+/*
+ * $Id: sysdep.c 5882 2007-12-13 19:46:05Z davew $
+ *
+ * Citadel "system dependent" stuff.
+ * See copyright.txt for copyright information.
+ *
+ * Here's where we have the Citadel thread implimentation
+ *
+ */
+
+#include <errno.h>
+
+#include "threads.h"
+#include "ctdl_module.h"
+#include "modules_init.h"
+#include "housekeeping.h"
+#include "config.h"
+
+/*
+ * New thread interface.
+ * To create a thread you must call one of the create thread functions.
+ * You must pass it the address of (a pointer to a CtdlThreadNode initialised to NULL) like this
+ * struct CtdlThreadNode *node = NULL;
+ * pass in &node
+ * If the thread is created *node will point to the thread control structure for the created thread.
+ * If the thread creation fails *node remains NULL
+ * Do not free the memory pointed to by *node, it doesn't belong to you.
+ * This new interface duplicates much of the eCrash stuff. We should go for closer integration since that would
+ * remove the need for the calls to eCrashRegisterThread and friends
+ */
+
+static int num_threads = 0; /* Current number of threads */
+static int num_workers = 0; /* Current number of worker threads */
+
+struct CtdlThreadNode *CtdlThreadList = NULL;
+struct CtdlThreadNode *CtdlThreadSchedList = NULL;
+
+/*
+ * Condition variable and Mutex for thread garbage collection
+ */
+/*static pthread_mutex_t thread_gc_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t thread_gc_cond = PTHREAD_COND_INITIALIZER;
+*/
+static pthread_t GC_thread;
+static char *CtdlThreadStates[CTDL_THREAD_LAST_STATE];
+double CtdlThreadLoadAvg = 0;
+double CtdlThreadWorkerAvg = 0;
+pthread_key_t ThreadKey;
+
+pthread_mutex_t Critters[MAX_SEMAPHORES]; /* Things needing locking */
+
+
+
+void InitialiseSemaphores(void)
+{
+ int i;
+
+ /* Set up a bunch of semaphores to be used for critical sections */
+ for (i=0; i<MAX_SEMAPHORES; ++i) {
+ pthread_mutex_init(&Critters[i], NULL);
+ }
+}
+
+
+
+
+/*
+ * Obtain a semaphore lock to begin a critical section.
+ * but only if no one else has one
+ */
+int try_critical_section(int which_one)
+{
+ /* For all types of critical sections except those listed here,
+ * ensure nobody ever tries to do a critical section within a
+ * transaction; this could lead to deadlock.
+ */
+ if ( (which_one != S_FLOORCACHE)
+#ifdef DEBUG_MEMORY_LEAKS
+ && (which_one != S_DEBUGMEMLEAKS)
+#endif
+ && (which_one != S_RPLIST)
+ ) {
+ cdb_check_handles();
+ }
+ return (pthread_mutex_trylock(&Critters[which_one]));
+}
+
+
+/*
+ * Obtain a semaphore lock to begin a critical section.
+ */
+void begin_critical_section(int which_one)
+{
+ /* CtdlLogPrintf(CTDL_DEBUG, "begin_critical_section(%d)\n", which_one); */
+
+ /* For all types of critical sections except those listed here,
+ * ensure nobody ever tries to do a critical section within a
+ * transaction; this could lead to deadlock.
+ */
+ if ( (which_one != S_FLOORCACHE)
+#ifdef DEBUG_MEMORY_LEAKS
+ && (which_one != S_DEBUGMEMLEAKS)
+#endif
+ && (which_one != S_RPLIST)
+ ) {
+ cdb_check_handles();
+ }
+ pthread_mutex_lock(&Critters[which_one]);
+}
+
+/*
+ * Release a semaphore lock to end a critical section.
+ */
+void end_critical_section(int which_one)
+{
+ pthread_mutex_unlock(&Critters[which_one]);
+}
+
+
+/*
+ * A function to destroy the TSD
+ */
+static void ctdl_thread_internal_dest_tsd(void *arg)
+{
+ if (arg != NULL) {
+ check_handles(arg);
+ free(arg);
+ }
+}
+
+
+/*
+ * A function to initialise the thread TSD
+ */
+void ctdl_thread_internal_init_tsd(void)
+{
+ int ret;
+
+ if ((ret = pthread_key_create(&ThreadKey, ctdl_thread_internal_dest_tsd))) {
+ lprintf(CTDL_EMERG, "pthread_key_create: %s\n",
+ strerror(ret));
+ exit(CTDLEXIT_DB);
+ }
+}
+
+/*
+ * Ensure that we have a key for thread-specific data.
