examples: Send only single packets in test_messages

For the burst ACK test, test_messages would send 3 packets. However,
that assumes that the underlying link is fast enough to send three
packets in time, and some devices are hard to operate without underruns
without also specifying a start-of burst timestamp. Often, test_messages
would report that no ACK was received, but instead, an underrun was
received.

test_messages also doesn't need to send three packets. The three packets
came from the "start of burst" flag, which no device in UHD supports.

The change is thus to send a single packet with an EOB marker for the
burst ACK test. This will work regardless of the link speed and CPU
power.

1 files changed, 3 insertions, 3 deletions

diff --git a/host/examples/test_messages.cpp b/host/examples/test_messages.cpp
index 637f086f0..78abd3c29 100644
--- a/host/examples/test_messages.cpp
+++ b/host/examples/test_messages.cpp
@@ -136,8 +136,7 @@ bool test_burst_ack_message(
     md.end_of_burst   = true;
     md.has_time_spec  = false;
 
-    // 3 times max-sps guarantees a SOB, no burst, and EOB packet
-    std::vector<std::complex<float>> buff(tx_stream->get_max_num_samps() * 3);
+    std::vector<std::complex<float>> buff(tx_stream->get_max_num_samps());
     tx_stream->send(&buff.front(), buff.size(), md);
 
     uhd::async_metadata_t async_md;
@@ -330,7 +329,8 @@ int UHD_SAFE_MAIN(int argc, char* argv[])
         ("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);
+        ("Test Late Command", &test_late_command_message)
+    ;
     // clang-format on
 
     if (vm.count("test-chain")) {