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-rw-r--r--1.4.23-rc4/main/sched.c404
1 files changed, 404 insertions, 0 deletions
diff --git a/1.4.23-rc4/main/sched.c b/1.4.23-rc4/main/sched.c
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+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 1999 - 2005, Digium, Inc.
+ *
+ * Mark Spencer <markster@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Scheduler Routines (from cheops-NG)
+ *
+ * \author Mark Spencer <markster@digium.com>
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#ifdef DEBUG_SCHEDULER
+#define DEBUG(a) do { \
+ if (option_debug) \
+ DEBUG_M(a) \
+ } while (0)
+#else
+#define DEBUG(a)
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "asterisk/sched.h"
+#include "asterisk/logger.h"
+#include "asterisk/channel.h"
+#include "asterisk/lock.h"
+#include "asterisk/utils.h"
+#include "asterisk/linkedlists.h"
+#include "asterisk/options.h"
+
+struct sched {
+ AST_LIST_ENTRY(sched) list;
+ int id; /*!< ID number of event */
+ struct timeval when; /*!< Absolute time event should take place */
+ int resched; /*!< When to reschedule */
+ int variable; /*!< Use return value from callback to reschedule */
+ const void *data; /*!< Data */
+ ast_sched_cb callback; /*!< Callback */
+};
+
+struct sched_context {
+ ast_mutex_t lock;
+ unsigned int eventcnt; /*!< Number of events processed */
+ unsigned int schedcnt; /*!< Number of outstanding schedule events */
+ AST_LIST_HEAD_NOLOCK(, sched) schedq; /*!< Schedule entry and main queue */
+
+#ifdef SCHED_MAX_CACHE
+ AST_LIST_HEAD_NOLOCK(, sched) schedc; /*!< Cache of unused schedule structures and how many */
+ unsigned int schedccnt;
+#endif
+};
+
+struct sched_context *sched_context_create(void)
+{
+ struct sched_context *tmp;
+
+ if (!(tmp = ast_calloc(1, sizeof(*tmp))))
+ return NULL;
+
+ ast_mutex_init(&tmp->lock);
+ tmp->eventcnt = 1;
+
+ return tmp;
+}
+
+void sched_context_destroy(struct sched_context *con)
+{
+ struct sched *s;
+
+ ast_mutex_lock(&con->lock);
+
+#ifdef SCHED_MAX_CACHE
+ /* Eliminate the cache */
+ while ((s = AST_LIST_REMOVE_HEAD(&con->schedc, list)))
+ free(s);
+#endif
+
+ /* And the queue */
+ while ((s = AST_LIST_REMOVE_HEAD(&con->schedq, list)))
+ free(s);
+
+ /* And the context */
+ ast_mutex_unlock(&con->lock);
+ ast_mutex_destroy(&con->lock);
+ free(con);
+}
+
+static struct sched *sched_alloc(struct sched_context *con)
+{
+ struct sched *tmp;
+
+ /*
+ * We keep a small cache of schedule entries
+ * to minimize the number of necessary malloc()'s
+ */
+#ifdef SCHED_MAX_CACHE
+ if ((tmp = AST_LIST_REMOVE_HEAD(&con->schedc, list)))
+ con->schedccnt--;
+ else
+#endif
+ tmp = ast_calloc(1, sizeof(*tmp));
+
+ return tmp;
+}
+
+static void sched_release(struct sched_context *con, struct sched *tmp)
+{
+ /*
+ * Add to the cache, or just free() if we
+ * already have too many cache entries
+ */
+
+#ifdef SCHED_MAX_CACHE
+ if (con->schedccnt < SCHED_MAX_CACHE) {
+ AST_LIST_INSERT_HEAD(&con->schedc, tmp, list);
+ con->schedccnt++;
+ } else
+#endif
+ free(tmp);
+}
+
+/*! \brief
+ * Return the number of milliseconds
+ * until the next scheduled event
+ */
+int ast_sched_wait(struct sched_context *con)
+{
+ int ms;
+
+ DEBUG(ast_log(LOG_DEBUG, "ast_sched_wait()\n"));
+
+ ast_mutex_lock(&con->lock);
+ if (AST_LIST_EMPTY(&con->schedq)) {
+ ms = -1;
+ } else {
+ ms = ast_tvdiff_ms(AST_LIST_FIRST(&con->schedq)->when, ast_tvnow());
+ if (ms < 0)
+ ms = 0;
+ }
+ ast_mutex_unlock(&con->lock);
+
+ return ms;
+}
+
+
+/*! \brief
+ * Take a sched structure and put it in the
+ * queue, such that the soonest event is
+ * first in the list.