+ *
+ * This should be called immediately after startup by any thread
+ *
+ */
+void CtdlThreadAllocTSD(void)
+{
+ ThreadTSD *tsd;
+
+ if (pthread_getspecific(ThreadKey) != NULL)
+ return;
+
+ tsd = malloc(sizeof(ThreadTSD));
+
+ tsd->tid = NULL;
+
+ memset(tsd->cursors, 0, sizeof tsd->cursors);
+ tsd->self = NULL;
+
+ pthread_setspecific(ThreadKey, tsd);
+}
+
+
+void ctdl_thread_internal_free_tsd(void)
+{
+ ctdl_thread_internal_dest_tsd(pthread_getspecific(ThreadKey));
+ pthread_setspecific(ThreadKey, NULL);
+}
+
+
+void ctdl_thread_internal_cleanup(void)
+{
+ int i;
+ struct CtdlThreadNode *this_thread, *that_thread;
+
+ for (i=0; i<CTDL_THREAD_LAST_STATE; i++)
+ {
+ free (CtdlThreadStates[i]);
+ }
+
+ /* Clean up the scheduled thread list */
+ this_thread = CtdlThreadSchedList;
+ while (this_thread)
+ {
+ that_thread = this_thread;
+ this_thread = this_thread->next;
+ pthread_mutex_destroy(&that_thread->ThreadMutex);
+ pthread_cond_destroy(&that_thread->ThreadCond);
+ pthread_mutex_destroy(&that_thread->SleepMutex);
+ pthread_cond_destroy(&that_thread->SleepCond);
+ pthread_attr_destroy(&that_thread->attr);
+ free(that_thread);
+ }
+ ctdl_thread_internal_free_tsd();
+}
+
+void ctdl_thread_internal_init(void)
+{
+ struct CtdlThreadNode *this_thread;
+ int ret = 0;
+
+ GC_thread = pthread_self();
+ CtdlThreadStates[CTDL_THREAD_INVALID] = strdup ("Invalid Thread");
+ CtdlThreadStates[CTDL_THREAD_VALID] = strdup("Valid Thread");
+ CtdlThreadStates[CTDL_THREAD_CREATE] = strdup("Thread being Created");
+ CtdlThreadStates[CTDL_THREAD_CANCELLED] = strdup("Thread Cancelled");
+ CtdlThreadStates[CTDL_THREAD_EXITED] = strdup("Thread Exited");
+ CtdlThreadStates[CTDL_THREAD_STOPPING] = strdup("Thread Stopping");
+ CtdlThreadStates[CTDL_THREAD_STOP_REQ] = strdup("Thread Stop Requested");
+ CtdlThreadStates[CTDL_THREAD_SLEEPING] = strdup("Thread Sleeping");
+ CtdlThreadStates[CTDL_THREAD_RUNNING] = strdup("Thread Running");
+ CtdlThreadStates[CTDL_THREAD_BLOCKED] = strdup("Thread Blocked");
+
+ /* Get ourself a thread entry */
+ this_thread = malloc(sizeof(struct CtdlThreadNode));
+ if (this_thread == NULL) {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, can't allocate CtdlThreadNode, exiting\n");
+ return;
+ }
+ // Ensuring this is zero'd means we make sure the thread doesn't start doing its thing until we are ready.
+ memset (this_thread, 0, sizeof(struct CtdlThreadNode));
+
+ pthread_mutex_init (&(this_thread->ThreadMutex), NULL);
+ pthread_cond_init (&(this_thread->ThreadCond), NULL);
+ pthread_mutex_init (&(this_thread->SleepMutex), NULL);
+ pthread_cond_init (&(this_thread->SleepCond), NULL);
+
+ /* We are garbage collector so create us as running */
+ this_thread->state = CTDL_THREAD_RUNNING;
+
+ if ((ret = pthread_attr_init(&this_thread->attr))) {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, pthread_attr_init: %s\n", strerror(ret));
+ free(this_thread);
+ return;
+ }
+
+ this_thread->name = "Garbage Collection Thread";
+
+ this_thread->tid = GC_thread;
+ CT = this_thread;
+
+ num_threads++; // Increase the count of threads in the system.
+
+ this_thread->next = CtdlThreadList;
+ CtdlThreadList = this_thread;
+ if (this_thread->next)
+ this_thread->next->prev = this_thread;
+ /* Set up start times */
+ gettimeofday(&this_thread->start_time, NULL); /* Time this thread started */
+ memcpy(&this_thread->last_state_change, &this_thread->start_time, sizeof (struct timeval)); /* Changed state so mark it. */
+}
+
+
+/*
+ * A function to update a threads load averages
+ */
+ void ctdl_thread_internal_update_avgs(struct CtdlThreadNode *this_thread)
+ {
+ struct timeval now, result;
+ double last_duration;
+
+ gettimeofday(&now, NULL);
+ timersub(&now, &(this_thread->last_state_change), &result);
+ pthread_mutex_lock(&this_thread->ThreadMutex);
+ // result now has a timeval for the time we spent in the last state since we last updated
+ last_duration = (double)result.tv_sec + ((double)result.tv_usec / (double) 1000000);
+ if (this_thread->state == CTDL_THREAD_SLEEPING)
+ this_thread->avg_sleeping += last_duration;
+ if (this_thread->state == CTDL_THREAD_RUNNING)
+ this_thread->avg_running += last_duration;
+ if (this_thread->state == CTDL_THREAD_BLOCKED)
+ this_thread->avg_blocked += last_duration;
+ memcpy (&this_thread->last_state_change, &now, sizeof (struct timeval));
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+}
+
+/*
+ * A function to chenge the state of a thread
+ */
+void ctdl_thread_internal_change_state (struct CtdlThreadNode *this_thread, enum CtdlThreadState new_state)
+{
+ /*
+ * Wether we change state or not we need update the load values
+ */
+ ctdl_thread_internal_update_avgs(this_thread);
+ pthread_mutex_lock(&this_thread->ThreadMutex); /* To prevent race condition of a sleeping thread */
+ if ((new_state == CTDL_THREAD_STOP_REQ) && (this_thread->state > CTDL_THREAD_STOP_REQ))
+ this_thread->state = new_state;
