X-Git-Url: http://vcs.maemo.org/git/?a=blobdiff_plain;f=src%2Ftimed_thread.c;h=ee4346dcdca5a7369c947f7c9d2837fe65e5945a;hb=b951f0f45f60917eea7104e44d0f14c3e0d1f189;hp=ae08c5443844443099e5a7a1ec7baf06c15149c3;hpb=358abc96c0ba1fc4377f575be7c7fb0b94637310;p=monky diff --git a/src/timed_thread.c b/src/timed_thread.c index ae08c54..ee4346d 100644 --- a/src/timed_thread.c +++ b/src/timed_thread.c @@ -1,221 +1,318 @@ -/* $Id$ */ - -/* timed_thread.c - * Author: Philip Kovacs +/* -*- mode: c; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*- + * vim: ts=4 sw=4 noet ai cindent syntax=c + * + * timed_thread.c: Abstraction layer for timed threads + * + * Copyright (C) 2006-2007 Philip Kovacs pkovacs@users.sourceforge.net + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. * - * Abstraction layer for timed threads - * */ + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 + * USA. + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif #include #include #include -#include -#include #include +#include +#ifndef HAVE_CLOCK_GETTIME +#include +#endif #include "timed_thread.h" /* Abstraction layer for timed threads */ +static int now(struct timespec *); + /* private */ -struct _timed_thread -{ - pthread_t thread; /* thread itself */ - pthread_attr_t thread_attr; /* thread attributes */ - pthread_mutex_t cs_mutex; /* critical section mutex */ - pthread_mutex_t runnable_mutex; /* only for the runnable_cond */ - pthread_cond_t runnable_cond; /* used to time and stop the thread */ - unsigned int interval_usecs; /* firing interval in microseconds */ +struct _timed_thread { + pthread_t thread; /* thread itself */ + pthread_attr_t thread_attr; /* thread attributes */ + pthread_mutex_t cs_mutex; /* critical section mutex */ + pthread_mutex_t runnable_mutex; /* only for the runnable_cond */ + pthread_cond_t runnable_cond; /* signalled to stop the thread */ + void *(*start_routine)(void *); /* thread function to run */ + void *arg; /* thread function argument */ + struct timespec interval_time; /* interval_usecs as a struct timespec */ + struct timespec wait_time; /* absolute future time next timed_thread_test will wait until */ + int pipefd[2]; + int die; }; /* linked list of created threads */ -typedef struct _timed_thread_list -{ - timed_thread *p_timed_thread; - timed_thread **addr_of_p_timed_thread; - struct _timed_thread_list *next; +typedef struct _timed_thread_list { + timed_thread *p_timed_thread; + timed_thread **addr_of_p_timed_thread; + struct _timed_thread_list *next; } timed_thread_node, timed_thread_list; static timed_thread_list *p_timed_thread_list_head = NULL; static timed_thread_list *p_timed_thread_list_tail = NULL; - -/* create a timed thread */ -timed_thread* -timed_thread_create (void *(*start_routine)(void*), void *arg, unsigned int interval_usecs) +int timed_thread_readfd(timed_thread *p_timed_thread) { - timed_thread *p_timed_thread; - - assert ((start_routine != NULL) && (interval_usecs >= MINIMUM_INTERVAL_USECS)); - - if ((p_timed_thread = calloc (sizeof(timed_thread), 1)) == 0) - return NULL; - - /* init attributes, e.g. joinable thread */ - pthread_attr_init (&p_timed_thread->thread_attr); - pthread_attr_setdetachstate (&p_timed_thread->thread_attr, PTHREAD_CREATE_JOINABLE); - /* init mutexes */ - pthread_mutex_init (&p_timed_thread->cs_mutex, NULL); - pthread_mutex_init (&p_timed_thread->runnable_mutex, NULL); - /* init cond */ - pthread_cond_init (&p_timed_thread->runnable_cond, NULL); - - p_timed_thread->interval_usecs = interval_usecs; + return p_timed_thread->pipefd[0]; +} - /* create thread */ - if (pthread_create (&p_timed_thread->thread, &p_timed_thread->thread_attr, start_routine, arg)) - { - timed_thread_destroy (p_timed_thread, NULL); - return