-/* $Id$ */
-
-/* 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 <config.h>
+#endif
#include <pthread.h>
#include <assert.h>
#include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
#include <time.h>
+#include <unistd.h>
+#ifndef HAVE_CLOCK_GETTIME
+#include <sys/time.h>
+#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;
}
-
projects / monky / blobdiff