+ if (((new_state == CTDL_THREAD_SLEEPING) || (new_state == CTDL_THREAD_BLOCKED)) && (this_thread->state == CTDL_THREAD_RUNNING))
+ this_thread->state = new_state;
+ if ((new_state == CTDL_THREAD_RUNNING) && ((this_thread->state == CTDL_THREAD_SLEEPING) || (this_thread->state == CTDL_THREAD_BLOCKED)))
+ this_thread->state = new_state;
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+}
+
+
+/*
+ * A function to tell all threads to exit
+ */
+void CtdlThreadStopAll(void)
+{
+ //FIXME: The signalling of the condition should not be in the critical_section
+ // We need to build a list of threads we are going to signal and then signal them afterwards
+
+ struct CtdlThreadNode *this_thread;
+
+ begin_critical_section(S_THREAD_LIST);
+ this_thread = CtdlThreadList;
+ while(this_thread)
+ {
+#ifdef THREADS_USESIGNALS
+ pthread_kill(this_thread->tid, SIGHUP);
+#endif
+ ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_STOP_REQ);
+ pthread_cond_signal(&this_thread->ThreadCond);
+ pthread_cond_signal(&this_thread->SleepCond);
+ CtdlLogPrintf(CTDL_DEBUG, "Thread system stopping thread \"%s\" (%ld).\n", this_thread->name, this_thread->tid);
+ this_thread = this_thread->next;
+ }
+ end_critical_section(S_THREAD_LIST);
+}
+
+
+/*
+ * A function to wake up all sleeping threads
+ */
+void CtdlThreadWakeAll(void)
+{
+ struct CtdlThreadNode *this_thread;
+
+ CtdlLogPrintf(CTDL_DEBUG, "Thread system waking all threads.\n");
+
+ begin_critical_section(S_THREAD_LIST);
+ this_thread = CtdlThreadList;
+ while(this_thread)
+ {
+ if (!this_thread->thread_func)
+ {
+ pthread_cond_signal(&this_thread->ThreadCond);
+ pthread_cond_signal(&this_thread->SleepCond);
+ }
+ this_thread = this_thread->next;
+ }
+ end_critical_section(S_THREAD_LIST);
+}
+
+
+/*
+ * A function to return the number of threads running in the system
+ */
+int CtdlThreadGetCount(void)
+{
+ return num_threads;
+}
+
+int CtdlThreadGetWorkers(void)
+{
+ return num_workers;
+}
+
+double CtdlThreadGetWorkerAvg(void)
+{
+ double ret;
+
+ begin_critical_section(S_THREAD_LIST);
+ ret = CtdlThreadWorkerAvg;
+ end_critical_section(S_THREAD_LIST);
+ return ret;
+}
+
+double CtdlThreadGetLoadAvg(void)
+{
+ double ret;
+
+ begin_critical_section(S_THREAD_LIST);
+ ret = CtdlThreadLoadAvg;
+ end_critical_section(S_THREAD_LIST);
+ return ret;
+}
+
+
+
+
+/*
+ * A function to rename a thread
+ * Returns a const char *
+ */
+const char *CtdlThreadName(const char *name)
+{
+ const char *old_name;
+
+ if (!CT)
+ {
+ CtdlLogPrintf(CTDL_WARNING, "Thread system WARNING. Attempt to CtdlThreadRename() a non thread. %s\n", name);
+ return NULL;
+ }
+// FIXME: do we need this lock? I think not since the pointer asignmaent should be atomic
+ pthread_mutex_lock(&CT->ThreadMutex);
+ old_name = CT->name;
+ if (name)
+ CT->name = name;
+ pthread_mutex_unlock(&CT->ThreadMutex);
+ return (old_name);
+}
+
+
+/*
+ * A function to force a thread to exit
+ */
+void CtdlThreadCancel(struct CtdlThreadNode *thread)
+{
+ struct CtdlThreadNode *this_thread;
+
+ if (!thread)
+ this_thread = CT;
+ else
+ this_thread = thread;
+ if (!this_thread)
+ {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC. Attempt to CtdlThreadCancel() a non thread.\n");
+ CtdlThreadStopAll();
+ return;
+ }
+
+ if (!this_thread->thread_func)
+ {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC. Attempt to CtdlThreadCancel() the garbage collector.\n");
+ CtdlThreadStopAll();
+ return;
+ }
+
+ ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_CANCELLED);
+ pthread_cancel(this_thread->tid);
+}
+
+
+
+/*
+ * A function for a thread to check if it has been asked to stop
+ */
+int CtdlThreadCheckStop(void)
+{
+ int state;
+
+ if (!CT)
+ {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, CtdlThreadCheckStop() called by a non thread.\n");
+ CtdlThreadStopAll();
+ return -1;
+ }
+
+ state = CT->state;
+
+#ifdef THREADS_USERSIGNALS
+ if (CT->signal)
+ CtdlLogPrintf(CTDL_DEBUG, "Thread \"%s\" caught signal %d.\n", CT->name, CT->signal);
+#endif
+ pthread_mutex_lock(&CT->ThreadMutex);
+ if(state == CTDL_THREAD_STOP_REQ)
+ {
+ CT->state = CTDL_THREAD_STOPPING;
+ pthread_mutex_unlock(&CT->ThreadMutex);
+ return -1;
+ }
+ else if((state < CTDL_THREAD_STOP_REQ) && (state > CTDL_THREAD_CREATE))
+ {
+ pthread_mutex_unlock(&CT->ThreadMutex);
+ return -1;
+ }
+ pthread_mutex_unlock(&CT->ThreadMutex);
+ return 0;
+}
+
+
+/*
+ * A function to ask a thread to exit
+ * The thread must call CtdlThreadCheckStop() periodically to determine if it should exit
+ */
+void CtdlThreadStop(struct CtdlThreadNode *thread)
+{
+ struct CtdlThreadNode *this_thread;
+
+ if (!thread)
+ this_thread = CT;
+ else
+ this_thread = thread;
+ if (!this_thread)
+ return;
+ if (!(this_thread->thread_func))
+ return; // Don't stop garbage collector
+#ifdef THREADS_USESIGNALS
+ pthread_kill(this_thread->tid, SIGHUP);
+#endif
+ ctdl_thread_internal_change_state (this_thread, CTDL_THREAD_STOP_REQ);
+ pthread_cond_signal(&this_thread->ThreadCond);
