Merge team/russell/frame_caching

There are some situations in Asterisk where ast_frame and/or iax_frame
structures are rapidly allocatted and freed (at least 50 times per second
for one call).

This code significantly improves the performance of ast_frame_header_new(), 
ast_frdup(), ast_frfree(), iax_frame_new(), and iax_frame_free() by keeping
a thread-local cache of these structures and using frames from the cache 
whenever possible instead of calling malloc/free every time.

This commit also converts the ast_frame and iax_frame structures to use the
linked list macros.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@41278 65c4cc65-6c06-0410-ace0-fbb531ad65f3

5 files changed, 135 insertions, 103 deletions

diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 624e1b914..d50b78b18 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -621,11 +621,11 @@ struct chan_iax2_pvt {
 };
 
 static struct ast_iax2_queue {
-	struct iax_frame *head;
-	struct iax_frame *tail;
+	AST_LIST_HEAD(, iax_frame) queue;
 	int count;
-	ast_mutex_t lock;
-} iaxq;
+} iaxq = {
+	.queue = AST_LIST_HEAD_INIT_VALUE
+};
 
 static AST_LIST_HEAD_STATIC(users, iax2_user);
 
@@ -1071,11 +1071,12 @@ static struct chan_iax2_pvt *new_iax(struct sockaddr_in *sin, int lockpeer, cons
 
 static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 {
-	/* Malloc() a copy of a frame */
 	struct iax_frame *new = iax_frame_new(DIRECTION_INGRESS, fr->af.datalen);
 	if (new) {
-		memcpy(new, fr, sizeof(struct iax_frame));	
+		size_t mallocd_datalen = new->mallocd_datalen;
+		memcpy(new, fr, sizeof(*new));
 		iax_frame_wrap(new, &fr->af);
+		new->mallocd_datalen = mallocd_datalen;
 		new->data = NULL;
 		new->datalen = 0;
 		new->direction = DIRECTION_INGRESS;
@@ -1754,7 +1755,7 @@ retry:
 			ast_queue_hangup(owner);
 		}
 
-		for (cur = iaxq.head; cur ; cur = cur->next) {
+		AST_LIST_TRAVERSE(&iaxq.queue, cur, list) {
 			/* Cancel any pending transmissions */
 			if (cur->callno == pvt->callno) 
 				cur->retries = -1;
@@ -1875,17 +1876,10 @@ static void __attempt_transmit(void *data)
 	/* Do not try again */
 	if (freeme) {
 		/* Don't attempt delivery, just remove it from the queue */
-		ast_mutex_lock(&iaxq.lock);
-		if (f->prev) 
-			f->prev->next = f->next;
-		else
-			iaxq.head = f->next;
-		if (f->next)
-			f->next->prev = f->prev;
-		else
-			iaxq.tail = f->prev;
+		AST_LIST_LOCK(&iaxq.queue);
+		AST_LIST_REMOVE(&iaxq.queue, f, list);
 		iaxq.count--;
-		ast_mutex_unlock(&iaxq.lock);
+		AST_LIST_UNLOCK(&iaxq.queue);
 		f->retrans = -1;
 		/* Free the IAX frame */
 		iax2_frame_free(f);
@@ -2082,7 +2076,7 @@ static int iax2_show_stats(int fd, int argc, char *argv[])
 	int cnt = 0, dead=0, final=0;
 	if (argc != 3)
 		return RESULT_SHOWUSAGE;
-	for (cur = iaxq.head; cur ; cur = cur->next) {
+	AST_LIST_TRAVERSE(&iaxq.queue, cur, list) {
 		if (cur->retries < 0)
 			dead++;
 		if (cur->final)
@@ -2092,7 +2086,8 @@ static int iax2_show_stats(int fd, int argc, char *argv[])
 	ast_cli(fd, "    IAX Statistics\n");
 	ast_cli(fd, "---------------------\n");
 	ast_cli(fd, "Outstanding frames: %d (%d ingress, %d egress)\n", iax_get_frames(), iax_get_iframes(), iax_get_oframes());
-	ast_cli(fd, "Packets in transmit queue: %d dead, %d final, %d total\n", dead, final, cnt);
+	ast_cli(fd, "Packets in transmit queue: %d dead, %d final, %d total\n\n", dead, final, cnt);
+	
 	return RESULT_SUCCESS;
 }
 
