lib,rf_imp: load rf plugins when loading this library

This fixes race of concurrently loading the same plugins
when srsran_rf_open_devname is called by multiple threads

Plugins are now loaded when srsran_rf is loaded (for
shared lib) or right before main() (for static lib)

lib/src/phy/rf/rf_imp.c

@@ -94,11 +94,6 @@ const char* srsran_rf_get_devname(srsran_rf_t* rf)
 
 int srsran_rf_open_devname(srsran_rf_t* rf, const char* devname, char* args, uint32_t nof_channels)
 {
-  if (srsran_rf_load_plugins() != SRSRAN_SUCCESS) {
-    ERROR("Failed to load RF plugins");
-    return SRSRAN_ERROR;
-  }
-
   rf->thread_gain_run = false;
 
   bool no_rf_devs_detected = true;
@@ -482,3 +477,11 @@ int srsran_rf_load_plugins()
 #endif /* ENABLE_RF_PLUGINS */
   return SRSRAN_SUCCESS;
 }
+
+// Search and load plugins when this library is loaded (shared) or right before main (static)
+void __attribute__((constructor)) init()
+{
+  if (srsran_rf_load_plugins() != SRSRAN_SUCCESS) {
+    ERROR("Failed to load RF plugins");
+  }
+}

lib/src/phy/rf/rf_zmq_test.c

@@ -233,7 +233,6 @@ int param_test(const char* args_param, const int num_channels)
 
 int main()
 {
-  srsran_rf_load_plugins();
   //  // two Rx ports
   //  if (param_test("rx_port=ipc://dl0,rx_port1=ipc://dl1", 2)) {
   //    fprintf(stderr, "Param test failed!\n");