retransmit random RLC AM PDU in case tx window is full

This commit is contained in:
Andre Puschmann 2018-09-24 15:15:35 +02:00
parent b75506ac16
commit ba87819ff1
2 changed files with 23 additions and 28 deletions

View File

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

View File

@ -469,19 +469,9 @@ int rlc_am::rlc_am_tx::read_pdu(uint8_t *payload, uint32_t nof_bytes)
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[vt_a].buf != NULL) {
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");
}
retransmit_random_pdu();
}
// RETX if required
@ -505,21 +495,10 @@ void rlc_am::rlc_am_tx::timer_expired(uint32_t timeout_id)
{
pthread_mutex_lock(&mutex);
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 (lcid=%d)\n", parent->lcid);
if ((not tx_window.empty() && 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);
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");
}
log->debug("Poll reTx timer expired for LCID=%d after %d ms\n", parent->lcid, poll_retx_timer->get_timeout());
// 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() && tx_sdu_queue.size() == 0)) {
retransmit_random_pdu();
}
} else
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);
}
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()
{
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->is_expired()) {
// re-arm timer
// re-arm timer (will be stopped when status PDU is received)
poll_retx_timer->reset();
poll_retx_timer->run();
return true;