@@ -2369,24 +2364,13 @@ static int schedule_delivery(struct iax_frame *fr, int updatehistory, int fromtr
 static int iax2_transmit(struct iax_frame *fr)
 {
 	/* Lock the queue and place this packet at the end */
-	fr->next = NULL;
-	fr->prev = NULL;
 	/* By setting this to 0, the network thread will send it for us, and
 	   queue retransmission if necessary */
 	fr->sentyet = 0;
-	ast_mutex_lock(&iaxq.lock);
-	if (!iaxq.head) {
-		/* Empty queue */
-		iaxq.head = fr;
-		iaxq.tail = fr;
-	} else {
-		/* Double link */
-		iaxq.tail->next = fr;
-		fr->prev = iaxq.tail;
-		iaxq.tail = fr;
-	}
+	AST_LIST_LOCK(&iaxq.queue);
+	AST_LIST_INSERT_TAIL(&iaxq.queue, fr, list);
 	iaxq.count++;
-	ast_mutex_unlock(&iaxq.lock);
+	AST_LIST_UNLOCK(&iaxq.queue);
 	/* Wake up the network and scheduler thread */
 	pthread_kill(netthreadid, SIGURG);
 	signal_condition(&sched_lock, &sched_cond);
@@ -5330,15 +5314,15 @@ static int complete_transfer(int callno, struct iax_ies *ies)
 	pvt->lastsent = 0;
 	pvt->nextpred = 0;
 	pvt->pingtime = DEFAULT_RETRY_TIME;
-	ast_mutex_lock(&iaxq.lock);
-	for (cur = iaxq.head; cur ; cur = cur->next) {
+	AST_LIST_LOCK(&iaxq.queue);
+	AST_LIST_TRAVERSE(&iaxq.queue, cur, list) {
 		/* We must cancel any packets that would have been transmitted
 		   because now we're talking to someone new.  It's okay, they
 		   were transmitted to someone that didn't care anyway. */
 		if (callno == cur->callno) 
 			cur->retries = -1;
 	}
-	ast_mutex_unlock(&iaxq.lock);
+	AST_LIST_UNLOCK(&iaxq.queue);
 	return 0; 
 }
 
@@ -5835,17 +5819,16 @@ static int iax2_vnak(int callno)
 static void vnak_retransmit(int callno, int last)
 {
 	struct iax_frame *f;
-	ast_mutex_lock(&iaxq.lock);
-	f = iaxq.head;
-	while(f) {
+
+	AST_LIST_LOCK(&iaxq.queue);
+	AST_LIST_TRAVERSE(&iaxq.queue, f, list) {
 		/* Send a copy immediately */
 		if ((f->callno == callno) && iaxs[f->callno] &&
 			(f->oseqno >= last)) {
 			send_packet(f);
 		}
-		f = f->next;
 	}
-	ast_mutex_unlock(&iaxq.lock);
+	AST_LIST_UNLOCK(&iaxq.queue);
 }
 