+ pthread_cond_signal(&this_thread->SleepCond);
+}
+
+/*
+ * So we now have a sleep command that works with threads but it is in seconds
+ */
+void CtdlThreadSleep(int secs)
+{
+ struct timespec wake_time;
+ struct timeval time_now;
+
+
+ if (!CT)
+ {
+ CtdlLogPrintf(CTDL_WARNING, "CtdlThreadSleep() called by something that is not a thread. Should we die?\n");
+ return;
+ }
+
+ memset (&wake_time, 0, sizeof(struct timespec));
+ gettimeofday(&time_now, NULL);
+ wake_time.tv_sec = time_now.tv_sec + secs;
+ wake_time.tv_nsec = time_now.tv_usec * 10;
+
+ ctdl_thread_internal_change_state (CT, CTDL_THREAD_SLEEPING);
+
+ pthread_mutex_lock(&CT->ThreadMutex); /* Prevent something asking us to awaken before we've gone to sleep */
+ pthread_cond_timedwait(&CT->SleepCond, &CT->ThreadMutex, &wake_time);
+ pthread_mutex_unlock(&CT->ThreadMutex);
+
+ ctdl_thread_internal_change_state (CT, CTDL_THREAD_RUNNING);
+}
+
+
+/*
+ * Routine to clean up our thread function on exit
+ */
+static void ctdl_internal_thread_cleanup(void *arg)
+{
+ /*
+ * In here we were called by the current thread because it is exiting
+ * NB. WE ARE THE CURRENT THREAD
+ */
+ CtdlLogPrintf(CTDL_NOTICE, "Thread \"%s\" (%ld) exited.\n", CT->name, CT->tid);
+
+ #ifdef HAVE_BACKTRACE
+ eCrash_UnregisterThread();
+ #endif
+
+ pthread_mutex_lock(&CT->ThreadMutex);
+ CT->state = CTDL_THREAD_EXITED; // needs to be last thing else house keeping will unlink us too early
+ pthread_mutex_unlock(&CT->ThreadMutex);
+}
+
+/*
+ * A quick function to show the load averages
+ */
+void ctdl_thread_internal_calc_loadavg(void)
+{
+ struct CtdlThreadNode *that_thread;
+ double load_avg, worker_avg;
+ int workers = 0;
+
+ that_thread = CtdlThreadList;
+ load_avg = 0;
+ worker_avg = 0;
+ while(that_thread)
+ {
+ /* Update load averages */
+ ctdl_thread_internal_update_avgs(that_thread);
+ pthread_mutex_lock(&that_thread->ThreadMutex);
+ that_thread->load_avg = that_thread->avg_sleeping + that_thread->avg_running + that_thread->avg_blocked;
+ that_thread->load_avg = that_thread->avg_running / that_thread->load_avg * 100;
+ that_thread->avg_sleeping /= 2;
+ that_thread->avg_running /= 2;
+ that_thread->avg_blocked /= 2;
+ load_avg += that_thread->load_avg;
+ if (that_thread->flags & CTDLTHREAD_WORKER)
+ {
+ worker_avg += that_thread->load_avg;
+ workers++;
+ }
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "CtdlThread, \"%s\" (%ld) \"%s\" %f %f %f %f.\n",
+ that_thread->name,
+ that_thread->tid,
+ CtdlThreadStates[that_thread->state],
+ that_thread->avg_sleeping,
+ that_thread->avg_running,
+ that_thread->avg_blocked,
+ that_thread->load_avg);
+#endif
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ that_thread = that_thread->next;
+ }
+ CtdlThreadLoadAvg = load_avg/num_threads;
+ CtdlThreadWorkerAvg = worker_avg/workers;
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_INFO, "System load average %f, workers averag %f, threads %d, workers %d, sessions %d\n", CtdlThreadLoadAvg, CtdlThreadWorkerAvg, num_threads, num_workers, num_sessions);
+#endif
+}
+
+
+/*
+ * Garbage collection routine.
+ * Gets called by main() in a loop to clean up the thread list periodically.
+ */
+void CtdlThreadGC (void)
+{
+ struct CtdlThreadNode *this_thread, *that_thread;
+ int workers = 0;
+ int ret=0;
+
+ begin_critical_section(S_THREAD_LIST);
+
+ /* Handle exiting of garbage collector thread */
+ if(num_threads == 1)
+ CtdlThreadList->state = CTDL_THREAD_EXITED;
+
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "Thread system running garbage collection.\n");
+#endif
+ /*
+ * Woke up to do garbage collection
+ */
+ this_thread = CtdlThreadList;
+ while(this_thread)
+ {
+ that_thread = this_thread;
+ this_thread = this_thread->next;
+
+ /* Do we need to clean up this thread? */
+ pthread_mutex_lock(&that_thread->ThreadMutex);
+ if (that_thread->state != CTDL_THREAD_EXITED)
+ {
+ if(that_thread->flags & CTDLTHREAD_WORKER)
+ workers++; /* Sanity check on number of worker threads */
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ continue;
+ }
+
+ if (pthread_equal(that_thread->tid, pthread_self()) && that_thread->thread_func)
+ { /* Sanity check */
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ end_critical_section(S_THREAD_LIST);
+ CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, a thread is trying to clean up after itself.\n");
+ abort();
+ return;
+ }
+
+ if (num_threads <= 0)
+ { /* Sanity check */
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ end_critical_section(S_THREAD_LIST);
+ CtdlLogPrintf(CTDL_EMERG, "Thread system PANIC, num_threads <= 0 and trying to do Garbage Collection.\n");
+ abort();
+ return;
+ }
+
+ if(that_thread->flags & CTDLTHREAD_WORKER)
+ num_workers--; /* This is a wroker thread so reduce the count. */
+ num_threads--;
+ /* If we are unlinking the list head then the next becomes the list head */
+ if(that_thread->prev)
+ that_thread->prev->next = that_thread->next;
