Proper Interrupt Handling

sunshine/main.cpp

@@ -7,6 +7,7 @@
 #include <thread>
 #include <filesystem>
 #include <iostream>
+#include <csignal>
 
 #include <boost/log/common.hpp>
 #include <boost/log/sinks.hpp>
@@ -49,6 +50,18 @@ void log_flush() {
   sink->flush();
 }
 
+std::map<int, std::function<void()>> signal_handlers;
+void on_signal_forwarder(int sig) {
+  signal_handlers.at(sig)();
+}
+
+template<class FN>
+void on_signal(int sig, FN &&fn) {
+  signal_handlers.emplace(sig, std::forward<FN>(fn));
+
+  std::signal(sig, on_signal_forwarder);
+}
+
 int main(int argc, char *argv[]) {
   if(argc > 1) {
     if(!std::filesystem::exists(argv[1])) {
@@ -96,6 +109,13 @@ int main(int argc, char *argv[]) {
   bl::core::get()->add_sink(sink);
   auto fg = util::fail_guard(log_flush);
 
+  // Create signal handler after logging has been initialized
+  auto shutdown_event = std::make_shared<safe::event_t<bool>>();
+  on_signal(SIGINT, [shutdown_event]() {
+    BOOST_LOG(info) << "Interrupt handler called"sv;
+    shutdown_event->raise(true);
+  });
+
   auto proc_opt = proc::parse(config::stream.file_apps);
   if(!proc_opt) {
     return 7;
@@ -107,9 +127,9 @@ int main(int argc, char *argv[]) {
 
   task_pool.start(1);
 
-  std::thread httpThread { nvhttp::start };
+  std::thread httpThread { nvhttp::start, shutdown_event };
+  stream::rtpThread(shutdown_event);
 
-  stream::rtpThread();
   httpThread.join();
 
   return 0;

sunshine/nvhttp.cpp

@@ -519,7 +519,7 @@ void launch(resp_https_t response, req_https_t request) {
 
   stream::launch_session_t launch_session;
 
-  if(stream::has_session) {
+  if(stream::session_state != stream::state_e::STOPPED) {
     tree.put("root.<xmlattr>.status_code", 503);
     tree.put("root.gamesession", 0);
 
@@ -576,7 +576,7 @@ void resume(resp_https_t response, req_https_t request) {
   });
 
   auto current_appid = proc::proc.running();
-  if(current_appid == -1 || stream::has_session) {
+  if(current_appid == -1 || stream::session_state != stream::state_e::STOPPED) {
     tree.put("root.resume", 0);
     tree.put("root.<xmlattr>.status_code", 503);
 
@@ -620,7 +620,7 @@ void cancel(resp_https_t response, req_https_t request) {
     return;
   }
 
-  if(stream::has_session) {
+  if(stream::session_state != stream::state_e::STOPPED) {
     tree.put("root.<xmlattr>.status_code", 503);
     tree.put("root.cancel", 0);
 
@@ -640,7 +640,7 @@ void appasset(resp_https_t response, req_https_t request) {
   response->write(SimpleWeb::StatusCode::success_ok, in);
 }
 
-void start() {
+void start(std::shared_ptr<safe::event_t<bool>> shutdown_event) {
   local_ip = platf::get_local_ip();
   origin_pin_allowed = net::from_enum_string(config::nvhttp.origin_pin_allowed);
 
@@ -734,6 +734,12 @@ void start() {
   std::thread ssl { &https_server_t::start, &https_server };
   std::thread tcp { &http_server_t::start, &http_server };
 
+  // Wait for any event
+  shutdown_event->view();
+
+  https_server.stop();
+  http_server.stop();
+
   ssl.join();
   tcp.join();
 }

sunshine/nvhttp.h

@@ -8,12 +8,14 @@
 #include <functional>
 #include <string>
 
+#include "thread_safe.h"
+
 #define CA_DIR SUNSHINE_ASSETS_DIR "/demoCA"
 #define PRIVATE_KEY_FILE CA_DIR    "/cakey.pem"
 #define CERTIFICATE_FILE CA_DIR    "/cacert.pem"
 
 namespace nvhttp {
-void start();
+void start(std::shared_ptr<safe::event_t<bool>> shutdown_event);
 }
 
