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lib,rlc_am_nr: Continue to add functionality to provide segments of retx'es. Started to add function to re-segment already existing SDU segment

This commit is contained in:
Pedro Alvarez 2022-01-20 18:46:16 +00:00
parent e4a72de342
commit 65d5df8b6e
3 changed files with 215 additions and 41 deletions
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10
lib/include/srsran/rlc/rlc_am_nr.h
View File

@ -108,8 +108,14 @@ public:
uint32_t build_new_sdu_segment(rlc_amd_tx_pdu_nr& tx_pdu, uint8_t* payload, uint32_t nof_bytes);
uint32_t build_continuation_sdu_segment(rlc_amd_tx_pdu_nr& tx_pdu, uint8_t* payload, uint32_t nof_bytes);
uint32_t build_retx_pdu(uint8_t* payload, uint32_t nof_bytes);
uint32_t build_retx_sdu_segment(rlc_amd_tx_pdu_nr& tx_pdu, uint8_t* payload, uint32_t nof_bytes);
uint32_t build_retx_pdu_from_full_sdu(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes);
uint32_t build_retx_segment_from_full_sdu(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes);
uint32_t build_retx_pdu_from_sdu_segment(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes);
uint32_t build_retx_segment_from_sdu_segment(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes);
/*
* uint32_t build_retx_sdu_segment(rlc_amd_retx_t& retx, rlc_amd_tx_pdu_nr& tx_pdu, uint8_t* payload, uint32_t
* nof_bytes);
*/
// Buffer State
bool has_data() final;
uint32_t get_buffer_state() final;

226
lib/src/rlc/rlc_am_nr.cc
View File

@ -380,8 +380,9 @@ uint32_t rlc_am_nr_tx::build_continuation_sdu_segment(rlc_amd_tx_pdu_nr& tx_pdu,
/**
* Builds a retx RLC PDU.
*
* Called by the MAC, trough the STACK thread.
* This will segment the RETX PDU if necessary
* This will use the retx_queue to get information about the RLC PDU
* being retx'ed. The retx may have been previously transmitted as
* a full SDU or an SDU segment.
*
* \param [tx_pdu] is the tx_pdu info contained in the tx_window.
* \param [payload] is a pointer to the MAC buffer that will hold the PDU segment.
@ -398,7 +399,7 @@ uint32_t rlc_am_nr_tx::build_retx_pdu(uint8_t* payload, uint32_t nof_bytes)
return 0;
}
rlc_amd_retx_t retx = retx_queue.front();
rlc_amd_retx_t& retx = retx_queue.front();
// Sanity check - drop any retx SNs not present in tx_window
while (not tx_window.has_sn(retx.sn)) {
@ -411,6 +412,29 @@ uint32_t rlc_am_nr_tx::build_retx_pdu(uint8_t* payload, uint32_t nof_bytes)
return 0;
}
}
if (retx.is_segment) {
return build_retx_pdu_from_sdu_segment(retx, payload, nof_bytes);
}
return build_retx_pdu_from_full_sdu(retx, payload, nof_bytes);
}
/**
* Builds a retx RLC PDU from a full SDU.
*
* The RETX of the full SDU may be further segmented if necessary.
*
* \param [tx_pdu] is the tx_pdu info contained in the tx_window.
* \param [payload] is a pointer to the MAC buffer that will hold the PDU segment.
* \param [nof_bytes] is the number of bytes the RLC is allowed to fill.
*
* \returns the number of bytes written to the payload buffer.
* \remark: This functions assumes that the SDU has already been copied to tx_pdu.sdu_buf.
