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   seastar::app_template app;
  18   seastar::file_desc begin_fd;
  19   std::unique_ptr<seastar::readable_eventfd> on_end;
  20
  21   std::thread thread;
  22
  23   SeastarRunner() :
  24     begin_fd{seastar::file_desc::eventfd(0, 0)} {}
  25
  26   ~SeastarRunner() {}
  27
  28   void init(int argc, char **argv)
  29   {
  30     thread = std::thread([argc, argv, this] { reactor(argc, argv); });
  31     eventfd_t result = 0;
  32     if (int r = ::eventfd_read(begin_fd.get(), &result); r < 0) {
  33       std::cerr << "unable to eventfd_read():" << errno << std::endl;
  34       throw std::runtime_error("Cannot start seastar");
  35     }
  36   }
  37
  38   void stop()
  39   {
  40     run([this] {
  41       on_end->write_side().signal(1);
  42       return seastar::now();
  43     });
  44     thread.join();
  45   }
  46
  47   void reactor(int argc, char **argv)
  48   {
  49     app.run(argc, argv, [this] {
  50       on_end.reset(new seastar::readable_eventfd);
  51       return seastar::now().then([this] {
  52         ::eventfd_write(begin_fd.get(), 1);
  53           return seastar::now();
  54       }).then([this] {
  55         return on_end->wait().then([](size_t){});
  56       }).handle_exception([](auto ep) {
  57         std::cerr << "Error: " << ep << std::endl;
  58       }).finally([this] {
  59         on_end.reset();
  60       });
  61     });
  62   }
  63
  64   template <typename Func>
  65   void run(Func &&func) {
  66     auto fut = seastar::alien::submit_to(0, std::forward<Func>(func));
  67     fut.get();
  68   }
  69 };
  70
  71