 #endif //SUNSHINE_NVHTTP_H

sunshine/platform/common.h

@@ -70,6 +70,7 @@ public:
   virtual ~mic_t() = default;
 };
 
+
 void freeInput(void*);
 
 using input_t = util::safe_ptr<void, freeInput>;

sunshine/stream.cpp

@@ -94,7 +94,6 @@ struct audio_packet_raw_t {
 
 safe::event_t<launch_session_t> launch_event;
 
-//FIXME: This smells bad
 std::shared_ptr<input::input_t> input;
 
 struct config_t {
@@ -123,7 +122,7 @@ struct session_t {
 
   bool has_process;
 } session;
-std::atomic_bool has_session;
+std::atomic<state_e> session_state;
 
 void free_host(ENetHost *host) {
   std::for_each(host->peers, host->peers + host->peerCount, [](ENetPeer &peer_ref) {
@@ -165,8 +164,8 @@ void stop(session_t &session) {
   session.video_packets->stop();
   session.audio_packets->stop();
 
-  input::reset(input);
-  has_session.store(false);
+  auto expected = state_e::RUNNING;
+  session_state.compare_exchange_strong(expected, state_e::STOPPING);
 }
 
 class rtsp_server_t {
@@ -549,7 +548,11 @@ void controlThread(video::idr_event_t idr_events) {
     input::passthrough(input, std::move(plaintext));
   });
 
-  while(has_session) {
+  while(session_state == state_e::STARTING) {
+    std::this_thread::sleep_for(1ms);
+  }
+
+  while(session_state == state_e::RUNNING) {
     if(std::chrono::steady_clock::now() > session.pingTimeout) {
       BOOST_LOG(debug) << "Ping timeout"sv;
 
@@ -641,6 +644,10 @@ std::optional<udp::endpoint> recv_peer(std::shared_ptr<safe::queue_t<T>> &queue,
 }
 
 void audioThread() {
+  while(session_state == state_e::STARTING) {
+    std::this_thread::sleep_for(1ms);
+  }
+
   auto &config = session.config;
 
   asio::io_service io;
@@ -676,6 +683,10 @@ void audioThread() {
 }
 
 void videoThread(video::idr_event_t idr_events) {
+  while(session_state == state_e::STARTING) {
+    std::this_thread::sleep_for(1ms);
+  }
+
   auto &config = session.config;
 
   int lowseq = 0;
@@ -908,9 +919,16 @@ void cmd_announce(host_t &host, peer_t peer, msg_t &&req) {
   auto seqn_str = std::to_string(req->sequenceNumber);
   option.content = const_cast<char*>(seqn_str.c_str());
 
-  if(has_session || !launch_event.peek()) {
+  auto expected_state = state_e::STOPPED;
+  auto abort = !session_state.compare_exchange_strong(expected_state, state_e::STARTING);
+
+  if(abort || !launch_event.peek()) {
     //Either already streaming or /launch has not been used
 
+    if(!abort) {
+      session_state.store(state_e::STOPPED);
+    }
+
     respond(host, peer, &option, 503, "Service Unavailable", req->sequenceNumber, {});
     return;
   }
@@ -980,8 +998,6 @@ void cmd_announce(host_t &host, peer_t peer, msg_t &&req) {
     return;
   }
 
-  has_session.store(true);
-
   auto &gcm_key  = launch_session->gcm_key;
   auto &iv       = launch_session->iv;
 
@@ -1001,6 +1017,7 @@ void cmd_announce(host_t &host, peer_t peer, msg_t &&req) {
   session.videoThread   = std::thread {videoThread, idr_events};
   session.controlThread = std::thread {controlThread, idr_events};
 
