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Commit d5f97b40 authored by Kevin P. Fleming's avatar Kevin P. Fleming
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Merged revisions 167620 via svnmerge from 

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r167620 | kpfleming | 2009-01-07 17:32:21 -0600 (Wed, 07 Jan 2009) | 5 lines
  
  When a SIP request or response arrives for a dialog with an associated Asterisk channel, and the lock on that channel cannot be obtained because it is held by another thread, instead of dropping the request/response, queue it for later processing when the channel lock becomes available.
  
  http://reviewboard.digium.com/r/123/
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@167700 65c4cc65-6c06-0410-ace0-fbb531ad65f3
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channels/chan_sip.c
+ 131
− 11
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......@@ -1177,6 +1177,7 @@ struct sip_request {
struct ast_str *data;
/* XXX Do we need to unref socket.ser when the request goes away? */
struct sip_socket socket; /*!< The socket used for this request */
AST_LIST_ENTRY(sip_request) next;
};
 
/*! \brief structure used in transfers */
......@@ -1656,6 +1657,8 @@ struct sip_pvt {
struct sip_history_head *history; /*!< History of this SIP dialog */
size_t history_entries; /*!< Number of entires in the history */
struct ast_variable *chanvars; /*!< Channel variables to set for inbound call */
AST_LIST_HEAD_NOLOCK(request_queue, sip_request) request_queue; /*!< Requests that arrived but could not be processed immediately */
int request_queue_sched_id; /*!< Scheduler ID of any scheduled action to process queued requests */
struct sip_invite_param *options; /*!< Options for INVITE */
int autoframing; /*!< The number of Asters we group in a Pyroflax
before strolling to the Grokyzpå
......@@ -2879,6 +2882,10 @@ static void *dialog_unlink_all(struct sip_pvt *dialog, int lockowner, int lockdi
if (dialog->autokillid > -1)
AST_SCHED_DEL_UNREF(sched, dialog->autokillid, dialog_unref(dialog, "when you delete the autokillid sched, you should dec the refcount for the stored dialog ptr"));
 
if (dialog->request_queue_sched_id > -1) {
AST_SCHED_DEL_UNREF(sched, dialog->request_queue_sched_id, dialog_unref(dialog, "when you delete the request_queue_sched_id sched, you should dec the refcount for the stored dialog ptr"));
}
dialog_unref(dialog, "Let's unbump the count in the unlink so the poor pvt can disappear if it is time");
return NULL;
}
......@@ -4986,6 +4993,7 @@ static void sip_subscribe_mwi_destroy(struct sip_subscription_mwi *mwi)
/*! \brief Execute destruction of SIP dialog structure, release memory */
static void __sip_destroy(struct sip_pvt *p, int lockowner, int lockdialoglist)
{
struct sip_request *req;
 
if (sip_debug_test_pvt(p))
ast_verbose("Really destroying SIP dialog '%s' Method: %s\n", p->callid, sip_methods[p->method].text);
......@@ -5082,6 +5090,10 @@ static void __sip_destroy(struct sip_pvt *p, int lockowner, int lockdialoglist)
p->history = NULL;
}
 
while ((req = AST_LIST_REMOVE_HEAD(&p->request_queue, next))) {
ast_free(req);
}
if (p->chanvars) {
ast_variables_destroy(p->chanvars);
p->chanvars = NULL;
......@@ -6519,6 +6531,7 @@ static struct sip_pvt *sip_alloc(ast_string_field callid, struct sockaddr_in *si
p->initid = -1;
p->waitid = -1;
p->autokillid = -1;
p->request_queue_sched_id = -1;
p->subscribed = NONE;
p->stateid = -1;
p->sessionversion_remote = -1;
......@@ -6625,6 +6638,7 @@ static struct sip_pvt *sip_alloc(ast_string_field callid, struct sockaddr_in *si
ast_string_field_set(p, context, default_context);
ast_string_field_set(p, parkinglot, default_parkinglot);
 
AST_LIST_HEAD_INIT_NOLOCK(&p->request_queue);
 
/* Add to active dialog list */
 
......@@ -20203,6 +20217,95 @@ static int handle_incoming(struct sip_pvt *p, struct sip_request *req, struct so
return res;
}
 
