[asterisk-commits] tzafrir: trunk r417059 - in /trunk/channels: chan_dahdi.c sig_pri.c sig_pri.h
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Mon Jun 23 02:44:28 CDT 2014
Author: tzafrir
Date: Mon Jun 23 02:44:19 2014
New Revision: 417059
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=417059
Log:
suspended destructions of pri spans on events
If a DAHDI span disappears, we wish for its representation in Asterisk
to be destroyed as well.
The information about the span's removal may come from several paths:
1. DAHDI sends DAHDI_EVENT_REMOVE on every channel.
2. An extra DAHDI_EVENT_REMOVED is sent on every subsequent call to
DAHDI_GET_EVENT.
3. Every read (including the internal one by libpri on the D-channel)
returns -ENODEV.
Asterisk responsds to DAHDI_EVENT_REMOVE on a channel by destroying it.
Destroying a channel requires holding the channel list lock (iflock).
Destroying a channel that is part of a span requires holding the span's
lock. Destroying a channel from a context that holds the span lock,
while at the same time another channel is destroyed directly, leads to a
deadlock. Solution: don't destroy span while holding the channels list
lock.
Thus changes in this patch:
* Deferring removal of PRI spans in response to events: doomed spans
are collected on a list.
* Doomed spans are removed periodically by the monitor thread.
* ENODEV reads from the D-channel will warant the same deferred removal.
Review: https://reviewboard.asterisk.org/r/3548/
Modified:
trunk/channels/chan_dahdi.c
trunk/channels/sig_pri.c
trunk/channels/sig_pri.h
Modified: trunk/channels/chan_dahdi.c
URL: http://svnview.digium.com/svn/asterisk/trunk/channels/chan_dahdi.c?view=diff&rev=417059&r1=417058&r2=417059
==============================================================================
--- trunk/channels/chan_dahdi.c (original)
+++ trunk/channels/chan_dahdi.c Mon Jun 23 02:44:19 2014
@@ -780,6 +780,14 @@
static struct dahdi_pvt *ifend = NULL; /*!< Main interface list end */
#if defined(HAVE_PRI)
+struct doomed_pri {
+ struct sig_pri_span *pri;
+ AST_LIST_ENTRY(doomed_pri) list;
+};
+static AST_LIST_HEAD_STATIC(doomed_pris, doomed_pri);
+
+static void pri_destroy_span(struct sig_pri_span *pri);
+
static struct dahdi_parms_pseudo {
int buf_no; /*!< Number of buffers */
int buf_policy; /*!< Buffer policy */
@@ -1111,6 +1119,69 @@
return index;
}
+
+/*!
+ * \internal
+ * \brief release all members on the doomed pris list
+ * \since 13.0
+ *
+ * Called priodically by the monitor threads to release spans marked for
+ * removal.
+ */
+static void release_doomed_pris(void)
+{
+#ifdef HAVE_PRI
+ struct doomed_pri *entry;
+
+ AST_LIST_LOCK(&doomed_pris);
+ while ((entry = AST_LIST_REMOVE_HEAD(&doomed_pris, list))) {
+ /* The span destruction must be done with this lock not held */
+ AST_LIST_UNLOCK(&doomed_pris);
+ ast_debug(4, "Destroying span %d from doomed queue.\n",
+ entry->pri->span);
+ pri_destroy_span(entry->pri);
+ ast_free(entry);
+ AST_LIST_LOCK(&doomed_pris);
+ }
+ AST_LIST_UNLOCK(&doomed_pris);
+#endif
+}
+
+#ifdef HAVE_PRI
+/*!
+ * \brief Queue a span for destruction
+ * \since 13.0
+ *
+ * \param pri the span to destroy
+ *
+ * Add a span to the list of spans to be destroyed later on
+ * by the monitor thread. Allows destroying a span while holding its
+ * lock.