+ */
+static void schedule(struct sched_context *con, struct sched *s)
+{
+
+ struct sched *cur = NULL;
+
+ AST_LIST_TRAVERSE_SAFE_BEGIN(&con->schedq, cur, list) {
+ if (ast_tvcmp(s->when, cur->when) == -1) {
+ AST_LIST_INSERT_BEFORE_CURRENT(&con->schedq, s, list);
+ break;
+ }
+ }
+ AST_LIST_TRAVERSE_SAFE_END
+ if (!cur)
+ AST_LIST_INSERT_TAIL(&con->schedq, s, list);
+
+ con->schedcnt++;
+}
+
+/*! \brief
+ * given the last event *tv and the offset in milliseconds 'when',
+ * computes the next value,
+ */
+static int sched_settime(struct timeval *tv, int when)
+{
+ struct timeval now = ast_tvnow();
+
+ /*ast_log(LOG_DEBUG, "TV -> %lu,%lu\n", tv->tv_sec, tv->tv_usec);*/
+ if (ast_tvzero(*tv)) /* not supplied, default to now */
+ *tv = now;
+ *tv = ast_tvadd(*tv, ast_samp2tv(when, 1000));
+ if (ast_tvcmp(*tv, now) < 0) {
+ *tv = now;
+ }
+ return 0;
+}
+
+
+/*! \brief
+ * Schedule callback(data) to happen when ms into the future
+ */
+int ast_sched_add_variable(struct sched_context *con, int when, ast_sched_cb callback, const void *data, int variable)
+{
+ struct sched *tmp;
+ int res = -1;
+
+ DEBUG(ast_log(LOG_DEBUG, "ast_sched_add()\n"));
+
+ ast_mutex_lock(&con->lock);
+ if ((tmp = sched_alloc(con))) {
+ tmp->id = con->eventcnt++;
+ tmp->callback = callback;
+ tmp->data = data;
+ tmp->resched = when;
+ tmp->variable = variable;
+ tmp->when = ast_tv(0, 0);
+ if (sched_settime(&tmp->when, when)) {
+ sched_release(con, tmp);
+ } else {
+ schedule(con, tmp);
+ res = tmp->id;
+ }
+ }
+#ifdef DUMP_SCHEDULER
+ /* Dump contents of the context while we have the lock so nothing gets screwed up by accident. */
+ if (option_debug)
+ ast_sched_dump(con);
+#endif
+ ast_mutex_unlock(&con->lock);
+
+ return res;
+}
+
+int ast_sched_add(struct sched_context *con, int when, ast_sched_cb callback, const void *data)
+{
+ return ast_sched_add_variable(con, when, callback, data, 0);
+}
+
+/*! \brief
+ * Delete the schedule entry with number
+ * "id". It's nearly impossible that there
+ * would be two or more in the list with that
+ * id.