+ else
+ CtdlThreadList = that_thread->next;
+ if(that_thread->next)
+ that_thread->next->prev = that_thread->prev;
+
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ pthread_cond_signal(&that_thread->ThreadCond);
+ pthread_cond_signal(&that_thread->SleepCond); // Make sure this thread is awake
+ pthread_mutex_lock(&that_thread->ThreadMutex); // Make sure it has done what its doing
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ /*
+ * Join on the thread to do clean up and prevent memory leaks
+ * Also makes sure the thread has cleaned up after itself before we remove it from the list
+ * We can join on the garbage collector thread the join should just return EDEADLCK
+ */
+ ret = pthread_join (that_thread->tid, NULL);
+ if (ret == EDEADLK)
+ CtdlLogPrintf(CTDL_DEBUG, "Garbage collection on own thread.\n");
+ else if (ret == EINVAL)
+ CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, that thread already joined on.\n");
+ else if (ret == ESRCH)
+ CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, no thread to join on.\n");
+ else if (ret != 0)
+ CtdlLogPrintf(CTDL_DEBUG, "Garbage collection, pthread_join returned an unknown error.\n");
+ /*
+ * Now we own that thread entry
+ */
+ CtdlLogPrintf(CTDL_INFO, "Garbage Collection for thread \"%s\" (%ld).\n", that_thread->name, that_thread->tid);
+ pthread_mutex_destroy(&that_thread->ThreadMutex);
+ pthread_cond_destroy(&that_thread->ThreadCond);
+ pthread_mutex_destroy(&that_thread->SleepMutex);
+ pthread_cond_destroy(&that_thread->SleepCond);
+ pthread_attr_destroy(&that_thread->attr);
+ free(that_thread);
+ }
+
+ /* Sanity check number of worker threads */
+ if (workers != num_workers)
+ {
+ end_critical_section(S_THREAD_LIST);
+ CtdlLogPrintf(CTDL_EMERG,
+ "Thread system PANIC, discrepancy in number of worker threads. Counted %d, should be %d.\n",
+ workers, num_workers
+ );
+ abort();
+ }
+ end_critical_section(S_THREAD_LIST);
+}
+
+
+
+
+/*
+ * Runtime function for a Citadel Thread.
+ * This initialises the threads environment and then calls the user supplied thread function
+ * Note that this is the REAL thread function and wraps the users thread function.
+ */
+static void *ctdl_internal_thread_func (void *arg)
+{
+ struct CtdlThreadNode *this_thread;
+ void *ret = NULL;
+
+ /* lock and unlock the thread list.
+ * This causes this thread to wait until all its creation stuff has finished before it
+ * can continue its execution.
+ */
+ begin_critical_section(S_THREAD_LIST);
+ this_thread = (struct CtdlThreadNode *) arg;
+ gettimeofday(&this_thread->start_time, NULL); /* Time this thread started */
+ pthread_mutex_lock(&this_thread->ThreadMutex);
+
+ // Register the cleanup function to take care of when we exit.
+ pthread_cleanup_push(ctdl_internal_thread_cleanup, NULL);
+ // Get our thread data structure
+ CtdlThreadAllocTSD();
+ CT = this_thread;
+ this_thread->pid = getpid();
+ memcpy(&this_thread->last_state_change, &this_thread->start_time, sizeof (struct timeval)); /* Changed state so mark it. */
+ /* Only change to running state if we weren't asked to stop during the create cycle
+ * Other wise there is a window to allow this threads creation to continue to full grown and
+ * therby prevent a shutdown of the server.
+ */
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+
+ if (!CtdlThreadCheckStop())
+ {
+ pthread_mutex_lock(&this_thread->ThreadMutex);
+ this_thread->state = CTDL_THREAD_RUNNING;
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+ }
+ end_critical_section(S_THREAD_LIST);
+
+ // Register for tracing
+ #ifdef HAVE_BACKTRACE
+ eCrash_RegisterThread(this_thread->name, 0);
+ #endif
+
+ // Tell the world we are here
+ CtdlLogPrintf(CTDL_NOTICE, "Created a new thread \"%s\" (%ld). \n", this_thread->name, this_thread->tid);
+
+
+
+ /*
+ * run the thread to do the work but only if we haven't been asked to stop
+ */
+ if (!CtdlThreadCheckStop())
+ ret = (this_thread->thread_func)(this_thread->user_args);
+
+ /*
+ * Our thread is exiting either because it wanted to end or because the server is stopping
+ * We need to clean up
+ */
+ pthread_cleanup_pop(1); // Execute our cleanup routine and remove it
+
+ return(ret);
+}
+
+
+
+/*
+ * Internal function to create a thread.
+ * Must be called from within a S_THREAD_LIST critical section
+ */
+struct CtdlThreadNode *ctdl_internal_create_thread(char *name, long flags, void *(*thread_func) (void *arg), void *args)
+{
+ int ret = 0;
+ struct CtdlThreadNode *this_thread;
+
+ if (num_threads >= 32767)
+ {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system. Thread list full.\n");
+ return NULL;
+ }
+
+ this_thread = malloc(sizeof(struct CtdlThreadNode));
+ if (this_thread == NULL) {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, can't allocate CtdlThreadNode, exiting\n");
+ return NULL;
+ }
+ // Ensuring this is zero'd means we make sure the thread doesn't start doing its thing until we are ready.
