[asterisk-commits] mmichelson: branch 1.6.0 r185087 - in /branches/1.6.0: ./ apps/app_queue.c
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Mon Mar 30 11:40:33 CDT 2009
Author: mmichelson
Date: Mon Mar 30 11:40:26 2009
New Revision: 185087
URL: http://svn.digium.com/svn-view/asterisk?view=rev&rev=185087
Log:
Merged revisions 185072 via svnmerge from
https://origsvn.digium.com/svn/asterisk/trunk
................
r185072 | mmichelson | 2009-03-30 11:26:48 -0500 (Mon, 30 Mar 2009) | 45 lines
Merged revisions 185031 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4
........
r185031 | mmichelson | 2009-03-30 11:17:35 -0500 (Mon, 30 Mar 2009) | 39 lines
Fix queue weight behavior so that calls in low-weight queues are not inappropriately blocked.
(This is copied and pasted from the review request I made for this patch)
Asterisk has some odd behavior when queue weights are used. The current logic used when
potentially calling a queue member is:
If the member we are going to call is part of another queue and _that other queue has any
callers in it_ and has a higher weight than the queue we are calling from, then don't try
to contact that member. The issue here is what I have marked with underscores. If the
higher-weighted queue has any callers in it at all, then the queue member will be unreachable
from the lower-weighted queue. This has the potential to be really really bad if using a
queue strategy, such as leastrecent or fewestcalls, with the potential to call the same
member repeatedly.
The fix proposed by garychen on issue 13220 is very simple and, as far as I can see, works
well for this situation. With this set of changes, the logic used becomes:
If the member we are going to call is part of another queue, the other queue has a higher
weight than the queue we are calling from, and the higher weight queue has at least as many
callers as available members, then do not try to contact the queue member. If the higher
weighted queue has fewer callers than available members, then there is no reason to deny
the call to this member since the other queue can afford to spare a member.
Since the fix involved writing a generic function for determining the number of available
members in the queue, I also modified the is_our_turn function to make use of the new
num_available_members function to determine if it is our turn to try calling a member. There
is one small behavior change. Before writing this patch, if you had autofill disabled, then
if you were the head caller in a queue, you would automatically be told that it was your
turn to try calling a member. This did not take into account whether there were actually any
queue members available to take the call. Now we actually make sure there is at least one
member available to take the call if autofill is disabled.
(closes issue #13220)
Reported by: garychen
Review: http://reviewboard.digium.com/r/202/
........
................
Modified:
branches/1.6.0/ (props changed)
branches/1.6.0/apps/app_queue.c
Propchange: branches/1.6.0/
------------------------------------------------------------------------------
Binary property 'trunk-merged' - no diff available.
Modified: branches/1.6.0/apps/app_queue.c
URL: http://svn.digium.com/svn-view/asterisk/branches/1.6.0/apps/app_queue.c?view=diff&rev=185087&r1=185086&r2=185087
==============================================================================
--- branches/1.6.0/apps/app_queue.c (original)
+++ branches/1.6.0/apps/app_queue.c Mon Mar 30 11:40:26 2009
@@ -2050,11 +2050,56 @@
}
}
-/*!
- * \brief traverse all defined queues which have calls waiting and contain this member
- * \retval 0 if no other queue has precedence (higher weight)
- * \retval 1 if found
-*/
+/*!
+ * \brief Get the number of members available to accept a call.
+ *
+ * \note The queue passed in should be locked prior to this function call
+ *
+ * \param[in] q The queue for which we are couting the number of available members
+ * \return Return the number of available members in queue q
+ */
+static int num_available_members(struct call_queue *q)
+{
+ struct member *mem;
+ int avl = 0;
+ struct ao2_iterator mem_iter;
+
+ mem_iter = ao2_iterator_init(q->members, 0);
+ while ((mem = ao2_iterator_next(&mem_iter))) {
+ switch (mem->status) {
+ case AST_DEVICE_INUSE:
+ if (!q->ringinuse)
+ break;
+ /* else fall through */
+ case AST_DEVICE_NOT_INUSE:
+ case AST_DEVICE_UNKNOWN:
+ if (!mem->paused) {
+ avl++;
+ }
+ break;
+ }
+ ao2_ref(mem, -1);
+
+ /* If autofill is not enabled or if the queue's strategy is ringall, then
+ * we really don't care about the number of available members so much as we
+ * do that there is at least one available.
+ *
+ * In fact, we purposely will return from this function stating that only
+ * one member is available if either of those conditions hold. That way,
+ * functions which determine what action to take based on the number of available
+ * members will operate properly. The reasoning is that even if multiple
+ * members are available, only the head caller can actually be serviced.