+ */
+#ifndef AST_DEVMODE
+int ast_sched_del(struct sched_context *con, int id)
+#else
+int _ast_sched_del(struct sched_context *con, int id, const char *file, int line, const char *function)
+#endif
+{
+ struct sched *s;
+
+ DEBUG(ast_log(LOG_DEBUG, "ast_sched_del()\n"));
+
+ ast_mutex_lock(&con->lock);
+ AST_LIST_TRAVERSE_SAFE_BEGIN(&con->schedq, s, list) {
+ if (s->id == id) {
+ AST_LIST_REMOVE_CURRENT(&con->schedq, list);
+ con->schedcnt--;
+ sched_release(con, s);
+ break;
+ }
+ }
+ AST_LIST_TRAVERSE_SAFE_END
+
+#ifdef DUMP_SCHEDULER
+ /* Dump contents of the context while we have the lock so nothing gets screwed up by accident. */
+ if (option_debug)
+ ast_sched_dump(con);
+#endif
+ ast_mutex_unlock(&con->lock);
+
+ if (!s) {
+ if (option_debug)
+ ast_log(LOG_DEBUG, "Attempted to delete nonexistent schedule entry %d!\n", id);
+#ifndef AST_DEVMODE
+ ast_assert(s != NULL);
+#else
+ _ast_assert(0, "s != NULL", file, line, function);
+#endif
+ return -1;
+ }
+
+ return 0;
+}
+
+/*! \brief Dump the contents of the scheduler to LOG_DEBUG */
+void ast_sched_dump(const struct sched_context *con)
+{
+ struct sched *q;
+ struct timeval tv = ast_tvnow();
+#ifdef SCHED_MAX_CACHE
+ ast_log(LOG_DEBUG, "Asterisk Schedule Dump (%d in Q, %d Total, %d Cache)\n", con->schedcnt, con->eventcnt - 1, con->schedccnt);
+#else
+ ast_log(LOG_DEBUG, "Asterisk Schedule Dump (%d in Q, %d Total)\n", con->schedcnt, con->eventcnt - 1);
+#endif
+
+ ast_log(LOG_DEBUG, "=============================================================\n");
+ ast_log(LOG_DEBUG, "|ID Callback Data Time (sec:ms) |\n");
+ ast_log(LOG_DEBUG, "+-----+-----------------+-----------------+-----------------+\n");
+ AST_LIST_TRAVERSE(&con->schedq, q, list) {
+ struct timeval delta = ast_tvsub(q->when, tv);
+
+ ast_log(LOG_DEBUG, "|%.4d | %-15p | %-15p | %.6ld : %.6ld |\n",
+ q->id,
+ q->callback,
+ q->data,
+ delta.tv_sec,
+ (long int)delta.tv_usec);
+ }
+ ast_log(LOG_DEBUG, "=============================================================\n");
+
+}
+
+/*! \brief
+ * Launch all events which need to be run at this time.
+ */
+int ast_sched_runq(struct sched_context *con)
+{
+ struct sched *current;
+ struct timeval tv;
+ int numevents;
+ int res;
+
+ DEBUG(ast_log(LOG_DEBUG, "ast_sched_runq()\n"));
+
+ ast_mutex_lock(&con->lock);
+
+ for (numevents = 0; !AST_LIST_EMPTY(&con->schedq); numevents++) {
+ /* schedule all events which are going to expire within 1ms.
+ * We only care about millisecond accuracy anyway, so this will
+ * help us get more than one event at one time if they are very
+ * close together.
+ */
+ tv = ast_tvadd(ast_tvnow(), ast_tv(0, 1000));
+ if (ast_tvcmp(AST_LIST_FIRST(&con->schedq)->when, tv) != -1)
+ break;
+
+ current = AST_LIST_REMOVE_HEAD(&con->schedq, list);
+ con->schedcnt--;
+
+ /*
+ * At this point, the schedule queue is still intact. We
+ * have removed the first event and the rest is still there,
+ * so it's permissible for the callback to add new events, but
+ * trying to delete itself won't work because it isn't in
+ * the schedule queue. If that's what it wants to do, it
+ * should return 0.
+ */
+
+ ast_mutex_unlock(&con->lock);
+ res = current->callback(current->data);
+ ast_mutex_lock(&con->lock);
+
+ if (res) {
+ /*
+ * If they return non-zero, we should schedule them to be
+ * run again.
+ */
+ if (sched_settime(&current->when, current->variable? res : current->resched)) {
+ sched_release(con, current);
+ } else
+ schedule(con, current);
+ } else {
+ /* No longer needed, so release it */
+ sched_release(con, current);
+ }
+ }
+
+ ast_mutex_unlock(&con->lock);
+
+ return numevents;
+}
+
+long ast_sched_when(struct sched_context *con,int id)
+{
+ struct sched *s;
+ long secs = -1;
+ DEBUG(ast_log(LOG_DEBUG, "ast_sched_when()\n"));
+
+ ast_mutex_lock(&con->lock);
+ AST_LIST_TRAVERSE(&con->schedq, s, list) {
+ if (s->id == id)
+ break;
+ }
+ if (s) {
+ struct timeval now = ast_tvnow();
+ secs = s->when.tv_sec - now.tv_sec;
+ }
+ ast_mutex_unlock(&con->lock);
+
+ return secs;
+}