add signal handlers; closes #564

src/SignalWatcher.hh

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <thread>
+
+#include <event2/event.h>
+
+#include "ServerState.hh"
+
+class SignalWatcher : public std::enable_shared_from_this<SignalWatcher> {
+public:
+  explicit SignalWatcher(std::shared_ptr<ServerState> state);
+  SignalWatcher(const SignalWatcher&) = delete;
+  SignalWatcher(SignalWatcher&&) = delete;
+  SignalWatcher& operator=(const SignalWatcher&) = delete;
+  SignalWatcher& operator=(SignalWatcher&&) = delete;
+  ~SignalWatcher() = default;
+
+protected:
+  phosg::PrefixedLogger log;
+  std::shared_ptr<ServerState> state;
+  std::unique_ptr<struct event, void (*)(struct event*)> sigusr1_event;
+  std::unique_ptr<struct event, void (*)(struct event*)> sigusr2_event;
+
+  static void dispatch_on_signal(evutil_socket_t, short, void* ctx);
+  void on_signal(int signum);
+};