SignalHandler: add helper async_sigwait_handler

include/sgnl/SignalHandler.h

@@ -6,9 +6,11 @@
 #include <csignal>
 #include <cstring>
 #include <functional>
+#include <future>
 #include <initializer_list>
 #include <stdexcept>
 #include <string>
+#include <utility>
 
 
 namespace sgnl {
@@ -78,6 +80,15 @@ public:
     }
   }
 
+  auto async_sigwait_handler(std::function<bool (int)> handler) const
+  {
+    return std::async(
+        std::launch::async,
+        &SignalHandler::sigwait_handler,
+        this,
+        std::move(handler));
+  }
+
 private:
   sigset_t set_;
 };

test/test.cpp

@@ -163,6 +163,37 @@ TEST_CASE("sigwait_handler")
   REQUIRE( signal_handler.sigwait_handler(handler) == SIGUSR2 );
 }
 
+TEST_CASE("async_sigwait_handler")
+{
+  sgnl::SignalHandler signal_handler({SIGUSR1,SIGUSR2});
+
+  auto handler = [](int){
+    return true;
+  };
+
+  auto future = signal_handler.async_sigwait_handler(handler);
+  kill(0, SIGUSR1);
+  REQUIRE( future.get() == SIGUSR1 );
+}
+
+TEST_CASE("async_sigwait_handler-condition")
+{
+  sgnl::SignalHandler signal_handler({SIGUSR1});
+  sgnl::AtomicCondition<int> condition(0);
+  REQUIRE( condition.get() == 0 );
+  REQUIRE( condition.get() != SIGUSR1 );
+
+  auto handler = [&condition](int signum){
+    condition.set_and_notify_one(signum);
+    return true;
+  };
+
+  auto future = signal_handler.async_sigwait_handler(handler);
+  kill(0, SIGUSR1);
+  REQUIRE( future.get() == SIGUSR1 );
+  REQUIRE( condition.get() == SIGUSR1 );
+}
+
 TEST_CASE("constructor-thread-blocks-signals")
 {
   std::atomic last_signal(0);