Commit 6b79dc9a authored by Wilson's avatar Wilson

fixing crash due to de-qeueueing the same PDCP SDU twice by two different threads

see issue #164
parent dfc537ff
......@@ -41,6 +41,7 @@ extern int otg_enabled;
#include "pdcp_primitives.h"
#ifdef USER_MODE
#include <pthread.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
......@@ -90,6 +91,21 @@ extern Packet_OTG_List_t *otg_pdcp_buffer;
# include "gtpv1u_eNB_task.h"
#endif
/* Prevent de-queueing the same PDCP SDU from the queue twice
* by multiple threads. This has happened in TDD when thread-odd
* is flushing a PDCP SDU after UE_RX() processing; whereas
* thread-even is at a special-subframe, skips the UE_RX() process
* and goes straight to the PDCP SDU flushing. The 2nd flushing
* dequeues the same SDU again causing unexpected behavior.
*
* comment out the MACRO below to disable this protection
*/
#define PDCP_SDU_FLUSH_LOCK
#ifdef PDCP_SDU_FLUSH_LOCK
static pthread_mutex_t mtex = PTHREAD_MUTEX_INITIALIZER;
#endif
pdcp_data_req_header_t pdcp_read_header_g;
//-----------------------------------------------------------------------------
......@@ -97,21 +113,13 @@ int pdcp_fifo_flush_sdus(const protocol_ctxt_t* const ctxt_pP)
{
//-----------------------------------------------------------------------------
mem_block_t *sdu_p = list_get_head (&pdcp_sdu_list);
int bytes_wrote = 0;
int pdcp_nb_sdu_sent = 0;
uint8_t cont = 1;
#if defined(LINK_ENB_PDCP_TO_GTPV1U)
//MessageDef *message_p = NULL;
#endif
#if defined(PDCP_USE_NETLINK) && defined(LINUX)
//#if defined(PDCP_USE_NETLINK) && defined(LINUX)
int ret = 0;
#endif
//#endif
#ifdef DEBUG_PDCP_FIFO_FLUSH_SDU
#define THREAD_NAME_LEN 16
char threadname[THREAD_NAME_LEN];
static char threadname[THREAD_NAME_LEN];
ret = pthread_getname_np(pthread_self(), threadname, THREAD_NAME_LEN);
if (ret != 0)
{
......@@ -121,6 +129,34 @@ int pdcp_fifo_flush_sdus(const protocol_ctxt_t* const ctxt_pP)
#undef THREAD_NAME_LEN
#endif
#ifdef PDCP_SDU_FLUSH_LOCK
ret = pthread_mutex_trylock(&mtex);
if (ret == EBUSY) {
#ifdef DEBUG_PDCP_FIFO_FLUSH_SDU
LOG_W(PDCP, "[%s] at SFN/SF=%d/%d wait for PDCP FIFO to be unlocked\n",
threadname, ctxt_pP->frame, ctxt_pP->subframe);
#endif
if (pthread_mutex_lock(&mtex)) {
exit_fun("PDCP_SDU_FLUSH_LOCK lock error!");
}
#ifdef DEBUG_PDCP_FIFO_FLUSH_SDU
LOG_I(PDCP, "[%s] at SFN/SF=%d/%d PDCP FIFO is unlocked\n",
threadname, ctxt_pP->frame, ctxt_pP->subframe);
#endif
} else if (ret != 0) {
exit_fun("PDCP_SDU_FLUSH_LOCK trylock error!");
}
#endif
mem_block_t *sdu_p = list_get_head (&pdcp_sdu_list);
int bytes_wrote = 0;
int pdcp_nb_sdu_sent = 0;
uint8_t cont = 1;
#if defined(LINK_ENB_PDCP_TO_GTPV1U)
//MessageDef *message_p = NULL;
#endif
VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME( VCD_SIGNAL_DUMPER_FUNCTIONS_PDCP_FIFO_FLUSH, 1 );
while (sdu_p && cont) {
......@@ -332,6 +368,10 @@ int pdcp_fifo_flush_sdus(const protocol_ctxt_t* const ctxt_pP)
#endif //PDCP_USE_RT_FIFO
#ifdef PDCP_SDU_FLUSH_LOCK
if (pthread_mutex_unlock(&mtex)) exit_fun("PDCP_SDU_FLUSH_LOCK unlock error!");
#endif
return pdcp_nb_sdu_sent;
}
......
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