retransmit random RLC AM PDU in case tx window is full

master
Andre Puschmann 6 years ago
parent b75506ac16
commit ba87819ff1

@ -139,6 +139,7 @@ private:
bool retx_queue_has_sn(uint32_t sn); bool retx_queue_has_sn(uint32_t sn);
int required_buffer_size(rlc_amd_retx_t retx); int required_buffer_size(rlc_amd_retx_t retx);
void retransmit_random_pdu();
// Timer checks // Timer checks
bool status_prohibited; bool status_prohibited;

@ -469,19 +469,9 @@ int rlc_am::rlc_am_tx::read_pdu(uint8_t *payload, uint32_t nof_bytes)
goto unlock_and_exit; goto unlock_and_exit;
} }
// if tx_window is full and retx_queue empty, retransmit next PDU to be ack'ed // Section 5.2.2.3 in TS 36.311, if tx_window is full and retx_queue empty, retransmit random PDU
if (tx_window.size() >= RLC_AM_WINDOW_SIZE && retx_queue.empty()) { if (tx_window.size() >= RLC_AM_WINDOW_SIZE && retx_queue.empty()) {
if (tx_window[vt_a].buf != NULL) { retransmit_random_pdu();
log->warning("Full Tx window, ReTx'ing first outstanding PDU\n");
rlc_amd_retx_t retx = {};
retx.is_segment = false;
retx.so_start = 0;
retx.so_end = tx_window[vt_a].buf->N_bytes;
retx.sn = vt_a;
retx_queue.push_back(retx);
} else {
log->error("Found invalid PDU in tx_window.\n");
}
} }
// RETX if required // RETX if required
@ -505,21 +495,10 @@ void rlc_am::rlc_am_tx::timer_expired(uint32_t timeout_id)
{ {
pthread_mutex_lock(&mutex); pthread_mutex_lock(&mutex);
if (poll_retx_timer != NULL && poll_retx_timer_id == timeout_id) { if (poll_retx_timer != NULL && poll_retx_timer_id == timeout_id) {
// if both tx and retx buffer are empty, retransmit next PDU to be ack'ed (Section 5.2.2.3 in TS 36.322) log->debug("Poll reTx timer expired for LCID=%d after %d ms\n", parent->lcid, poll_retx_timer->get_timeout());
log->debug("Poll reTx timer expired (lcid=%d)\n", parent->lcid); // Section 5.2.2.3 in TS 36.311, if tx_window is full and retx_queue empty, retransmit random PDU
if ((not tx_window.empty() && retx_queue.empty() && tx_sdu_queue.size() == 0)) { if ((tx_window.size() >= RLC_AM_WINDOW_SIZE && retx_queue.empty() && tx_sdu_queue.size() == 0)) {
std::map<uint32_t, rlc_amd_tx_pdu_t>::iterator it = tx_window.find(vt_s - 1); retransmit_random_pdu();
if (it != tx_window.end()) {
log->info("Schedule last PDU (SN=%d) for reTx.\n", vt_s - 1);
rlc_amd_retx_t retx = {};
retx.is_segment = false;
retx.so_start = 0;
retx.so_end = tx_window[vt_s - 1].buf->N_bytes;
retx.sn = vt_s - 1;
retx_queue.push_back(retx);
} else {
log->error("Found invalid PDU in tx_window.\n");
}
} }
} else } else
if (status_prohibit_timer != NULL && status_prohibit_timer_id == timeout_id) { if (status_prohibit_timer != NULL && status_prohibit_timer_id == timeout_id) {
@ -528,6 +507,21 @@ void rlc_am::rlc_am_tx::timer_expired(uint32_t timeout_id)
pthread_mutex_unlock(&mutex); pthread_mutex_unlock(&mutex);
} }
void rlc_am::rlc_am_tx::retransmit_random_pdu()
{
// randomly select PDU in tx window for retransmission
std::map<uint32_t, rlc_amd_tx_pdu_t>::iterator it = tx_window.begin();
std::advance(it, rand() % tx_window.size());
log->info("Schedule SN=%d for reTx.\n", it->first);
rlc_amd_retx_t retx = {};
retx.is_segment = false;
retx.so_start = 0;
retx.so_end = it->second.buf->N_bytes;
retx.sn = it->first;
retx_queue.push_back(retx);
}
uint32_t rlc_am::rlc_am_tx::get_num_tx_bytes() uint32_t rlc_am::rlc_am_tx::get_num_tx_bytes()
{ {
return num_tx_bytes; return num_tx_bytes;
@ -556,7 +550,7 @@ bool rlc_am::rlc_am_tx::poll_required()
if (poll_retx_timer != NULL) { if (poll_retx_timer != NULL) {
if (poll_retx_timer->is_expired()) { if (poll_retx_timer->is_expired()) {
// re-arm timer // re-arm timer (will be stopped when status PDU is received)
poll_retx_timer->reset(); poll_retx_timer->reset();
poll_retx_timer->run(); poll_retx_timer->run();
return true; return true;

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