Add a common implementation of a scheduler context with a dedicated thread.

This commit expands the Asterisk scheduler API to include a common implementation
of a scheduler context being processed by a dedicated thread.  chan_iax2 has been
updated to use this new code.  Also, as a result, this resolves some race
conditions related to the previous chan_iax2 scheduler handling.

Related to rev 171452 which resolved the same issues in 1.4.

Code from team/russell/sched_thread2

Review: http://reviewboard.digium.com/r/129/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@173858 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 39 insertions, 86 deletions

diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index c7ff9fd12..f263dcc2b 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -305,7 +305,7 @@ int (*iax2_regfunk)(const char *username, int onoff) = NULL;
 	} while(0)
 
 static	struct io_context *io;
-static	struct sched_context *sched;
+static	struct ast_sched_thread *sched;
 
 static int iax2_capability = IAX_CAPABILITY_FULLBANDWIDTH;
 
@@ -332,9 +332,6 @@ static int iax2_encryption = 0;
 static struct ast_flags globalflags = { 0 };
 
 static pthread_t netthreadid = AST_PTHREADT_NULL;
-static pthread_t schedthreadid = AST_PTHREADT_NULL;
-AST_MUTEX_DEFINE_STATIC(sched_lock);
-static ast_cond_t sched_cond;
 
 enum iax2_state {
 	IAX_STATE_STARTED = 		(1 << 0),
@@ -1261,22 +1258,18 @@ static int __schedule_action(void (*func)(const void *data), const void *data, c
 #define schedule_action(func, data) __schedule_action(func, data, __PRETTY_FUNCTION__)
 #endif
 
-static int iax2_sched_replace(int id, struct sched_context *con, int when, ast_sched_cb callback, const void *data)
+static int iax2_sched_replace(int id, struct ast_sched_thread *st, int when, 
+		ast_sched_cb callback, const void *data)
 {
-	AST_SCHED_REPLACE(id, con, when, callback, data);
-	signal_condition(&sched_lock, &sched_cond);
+	ast_sched_thread_del(st, id);
 
-	return id;
+	return ast_sched_thread_add(st, when, callback, data);
 }
 
-static int iax2_sched_add(struct sched_context *con, int when, ast_sched_cb callback, const void *data)
+static int iax2_sched_add(struct ast_sched_thread *st, int when, 
+		ast_sched_cb callback, const void *data)
 {
-	int res;
-
-	res = ast_sched_add(con, when, callback, data);
-	signal_condition(&sched_lock, &sched_cond);
-
-	return res;
+	return ast_sched_thread_add(st, when, callback, data);
 }
 
 static int send_ping(const void *data);
@@ -1525,18 +1518,18 @@ static void iax2_destroy_helper(struct chan_iax2_pvt *pvt)
 		ast_clear_flag(pvt, IAX_MAXAUTHREQ);
 	}
 	/* No more pings or lagrq's */
-	AST_SCHED_DEL_SPINLOCK(sched, pvt->pingid, &iaxsl[pvt->callno]);
-	AST_SCHED_DEL_SPINLOCK(sched, pvt->lagid, &iaxsl[pvt->callno]);
-	AST_SCHED_DEL(sched, pvt->autoid);
-	AST_SCHED_DEL(sched, pvt->authid);
-	AST_SCHED_DEL(sched, pvt->initid);
-	AST_SCHED_DEL(sched, pvt->jbid);
-	AST_SCHED_DEL(sched, pvt->keyrotateid);
+	AST_SCHED_DEL_SPINLOCK(ast_sched_thread_get_context(sched), pvt->pingid, &iaxsl[pvt->callno]);
+	AST_SCHED_DEL_SPINLOCK(ast_sched_thread_get_context(sched), pvt->lagid, &iaxsl[pvt->callno]);
+	ast_sched_thread_del(sched, pvt->autoid);
+	ast_sched_thread_del(sched, pvt->authid);
+	ast_sched_thread_del(sched, pvt->initid);
+	ast_sched_thread_del(sched, pvt->jbid);
+	ast_sched_thread_del(sched, pvt->keyrotateid);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
 {
-	AST_SCHED_DEL(sched, fr->retrans);
+	ast_sched_thread_del(sched, fr->retrans);
 	iax_frame_free(fr);
 }
 