NULL; - } +static int now(struct timespec *abstime) +{ +#ifndef HAVE_CLOCK_GETTIME + struct timeval tv; +#endif + + if (!abstime) { + return -1; + } + +#ifdef HAVE_CLOCK_GETTIME + return clock_gettime(CLOCK_REALTIME, abstime); +#else + /* fallback to gettimeofday () */ + if (gettimeofday(&tv, NULL) != 0) { + return -1; + } + + abstime->tv_sec = tv.tv_sec; + abstime->tv_nsec = tv.tv_usec * 1000; + return 0; +#endif +} - /*fprintf (stderr, "created timed thread 0x%08X\n", (unsigned)p_timed_thread);*/ - return p_timed_thread; +/* create a timed thread (object creation only) */ +timed_thread *timed_thread_create(void *start_routine(void *), void *arg, + unsigned int interval_usecs) +{ + timed_thread *p_timed_thread; + + assert(start_routine != NULL); + assert(interval_usecs >= MINIMUM_INTERVAL_USECS); + + if ((p_timed_thread = calloc(sizeof(timed_thread), 1)) == 0) { + return NULL; + } + + /* create thread pipe (used to tell threads to die) */ + if (pipe(p_timed_thread->pipefd)) { + return NULL; + } + + /* init attributes, e.g. joinable thread */ + pthread_attr_init(&p_timed_thread->thread_attr); + pthread_attr_setdetachstate(&p_timed_thread->thread_attr, + PTHREAD_CREATE_JOINABLE); + /* init mutexes */ + pthread_mutex_init(&p_timed_thread->cs_mutex, NULL); + pthread_mutex_init(&p_timed_thread->runnable_mutex, NULL); + /* init cond */ + pthread_cond_init(&p_timed_thread->runnable_cond, NULL); + + p_timed_thread->start_routine = start_routine; + p_timed_thread->arg = arg; + + /* set wait time to current time */ + if (now(&p_timed_thread->wait_time)) { + return NULL; + } + + /* seconds portion of the microseconds interval */ + p_timed_thread->interval_time.tv_sec = (time_t) (interval_usecs / 1000000); + /* remaining microseconds convert to nanoseconds */ + p_timed_thread->interval_time.tv_nsec = + (long) ((interval_usecs % 1000000) * 1000); + + /* printf("interval_time.tv_sec = %li, .tv_nsec = %li\n", + p_timed_thread->interval_time.tv_sec, + p_timed_thread->interval_time.tv_nsec); */ + return p_timed_thread; } +/* run a timed thread (drop the thread and run it) */ +int timed_thread_run(timed_thread *p_timed_thread) +{ + return pthread_create(&p_timed_thread->thread, &p_timed_thread->thread_attr, + p_timed_thread->start_routine, p_timed_thread->arg); +} /* destroy a timed thread. - * optional addr_of_p_timed_thread to set callers pointer to NULL as a convenience. */ -void -timed_thread_destroy (timed_thread* p_timed_thread, timed_thread** addr_of_p_timed_thread) + * optional addr_of_p_timed_thread to set callers pointer to NULL as a + * convenience. */ +void timed_thread_destroy(timed_thread *p_timed_thread, + timed_thread **addr_of_p_timed_thread) { - assert (p_timed_thread != NULL); - assert ((addr_of_p_timed_thread == NULL) || (*addr_of_p_timed_thread == p_timed_thread)); - - /* signal thread to stop */ - pthread_mutex_lock (&p_timed_thread->runnable_mutex); - pthread_cond_signal (&p_timed_thread->runnable_cond); - pthread_mutex_unlock (&p_timed_thread->runnable_mutex); - - /* join the terminating thread */ - pthread_join (p_timed_thread->thread, NULL); - - /* clean up */ - pthread_attr_destroy (&p_timed_thread->thread_attr); - pthread_mutex_destroy (&p_timed_thread->cs_mutex); - pthread_mutex_destroy (&p_timed_thread->runnable_mutex); - pthread_cond_destroy (&p_timed_thread->runnable_cond); - - fprintf (stderr, "destroying timed thread 0x%08X\n", (unsigned)p_timed_thread); - free (p_timed_thread); - if (addr_of_p_timed_thread) - *addr_of_p_timed_thread = NULL; + assert(p_timed_thread != NULL); + assert((addr_of_p_timed_thread == NULL) + || (*addr_of_p_timed_thread == p_timed_thread)); + + /* signal thread to stop */ + pthread_mutex_lock(&p_timed_thread->runnable_mutex); + pthread_cond_signal(&p_timed_thread->runnable_cond); + p_timed_thread->die = 1; + pthread_mutex_unlock(&p_timed_thread->runnable_mutex); + write(p_timed_thread->pipefd[1], "die", 3); + + /* join the terminating thread */ + if (p_timed_thread->thread) { + pthread_join(p_timed_thread->thread, NULL); + } + + /* clean up */ + pthread_attr_destroy(&p_timed_thread->thread_attr); + pthread_mutex_destroy(&p_timed_thread->cs_mutex); + pthread_mutex_destroy(&p_timed_thread->runnable_mutex); + pthread_cond_destroy(&p_timed_thread->runnable_cond); + + free(p_timed_thread); + if (addr_of_p_timed_thread) { + *addr_of_p_timed_thread = NULL; + } } - /* lock a timed thread for critical section activity */ -int -timed_thread_lock (timed_thread* p_timed_thread) +int timed_thread_lock(timed_thread *p_timed_thread) { - assert (p_timed_thread != NULL); + assert(p_timed_thread != NULL); - return pthread_mutex_lock (&p_timed_thread->cs_mutex); + return pthread_mutex_lock(&p_timed_thread->cs_mutex); } - /* unlock a timed thread after critical section activity */ -int -timed_thread_unlock (timed_thread* p_timed_thread) +int timed_thread_unlock(timed_thread *p_timed_thread) { - assert (p_timed_thread != NULL); + assert(p_timed_thread != NULL); - return pthread_mutex_unlock (&p_timed_thread->cs_mutex); + return pthread_mutex_unlock(&p_timed_thread->cs_mutex); } - -/* waits required interval for termination signal and returns 1 if got it, 0 otherwise */ -int -timed_thread_test (timed_thread* p_timed_thread) +/* thread waits interval_usecs for runnable_cond to be signaled. + * returns 1 if signaled, -1 on error, and 0 otherwise. + * caller should call timed_thread_exit() on any non-zero return value. */ +int timed_thread_test(timed_thread *p_timed_thread, int override_wait_time) { - struct timespec abstime, reltime; - - assert (p_timed_thread != NULL); - - /* get the absolute time in the future we stop waiting for condition to signal */ - clock_gettime (CLOCK_REALTIME, &abstime); - /* seconds portion of the microseconds interval */ - reltime.tv_sec = (time_t)(p_timed_thread->interval_usecs / 1000000); - /* remaining microseconds convert to nanoseconds */ - reltime.tv_nsec = (long)((p_timed_thread->interval_usecs % 1000000) * 1000); - /* absolute future time */ - abstime.tv_sec += reltime.tv_sec; - abstime.tv_nsec += reltime.tv_nsec; - - /* wait until future time for runnable_cond to signal */ - if (pthread_cond_timedwait (&p_timed_thread->runnable_cond, - &p_timed_thread->runnable_mutex, - &abstime) != ETIMEDOUT) - { - /* runnable_cond was signalled or some error occured */ - pthread_mutex_unlock (&p_timed_thread->runnable_mutex); - /* tell caller to exit */ - return 1; - } - - /* tell caller not to exit yet */ - return 0; + struct timespec now_time; + int rc; + + assert(p_timed_thread != NULL); + + /* acquire runnable_cond mutex */ + if (pthread_mutex_lock(&p_timed_thread->runnable_mutex)) { + /* could not acquire runnable_cond mutex, + * so tell caller to exit thread */ + return -1; + } + + if (p_timed_thread->die) { + /* if we were kindly asked to die, then die */ + return 1; + } + + if (override_wait_time && now(&p_timed_thread->wait_time)) { + return -1; + } + + /* release mutex and wait until future time for runnable_cond to signal */ + rc = pthread_cond_timedwait(&p_timed_thread->runnable_cond, + &p_timed_thread->runnable_mutex, &p_timed_thread->wait_time); + /* mutex re-acquired, so release it */ + pthread_mutex_unlock(&p_timed_thread->runnable_mutex); + + if (now(&now_time)) { + return -1; + } + + if (rc == 0) { + /* runnable_cond was signaled, so tell caller to exit thread */ + return 1; + } + + /* absolute future time for next pass */ + p_timed_thread->wait_time.tv_sec += p_timed_thread->interval_time.tv_sec; + p_timed_thread->wait_time.tv_nsec += p_timed_thread->interval_time.tv_nsec; + p_timed_thread->wait_time.tv_sec += p_timed_thread->wait_time.tv_nsec / 1000000000; + p_timed_thread->wait_time.tv_nsec = p_timed_thread->wait_time.tv_nsec % 1000000000; + + /* ensure our future wait time is sane */ + if (p_timed_thread->wait_time.tv_sec > (now_time.tv_sec + p_timed_thread->interval_time.tv_sec) || p_timed_thread->wait_time.tv_sec < now_time.tv_sec) { + p_timed_thread->wait_time.tv_sec = now_time.tv_sec + p_timed_thread->interval_time.tv_sec; + p_timed_thread->wait_time.tv_nsec = now_time.tv_nsec + p_timed_thread->interval_time.tv_nsec; + p_timed_thread->wait_time.tv_sec += p_timed_thread->wait_time.tv_nsec / 1000000000; + p_timed_thread->wait_time.tv_nsec = p_timed_thread->wait_time.tv_nsec % 1000000000; + } + + /* tell caller not to exit yet */ + return 0; } - /* exit a timed thread */ -void -timed_thread_exit (timed_thread* p_timed_thread) +void timed_thread_exit(timed_thread *p_timed_thread) { - assert (p_timed_thread != NULL); + assert(p_timed_thread != NULL); - pthread_exit (NULL); -} + close(p_timed_thread->pipefd[0]); + close(p_timed_thread->pipefd[1]); + pthread_exit(NULL); +} -/* register a timed thread for future destruction via timed_thread_destroy_registered_threads() */ -int -timed_thread_register (timed_thread* p_timed_thread, timed_thread** addr_of_p_timed_thread) +/* register a timed thread for future destruction via + * timed_thread_destroy_registered_threads() */ +int timed_thread_register(timed_thread *p_timed_thread, + timed_thread **addr_of_p_timed_thread) { - timed_thread_node *p_node; + timed_thread_node *p_node; + + assert((addr_of_p_timed_thread == NULL) + || (*addr_of_p_timed_thread == p_timed_thread)); - assert (p_timed_thread != NULL); - assert ((addr_of_p_timed_thread == NULL) || (*addr_of_p_timed_thread == p_timed_thread)); + if ((p_node = calloc(sizeof(timed_thread_node), 1)) == 0) { + return 0; + } + + p_node->p_timed_thread = p_timed_thread; + p_node->addr_of_p_timed_thread = addr_of_p_timed_thread; + p_node->next = NULL; + + if (!p_timed_thread_list_tail) { + /* first node of empty list */ + p_timed_thread_list_tail = p_node; + p_timed_thread_list_head = p_node; + } else { + /* add node to tail of non-empty list */ + p_timed_thread_list_tail->next = p_node; + p_timed_thread_list_tail = p_node; + } - if ((p_node = calloc (sizeof (timed_thread_node), 1)) == 0) return 0; - - p_node->p_timed_thread = p_timed_thread; - p_node->addr_of_p_timed_thread = addr_of_p_timed_thread; - p_node->next = NULL; - - if (!p_timed_thread_list_tail) - { - /* first node of empty list */ - p_timed_thread_list_tail = p_node; - p_timed_thread_list_head = p_node; - } - else - { - /* add node to tail of non-empty list */ - p_timed_thread_list_tail->next = p_node; - p_timed_thread_list_tail = p_node; - } - - return 0; } - /* destroy all registered timed threads */ -void -timed_thread_destroy_registered_threads (void) +void timed_thread_destroy_registered_threads(void) { - timed_thread_node *p_node, *p_next; - - for (p_node=p_timed_thread_list_head; - p_node; - p_node=p_next) - { - p_next = p_node->next; - timed_thread_destroy (p_node->p_timed_thread, p_node->addr_of_p_timed_thread); - free (p_node); - p_node = NULL; - } - - p_timed_thread_list_head = NULL; - p_timed_thread_list_tail = NULL; + timed_thread_node *p_node, *p_next; + + for (p_node = p_timed_thread_list_head; p_node; p_node = p_next) { + p_next = p_node->next; + timed_thread_destroy(p_node->p_timed_thread, + p_node->addr_of_p_timed_thread); + free(p_node); + p_node = NULL; + } + + p_timed_thread_list_head = NULL; + p_timed_thread_list_tail = NULL; } -