examples: Update test_messages example

The example assumed that there was always at least one TX and on RX
channel.  Since that is not always true, this change checks for TX
and RX channels and only exucutes tests for what exists on the device.

Signed-off-by: Michael West <michael.west@ettus.com>

1 files changed, 23 insertions, 12 deletions

diff --git a/host/examples/test_messages.cpp b/host/examples/test_messages.cpp
index fb930ac7c..512d22d86 100644
--- a/host/examples/test_messages.cpp
+++ b/host/examples/test_messages.cpp
@@ -316,22 +316,29 @@ int UHD_SAFE_MAIN(int argc, char* argv[])
 
     // create RX and TX streamers
     uhd::stream_args_t stream_args("fc32"); // complex floats
-    uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);
-    uhd::tx_streamer::sptr tx_stream = usrp->get_tx_stream(stream_args);
+    uhd::rx_streamer::sptr rx_stream;
+    uhd::tx_streamer::sptr tx_stream;
+    if (usrp->get_rx_num_channels()) {
+        rx_stream = usrp->get_rx_stream(stream_args);
+    }
+    if (usrp->get_tx_num_channels()) {
+        tx_stream = usrp->get_tx_stream(stream_args);
+    }
 
     //------------------------------------------------------------------
     // begin messages test
     //------------------------------------------------------------------
     using test_executor_fn = std::function<bool(
         uhd::usrp::multi_usrp::sptr, uhd::rx_streamer::sptr, uhd::tx_streamer::sptr)>;
-    // clang-format off
-    uhd::dict<std::string, test_executor_fn> tests = boost::assign::map_list_of
-        ("Test Burst ACK ", &test_burst_ack_message)
-        ("Test Underflow ", &test_underflow_message)
-        ("Test Time Error", &test_time_error_message)
-        ("Test Late Command", &test_late_command_message)
-    ;
-    // clang-format on
+    uhd::dict<std::string, test_executor_fn> tests;
+    if (tx_stream) {
+        tests["Test Burst ACK "] = &test_burst_ack_message;
+        tests["Test Underflow "] = &test_underflow_message;
+        tests["Test Time Error"] = &test_time_error_message;
+    }
+    if (rx_stream) {
+        tests["Test Late Command"] = &test_late_command_message;
+    }
 
     if (vm.count("test-chain")) {
         tests["Test Broken Chain"] = &test_broken_chain_message;
@@ -350,8 +357,12 @@ int UHD_SAFE_MAIN(int argc, char* argv[])
         std::string key = tests.keys()[std::rand() % tests.size()];
         bool pass       = tests[key](usrp, rx_stream, tx_stream);
 
-        flush_recv(rx_stream);
-        flush_async(tx_stream);
+        if (rx_stream) {
+            flush_recv(rx_stream);
+        }
+        if (tx_stream) {
+            flush_async(tx_stream);
+        }
 
         // store result
         if (pass)