@@ -1725,8 +1718,8 @@ static int make_trunk(unsigned short callno, int locked)
 			 * \note We delete these before switching the slot, because if
 			 * they fire in the meantime, they will generate a warning.
 			 */
-			AST_SCHED_DEL(sched, iaxs[callno]->pingid);
-			AST_SCHED_DEL(sched, iaxs[callno]->lagid);
+			ast_sched_thread_del(sched, iaxs[callno]->pingid);
+			ast_sched_thread_del(sched, iaxs[callno]->lagid);
 			iaxs[x] = iaxs[callno];
 			iaxs[x]->callno = x;
 			iaxs[callno] = NULL;
@@ -3214,7 +3207,7 @@ static int schedule_delivery(struct iax_frame *fr, int updatehistory, int fromtr
 
 		jb_reset(iaxs[fr->callno]->jb);
 
-		AST_SCHED_DEL(sched, iaxs[fr->callno]->jbid);
+		ast_sched_thread_del(sched, iaxs[fr->callno]->jbid);
 
 		/* deliver this frame now */
 		if (tsout)
@@ -3254,7 +3247,7 @@ static int iax2_transmit(struct iax_frame *fr)
 	/* Wake up the network and scheduler thread */
 	if (netthreadid != AST_PTHREADT_NULL)
 		pthread_kill(netthreadid, SIGURG);
-	signal_condition(&sched_lock, &sched_cond);
+	ast_sched_thread_poke(sched);
 	return 0;
 }
 
@@ -3390,7 +3383,7 @@ static struct iax2_peer *realtime_peer(const char *peername, struct sockaddr_in
 		ast_copy_flags(peer, &globalflags, IAX_RTAUTOCLEAR|IAX_RTCACHEFRIENDS);
 		if (ast_test_flag(peer, IAX_RTAUTOCLEAR)) {
  			if (peer->expire > -1) {
- 				if (!ast_sched_del(sched, peer->expire)) {
+ 				if (!ast_sched_thread_del(sched, peer->expire)) {
  					peer->expire = -1;
  					peer_unref(peer);
  				}
@@ -3948,7 +3941,7 @@ static int iax2_hangup(struct ast_channel *c)
 			ast_debug(1, "Really destroying %s now...\n", c->name);
 			iax2_destroy(callno);
 		} else if (iaxs[callno]) {
-			if (ast_sched_add(sched, 10000, scheduled_destroy, CALLNO_TO_PTR(callno)) < 0) {
+			if (ast_sched_thread_add(sched, 10000, scheduled_destroy, CALLNO_TO_PTR(callno)) < 0) {
 				ast_log(LOG_ERROR, "Unable to schedule iax2 callno %d destruction?!!  Destroying immediately.\n", callno);
 				iax2_destroy(callno);
 			}
@@ -4051,7 +4044,7 @@ static int iax2_key_rotate(const void *vpvt)
 	ast_mutex_lock(&iaxsl[pvt->callno]);
 
 	pvt->keyrotateid = 
-		ast_sched_add(sched, 120000 + (ast_random() % 180001), iax2_key_rotate, vpvt);
+		ast_sched_thread_add(sched, 120000 + (ast_random() % 180001), iax2_key_rotate, vpvt);
 
 	snprintf(key, sizeof(key), "%lX", ast_random());
 
