Fixes issue #545 and unlocking of tti_sync condvar before closing causing deadlock at stop

lib/src/common/tti_sync_cv.cc

@@ -34,7 +34,11 @@ namespace srslte {
 
   tti_sync_cv::~tti_sync_cv()
   {
+    // Wake up any thread waiting on cond before destroying it
+    pthread_mutex_lock(&mutex);
+    pthread_cond_signal(&cond);
     pthread_cond_destroy(&cond);
+    pthread_mutex_unlock(&mutex);
     pthread_mutex_destroy(&mutex);
   }
 

srsenb/src/stack/mac/mac.cc

@@ -532,12 +532,12 @@ int mac::rach_detected(uint32_t tti, uint32_t preamble_idx, uint32_t time_adv)
 
 int mac::get_dl_sched(uint32_t tti, dl_sched_t *dl_sched_res)
 {
-  log_h->step(tti);
-
   if (!started) {
     return 0;
   }
 
+  log_h->step(tti);
+
   if (!dl_sched_res) {
     return SRSLTE_ERROR_INVALID_INPUTS;
   }