+ */
+ if ((!q->autofill || q->strategy == QUEUE_STRATEGY_RINGALL) && avl) {
+ break;
+ }
+ }
+
+ return avl;
+}
+
+/* traverse all defined queues which have calls waiting and contain this member
+ return 0 if no other queue has precedence (higher weight) or 1 if found */
static int compare_weight(struct call_queue *rq, struct member *member)
{
struct call_queue *q;
@@ -2074,7 +2119,7 @@
if (q->count && q->members) {
if ((mem = ao2_find(q->members, member, OBJ_POINTER))) {
ast_debug(1, "Found matching member %s in queue '%s'\n", mem->interface, q->name);
- if (q->weight > rq->weight) {
+ if (q->weight > rq->weight && q->count >= num_available_members(q)) {
ast_debug(1, "Queue '%s' (weight %d, calls %d) is preferred over '%s' (weight %d, calls %d)\n", q->name, q->weight, q->count, rq->name, rq->weight, rq->count);
found = 1;
}
@@ -2734,78 +2779,44 @@
/*!
* \brief Check if we should start attempting to call queue members.
*
- * The behavior of this function is dependent first on whether autofill is enabled
- * and second on whether the ring strategy is ringall. If autofill is not enabled,
- * then return true if we're the head of the queue. If autofill is enabled, then
- * we count the available members and see if the number of available members is enough
- * that given our position in the queue, we would theoretically be able to connect to
- * one of those available members
+ * A simple process, really. Count the number of members who are available
+ * to take our call and then see if we are in a position in the queue at
+ * which a member could accept our call.
+ *
+ * \param[in] qe The caller who wants to know if it is his turn
+ * \retval 0 It is not our turn
+ * \retval 1 It is our turn
*/
static int is_our_turn(struct queue_ent *qe)
{
struct queue_ent *ch;
- struct member *cur;
- int avl = 0;
+ int res;
+ int avl;
int idx = 0;
- int res;
-
- if (!qe->parent->autofill) {
- /* Atomically read the parent head -- does not need a lock */
- ch = qe->parent->head;
- /* If we are now at the top of the head, break out */
- if (ch == qe) {
- ast_debug(1, "It's our turn (%s).\n", qe->chan->name);
- res = 1;
- } else {
- ast_debug(1, "It's not our turn (%s).\n", qe->chan->name);
- res = 0;
- }
-
+ /* This needs a lock. How many members are available to be served? */
+ ao2_lock(qe->parent);
+
+ avl = num_available_members(qe->parent);
+
+ ch = qe->parent->head;
+
+ ast_debug(1, "There %s %d available %s.\n", avl != 1 ? "are" : "is", avl, avl != 1 ? "members" : "member");
+
+ while ((idx < avl) && (ch) && (ch != qe)) {
+ if (!ch->pending)
+ idx++;
+ ch = ch->next;
+ }
+
+ ao2_unlock(qe->parent);
+
+ /* If the queue entry is within avl [the number of available members] calls from the top ... */
+ if (ch && idx < avl) {
+ ast_debug(1, "It's our turn (%s).\n", qe->chan->name);
+ res = 1;
} else {
- /* This needs a lock. How many members are available to be served? */
- ao2_lock(qe->parent);
-
- ch = qe->parent->head;
-
- if (qe->parent->strategy == QUEUE_STRATEGY_RINGALL) {
- ast_debug(1, "Even though there may be multiple members available, the strategy is ringall so only the head call is allowed in\n");
- avl = 1;
- } else {
- struct ao2_iterator mem_iter = ao2_iterator_init(qe->parent->members, 0);
- while ((cur = ao2_iterator_next(&mem_iter))) {
- switch (cur->status) {
- case AST_DEVICE_INUSE:
- if (!qe->parent->ringinuse)
- break;
- /* else fall through */
- case AST_DEVICE_NOT_INUSE:
- case AST_DEVICE_UNKNOWN:
- if (!cur->paused)
- avl++;
- break;
- }
- ao2_ref(cur, -1);
- }
- }
-
- ast_debug(1, "There are %d available members.\n", avl);
-
- while ((idx < avl) && (ch) && (ch != qe)) {
- if (!ch->pending)
- idx++;
- ch = ch->next;
- }
-
- /* If the queue entry is within avl [the number of available members] calls from the top ... */
- if (ch && idx < avl) {
- ast_debug(1, "It's our turn (%s).\n", qe->chan->name);
- res = 1;
- } else {
- ast_debug(1, "It's not our turn (%s).\n", qe->chan->name);
- res = 0;
- }
-
- ao2_unlock(qe->parent);
+ ast_debug(1, "It's not our turn (%s).\n", qe->chan->name);
+ res = 0;
}
return res;
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