[svn-commits] rmudgett: branch 1.4 r2200 - in /branches/1.4: pri_q921.h q921.c
SVN commits to the Digium repositories
svn-commits at lists.digium.com
Mon Feb 14 17:34:00 CST 2011
Author: rmudgett
Date: Mon Feb 14 17:33:56 2011
New Revision: 2200
URL: http://svnview.digium.com/svn/libpri?view=rev&rev=2200
Log:
Fix I-frame retransmission quirks.
Revamped the I-frame retransmission queue to better comply with Q.921:
Figure B.7/Q.921 (sheet 1 of 10) and Figure B.9/Q.921 (Sheet 5 of 5). The
changes prevent retransmitting I-frames when the peer is busy (RNR) (Q.921
Section 5.6.5) and eliminate an unnecessary delay sending new I-frames
after an I-frame retransmission.
Related to JIRA LIBPRI-60
Modified:
branches/1.4/pri_q921.h
branches/1.4/q921.c
Modified: branches/1.4/pri_q921.h
URL: http://svnview.digium.com/svn/libpri/branches/1.4/pri_q921.h?view=diff&rev=2200&r1=2199&r2=2200
==============================================================================
--- branches/1.4/pri_q921.h (original)
+++ branches/1.4/pri_q921.h Mon Feb 14 17:33:56 2011
@@ -163,11 +163,17 @@
struct q921_header h;
} q921_h;
+enum q921_tx_frame_status {
+ Q921_TX_FRAME_NEVER_SENT,
+ Q921_TX_FRAME_PUSHED_BACK,
+ Q921_TX_FRAME_SENT,
+};
+
typedef struct q921_frame {
- struct q921_frame *next; /* Next in list */
- int len; /* Length of header + body */
- int transmitted; /* Have we been transmitted */
- q921_i h;
+ struct q921_frame *next; /*!< Next in list */
+ int len; /*!< Length of header + body */
+ enum q921_tx_frame_status status; /*!< Tx frame status */
+ q921_i h; /*!< Actual frame contents. */
} q921_frame;
#define Q921_INC(j) (j) = (((j) + 1) % 128)
Modified: branches/1.4/q921.c
URL: http://svnview.digium.com/svn/libpri/branches/1.4/q921.c?view=diff&rev=2200&r1=2199&r2=2200
==============================================================================
--- branches/1.4/q921.c (original)
+++ branches/1.4/q921.c Mon Feb 14 17:33:56 2011
@@ -406,7 +406,7 @@
ctrl = link->ctrl;
for (prev = NULL, f = link->tx_queue; f; prev = f, f = f->next) {
- if (!f->transmitted) {
+ if (f->status != Q921_TX_FRAME_SENT) {
break;
}
if (f->h.n_s == num) {
@@ -421,7 +421,7 @@
"-- ACKing N(S)=%d, tx_queue head is N(S)=%d (-1 is empty, -2 is not transmitted)\n",
f->h.n_s,
link->tx_queue
- ? link->tx_queue->transmitted
+ ? link->tx_queue->status == Q921_TX_FRAME_SENT
? link->tx_queue->h.n_s
: -2
: -1);
@@ -461,22 +461,6 @@
pri_message(ctrl, "-- Restarting T203 timer\n");
pri_schedule_del(ctrl, link->t203_timer);
link->t203_timer = pri_schedule_event(ctrl, ctrl->timers[PRI_TIMER_T203], t203_expire, link);
-}
-#endif
-
-#if 0
-static int q921_unacked_iframes(struct q921_link *link)
-{
- struct q921_frame *f = link->tx_queue;
- int cnt = 0;
-
- while (f) {
- if (f->transmitted)
- cnt++;
- f = f->next;
- }
-
- return cnt;
}
#endif
@@ -642,8 +626,8 @@
ctrl = link->ctrl;
for (f = link->tx_queue; f; f = f->next) {
- if (!f->transmitted) {
- /* This frame has not been sent yet. */
+ if (f->status != Q921_TX_FRAME_SENT) {
+ /* This frame needs to be sent. */
break;
}
}
@@ -652,12 +636,20 @@
return 0;
}
- if (link->peer_rx_busy
- || (link->v_s == Q921_ADD(link->v_a, ctrl->timers[PRI_TIMER_K]))) {
+ if (link->peer_rx_busy) {
/* Don't flood debug trace if not really looking at Q.921 layer. */
if (ctrl->debug & (/* PRI_DEBUG_Q921_STATE | */ PRI_DEBUG_Q921_DUMP)) {
pri_message(ctrl,
- "TEI=%d Couldn't transmit I-frame at this time due to peer busy condition or window shut\n",