+ memset (this_thread, 0, sizeof(struct CtdlThreadNode));
+
+ /* Create the mutex's early so we can use them */
+ pthread_mutex_init (&(this_thread->ThreadMutex), NULL);
+ pthread_cond_init (&(this_thread->ThreadCond), NULL);
+ pthread_mutex_init (&(this_thread->SleepMutex), NULL);
+ pthread_cond_init (&(this_thread->SleepCond), NULL);
+
+ pthread_mutex_lock(&this_thread->ThreadMutex);
+
+ this_thread->state = CTDL_THREAD_CREATE;
+
+ if ((ret = pthread_attr_init(&this_thread->attr))) {
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+ pthread_mutex_destroy(&(this_thread->ThreadMutex));
+ pthread_cond_destroy(&(this_thread->ThreadCond));
+ pthread_mutex_destroy(&(this_thread->SleepMutex));
+ pthread_cond_destroy(&(this_thread->SleepCond));
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, pthread_attr_init: %s\n", strerror(ret));
+ free(this_thread);
+ return NULL;
+ }
+
+ /* Our per-thread stacks need to be bigger than the default size,
+ * otherwise the MIME parser crashes on FreeBSD, and the IMAP service
+ * crashes on 64-bit Linux.
+ */
+ if (flags & CTDLTHREAD_BIGSTACK)
+ {
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_INFO, "Thread system. Creating BIG STACK thread.\n");
+#endif
+ if ((ret = pthread_attr_setstacksize(&this_thread->attr, THREADSTACKSIZE))) {
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+ pthread_mutex_destroy(&(this_thread->ThreadMutex));
+ pthread_cond_destroy(&(this_thread->ThreadCond));
+ pthread_mutex_destroy(&(this_thread->SleepMutex));
+ pthread_cond_destroy(&(this_thread->SleepCond));
+ pthread_attr_destroy(&this_thread->attr);
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, pthread_attr_setstacksize: %s\n",
+ strerror(ret));
+ free(this_thread);
+ return NULL;
+ }
+ }
+
+ /*
+ * If we got here we are going to create the thread so we must initilise the structure
+ * first because most implimentations of threading can't create it in a stopped state
+ * and it might want to do things with its structure that aren't initialised otherwise.
+ */
+ if(name)
+ {
+ this_thread->name = name;
+ }
+ else
+ {
+ this_thread->name = "Un-named Thread";
+ }
+
+ this_thread->flags = flags;
+ this_thread->thread_func = thread_func;
+ this_thread->user_args = args;
+ /* Set this new thread with an avg_blocked of 2. We do this so that its creation affects the
+ * load average for the system. If we don't do this then we create a mass of threads at the same time
+ * because the creation didn't affect the load average.
+ */
+ this_thread->avg_blocked = 2;
+
+ /*
+ * We pass this_thread into the thread as its args so that it can find out information
+ * about itself and it has a bit of storage space for itself, not to mention that the REAL
+ * thread function needs to finish off the setup of the structure
+ */
+ if ((ret = pthread_create(&this_thread->tid, &this_thread->attr, ctdl_internal_thread_func, this_thread) != 0))
+ {
+
+ CtdlLogPrintf(CTDL_ALERT, "Thread system, Can't create thread: %s\n",
+ strerror(ret));
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+ pthread_mutex_destroy(&(this_thread->ThreadMutex));
+ pthread_cond_destroy(&(this_thread->ThreadCond));
+ pthread_mutex_destroy(&(this_thread->SleepMutex));
+ pthread_cond_destroy(&(this_thread->SleepCond));
+ pthread_attr_destroy(&this_thread->attr);
+ free(this_thread);
+ return NULL;
+ }
+
+ num_threads++; // Increase the count of threads in the system.
+ if(this_thread->flags & CTDLTHREAD_WORKER)
+ num_workers++;
+
+ this_thread->next = CtdlThreadList;
+ CtdlThreadList = this_thread;
+ if (this_thread->next)
+ this_thread->next->prev = this_thread;
+
+ pthread_mutex_unlock(&this_thread->ThreadMutex);
+
+ ctdl_thread_internal_calc_loadavg();
+ return this_thread;
+}
+
+/*
+ * Wrapper function to create a thread
+ * ensures the critical section and other protections are in place.
+ * char *name = name to give to thread, if NULL, use generic name
+ * int flags = flags to determine type of thread and standard facilities
+ */
+struct CtdlThreadNode *CtdlThreadCreate(char *name, long flags, void *(*thread_func) (void *arg), void *args)
+{
+ struct CtdlThreadNode *ret = NULL;
+
+ begin_critical_section(S_THREAD_LIST);
+ ret = ctdl_internal_create_thread(name, flags, thread_func, args);
+ end_critical_section(S_THREAD_LIST);
+ return ret;
+}
+
+
+
+/*
+ * Internal function to schedule a thread.
+ * Must be called from within a S_THREAD_LIST critical section
+ */
+struct CtdlThreadNode *CtdlThreadSchedule(char *name, long flags, void *(*thread_func) (void *arg), void *args, time_t when)
+{
+ int ret = 0;
+ struct CtdlThreadNode *this_thread;
+
+ if (num_threads >= 32767)
+ {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system. Thread list full.\n");
+ return NULL;
+ }
+
+ this_thread = malloc(sizeof(struct CtdlThreadNode));
+ if (this_thread == NULL) {
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, can't allocate CtdlThreadNode, exiting\n");
+ return NULL;
+ }
+ // Ensuring this is zero'd means we make sure the thread doesn't start doing its thing until we are ready.