 static void __iax2_poke_peer_s(void *data)
@@ -6570,8 +6553,8 @@ static int socket_process(struct iax2_thread *thread)
 					/* Ack the packet with the given timestamp */
 					if (option_debug && iaxdebug)
 						ast_log(LOG_DEBUG, "Cancelling transmission of packet %d\n", x);
-					ast_mutex_lock(&iaxq.lock);
-					for (cur = iaxq.head; cur ; cur = cur->next) {
+					AST_LIST_LOCK(&iaxq.queue);
+					AST_LIST_TRAVERSE(&iaxq.queue, cur, list) {
 						/* If it's our call, and our timestamp, mark -1 retries */
 						if ((fr->callno == cur->callno) && (x == cur->oseqno)) {
 							cur->retries = -1;
@@ -6583,7 +6566,7 @@ static int socket_process(struct iax2_thread *thread)
 							}
 						}
 					}
-					ast_mutex_unlock(&iaxq.lock);
+					AST_LIST_UNLOCK(&iaxq.queue);
 				}
 				/* Note how much we've received acknowledgement for */
 				if (iaxs[fr->callno])
@@ -6723,13 +6706,13 @@ retryowner:
 			case IAX_COMMAND_TXACC:
 				if (iaxs[fr->callno]->transferring == TRANSFER_BEGIN) {
 					/* Ack the packet with the given timestamp */
-					ast_mutex_lock(&iaxq.lock);
-					for (cur = iaxq.head; cur ; cur = cur->next) {
+					AST_LIST_LOCK(&iaxq.queue);
+					AST_LIST_TRAVERSE(&iaxq.queue, cur, list) {
 						/* Cancel any outstanding txcnt's */
 						if ((fr->callno == cur->callno) && (cur->transfer))
 							cur->retries = -1;
 					}
-					ast_mutex_unlock(&iaxq.lock);
+					AST_LIST_UNLOCK(&iaxq.queue);
 					memset(&ied1, 0, sizeof(ied1));
 					iax_ie_append_short(&ied1, IAX_IE_CALLNO, iaxs[fr->callno]->callno);
 					send_command(iaxs[fr->callno], AST_FRAME_IAX, IAX_COMMAND_TXREADY, 0, ied1.buf, ied1.pos, -1);
@@ -8031,49 +8014,42 @@ static void *network_thread(void *ignore)
 	/* Our job is simple: Send queued messages, retrying if necessary.  Read frames 
 	   from the network, and queue them for delivery to the channels */
 	int res, count;
-	struct iax_frame *f, *freeme;
+	struct iax_frame *f;
+
 	if (timingfd > -1)
 		ast_io_add(io, timingfd, timing_read, AST_IO_IN | AST_IO_PRI, NULL);
+	
 	for(;;) {
 		/* Go through the queue, sending messages which have not yet been
 		   sent, and scheduling retransmissions if appropriate */
-		ast_mutex_lock(&iaxq.lock);
-		f = iaxq.head;
+		AST_LIST_LOCK(&iaxq.queue);
 		count = 0;
-		while(f) {
-			freeme = NULL;
-			if (!f->sentyet) {
-				f->sentyet++;
-				/* Send a copy immediately -- errors here are ok, so don't bother locking */
-				if (iaxs[f->callno]) {
-					send_packet(f);
-					count++;
-				} 
-				if (f->retries < 0) {
-					/* This is not supposed to be retransmitted */
-					if (f->prev) 
-						f->prev->next = f->next;
-					else
-						iaxq.head = f->next;
-					if (f->next)
-						f->next->prev = f->prev;
-					else
-						iaxq.tail = f->prev;
-					iaxq.count--;
-					/* Free the iax frame */
-					freeme = f;
-				} else {
-					/* We need reliable delivery.  Schedule a retransmission */
-					f->retries++;
-					f->retrans = ast_sched_add(sched, f->retrytime, attempt_transmit, f);
-					signal_condition(&sched_lock, &sched_cond);
-				}
+		AST_LIST_TRAVERSE_SAFE_BEGIN(&iaxq.queue, f, list) {
+			if (f->sentyet)
+				continue;
+			
+			f->sentyet++;
+			/* Send a copy immediately -- errors here are ok, so don't bother locking */
+			if (iaxs[f->callno]) {
+				send_packet(f);
+				count++;
+			} 
+			if (f->retries < 0) {
+				/* This is not supposed to be retransmitted */
+				AST_LIST_REMOVE(&iaxq.queue, f, list);
+				iaxq.count--;
+				/* Free the iax frame */
+				iax_frame_free(f);
+			} else {
+				/* We need reliable delivery.  Schedule a retransmission */
+				f->retries++;
+				f->retrans = ast_sched_add(sched, f->retrytime, attempt_transmit, f);
+				signal_condition(&sched_lock, &sched_cond);
 			}
-			f = f->next;
-			if (freeme)
-				iax_frame_free(freeme);
 		}
-		ast_mutex_unlock(&iaxq.lock);
+		AST_LIST_TRAVERSE_SAFE_END
+		AST_LIST_UNLOCK(&iaxq.queue);
+
 		if (count >= 20)
 			ast_log(LOG_DEBUG, "chan_iax2: Sent %d queued outbound frames all at once\n", count);
 