static void process_request_queue(struct sip_pvt *p, int *recount, int *nounlock)
{
struct sip_request *req;
while ((req = AST_LIST_REMOVE_HEAD(&p->request_queue, next))) {
if (handle_incoming(p, req, &p->recv, recount, nounlock) == -1) {
/* Request failed */
if (option_debug) {
ast_log(LOG_DEBUG, "SIP message could not be handled, bad request: %-70.70s\n", p->callid[0] ? p->callid : "<no callid>");
}
}
ast_free(req);
}
}
static int scheduler_process_request_queue(const void *data)
{
struct sip_pvt *p = (struct sip_pvt *) data;
int recount = 0;
int nounlock = 0;
int lockretry;
for (lockretry = 10; lockretry > 0; lockretry--) {
sip_pvt_lock(p);
/* lock the owner if it has one -- we may need it */
/* because this is deadlock-prone, we need to try and unlock if failed */
if (!p->owner || !ast_channel_trylock(p->owner)) {
break; /* locking succeeded */
}
if (lockretry != 1) {
sip_pvt_unlock(p);
/* Sleep for a very short amount of time */
usleep(1);
}
}
if (!lockretry) {
int retry = !AST_LIST_EMPTY(&p->request_queue);
/* we couldn't get the owner lock, which is needed to process
the queued requests, so return a non-zero value, which will
cause the scheduler to run this request again later if there
still requests to be processed
*/
sip_pvt_unlock(p);
if (!retry) {
dialog_unref(p, "The ref to a dialog passed to this sched callback is going out of scope; unref it.");
}
return retry;
};
process_request_queue(p, &recount, &nounlock);
p->request_queue_sched_id = -1;
if (p->owner && !nounlock) {
ast_channel_unlock(p->owner);
}
sip_pvt_unlock(p);
if (recount) {
ast_update_use_count();
}
dialog_unref(p, "The ref to a dialog passed to this sched callback is going out of scope; unref it.");
return 0;
}
static int queue_request(struct sip_pvt *p, const struct sip_request *req, const struct sockaddr_in *sin)
{
struct sip_request *newreq;
if (!(newreq = ast_calloc(1, sizeof(*newreq)))) {
return -1;
}
copy_request(newreq, req);
AST_LIST_INSERT_TAIL(&p->request_queue, newreq, next);
if (p->request_queue_sched_id == -1) {
if ((p->request_queue_sched_id = ast_sched_add(sched, 10, scheduler_process_request_queue, dialog_ref(p, "Increment refcount to pass dialog pointer to sched callback"))) == -1) {
dialog_unref(p, "Decrement refcount due to sched_add failure");
}
}
return 0;
}
/*! \brief Read data from SIP UDP socket
\note sipsock_read locks the owner channel while we are processing the SIP message
\return 1 on error, 0 on success
......@@ -20275,11 +20378,10 @@ static int handle_request_do(struct sip_request *req, struct sockaddr_in *sin)
ntohs(sin->sin_port), req->data->str);
}
 
if(parse_request(req) == -1) { /* Bad packet, can't parse */
if (parse_request(req) == -1) { /* Bad packet, can't parse */
ast_str_reset(req->data); /* nulling this out is NOT a good idea here. */
return 1;
}
req->method = find_sip_method(req->rlPart1);
 
if (req->debug)
......@@ -20291,7 +20393,7 @@ static int handle_request_do(struct sip_request *req, struct sockaddr_in *sin)
}
 
/* Process request, with netlock held, and with usual deadlock avoidance */
for (lockretry = 100; lockretry > 0; lockretry--) {
for (lockretry = 10; lockretry > 0; lockretry--) {
ast_mutex_lock(&netlock);
 
/* Find the active SIP dialog or create a new one */
......@@ -20308,13 +20410,14 @@ static int handle_request_do(struct sip_request *req, struct sockaddr_in *sin)
/* becaues this is deadlock-prone, we need to try and unlock if failed */
if (!p->owner || !ast_channel_trylock(p->owner))
break; /* locking succeeded */
ast_debug(1, "Failed to grab owner channel lock, trying again. (SIP call %s)\n", p->callid);
sip_pvt_unlock(p);
if (lockretry != 1)
if (lockretry != 1) {
sip_pvt_unlock(p);
ao2_t_ref(p, -1, "release p (from find_call) inside lockretry loop"); /* we'll look for it again, but p is dead now */
ast_mutex_unlock(&netlock);
/* Sleep for a very short amount of time */
usleep(1);
ast_mutex_unlock(&netlock);
/* Sleep for a very short amount of time */
usleep(1);
}
}
p->recv = *sin;
 
......@@ -20322,18 +20425,35 @@ static int handle_request_do(struct sip_request *req, struct sockaddr_in *sin)
append_history(p, "Rx", "%s / %s / %s", req->data->str, get_header(req, "CSeq"), req->rlPart2);
 
if (!lockretry) {
if (!queue_request(p, req, sin)) {
/* the request has been queued for later handling */
sip_pvt_unlock(p);
ao2_t_ref(p, -1, "release p (from find_call) after queueing request");
ast_mutex_unlock(&netlock);
return 1;
}
if (p->owner)
ast_log(LOG_ERROR, "We could NOT get the channel lock for %s! \n", S_OR(p->owner->name, "- no channel name ??? - "));
ast_log(LOG_ERROR, "Channel lock for %s could not be obtained, and request was unable to be queued.\n", S_OR(p->owner->name, "- no channel name ??? - "));
ast_log(LOG_ERROR, "SIP transaction failed: %s \n", p->callid);
if (req->method != SIP_ACK)
transmit_response(p, "503 Server error", req); /* We must respond according to RFC 3261 sec 12.2 */
/* XXX We could add retry-after to make sure they come back */
append_history(p, "LockFail", "Owner lock failed, transaction failed.");
sip_pvt_unlock(p);
ao2_t_ref(p, -1, "release p (from find_call) at end of lockretry"); /* p is gone after the return */
ast_mutex_unlock(&netlock);
return 1;
}
 
nounlock = 0;
/* if there are queued requests on this sip_pvt, process them first, so that everything is
handled in order
*/
if (!AST_LIST_EMPTY(&p->request_queue)) {
AST_SCHED_DEL_UNREF(sched, p->request_queue_sched_id, dialog_unref(p, "when you delete the request_queue_sched_id sched, you should dec the refcount for the stored dialog ptr"));
process_request_queue(p, &recount, &nounlock);
}
if (handle_incoming(p, req, sin, &recount, &nounlock) == -1) {
/* Request failed */
ast_debug(1, "SIP message could not be handled, bad request: %-70.70s\n", p->callid[0] ? p->callid : "<no callid>");
......
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