*/
uint32_t rlc_am_nr_tx::build_retx_pdu_from_full_sdu(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes)
{
srsran_assert(tx_window.has_sn(retx.sn), "Called %s without checking retx SN", __FUNCTION__);
// Get tx_pdu info from tx_window
rlc_amd_tx_pdu_nr& tx_pdu = tx_window[retx.sn];
// Update & write header
@ -422,11 +446,7 @@ uint32_t rlc_am_nr_tx::build_retx_pdu(uint8_t* payload, uint32_t nof_bytes)
if (hdr_len + tx_window[retx.sn].sdu_buf->N_bytes > nof_bytes) {
RlcInfo("Trying to segment retx PDU. SN=%d", retx.sn);
log_rlc_am_nr_pdu_header_to_string(logger.debug, new_header);
if (tx_pdu.header.si == rlc_nr_si_field_t::full_sdu) {
return build_new_sdu_segment(tx_pdu, payload, nof_bytes);
}
RlcWarning("Trying to segment retx PDU");
return 0;
return build_retx_segment_from_full_sdu(retx, payload, nof_bytes);
}
// RETX full PDU
@ -434,7 +454,6 @@ uint32_t rlc_am_nr_tx::build_retx_pdu(uint8_t* payload, uint32_t nof_bytes)
uint32_t pdu_bytes = hdr_len + tx_window[retx.sn].sdu_buf->N_bytes;
retx_queue.pop();
RlcHexInfo(tx_window[retx.sn].sdu_buf->msg,
tx_window[retx.sn].sdu_buf->N_bytes,
"Original SDU SN=%d (%d B) (attempt %d/%d)",
@ -450,9 +469,12 @@ uint32_t rlc_am_nr_tx::build_retx_pdu(uint8_t* payload, uint32_t nof_bytes)
}
/**
* Builds RLC PDU segment from an RETX.
* Builds a retx RLC PDU from a full SDU.
*
* Called by the MAC, trough the STACK thread.
* This function will further segment the previously transmitted SDU.
* There should not be enough bytes granted to transmit the previous
* SDU full; this should have been checked previous to calling this
* function.
*
* \param [tx_pdu] is the tx_pdu info contained in the tx_window.
* \param [payload] is a pointer to the MAC buffer that will hold the PDU segment.
@ -461,51 +483,183 @@ uint32_t rlc_am_nr_tx::build_retx_pdu(uint8_t* payload, uint32_t nof_bytes)
* \returns the number of bytes written to the payload buffer.
* \remark: This functions assumes that the SDU has already been copied to tx_pdu.sdu_buf.
*/
uint32_t rlc_am_nr_tx::build_retx_sdu_segment(rlc_amd_tx_pdu_nr& tx_pdu, uint8_t* payload, uint32_t nof_bytes)
uint32_t rlc_am_nr_tx::build_retx_segment_from_full_sdu(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes)
{
RlcInfo("creating SDU segment from retx. Tx SDU (%d B), nof_bytes=%d B ", tx_pdu.sdu_buf->N_bytes, nof_bytes);
// Get tx_pdu info from tx_window
srsran_assert(tx_window.has_sn(retx.sn), "Called %s without checking retx SN", __FUNCTION__);
rlc_amd_tx_pdu_nr& tx_pdu = tx_window[retx.sn];
// Sanity check: can this SDU be sent this in a single PDU?
if ((tx_pdu.sdu_buf->N_bytes + min_hdr_size) < nof_bytes) {
RlcError("calling build_new_sdu_segment(), but there are enough bytes to tx in a single PDU. Tx SDU (%d B), "
"nof_bytes=%d B ",
tx_pdu.sdu_buf->N_bytes,
nof_bytes);
RlcInfo("creating SDU segment from full SDU. Tx SDU (%d B), nof_bytes=%d B ", tx_pdu.sdu_buf->N_bytes, nof_bytes);
// Sanity check: is this an SDU segment retx?
if (retx.is_segment) {
RlcError("called %s, but retx contains a SDU segment. SN=%d, so_start=%d, so_end=%d",
__FUNCTION__,
retx.sn,
retx.so_start,
retx.so_end);
return 0;
}
// Sanity check: can this SDU be sent considering header overhead?
if (nof_bytes <= min_hdr_size) { // Small header as SO is not present
RlcError("cannot build new sdu_segment, there are not enough bytes allocated to tx header plus data. nof_bytes=%d",
nof_bytes);
// Sanity check: are there enough bytes for header plus data?
if (nof_bytes <= min_hdr_size) {
RlcError("called %s, but there are not enough bytes for data plus header. SN=%d", __FUNCTION__, retx.sn);
return 0;
}
// Prepare header
rlc_am_nr_pdu_header_t hdr = tx_pdu.header;
hdr.si = rlc_nr_si_field_t::first_segment;
log_rlc_am_nr_pdu_header_to_string(logger.info, hdr);
// Sanity check: could this have been transmitted without segmentation?
if (nof_bytes > (tx_pdu.sdu_buf->N_bytes + min_hdr_size)) {
RlcError("called %s, but there are enough bytes to avoid segmentation. SN=%d", __FUNCTION__, retx.sn);
return 0;
}
// Can the RETX PDU be transmitted in a single PDU?
