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Diffstat (limited to 'src/charon/processing/event_queue.c')
| -rw-r--r-- | src/charon/processing/event_queue.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/src/charon/processing/event_queue.c b/src/charon/processing/event_queue.c new file mode 100644 index 000000000..40bcb1ed8 --- /dev/null +++ b/src/charon/processing/event_queue.c @@ -0,0 +1,290 @@ +/** + * @file event_queue.c + * + * @brief Implementation of event_queue_t + * + */ + +/* + * Copyright (C) 2005-2006 Martin Willi + * Copyright (C) 2005 Jan Hutter + * Hochschule fuer Technik Rapperswil + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include <pthread.h> +#include <stdlib.h> + +#include "event_queue.h" + +#include <library.h> +#include <utils/linked_list.h> + + + +typedef struct event_t event_t; + +/** + * Event containing a job and a schedule time + */ +struct event_t { + /** + * Time to fire the event. + */ + timeval_t time; + + /** + * Every event has its assigned job. + */ + job_t * job; +}; + +/** + * destroy an event and its job + */ +static void event_destroy(event_t *event) +{ + event->job->destroy(event->job); + free(event); +} + +typedef struct private_event_queue_t private_event_queue_t; + +/** + * Private Variables and Functions of event_queue_t class. + */ +struct private_event_queue_t { + /** + * Public part. + */ + event_queue_t public; + + /** + * The events are stored in a linked list of type linked_list_t. + */ + linked_list_t *list; + + /** + * Access to linked_list is locked through this mutex. + */ + pthread_mutex_t mutex; + + /** + * If the queue is empty or an event has not to be fired + * a thread has to wait. + * + * This condvar is used to wake up such a thread. + */ + pthread_cond_t condvar; +}; + +/** + * Returns the difference of to timeval structs in milliseconds + */ +static long time_difference(struct timeval *end_time, struct timeval *start_time) +{ + time_t s; + suseconds_t us; + + s = (end_time->tv_sec - start_time->tv_sec); + us = (end_time->tv_usec - start_time->tv_usec); + return ((s * 1000) + us/1000); +} + +/** + * Implements event_queue_t.get_count + */ +static int get_count(private_event_queue_t *this) +{ + int count; + pthread_mutex_lock(&(this->mutex)); + count = this->list->get_count(this->list); + pthread_mutex_unlock(&(this->mutex)); + return count; +} + +/** + * Implements event_queue_t.get + */ +static job_t *get(private_event_queue_t *this) +{ + timespec_t timeout; + timeval_t current_time; + event_t * next_event; + job_t *job; + int oldstate; + + pthread_mutex_lock(&(this->mutex)); + + while (TRUE) + { + while(this->list->get_count(this->list) == 0) + { + /* add mutex unlock handler for cancellation, enable cancellation */ + pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex)); + pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); + + pthread_cond_wait( &(this->condvar), &(this->mutex)); + + /* reset cancellation, remove mutex-unlock handler (without executing) */ + pthread_setcancelstate(oldstate, NULL); + pthread_cleanup_pop(0); + } + + this->list->get_first(this->list, (void **)&next_event); + + gettimeofday(¤t_time, NULL); + long difference = time_difference(¤t_time,&(next_event->time)); + if (difference <= 0) + { + timeout.tv_sec = next_event->time.tv_sec; + timeout.tv_nsec = next_event->time.tv_usec * 1000; + + /* add mutex unlock handler for cancellation, enable cancellation */ + pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex)); + pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); + + pthread_cond_timedwait(&(this->condvar), &(this->mutex), &timeout); + + /* reset cancellation, remove mutex-unlock handler (without executing) */ + pthread_setcancelstate(oldstate, NULL); + pthread_cleanup_pop(0); + } + else + { + /* event available */ + this->list->remove_first(this->list, (void **)&next_event); + job = next_event->job; + free(next_event); + break; + } + } + pthread_cond_signal( &(this->condvar)); + pthread_mutex_unlock(&(this->mutex)); + + return job; +} + +/** + * Implements function add_absolute of event_queue_t. + * See #event_queue_s.add_absolute for description. + */ +static void add_absolute(private_event_queue_t *this, job_t *job, timeval_t time) +{ + event_t *event; + event_t *current_event; + iterator_t *iterator; + + /* create event */ + event = malloc_thing(event_t); + event->time = time; + event->job = job; + + pthread_mutex_lock(&(this->mutex)); + + /* while just used to break out */ + while(TRUE) + { + if (this->list->get_count(this->list) == 0) + { + this->list->insert_first(this->list,event); + break; + } + + /* check last entry */ + this->list->get_last(this->list,(void **) ¤t_event); + + if (time_difference(&(event->time), &(current_event->time)) >= 0) + { + /* my event has to be fired after the last event in list */ + this->list->insert_last(this->list,event); + break; + } + + /* check first entry */ + this->list->get_first(this->list,(void **) ¤t_event); + + if (time_difference(&(event->time), &(current_event->time)) < 0) + { + /* my event has to be fired before the first event in list */ + this->list->insert_first(this->list,event); + break; + } + + iterator = this->list->create_iterator(this->list,TRUE); + iterator->iterate(iterator, (void**)¤t_event); + /* first element has not to be checked (already done) */ + while(iterator->iterate(iterator, (void**)¤t_event)) + { + if (time_difference(&(event->time), &(current_event->time)) <= 0) + { + /* my event has to be fired before the current event in list */ + iterator->insert_before(iterator,event); + break; + } + } + iterator->destroy(iterator); + break; + } + + pthread_cond_signal( &(this->condvar)); + pthread_mutex_unlock(&(this->mutex)); +} + +/** + * Implements event_queue_t.add_relative. + */ +static void add_relative(event_queue_t *this, job_t *job, u_int32_t ms) +{ + timeval_t current_time; + timeval_t time; + + time_t s = ms / 1000; + suseconds_t us = (ms - s * 1000) * 1000; + + gettimeofday(¤t_time, NULL); + + time.tv_usec = (current_time.tv_usec + us) % 1000000; + time.tv_sec = current_time.tv_sec + (current_time.tv_usec + us)/1000000 + s; + + this->add_absolute(this, job, time); +} + + +/** + * Implements event_queue_t.destroy. + */ +static void event_queue_destroy(private_event_queue_t *this) +{ + this->list->destroy_function(this->list, (void*)event_destroy); + free(this); +} + +/* + * Documented in header + */ +event_queue_t *event_queue_create() +{ + private_event_queue_t *this = malloc_thing(private_event_queue_t); + + this->public.get_count = (int (*) (event_queue_t *event_queue)) get_count; + this->public.get = (job_t *(*) (event_queue_t *event_queue)) get; + this->public.add_absolute = (void (*) (event_queue_t *event_queue, job_t *job, timeval_t time)) add_absolute; + this->public.add_relative = (void (*) (event_queue_t *event_queue, job_t *job, u_int32_t ms)) add_relative; + this->public.destroy = (void (*) (event_queue_t *event_queue)) event_queue_destroy; + + this->list = linked_list_create(); + pthread_mutex_init(&(this->mutex), NULL); + pthread_cond_init(&(this->condvar), NULL); + + return (&this->public); +} |