+ memset (this_thread, 0, sizeof(struct CtdlThreadNode));
+
+ /* Create the mutex's early so we can use them */
+ pthread_mutex_init (&(this_thread->ThreadMutex), NULL);
+ pthread_cond_init (&(this_thread->ThreadCond), NULL);
+ pthread_mutex_init (&(this_thread->SleepMutex), NULL);
+ pthread_cond_init (&(this_thread->SleepCond), NULL);
+
+ this_thread->state = CTDL_THREAD_CREATE;
+
+ if ((ret = pthread_attr_init(&this_thread->attr))) {
+ pthread_mutex_destroy(&(this_thread->ThreadMutex));
+ pthread_cond_destroy(&(this_thread->ThreadCond));
+ pthread_mutex_destroy(&(this_thread->SleepMutex));
+ pthread_cond_destroy(&(this_thread->SleepCond));
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, pthread_attr_init: %s\n", strerror(ret));
+ free(this_thread);
+ return NULL;
+ }
+
+ /* Our per-thread stacks need to be bigger than the default size,
+ * otherwise the MIME parser crashes on FreeBSD, and the IMAP service
+ * crashes on 64-bit Linux.
+ */
+ if (flags & CTDLTHREAD_BIGSTACK)
+ {
+ CtdlLogPrintf(CTDL_INFO, "Thread system. Creating BIG STACK thread.\n");
+ if ((ret = pthread_attr_setstacksize(&this_thread->attr, THREADSTACKSIZE))) {
+ pthread_mutex_destroy(&(this_thread->ThreadMutex));
+ pthread_cond_destroy(&(this_thread->ThreadCond));
+ pthread_mutex_destroy(&(this_thread->SleepMutex));
+ pthread_cond_destroy(&(this_thread->SleepCond));
+ pthread_attr_destroy(&this_thread->attr);
+ CtdlLogPrintf(CTDL_EMERG, "Thread system, pthread_attr_setstacksize: %s\n",
+ strerror(ret));
+ free(this_thread);
+ return NULL;
+ }
+ }
+
+ /*
+ * If we got here we are going to create the thread so we must initilise the structure
+ * first because most implimentations of threading can't create it in a stopped state
+ * and it might want to do things with its structure that aren't initialised otherwise.
+ */
+ if(name)
+ {
+ this_thread->name = name;
+ }
+ else
+ {
+ this_thread->name = "Un-named Thread";
+ }
+
+ this_thread->flags = flags;
+ this_thread->thread_func = thread_func;
+ this_thread->user_args = args;
+ /* Set this new thread with an avg_blocked of 2. We do this so that its creation affects the
+ * load average for the system. If we don't do this then we create a mass of threads at the same time
+ * because the creation didn't affect the load average.
+ */
+ this_thread->avg_blocked = 2;
+
+ /*
+ * When to start this thread
+ */
+ this_thread->when = when;
+
+ begin_critical_section(S_SCHEDULE_LIST);
+ this_thread->next = CtdlThreadSchedList;
+ CtdlThreadSchedList = this_thread;
+ if (this_thread->next)
+ this_thread->next->prev = this_thread;
+ end_critical_section(S_SCHEDULE_LIST);
+
+ return this_thread;
+}
+
+
+
+struct CtdlThreadNode *ctdl_thread_internal_start_scheduled (struct CtdlThreadNode *this_thread)
+{
+ int ret = 0;
+
+ /*
+ * We pass this_thread into the thread as its args so that it can find out information
+ * about itself and it has a bit of storage space for itself, not to mention that the REAL
+ * thread function needs to finish off the setup of the structure
+ */
+ if ((ret = pthread_create(&this_thread->tid, &this_thread->attr, ctdl_internal_thread_func, this_thread) != 0))
+ {
+
+ CtdlLogPrintf(CTDL_ALERT, "Thread system, Can't create thread: %s\n",
+ strerror(ret));
+ return NULL;
+ }
+
+
+ num_threads++; // Increase the count of threads in the system.
+ if(this_thread->flags & CTDLTHREAD_WORKER)
+ num_workers++;
+
+ this_thread->next = CtdlThreadList;
+ CtdlThreadList = this_thread;
+ if (this_thread->next)
+ this_thread->next->prev = this_thread;
+
+ return this_thread;
+}
+
+
+
+void ctdl_thread_internal_check_scheduled(void)
+{
+ struct CtdlThreadNode *this_thread, *that_thread;
+ time_t now;
+
+ if (try_critical_section(S_SCHEDULE_LIST))
+ return; /* If this list is locked we wait till the next chance */
+
+ now = time(NULL);
+
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "Checking for scheduled threads to start.\n");
+#endif
+
+ this_thread = CtdlThreadSchedList;
+ while(this_thread)
+ {
+ that_thread = this_thread;
+ this_thread = this_thread->next;
+
+ if (now > that_thread->when)
+ {
+ /* Unlink from schedule list */
+ if (that_thread->prev)
+ that_thread->prev->next = that_thread->next;
+ else
+ CtdlThreadSchedList = that_thread->next;
+ if (that_thread->next)
+ that_thread->next->prev = that_thread->prev;
+
+ that_thread->next = that_thread->prev = NULL;
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "About to start scheduled thread \"%s\".\n", that_thread->name);
+#endif
+ begin_critical_section(S_THREAD_LIST);
+ if (CT->state > CTDL_THREAD_STOP_REQ)
+ { /* Only start it if the system is not stopping */
+ pthread_mutex_lock(&that_thread->ThreadMutex);
+ if (ctdl_thread_internal_start_scheduled (that_thread) == NULL)
+ {
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "Failed to start scheduled thread \"%s\".\n", that_thread->name);
+#endif
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ pthread_mutex_destroy(&(that_thread->ThreadMutex));
+ pthread_cond_destroy(&(that_thread->ThreadCond));
+ pthread_mutex_destroy(&(that_thread->SleepMutex));
+ pthread_cond_destroy(&(that_thread->SleepCond));
+ pthread_attr_destroy(&that_thread->attr);
+ free(that_thread);
+ }
+ else
+ {
+ CtdlLogPrintf(CTDL_INFO, "Thread system, Started a scheduled thread \"%s\" (%ld).\n",
+ that_thread->name, that_thread->tid);
+ pthread_mutex_unlock(&that_thread->ThreadMutex);
+ ctdl_thread_internal_calc_loadavg();
+ }
+ }
+ end_critical_section(S_THREAD_LIST);
+ }
+ else
+ {
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "Thread \"%s\" will start in %ld seconds.\n", that_thread->name, that_thread->when - time(NULL));
+#endif
+ }
+ }
+ end_critical_section(S_SCHEDULE_LIST);
+}
+
+
+/*
+ * A warapper function for select so we can show a thread as blocked
+ */
+int CtdlThreadSelect(int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
+{
+ int ret;
+
+ ctdl_thread_internal_change_state(CT, CTDL_THREAD_BLOCKED);
+ ret = select(n, readfds, writefds, exceptfds, timeout);
+ ctdl_thread_internal_change_state(CT, CTDL_THREAD_RUNNING);
+ return ret;
+}
+
+
+
+
+
+
+void go_threading(void)
+{
+ int i;
+ struct CtdlThreadNode *last_worker;
+
+ /*
+ * Initialise the thread system
+ */
+ ctdl_thread_internal_init();
+ /*
+ * Now create a bunch of worker threads.