@@ -7072,14 +7065,14 @@ static void prune_peers(void);
 static void unlink_peer(struct iax2_peer *peer)
 {
 	if (peer->expire > -1) {
-		if (!ast_sched_del(sched, peer->expire)) {
+		if (!ast_sched_thread_del(sched, peer->expire)) {
 			peer->expire = -1;
 			peer_unref(peer);
 		}
 	}
 
 	if (peer->pokeexpire > -1) {
-		if (!ast_sched_del(sched, peer->pokeexpire)) {
+		if (!ast_sched_thread_del(sched, peer->pokeexpire)) {
 			peer->pokeexpire = -1;
 			peer_unref(peer);
 		}
@@ -7153,7 +7146,7 @@ static void reg_source_db(struct iax2_peer *p)
 					p->addr.sin_addr = in;
 					p->addr.sin_port = htons(atoi(c));
  					if (p->expire > -1) {
- 						if (!ast_sched_del(sched, p->expire)) {
+ 						if (!ast_sched_thread_del(sched, p->expire)) {
  							p->expire = -1;
  							peer_unref(p);
  						}
@@ -7249,7 +7242,7 @@ static int update_registry(struct sockaddr_in *sin, int callno, char *devtype, i
 	p->sockfd = fd;
 	/* Setup the expiry */
 	if (p->expire > -1) {
-		if (!ast_sched_del(sched, p->expire)) {
+		if (!ast_sched_thread_del(sched, p->expire)) {
 			p->expire = -1;
 			peer_unref(p);
 		}
@@ -8733,7 +8726,7 @@ retryowner:
 			}
 		}
 		if (f.frametype == AST_FRAME_IAX) {
-			AST_SCHED_DEL(sched, iaxs[fr->callno]->initid);
+			ast_sched_thread_del(sched, iaxs[fr->callno]->initid);
 			/* Handle the IAX pseudo frame itself */
 			if (iaxdebug)
 				ast_debug(1, "IAX subclass %d received\n", f.subclass);
@@ -9215,7 +9208,7 @@ retryowner2:
 
 					/* Remove scheduled iax2_poke_noanswer */
 					if (peer->pokeexpire > -1) {
-						if (!ast_sched_del(sched, peer->pokeexpire)) {
+						if (!ast_sched_thread_del(sched, peer->pokeexpire)) {
 							peer_unref(peer);
 							peer->pokeexpire = -1;
 						}
@@ -10268,7 +10261,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	iaxs[peer->callno]->peerpoke = peer;
 
  	if (peer->pokeexpire > -1) {
- 		if (!ast_sched_del(sched, peer->pokeexpire)) {
+ 		if (!ast_sched_thread_del(sched, peer->pokeexpire)) {
  			peer->pokeexpire = -1;
  			peer_unref(peer);
  		}
@@ -10383,34 +10376,6 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	return c;
 }
 
-static void *sched_thread(void *ignore)
-{
-	int count;
-	int res;
-	struct timeval wait;
-	struct timespec ts;
-
-	for (;;) {
-		pthread_testcancel();
-		ast_mutex_lock(&sched_lock);
-		res = ast_sched_wait(sched);
-		if ((res > 1000) || (res < 0))
-			res = 1000;
-		wait = ast_tvadd(ast_tvnow(), ast_samp2tv(res, 1000));
-		ts.tv_sec = wait.tv_sec;
-		ts.tv_nsec = wait.tv_usec * 1000;
-		ast_cond_timedwait(&sched_cond, &sched_lock, &ts);
-		ast_mutex_unlock(&sched_lock);
-		pthread_testcancel();
-
-		count = ast_sched_runq(sched);
-		if (count >= 20)
-			ast_debug(1, "chan_iax2: ast_sched_runq ran %d scheduled tasks all at once\n", count);
-	}
-
-	return NULL;
-}
-
 static void *network_thread(void *ignore)
 {
 	/* Our job is simple: Send queued messages, retrying if necessary.  Read frames 
@@ -10498,7 +10463,6 @@ static int start_network_thread(void)
 			AST_LIST_UNLOCK(&idle_list);
 		}
 	}
-	ast_pthread_create_background(&schedthreadid, NULL, sched_thread, NULL);
 	ast_pthread_create_background(&netthreadid, NULL, network_thread, NULL);
 	ast_verb(2, "%d helper threads started\n", threadcount);
 	return 0;
@@ -10771,7 +10735,7 @@ static struct iax2_peer *build_peer(const char *name, struct ast_variable *v, st
 					}
 				} else {
 					/* Non-dynamic.  Make sure we become that way if we're not */
-					AST_SCHED_DEL(sched, peer->expire);
+					ast_sched_thread_del(sched, peer->expire);
 					ast_clear_flag(peer, IAX_DYNAMIC);
 					if (ast_dnsmgr_lookup(v->value, &peer->addr, &peer->dnsmgr, srvlookup ? "_iax._udp" : NULL))
 						return peer_unref(peer);
@@ -11144,7 +11108,7 @@ static void delete_users(void)
 