+  session_state.store(state_e::RUNNING);
   respond(host, peer, &option, 200, "OK", req->sequenceNumber, {});
 }
 
@@ -1016,8 +1033,12 @@ void cmd_play(host_t &host, peer_t peer, msg_t &&req) {
   respond(host, peer, &option, 200, "OK", req->sequenceNumber, {});
 }
 
-void rtpThread() {
+void rtpThread(std::shared_ptr<safe::event_t<bool>> shutdown_event) {
   input = std::make_shared<input::input_t>();
+  auto fg = util::fail_guard([&]() {
+    input.reset();
+  });
+
   rtsp_server_t server(RTSP_SETUP_PORT);
 
   server.map("OPTIONS"sv, &cmd_option);
@@ -1027,13 +1048,10 @@ void rtpThread() {
 
   server.map("PLAY"sv, &cmd_play);
 
-  while(true) {
-    server.iterate(config::stream.ping_timeout);
-
-    if(session.video_packets && !session.video_packets->running()) {
-      // Ensure all threads are stopping
-      stop(session);
+  while(!shutdown_event->peek()) {
+    server.iterate(std::min(500ms, config::stream.ping_timeout));
 
+    if(session_state == state_e::STOPPING) {
       BOOST_LOG(debug) << "Waiting for Audio to end..."sv;
       session.audioThread.join();
       BOOST_LOG(debug) << "Waiting for Video to end..."sv;
@@ -1044,8 +1062,30 @@ void rtpThread() {
       BOOST_LOG(debug) << "Resetting Session..."sv << std::endl;
       session.video_packets = video::packet_queue_t();
       session.audio_packets = audio::packet_queue_t();
+
+      input::reset(input);
+
+      session_state.store(state_e::STOPPED);
     }
   }
+
+  if(session_state != state_e::STOPPED) {
+    // Wait until the session is properly running
+    while(session_state == state_e::STARTING) {
+      std::this_thread::sleep_for(1ms);
+    }
+
+    stop(session);
+
+    BOOST_LOG(debug) << "Waiting for Audio to end..."sv;
+    session.audioThread.join();
+    BOOST_LOG(debug) << "Waiting for Video to end..."sv;
+    session.videoThread.join();
+    BOOST_LOG(debug) << "Waiting for Control to end..."sv;
+    session.controlThread.join();
+
+    input::reset(input);
+  }
 }
 
 }

sunshine/stream.h

@@ -9,8 +9,16 @@
 
 #include "crypto.h"
 #include "thread_safe.h"
+
 namespace stream {
 
+enum class state_e : int {
+  STOPPED,
+  STOPPING,
+  STARTING,
+  RUNNING,
+};
+
 struct launch_session_t {
   crypto::aes_t gcm_key;
   crypto::aes_t iv;
@@ -19,9 +27,9 @@ struct launch_session_t {
 };
 
 extern safe::event_t<launch_session_t> launch_event;
-extern std::atomic_bool has_session;
+extern std::atomic<state_e> session_state;
 
-void rtpThread();
+void rtpThread(std::shared_ptr<safe::event_t<bool>> shutdown_event);
 
 }
 

sunshine/thread_safe.h

@@ -29,6 +29,7 @@ public:
     _cv.notify_all();
   }
 
+  // pop and view shoud not be used interchangebly
   status_t pop() {
     std::unique_lock ul{_lock};
 
@@ -49,6 +50,25 @@ public:
     return val;
   }
 
+  // pop and view shoud not be used interchangebly
+  const status_t &view() {
+    std::unique_lock ul{_lock};
+
+    if (!_continue) {
+      return util::false_v<status_t>;
+    }
+
+    while (!_status) {
+      _cv.wait(ul);
+
+      if (!_continue) {
+        return util::false_v<status_t>;
+      }
+    }
+
+    return _status;
+  }
+
   bool peek() {
     std::lock_guard lg { _lock };