uint32_t retx_pdu_payload_size = nof_bytes - min_hdr_size;
// Write header
uint32_t hdr_len = rlc_am_nr_write_data_pdu_header(hdr, payload);
rlc_am_nr_pdu_header_t hdr = tx_pdu.header;
hdr.si = rlc_nr_si_field_t::first_segment;
uint32_t hdr_len = rlc_am_nr_write_data_pdu_header(hdr, payload);
if (hdr_len >= nof_bytes || hdr_len != min_hdr_size) {
RlcError("error writing AMD PDU header");
return 0;
}
log_rlc_am_nr_pdu_header_to_string(logger.info, hdr);
// Copy PDU to payload
uint32_t segment_payload_len = nof_bytes - hdr_len;
srsran_assert((hdr_len + segment_payload_len) <= nof_bytes, "Error calculating hdr_len and segment_payload_len");
memcpy(&payload[hdr_len], tx_pdu.sdu_buf->msg, segment_payload_len);
// Save SDU currently being segmented
retx_under_segmentation_sn = hdr.sn;
srsran_assert((hdr_len + retx_pdu_payload_size) <= nof_bytes, "Error calculating hdr_len and segment_payload_len");
memcpy(&payload[hdr_len], tx_pdu.sdu_buf->msg, retx_pdu_payload_size);
// Store Segment Info
rlc_amd_tx_pdu_nr::pdu_segment segment_info;
segment_info.payload_len = segment_payload_len;
segment_info.payload_len = retx_pdu_payload_size;
tx_pdu.segment_list.push_back(segment_info);
return hdr_len + segment_payload_len;
// Update retx queue. Next SDU segment will be the rest of the PDU
retx.is_segment = true;
retx.so_start = retx_pdu_payload_size;
retx.so_end = tx_pdu.sdu_buf->N_bytes;
return hdr_len + retx_pdu_payload_size;
}
/**
* Builds a retx RLC PDU from an RETX SDU segment.
*
* The
* \param [tx_pdu] is the tx_pdu info contained in the tx_window.
* \param [payload] is a pointer to the MAC buffer that will hold the PDU segment.
* \param [nof_bytes] is the number of bytes the RLC is allowed to fill.
*
* \returns the number of bytes written to the payload buffer.
* \remark: This functions assumes that the SDU has already been copied to tx_pdu.sdu_buf.
*/
uint32_t rlc_am_nr_tx::build_retx_pdu_from_sdu_segment(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes)
{
// Get tx_pdu info from tx_window
srsran_assert(tx_window.has_sn(retx.sn), "Called %s without checking retx SN", __FUNCTION__);
rlc_amd_tx_pdu_nr& tx_pdu = tx_window[retx.sn];
RlcInfo("creating RETX PDU from SDU segment. Tx SDU (%d B), nof_bytes=%d B ", tx_pdu.sdu_buf->N_bytes, nof_bytes);
// Sanity check: is this an SDU segment retx?
if (not retx.is_segment) {
RlcError("called %s, but retx contains a SDU segment. SN=%d, so_start=%d, so_end=%d",
__FUNCTION__,
retx.sn,
retx.so_start,
retx.so_end);
return 0;
}
uint32_t expected_hdr_len = min_hdr_size;
if (retx.so_start != 0) {
expected_hdr_len = max_hdr_size;
}
// Sanity check: are there enough bytes for header plus data?
if (nof_bytes <= expected_hdr_len) {
RlcError("called %s, but there are not enough bytes for data plus header. SN=%d", __FUNCTION__, retx.sn);
return 0;
}
// Can this have be transmitted without segmentation?
if (nof_bytes < (retx.so_end - retx.so_start) + expected_hdr_len) {
RlcInfo("called %s, but there are enough bytes to avoid segmentation. SN=%d", __FUNCTION__, retx.sn);
return build_retx_segment_from_sdu_segment(retx, payload, nof_bytes);
}
// Can the RETX PDU be transmitted in a single PDU?