@@ -9751,7 +9727,6 @@ static int __unload_module(void)
 
 static int unload_module(void)
 {
-	ast_mutex_destroy(&iaxq.lock);
 	ast_mutex_destroy(&waresl.lock);
 	ast_custom_function_unregister(&iaxpeer_function);
 	return __unload_module();
@@ -9803,7 +9778,6 @@ static int load_module(void)
 	}
 	ast_netsock_init(netsock);
 
-	ast_mutex_init(&iaxq.lock);
 	ast_mutex_init(&waresl.lock);
 	
 	ast_cli_register_multiple(iax2_cli, sizeof(iax2_cli) / sizeof(iax2_cli[0]));
diff --git a/channels/chan_local.c b/channels/chan_local.c
index 815f9cc1a..a9b0582f9 100644
--- a/channels/chan_local.c
+++ b/channels/chan_local.c
@@ -226,7 +226,7 @@ static void check_bridge(struct local_pvt *p, int isoutbound)
 	   frames on the owner channel (because they would be transferred to the
 	   outbound channel during the masquerade)
 	*/
-	if (isoutbound && p->chan->_bridge /* Not ast_bridged_channel!  Only go one step! */ && !p->owner->readq) {
+	if (isoutbound && p->chan->_bridge /* Not ast_bridged_channel!  Only go one step! */ && AST_LIST_EMPTY(&p->owner->readq)) {
 		/* Masquerade bridged channel into owner */
 		/* Lock everything we need, one by one, and give up if
 		   we can't get everything.  Remember, we'll get another
@@ -248,7 +248,7 @@ static void check_bridge(struct local_pvt *p, int isoutbound)
 	   when the local channels go away.
 	*/
 #if 0
-	} else if (!isoutbound && p->owner && p->owner->_bridge && p->chan && !p->chan->readq) {
+	} else if (!isoutbound && p->owner && p->owner->_bridge && p->chan && AST_LIST_EMPTY(&p->chan->readq)) {
 		/* Masquerade bridged channel into chan */
 		if (!ast_mutex_trylock(&(p->owner->_bridge)->lock)) {
 			if (!p->owner->_bridge->_softhangup) {
diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index 4eafcdac3..60b6e9521 100644
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -3516,7 +3516,6 @@ static struct ast_frame *zt_handle_event(struct ast_channel *ast)
 	pthread_t threadid;
 	pthread_attr_t attr;
 	struct ast_channel *chan;
-	struct ast_frame dtmf_frame = { .frametype = AST_FRAME_DTMF };
 
 	pthread_attr_init(&attr);
 	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
@@ -3560,8 +3559,6 @@ static struct ast_frame *zt_handle_event(struct ast_channel *ast)
 			*/
 			p->subs[index].f.frametype = AST_FRAME_DTMF_BEGIN;
 			p->subs[index].f.subclass = res & 0xff;
-			dtmf_frame.subclass = res & 0xff;
-			p->subs[index].f.next = ast_frdup(&dtmf_frame);
 #ifdef HAVE_PRI
 		}
 #endif
diff --git a/channels/iax2-parser.c b/channels/iax2-parser.c
index 67341fc5e..94aaf4c70 100644
--- a/channels/iax2-parser.c
+++ b/channels/iax2-parser.c
@@ -40,6 +40,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/utils.h"
 #include "asterisk/unaligned.h"
 #include "asterisk/lock.h"
+#include "asterisk/threadstorage.h"
 
 #include "iax2.h"
 #include "iax2-parser.h"
@@ -49,6 +50,15 @@ static int frames = 0;
 static int iframes = 0;
 static int oframes = 0;
 
+static void frame_cache_cleanup(void *data);
+
+/*! \brief A per-thread cache of iax_frame structures */
+AST_THREADSTORAGE_CUSTOM(frame_cache, frame_cache_init, frame_cache_cleanup);
+
+/*! \brief This is just so iax_frames, a list head struct for holding a list of
+ *  iax_frame structures, is defined. */
+AST_LIST_HEAD_NOLOCK(iax_frames, iax_frame);
+
 static void internaloutput(const char *str)
 {
 	fputs(str, stdout);
@@ -926,22 +936,44 @@ void iax_frame_wrap(struct iax_frame *fr, struct ast_frame *f)
 
