diff options
| -rw-r--r-- | host/lib/usrp/mpmd/mpmd_mboard_impl.cpp | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/host/lib/usrp/mpmd/mpmd_mboard_impl.cpp b/host/lib/usrp/mpmd/mpmd_mboard_impl.cpp index 501f7f701..087cb1373 100644 --- a/host/lib/usrp/mpmd/mpmd_mboard_impl.cpp +++ b/host/lib/usrp/mpmd/mpmd_mboard_impl.cpp @@ -22,12 +22,15 @@ namespace { const size_t MPMD_DEFAULT_RPC_TIMEOUT = 2000; //! Default session ID (MPM will recognize a session by this name) const std::string MPMD_DEFAULT_SESSION_ID = "UHD"; + //! Key to initialize a ping/measurement latency test + const std::string MPMD_MEAS_LATENCY_KEY = "measure_rpc_latency"; + //! Duration of a latency measurement test + constexpr size_t MPMD_MEAS_LATENCY_DURATION = 1000; /************************************************************************* * Helper functions ************************************************************************/ - void init_device( uhd::rpc_client::sptr rpc, const uhd::device_addr_t mb_args @@ -53,6 +56,41 @@ namespace { )); } + void measure_rpc_latency( + uhd::rpc_client::sptr rpc, + const size_t duration_ms=MPMD_MEAS_LATENCY_DURATION + ) { + const double alpha = 0.99; + const std::string payload = "1234567890"; + auto measure_once = [payload, rpc](){ + const auto start = std::chrono::steady_clock::now(); + rpc->request<std::string>("ping", payload); + return (double) std::chrono::duration_cast<std::chrono::microseconds>( + std::chrono::steady_clock::now() - start + ).count(); + }; + + double max_latency = measure_once(); + double avg_latency = max_latency; + + auto end_time = std::chrono::steady_clock::now() + + std::chrono::milliseconds(duration_ms); + size_t ctr = 1; + while (std::chrono::steady_clock::now() < end_time) { + const auto duration = measure_once(); + max_latency = std::max(max_latency, duration); + avg_latency = avg_latency * alpha + (1-alpha) * duration; + ctr++; + // Light throttle: + std::this_thread::sleep_for(std::chrono::milliseconds(1)); + } + + UHD_LOG_INFO("MPMD", + "RPC latency (coarse estimate): Avg = " << avg_latency << " us, " + "Max = " << max_latency + << ", n = " << ctr); + } + } using namespace uhd; @@ -78,6 +116,10 @@ mpmd_mboard_impl::mpmd_mboard_impl( ; _claimer_task = claim_device_and_make_task(rpc, mb_args); + if (mb_args_.has_key(MPMD_MEAS_LATENCY_KEY)) { + measure_rpc_latency(rpc, MPMD_MEAS_LATENCY_DURATION); + } + // No one else can now claim the device. if (mb_args_.has_key("skip_init")) { UHD_LOG_DEBUG("MPMD", "Claimed device, but skipped init."); |