uint32_t retx_pdu_payload_size = (retx.so_end - retx.so_start);
// Write header
rlc_am_nr_pdu_header_t hdr = tx_pdu.header;
uint32_t hdr_len = rlc_am_nr_write_data_pdu_header(hdr, payload);
if (hdr_len >= nof_bytes || hdr_len != expected_hdr_len) {
RlcError("error writing AMD PDU header");
return 0;
}
log_rlc_am_nr_pdu_header_to_string(logger.info, hdr);
// Copy SDU segment into payload
srsran_assert((hdr_len + retx_pdu_payload_size) <= nof_bytes, "Error calculating hdr_len and segment_payload_len");
memcpy(&payload[hdr_len], tx_pdu.sdu_buf->msg, retx_pdu_payload_size);
// Update retx queue
retx.so_start = retx.so_end;
retx.so_end += retx_pdu_payload_size;
if (retx.so_end == tx_pdu.sdu_buf->N_bytes) {
// Last segment to retx, remove retx from queue
retx_queue.pop();
}
// Update SDU segment info
// TODO
return hdr_len + retx_pdu_payload_size;
}
/**
* Builds a retx RLC PDU from an SDU SDU segment.
*
* \param [tx_pdu] is the tx_pdu info contained in the tx_window.
* \param [payload] is a pointer to the MAC buffer that will hold the PDU segment.
* \param [nof_bytes] is the number of bytes the RLC is allowed to fill.
*
* \returns the number of bytes written to the payload buffer.
* \remark: This functions assumes that the SDU has already been copied to tx_pdu.sdu_buf.
*/
uint32_t rlc_am_nr_tx::build_retx_segment_from_sdu_segment(rlc_amd_retx_t& retx, uint8_t* payload, uint32_t nof_bytes)
{
// Get tx_pdu info from tx_window
srsran_assert(tx_window.has_sn(retx.sn), "Called %s without checking retx SN", __FUNCTION__);
rlc_amd_tx_pdu_nr& tx_pdu = tx_window[retx.sn];
RlcInfo("creating SDU segment from full SDU. Tx SDU (%d B), nof_bytes=%d B ", tx_pdu.sdu_buf->N_bytes, nof_bytes);
// Sanity check: is this an SDU segment retx?
if (not retx.is_segment) {
RlcError("called %s, but retx contains a SDU segment. SN=%d, so_start=%d, so_end=%d",
__FUNCTION__,
retx.sn,
retx.so_start,
retx.so_end);
return 0;
}
// Sanity check: are there enough bytes for header plus data?
if (nof_bytes <= min_hdr_size) {
RlcError("called %s, but there are not enough bytes for data plus header. SN=%d", __FUNCTION__, retx.sn);
return 0;
}
// Sanity check: could this have been transmitted without segmentation?
if (nof_bytes > (tx_pdu.sdu_buf->N_bytes + min_hdr_size)) {
RlcError("called %s, but there are enough bytes to avoid segmentation. SN=%d", __FUNCTION__, retx.sn);
return 0;
}
return 0;
}
uint32_t rlc_am_nr_tx::build_status_pdu(byte_buffer_t* payload, uint32_t nof_bytes)

20
lib/test/rlc/rlc_am_nr_test.cc
View File

@ -512,13 +512,27 @@ int segment_retx_test()
// Re-transmit PDU in 3 segments
for (int i = 0; i < 3; i++) {
byte_buffer_t retx_buf;
int len = rlc1.read_pdu(retx_buf.msg, 3);
retx_buf.N_bytes = len;
TESTASSERT(3 == len);
uint32_t len = 0;
if (i == 0) {
len = rlc1.read_pdu(retx_buf.msg, 3);
TESTASSERT(3 == len);
} else {
len = rlc1.read_pdu(retx_buf.msg, 5);
TESTASSERT(5 == len);
}
retx_buf.N_bytes = len;
rlc_am_nr_pdu_header_t header_check = {};
uint32_t hdr_len = rlc_am_nr_read_data_pdu_header(&retx_buf, rlc_am_nr_sn_size_t::size12bits, &header_check);
// Double check header.
TESTASSERT(header_check.sn == 3); // Double check RETX SN
if (i == 0) {
TESTASSERT(header_check.si == rlc_nr_si_field_t::first_segment);
} else if (i == 1) {
TESTASSERT(header_check.si == rlc_nr_si_field_t::neither_first_nor_last_segment);
} else {
TESTASSERT(header_check.si == rlc_nr_si_field_t::last_segment);
}
rlc2.write_pdu(retx_buf.msg, retx_buf.N_bytes);
}