 struct iax_frame *iax_frame_new(int direction, int datalen)
 {
-	struct iax_frame *fr;
-	fr = malloc((int)sizeof(struct iax_frame) + datalen);
-	if (fr) {
-		fr->direction = direction;
-		fr->retrans = -1;
-		ast_atomic_fetchadd_int(&frames, 1);
-		if (fr->direction == DIRECTION_INGRESS)
-			ast_atomic_fetchadd_int(&iframes, 1);
-		else
-			ast_atomic_fetchadd_int(&oframes, 1);
+	struct iax_frame *fr = NULL;
+	struct iax_frames *iax_frames;
+
+	/* Attempt to get a frame from this thread's cache */
+	if ((iax_frames = ast_threadstorage_get(&frame_cache, sizeof(*iax_frames)))) {
+		AST_LIST_TRAVERSE_SAFE_BEGIN(iax_frames, fr, list) {
+			if (fr->mallocd_datalen >= datalen) {
+				size_t mallocd_datalen = fr->mallocd_datalen;
+				AST_LIST_REMOVE_CURRENT(iax_frames, list);
+				memset(fr, 0, sizeof(*fr));
+				fr->mallocd_datalen = mallocd_datalen;
+				break;
+			}
+		}
+		AST_LIST_TRAVERSE_SAFE_END
+	}
+
+	if (!fr) {
+		if (!(fr = ast_calloc(1, sizeof(*fr) + datalen)))
+			return NULL;
+		fr->mallocd_datalen = datalen;
 	}
+
+	fr->direction = direction;
+	fr->retrans = -1;
+	
+	if (fr->direction == DIRECTION_INGRESS)
+		ast_atomic_fetchadd_int(&iframes, 1);
+	else
+		ast_atomic_fetchadd_int(&oframes, 1);
+	
 	return fr;
 }
 
-void iax_frame_free(struct iax_frame *fr)
+static void __iax_frame_free(struct iax_frame *fr, int cache)
 {
+	struct iax_frames *iax_frames;
+
 	/* Note: does not remove from scheduler! */
 	if (fr->direction == DIRECTION_INGRESS)
 		ast_atomic_fetchadd_int(&iframes, -1);
@@ -952,8 +984,34 @@ void iax_frame_free(struct iax_frame *fr)
 		return;
 	}
 	fr->direction = 0;
-	free(fr);
 	ast_atomic_fetchadd_int(&frames, -1);
+	if (!cache) {
+		free(fr);
+		return;
+	}
+
+	if (!(iax_frames = ast_threadstorage_get(&frame_cache, sizeof(*iax_frames)))) {
+		free(fr);
+		return;
+	}
+
+	AST_LIST_INSERT_HEAD(iax_frames, fr, list);
+}
+
+static void frame_cache_cleanup(void *data)
+{
+	struct iax_frames *frames = data;
+	struct iax_frame *cur;
+
+	while ((cur = AST_LIST_REMOVE_HEAD(frames, list)))
+		__iax_frame_free(cur, 0);
+
+	free(frames);
+}
+
+void iax_frame_free(struct iax_frame *fr)
+{
+	__iax_frame_free(fr, 1);
 }
 
 int iax_get_frames(void) { return frames; }
diff --git a/channels/iax2-parser.h b/channels/iax2-parser.h
index b926b4b94..2970c9f61 100644
--- a/channels/iax2-parser.h
+++ b/channels/iax2-parser.h
@@ -18,6 +18,8 @@
 #ifndef _IAX2_PARSER_H
 #define _IAX2_PARSER_H
 
+#include "asterisk/linkedlists.h"
+
 struct iax_ies {
 	char *called_number;
 	char *calling_number;
@@ -115,10 +117,11 @@ struct iax_frame {
 	/* Retransmission ID */
 	int retrans;
 	/* Easy linking */
-	struct iax_frame *next;
-	struct iax_frame *prev;
+	AST_LIST_ENTRY(iax_frame) list;
 	/* Actual, isolated frame header */
 	struct ast_frame af;
+	/*! Amount of space _allocated_ for data */
+	size_t mallocd_datalen;
 	unsigned char unused[AST_FRIENDLY_OFFSET];
 	unsigned char afdata[0];	/* Data for frame */
 };