ceph/src/test/crimson/seastar_runner.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #pragma once
   5
   6 #include <stdio.h>
   7 #include <signal.h>
   8 #include <thread>
   9
  10 #include <seastar/core/app-template.hh>
  11 #include <seastar/core/future-util.hh>
  12 #include <seastar/core/reactor.hh>
  13 #include <seastar/core/alien.hh>
  14 #include <seastar/core/thread.hh>
  15
  16 struct SeastarRunner {
  17   static constexpr eventfd_t APP_RUNNING = 1;
  18   static constexpr eventfd_t APP_NOT_RUN = 2;
  19
  20   seastar::app_template app;
  21   seastar::file_desc begin_fd;
  22   std::unique_ptr<seastar::readable_eventfd> on_end;
  23
  24   std::thread thread;
  25
  26   bool begin_signaled = false;
  27
  28   SeastarRunner() :
  29     begin_fd{seastar::file_desc::eventfd(0, 0)} {}
  30
  31   ~SeastarRunner() {}
  32
  33   bool is_running() const {
  34     return !!on_end;
  35   }
  36
  37   int init(int argc, char **argv)
  38   {
  39     thread = std::thread([argc, argv, this] { reactor(argc, argv); });
  40     eventfd_t result;
  41     if (int r = ::eventfd_read(begin_fd.get(), &result); r < 0) {
  42       std::cerr << "unable to eventfd_read():" << errno << std::endl;
  43       return r;
  44     }
  45     assert(begin_signaled == true);
  46     if (result == APP_RUNNING) {
  47       assert(is_running());
  48       return 0;
  49     } else {
  50       assert(result == APP_NOT_RUN);
  51       assert(!is_running());
  52       return 1;
  53     }
  54   }
  55
  56   void stop()
  57   {
  58     if (is_running()) {
  59       run([this] {
  60         on_end->write_side().signal(1);
  61         return seastar::now();
  62       });
  63     }
  64     thread.join();
  65   }
  66
  67   void reactor(int argc, char **argv)
  68   {
  69     auto ret = app.run(argc, argv, [this] {
  70       on_end.reset(new seastar::readable_eventfd);
  71       return seastar::now().then([this] {
  72         begin_signaled = true;
  73         auto r = ::eventfd_write(begin_fd.get(), APP_RUNNING);
  74         assert(r == 0);
  75         return seastar::now();
  76       }).then([this] {
  77         return on_end->wait().then([](size_t){});
  78       }).handle_exception([](auto ep) {
  79         std::cerr << "Error: " << ep << std::endl;
  80       }).finally([this] {
  81         on_end.reset();
  82       });
  83     });
  84     if (ret != 0) {
  85       std::cerr << "Seastar app returns " << ret << std::endl;
  86     }
  87     if (!begin_signaled) {
  88       begin_signaled = true;
  89       ::eventfd_write(begin_fd.get(), APP_NOT_RUN);
  90     }
  91   }
  92
  93   template <typename Func>
  94   void run(Func &&func) {
  95     assert(is_running());
  96     auto fut = seastar::alien::submit_to(app.alien(), 0,
  97                                          std::forward<Func>(func));
  98     fut.get();
  99   }
 100 };
 101
 102