+ */
+static void pri_queue_for_destruction(struct sig_pri_span *pri)
+{
+ struct doomed_pri *entry;
+
+ AST_LIST_LOCK(&doomed_pris);
+ AST_LIST_TRAVERSE(&doomed_pris, entry, list) {
+ if (entry->pri == pri) {
+ AST_LIST_UNLOCK(&doomed_pris);
+ return;
+ }
+ }
+ entry = ast_calloc(sizeof(struct doomed_pri), 1);
+ if (!entry) {
+ /* Nothing useful to do here. Panic? */
+ ast_log(LOG_WARNING, "Failed allocating memory for a doomed_pri.\n");
+ AST_LIST_UNLOCK(&doomed_pris);
+ return;
+ }
+ entry->pri = pri;
+ ast_debug(4, "Queue span %d for destruction.\n", pri->span);
+ AST_LIST_INSERT_TAIL(&doomed_pris, entry, list);
+ AST_LIST_UNLOCK(&doomed_pris);
+}
+#endif
/*!
* \internal
@@ -2654,8 +2725,6 @@
#endif /* defined(HAVE_PRI) */
#if defined(HAVE_PRI)
-static void pri_destroy_span(struct sig_pri_span *pri);
-
static void my_handle_dchan_exception(struct sig_pri_span *pri, int index)
{
int x;
@@ -2684,7 +2753,7 @@
pri_event_noalarm(pri, index, 0);
break;
case DAHDI_EVENT_REMOVED:
- pri_destroy_span(pri);
+ pri_queue_for_destruction(pri);
break;
default:
break;
@@ -2967,6 +3036,7 @@
.dial_digits = my_pri_dial_digits,
.open_media = my_pri_ss7_open_media,
.ami_channel_event = my_ami_channel_event,
+ .destroy_later = pri_queue_for_destruction,
};
#endif /* defined(HAVE_PRI) */
@@ -11469,6 +11539,7 @@
}
}
ast_mutex_unlock(&iflock);
+ release_doomed_pris();
}
/* Never reached */
pthread_cleanup_pop(1);
@@ -14217,6 +14288,7 @@
for (i = 0; i < SIG_PRI_NUM_DCHANS; i++) {
ast_debug(4, "closing pri_fd %d\n", i);
dahdi_close_pri_fd(dahdi_pri, i);
+ dahdi_pri->dchannels[i] = 0;
}
sig_pri_init_pri(pri);
ast_debug(1, "PRI span %d destroyed\n", pri->span);
Modified: trunk/channels/sig_pri.c
URL: http://svnview.digium.com/svn/asterisk/trunk/channels/sig_pri.c?view=diff&rev=417059&r1=417058&r2=417059
==============================================================================
--- trunk/channels/sig_pri.c (original)
+++ trunk/channels/sig_pri.c Mon Jun 23 02:44:19 2014
@@ -1448,6 +1448,27 @@
}
}
return -1;
+}
+
+/*!
+ * \internal
+ * \brief Queue the span for destruction
+ * \since 13.0
+ *
+ * \param pri PRI span control structure.
+ *
+ * Asks the channel driver to queue the span for destruction at a
+ * possibly later time, if (e.g.) locking considerations don't allow
+ * destroying it right now.
+ *
+ * \return Nothing
+ */
+static void pri_destroy_later(struct sig_pri_span *pri)
+{
+ if (!sig_pri_callbacks.destroy_later) {
+ return;
+ }
+ sig_pri_callbacks.destroy_later(pri);
}
/*!
@@ -6427,6 +6448,14 @@
}
if (e)
break;
+
+ if ((errno != 0) && (errno != EINTR)) {
+ ast_log(LOG_NOTICE, "pri_check_event returned error %d (%s)\n",
+ errno, strerror(errno));
+ }
+ if (errno == ENODEV) {
+ pri_destroy_later(pri);
+ }
}
} else if (errno != EINTR)
ast_log(LOG_WARNING, "pri_event returned error %d (%s)\n", errno, strerror(errno));
Modified: trunk/channels/sig_pri.h
URL: http://svnview.digium.com/svn/asterisk/trunk/channels/sig_pri.h?view=diff&rev=417059&r1=417058&r2=417059
==============================================================================
--- trunk/channels/sig_pri.h (original)
+++ trunk/channels/sig_pri.h Mon Jun 23 02:44:19 2014
@@ -231,6 +231,8 @@
void (*module_ref)(void);
/*! Unreference the parent module. */
void (*module_unref)(void);
+ /*! Mark the span for destruction. */
+ void (*destroy_later)(struct sig_pri_span *pri);
};
/*! Global sig_pri callbacks to the upper layer. */
More information about the asterisk-commits
mailing list