+ "TEI=%d Couldn't transmit I-frame at this time due to peer busy condition\n",
+ link->tei);
+ }
+ return 0;
+ }
+ if (link->v_s == Q921_ADD(link->v_a, ctrl->timers[PRI_TIMER_K])) {
+ /* Don't flood debug trace if not really looking at Q.921 layer. */
+ if (ctrl->debug & (/* PRI_DEBUG_Q921_STATE | */ PRI_DEBUG_Q921_DUMP)) {
+ pri_message(ctrl,
+ "TEI=%d Couldn't transmit I-frame at this time due to window shut\n",
link->tei);
}
return 0;
@@ -671,7 +663,30 @@
}
/* Send it now... */
- ++f->transmitted;
+ switch (f->status) {
+ case Q921_TX_FRAME_NEVER_SENT:
+ if (ctrl->debug & PRI_DEBUG_Q921_STATE) {
+ pri_message(ctrl,
+ "TEI=%d Transmitting N(S)=%d, window is open V(A)=%d K=%d\n",
+ link->tei, link->v_s, link->v_a, ctrl->timers[PRI_TIMER_K]);
+ }
+ break;
+ case Q921_TX_FRAME_PUSHED_BACK:
+ if (f->h.n_s != link->v_s) {
+ /* Should never happen. */
+ pri_error(ctrl,
+ "TEI=%d Retransmitting frame with old N(S)=%d as N(S)=%d!\n",
+ link->tei, f->h.n_s, link->v_s);
+ } else if (ctrl->debug & PRI_DEBUG_Q921_STATE) {
+ pri_message(ctrl, "TEI=%d Retransmitting frame N(S)=%d now!\n",
+ link->tei, link->v_s);
+ }
+ break;
+ default:
+ /* Should never happen. */
+ pri_error(ctrl, "Unexpected Tx Q frame status: %d", f->status);
+ break;
+ }
/*
* Send the frame out on the assigned TEI.
@@ -684,26 +699,23 @@
f->h.n_r = link->v_r;
f->h.ft = 0;
f->h.p_f = 0;
- if (ctrl->debug & PRI_DEBUG_Q921_STATE) {
- pri_message(ctrl,
- "TEI=%d Transmitting N(S)=%d, window is open V(A)=%d K=%d\n",
- link->tei, f->h.n_s, link->v_a, ctrl->timers[PRI_TIMER_K]);
- }
q921_transmit(ctrl, (q921_h *) (&f->h), f->len);
Q921_INC(link->v_s);
++frames_txd;
- if (ctrl->debug & PRI_DEBUG_Q931_DUMP) {
+ if ((ctrl->debug & PRI_DEBUG_Q931_DUMP)
+ && f->status == Q921_TX_FRAME_NEVER_SENT) {
/*
* The transmit operation might dump the Q.921 header, so logging
* the Q.931 message body after the transmit puts the sections of
* the message in the right order in the log.
*
- * Also the dump is done here so the Q.931 part is decoded only
- * once instead of for every retransmission.
+ * Also dump the Q.931 part only once instead of for every
+ * retransmission.
*/
q931_dump(ctrl, link->tei, (q931_h *) f->h.data, f->len - 4, 1);
}
+ f->status = Q921_TX_FRAME_SENT;
}
if (frames_txd) {
@@ -934,7 +946,7 @@
/* This is the equivalent of a DL-DATA request, as well as the I-frame queued up outcome */
int q921_transmit_iframe(struct q921_link *link, void *buf, int len, int cr)
{
- q921_frame *f, *prev=NULL;
+ struct q921_frame *f, *prev=NULL;
struct pri *ctrl;
ctrl = link->ctrl;
@@ -979,7 +991,7 @@
prev = f;
}
- f = calloc(1, sizeof(q921_frame) + len + 2);
+ f = calloc(1, sizeof(struct q921_frame) + len + 2);
if (f) {
Q921_INIT(link, f->h);
switch (ctrl->localtype) {
@@ -999,7 +1011,7 @@
/* Put new frame on queue tail. */
f->next = NULL;
- f->transmitted = 0;
+ f->status = Q921_TX_FRAME_NEVER_SENT;
f->len = len + 4;
memcpy(f->h.data, buf, len);
if (prev)
@@ -1016,17 +1028,30 @@
}
break;
}
-
- if (link->peer_rx_busy || (link->v_s == Q921_ADD(link->v_a, ctrl->timers[PRI_TIMER_K]))) {
+ if (link->peer_rx_busy) {
if (ctrl->debug & PRI_DEBUG_Q921_STATE) {
pri_message(ctrl,
- "TEI=%d Just queued I-frame due to peer busy condition or window shut\n",
+ "TEI=%d Just queued I-frame due to peer busy condition\n",
link->tei);
}
break;
}
- q921_send_queued_iframes(link);
+ if (!q921_send_queued_iframes(link)) {
+ /*
+ * No frames sent even though we just put a frame on the queue.