 	AST_LIST_LOCK(&registrations);
 	while ((reg = AST_LIST_REMOVE_HEAD(&registrations, entry))) {
-		AST_SCHED_DEL(sched, reg->expire);
+		ast_sched_thread_del(sched, reg->expire);
 		if (reg->callno) {
 			int callno = reg->callno;
 			ast_mutex_lock(&iaxsl[callno]);
@@ -12327,21 +12291,13 @@ static int __unload_module(void)
 	/* Cancel the network thread, close the net socket */
 	if (netthreadid != AST_PTHREADT_NULL) {
 		AST_LIST_LOCK(&frame_queue);
-		ast_mutex_lock(&sched_lock);
 		pthread_cancel(netthreadid);
-		ast_cond_signal(&sched_cond);
-		ast_mutex_unlock(&sched_lock);	/* Release the schedule lock resource */
 		AST_LIST_UNLOCK(&frame_queue);
 		pthread_join(netthreadid, NULL);
 	}
-	if (schedthreadid != AST_PTHREADT_NULL) {
-		ast_mutex_lock(&sched_lock);
-		pthread_cancel(schedthreadid);
-		ast_cond_signal(&sched_cond);
-		ast_mutex_unlock(&sched_lock);
-		pthread_join(schedthreadid, NULL);
-	}
 
+	sched = ast_sched_thread_destroy(sched);
+	
 	/* Call for all threads to halt */
 	AST_LIST_LOCK(&idle_list);
 	while ((thread = AST_LIST_REMOVE_HEAD(&idle_list, list)))
@@ -12379,7 +12335,6 @@ static int __unload_module(void)
 	ast_channel_unregister(&iax2_tech);
 	delete_users();
 	iax_provision_unload();
-	sched_context_destroy(sched);
 	reload_firmware(1);
 
 	for (x = 0; x < ARRAY_LEN(iaxsl); x++) {
@@ -12494,23 +12449,21 @@ static int load_module(void)
 		ast_mutex_init(&iaxsl[x]);
 	}
 
-	ast_cond_init(&sched_cond, NULL);
-
-	if (!(sched = sched_context_create())) {
-		ast_log(LOG_ERROR, "Failed to create scheduler context\n");
+	if (!(sched = ast_sched_thread_create())) {
+		ast_log(LOG_ERROR, "Failed to create scheduler thread\n");
 		return AST_MODULE_LOAD_FAILURE;
 	}
 
 	if (!(io = io_context_create())) {
 		ast_log(LOG_ERROR, "Failed to create I/O context\n");
-		sched_context_destroy(sched);
+		sched = ast_sched_thread_destroy(sched);
 		return AST_MODULE_LOAD_FAILURE;
 	}
 
 	if (!(netsock = ast_netsock_list_alloc())) {
 		ast_log(LOG_ERROR, "Failed to create netsock list\n");
 		io_context_destroy(io);
-		sched_context_destroy(sched);
+		sched = ast_sched_thread_destroy(sched);
 		return AST_MODULE_LOAD_FAILURE;
 	}
 	ast_netsock_init(netsock);
@@ -12519,7 +12472,7 @@ static int load_module(void)
 	if (!outsock) {
 		ast_log(LOG_ERROR, "Could not allocate outsock list.\n");
 		io_context_destroy(io);
-		sched_context_destroy(sched);
+		sched = ast_sched_thread_destroy(sched);
 		return AST_MODULE_LOAD_FAILURE;
 	}
 	ast_netsock_init(outsock);