+ */
+// CtdlLogPrintf(CTDL_DEBUG, "Starting %d worker threads\n", config.c_min_workers);
+// begin_critical_section(S_THREAD_LIST);
+// i=0; /* Always start at least 1 worker thread */
+// do
+// {
+// ctdl_internal_create_thread("Worker Thread", CTDLTHREAD_BIGSTACK + CTDLTHREAD_WORKER, worker_thread, NULL);
+// } while (++i < config.c_min_workers);
+// end_critical_section(S_THREAD_LIST);
+
+ /* Second call to module init functions now that threading is up */
+ initialise_modules(1);
+
+ /*
+ * This thread is now used for garbage collection of other threads in the thread list
+ */
+ CtdlLogPrintf(CTDL_INFO, "Startup thread %d becoming garbage collector,\n", pthread_self());
+
+ /*
+ * We do a lot of locking and unlocking of the thread list in here.
+ * We do this so that we can repeatedly release time for other threads
+ * that may be waiting on the thread list.
+ * We are a low priority thread so we can afford to do this
+ */
+
+ while (CtdlThreadGetCount())
+ {
+ if (CT->signal)
+ exit_signal = CT->signal;
+ if (exit_signal)
+ CtdlThreadStopAll();
+ check_sched_shutdown();
+ if (CT->state > CTDL_THREAD_STOP_REQ)
+ {
+ begin_critical_section(S_THREAD_LIST);
+ ctdl_thread_internal_calc_loadavg();
+ end_critical_section(S_THREAD_LIST);
+
+ ctdl_thread_internal_check_scheduled(); /* start scheduled threads */
+ }
+
+ /* Reduce the size of the worker thread pool if necessary. */
+ if ((CtdlThreadGetWorkers() > config.c_min_workers) && (CtdlThreadWorkerAvg < 20) && (CT->state > CTDL_THREAD_STOP_REQ))
+ {
+ /* Ask a worker thread to stop as we no longer need it */
+ begin_critical_section(S_THREAD_LIST);
+ last_worker = CtdlThreadList;
+ while (last_worker)
+ {
+ pthread_mutex_lock(&last_worker->ThreadMutex);
+ if (last_worker->flags & CTDLTHREAD_WORKER && last_worker->state > CTDL_THREAD_STOPPING)
+ {
+ pthread_mutex_unlock(&last_worker->ThreadMutex);
+ break;
+ }
+ pthread_mutex_unlock(&last_worker->ThreadMutex);
+ last_worker = last_worker->next;
+ }
+ end_critical_section(S_THREAD_LIST);
+ if (last_worker)
+ {
+#ifdef WITH_THREADLOG
+ CtdlLogPrintf(CTDL_DEBUG, "Thread system, stopping excess worker thread \"%s\" (%ld).\n",
+ last_worker->name,
+ last_worker->tid
+ );
+#endif
+ CtdlThreadStop(last_worker);
+ }
+ }
+
+ /*
+ * If all our workers are working hard, start some more to help out
+ * with things
+ */
+ /* FIXME: come up with a better way to dynamically alter the number of threads
+ * based on the system load
+ */
+// if ((CtdlThreadGetWorkers() < config.c_max_workers) && (CtdlThreadGetWorkers() < num_sessions))
+ // && (CtdlThreadLoadAvg < 90) )
+ if ((((CtdlThreadGetWorkers() < config.c_max_workers) && (CtdlThreadGetWorkerAvg() > 60) && (CtdlThreadGetLoadAvg() < 90) ) || CtdlThreadGetWorkers() < config.c_min_workers) && (CT->state > CTDL_THREAD_STOP_REQ))
+ {
+ for (i=0; i<5 ; i++)
+// for (i=0; i< (num_sessions - CtdlThreadGetWorkers()) ; i++)
+// for (i=0; i< (10 - (55 - CtdlThreadWorkerAvg) / CtdlThreadWorkerAvg / CtdlThreadGetWorkers()) ; i++)
+ {
+// begin_critical_section(S_THREAD_LIST);
+ CtdlThreadCreate("Worker Thread",
+ CTDLTHREAD_BIGSTACK + CTDLTHREAD_WORKER,
+ worker_thread,
+ NULL
+ );
+// end_critical_section(S_THREAD_LIST);
+ }
+ }
+
+ CtdlThreadGC();
+
+ if (CtdlThreadGetCount() <= 1) // Shutting down clean up the garbage collector
+ {
+ CtdlThreadGC();
+ }
+
+ if (CtdlThreadGetCount())
+ CtdlThreadSleep(1);
+ }
+ /*
+ * If the above loop exits we must be shutting down since we obviously have no threads
+ */
+ ctdl_thread_internal_cleanup();
+}