtdlThreadGetCount() && CT->state > CTDL_THREAD_STOP_REQ)
1389 if (CtdlThreadGetCount())
1394 * If the above loop exits we must be shutting down since we obviously have no threads
1396 ctdl_thread_internal_cleanup();
1399 gettimeofday(&now, NULL);
1400 timersub(&now, &start, &result);
1401 last_duration = (double)result.tv_sec + ((double)result.tv_usec / (double) 1000000);
1402 CtdlLogPrintf(CTDL_EMERG, "Simulated %ld connections in %f seconds\n", stats_done, last_duration);