Add applications to benchmark various IPC mechanisms
Change-Id: I1d4f225bbf4be8a4f67055e3694f1bd664097edd
diff --git a/aos/ipc_lib/named_pipe_latency.cc b/aos/ipc_lib/named_pipe_latency.cc
new file mode 100644
index 0000000..6683f59
--- /dev/null
+++ b/aos/ipc_lib/named_pipe_latency.cc
@@ -0,0 +1,174 @@
+#include "gflags/gflags.h"
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <chrono>
+#include <random>
+#include <thread>
+
+#include "aos/events/epoll.h"
+#include "aos/init.h"
+#include "aos/ipc_lib/latency_lib.h"
+#include "aos/logging/implementations.h"
+#include "aos/logging/logging.h"
+#include "aos/realtime.h"
+#include "aos/time/time.h"
+
+// This is a demo program which uses named pipes to communicate.
+// It measures both latency of a random timer thread, and latency of the
+// pipe.
+
+DEFINE_bool(sender, true, "If true, send signals to the other process.");
+DEFINE_string(fifo, "/dev/shm/aos/named_pipe_latency", "FIFO to use for the test.");
+DEFINE_int32(seconds, 10, "Duration of the test to run");
+DEFINE_int32(
+ latency_threshold, 1000,
+ "Disable tracing when anything takes more than this many microseoncds");
+DEFINE_int32(core, 7, "Core to pin to");
+DEFINE_int32(sender_priority, 53, "RT priority to send at");
+DEFINE_int32(receiver_priority, 52, "RT priority to receive at");
+DEFINE_int32(timer_priority, 51, "RT priority to spin the timer at");
+
+DEFINE_bool(log_latency, false, "If true, log the latency");
+
+namespace chrono = ::std::chrono;
+
+namespace aos {
+
+void SenderThread() {
+ int pipefd = open(FLAGS_fifo.c_str(), FD_CLOEXEC | O_NONBLOCK | O_WRONLY | O_NOATIME);
+ const monotonic_clock::time_point end_time =
+ monotonic_clock::now() + chrono::seconds(FLAGS_seconds);
+ // Standard mersenne_twister_engine seeded with 0
+ ::std::mt19937 generator(0);
+
+ // Sleep between 1 and 15 ms.
+ ::std::uniform_int_distribution<> distribution(1000, 15000);
+
+ PinCurrentThreadToCPU(FLAGS_core);
+ SetCurrentThreadRealtimePriority(FLAGS_sender_priority);
+ while (true) {
+ const monotonic_clock::time_point wakeup_time =
+ monotonic_clock::now() + chrono::microseconds(distribution(generator));
+
+ ::std::this_thread::sleep_until(wakeup_time);
+ const monotonic_clock::time_point monotonic_now = monotonic_clock::now();
+ char sent_time_buffer[8];
+ memcpy(sent_time_buffer, &monotonic_now, sizeof(sent_time_buffer));
+ PCHECK(write(pipefd, static_cast<void *>(sent_time_buffer),
+ sizeof(sent_time_buffer)));
+
+ if (monotonic_now > end_time) {
+ break;
+ }
+ }
+
+ {
+ char sent_time_buffer[8];
+ memset(sent_time_buffer, 0, sizeof(sent_time_buffer));
+ PCHECK(write(pipefd, static_cast<void *>(sent_time_buffer),
+ sizeof(sent_time_buffer)));
+ }
+ UnsetCurrentThreadRealtimePriority();
+
+ PCHECK(close(pipefd));
+}
+
+void ReceiverThread() {
+ int pipefd = open(FLAGS_fifo.c_str(), O_CLOEXEC | O_NONBLOCK | O_RDONLY | O_NOATIME);
+ Tracing t;
+ t.Start();
+
+ chrono::nanoseconds max_wakeup_latency = chrono::nanoseconds(0);
+
+ chrono::nanoseconds sum_latency = chrono::nanoseconds(0);
+ int latency_count = 0;
+
+ internal::EPoll epoll;
+
+ epoll.OnReadable(pipefd, [&t, &epoll, &max_wakeup_latency, &sum_latency,
+ &latency_count, pipefd]() {
+ char sent_time_buffer[8];
+ const int ret = read(pipefd, static_cast<void *>(sent_time_buffer),
+ sizeof(sent_time_buffer));
+ const monotonic_clock::time_point monotonic_now = monotonic_clock::now();
+ CHECK_EQ(ret, 8);
+
+ monotonic_clock::time_point sent_time;
+ memcpy(&sent_time, sent_time_buffer, sizeof(sent_time_buffer));
+
+ if (sent_time == monotonic_clock::epoch()) {
+ epoll.Quit();
+ return;
+ }
+
+ const chrono::nanoseconds wakeup_latency = monotonic_now - sent_time;
+
+ sum_latency += wakeup_latency;
+ ++latency_count;
+
+ max_wakeup_latency = ::std::max(wakeup_latency, max_wakeup_latency);
+
+ if (wakeup_latency > chrono::microseconds(FLAGS_latency_threshold)) {
+ t.Stop();
+ AOS_LOG(INFO, "Stopped tracing, latency %" PRId64 "\n",
+ static_cast<int64_t>(wakeup_latency.count()));
+ }
+
+ if (FLAGS_log_latency) {
+ AOS_LOG(INFO, "dt: %8d.%03d\n",
+ static_cast<int>(wakeup_latency.count() / 1000),
+ static_cast<int>(wakeup_latency.count() % 1000));
+ }
+ });
+
+ PinCurrentThreadToCPU(FLAGS_core);
+ SetCurrentThreadRealtimePriority(FLAGS_receiver_priority);
+ epoll.Run();
+ UnsetCurrentThreadRealtimePriority();
+ epoll.DeleteFd(pipefd);
+
+ const chrono::nanoseconds average_latency = sum_latency / latency_count;
+
+ AOS_LOG(
+ INFO,
+ "Max named pip wakeup latency: %d.%03d microseconds, average: %d.%03d "
+ "microseconds\n",
+ static_cast<int>(max_wakeup_latency.count() / 1000),
+ static_cast<int>(max_wakeup_latency.count() % 1000),
+ static_cast<int>(average_latency.count() / 1000),
+ static_cast<int>(average_latency.count() % 1000));
+
+ PCHECK(close(pipefd));
+}
+
+int Main(int /*argc*/, char ** /*argv*/) {
+ mkfifo(FLAGS_fifo.c_str(), 0777);
+
+ AOS_LOG(INFO, "Main!\n");
+ ::std::thread t([]() {
+ TimerThread(monotonic_clock::now() + chrono::seconds(FLAGS_seconds),
+ FLAGS_timer_priority);
+ });
+
+ ::std::thread st(
+ []() { SenderThread(); });
+
+ ReceiverThread();
+ st.join();
+
+ t.join();
+ return 0;
+}
+
+} // namespace aos
+
+int main(int argc, char **argv) {
+ ::gflags::ParseCommandLineFlags(&argc, &argv, true);
+
+ ::aos::logging::Init();
+ ::aos::logging::SetImplementation(
+ new ::aos::logging::StreamLogImplementation(stdout));
+
+ return ::aos::Main(argc, argv);
+}