+ *
+ * Special debug message/test here because we want to say what
+ * happened to the Q.931 message just queued but we don't want
+ * to flood the debug trace if we are not really looking at the
+ * Q.921 layer.
+ */
+ if ((ctrl->debug & (PRI_DEBUG_Q921_STATE | PRI_DEBUG_Q921_DUMP))
+ == PRI_DEBUG_Q921_STATE) {
+ pri_message(ctrl, "TEI=%d Just queued I-frame due to window shut\n",
+ link->tei);
+ }
+ }
} else {
pri_error(ctrl, "!! Out of memory for Q.921 transmit\n");
return -1;
@@ -1073,14 +1098,13 @@
{
struct pri *ctrl;
struct q921_frame *f;
- int pending = 0, unacked = 0;
-
- ctrl = link->ctrl;
-
- unacked = pending = 0;
+ int pending = 0;
+ int unacked = 0;
+
+ ctrl = link->ctrl;
for (f = link->tx_queue; f; f = f->next) {
- if (f->transmitted) {
+ if (f->status == Q921_TX_FRAME_SENT) {
unacked++;
} else {
pending++;
@@ -2217,11 +2241,11 @@
link->v_a = n_r;
}
+/*! \brief Is V(A) <= N(R) <= V(S) ? */
static int n_r_is_valid(struct q921_link *link, int n_r)
{
int x;
- /* Is V(A) <= N(R) <= V(S) */
for (x = link->v_a; x != n_r && x != link->v_s; Q921_INC(x)) {
}
if (x != n_r) {
@@ -2346,37 +2370,27 @@
static int q921_invoke_retransmission(struct q921_link *link, int n_r)
{
- int frames_txd = 0;
- int frames_supposed_to_tx = 0;
- q921_frame *f;
- unsigned int local_v_s = link->v_s;
- struct pri *ctrl;
-
- ctrl = link->ctrl;
-
- /* All acked frames should already have been removed from the queue. */
- for (f = link->tx_queue; f && f->transmitted; f = f->next) {
- if (ctrl->debug & PRI_DEBUG_Q921_STATE) {
- pri_message(ctrl, "TEI=%d Retransmitting frame N(S)=%d now!\n",
- link->tei, f->h.n_s);
- }
-
- /* Give the other side our current N(R) */
- f->h.n_r = link->v_r;
- f->h.p_f = 0;
- q921_transmit(ctrl, (q921_h *) (&f->h), f->len);
- frames_txd++;
- }
-
- while (local_v_s != n_r) {
- Q921_DEC(local_v_s);
- frames_supposed_to_tx++;
- }
- if (frames_supposed_to_tx != frames_txd) {
- pri_error(ctrl, "!!!!!!!!!!!! Should have only transmitted %d frames!\n", frames_supposed_to_tx);
- }
-
- return frames_txd;
+ struct q921_frame *f;
+ struct pri *ctrl;
+
+ ctrl = link->ctrl;
+
+ /*
+ * All acked frames should already have been removed from the queue.
+ * Push back all sent frames.
+ */
+ for (f = link->tx_queue; f && f->status == Q921_TX_FRAME_SENT; f = f->next) {
+ f->status = Q921_TX_FRAME_PUSHED_BACK;
+
+ /* Sanity check: Is V(A) <= N(S) <= V(S)? */
+ if (!n_r_is_valid(link, f->h.n_s)) {
+ pri_error(ctrl,
+ "Tx Q frame with invalid N(S)=%d. Must be (V(A)=%d) <= N(S) <= (V(S)=%d)\n",
+ f->h.n_s, link->v_a, link->v_s);
+ }
+ }
+ link->v_s = n_r;
+ return q921_send_queued_iframes(link);
}
static pri_event *q921_rej_rx(struct q921_link *link, q921_h *h)
@@ -2494,7 +2508,6 @@
delay_q931_receive = 0;
/* FIXME: Verify that it's a command ... */
if (link->own_rx_busy) {
- /* XXX: Note: There's a difference in th P/F between both states */
/* DEVIATION: Handle own rx busy */
} else if (h->i.n_s == link->v_r) {
Q921_INC(link->v_r);
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