adding async thread to soapy

lib/src/phy/rf/rf_soapy_imp.c

@@ -40,6 +40,8 @@
 #include <SoapySDR/Logger.h>
 #include <Types.h>
 
+#define HAVE_ASYNC_THREAD 1
+
 #define USE_TX_MTU 0
 #define SET_RF_BW 1
 
@@ -64,6 +66,9 @@ typedef struct {
 
   srslte_rf_error_handler_t soapy_error_handler;
 
+  bool async_thread_running;
+  pthread_t async_thread;
+
   uint32_t num_time_errors;
   uint32_t num_lates;
   uint32_t num_overflows;
@@ -111,6 +116,41 @@ static void log_underflow(rf_soapy_handler_t *h) {
 }
 
 
+#if HAVE_ASYNC_THREAD
+static void* async_thread(void *h) {
+  rf_soapy_handler_t *handler = (rf_soapy_handler_t*) h;
+
+  while(handler->async_thread_running) {
+    int ret = 0;
+    size_t chanMask = 0;
+    int flags = 0;
+    const long timeoutUs = 400000; // arbitrarily chosen
+    long long timeNs;
+
+    ret = SoapySDRDevice_readStreamStatus(handler->device, handler->txStream, &chanMask, &flags, &timeNs, timeoutUs);
+    if (ret == SOAPY_SDR_TIME_ERROR) {
+      // this is a late
+      log_late(handler, false);
+    } else if (ret == SOAPY_SDR_UNDERFLOW) {
+      log_underflow(handler);
+    } else if (ret == SOAPY_SDR_OVERFLOW) {
+      log_overflow(handler);
+    } else if (ret == SOAPY_SDR_TIMEOUT) {
+      // this is a timeout of the readStreamStatus call, ignoring it ..
+    } else if (ret == SOAPY_SDR_NOT_SUPPORTED) {
+      // stopping async thread
+      fprintf(stderr, "Receiving async metadata not supported by device. Exiting thread.\n");
+      handler->async_thread_running = false;
+    } else {
+      fprintf(stderr, "Error while receiving aync metadata: %s (%d), flags=%d, channel=%zu, timeNs=%lld\n", SoapySDR_errToStr(ret), ret, flags, chanMask, timeNs);
+      handler->async_thread_running = false;
+    }
+  }
+  return NULL;
+}
+#endif
+
+
 int soapy_error(void *h)
 {
   return 0;
@@ -397,6 +437,14 @@ int rf_soapy_open_multi(char *args, void **h, uint32_t nof_rx_antennas)
     }
   }
 
+#if HAVE_ASYNC_THREAD
+  bool start_async_thread = true;
+  if (strstr(args, "silent")) {
+    REMOVE_SUBSTRING_WITHCOMAS(args, "silent");
+    start_async_thread = false;
+  }
+#endif
+
   // receive one subframe to allow for transceiver calibration
   if (strstr(devname, "lime")) {
     // set default tx gain and leave some time to calibrate tx
@@ -434,6 +482,17 @@ int rf_soapy_open_multi(char *args, void **h, uint32_t nof_rx_antennas)
   ant = SoapySDRDevice_getAntenna(handler->device, SOAPY_SDR_TX, 0);
   printf("Tx antenna set to %s\n", ant);
 
+#if HAVE_ASYNC_THREAD
+  if (start_async_thread) {
+    // Start low priority thread to receive async commands
+    handler->async_thread_running = true;
+    if (pthread_create(&handler->async_thread, NULL, async_thread, handler)) {
+      perror("pthread_create");
+      return -1;
+    }
+  }
+#endif
+
   return SRSLTE_SUCCESS;
 }
 
@@ -447,6 +506,14 @@ int rf_soapy_open(char *args, void **h)
 int rf_soapy_close(void *h)
 {
   rf_soapy_handler_t *handler = (rf_soapy_handler_t*) h;
+
+#if HAVE_ASYNC_THREAD
+  if (handler->async_thread_running) {
+    handler->async_thread_running = false;
+    pthread_join(handler->async_thread, NULL);
+  }
+#endif
+
   if (handler->tx_stream_active) {
     rf_soapy_stop_tx_stream(handler);
     SoapySDRDevice_closeStream(handler->device, handler->txStream);