event/PollGroup: ReadEvents() returns PollResult

src/event/Loop.cxx

@@ -257,8 +257,8 @@ EventLoop::Run() noexcept
 
 		/* wait for new event */
 
-		PollResult poll_result;
-		poll_group.ReadEvents(poll_result, ExportTimeoutMS(timeout));
+		const auto poll_result =
+			poll_group.ReadEvents(ExportTimeoutMS(timeout));
 
 		ready_sockets.clear();
 		for (size_t i = 0; i < poll_result.GetSize(); ++i) {

src/event/PollGroup.hxx

@@ -25,19 +25,16 @@
 #ifdef _WIN32
 
 #include "PollGroupWinSelect.hxx"
-typedef PollResultGeneric  PollResult;
 typedef PollGroupWinSelect PollGroup;
 
 #elif defined(USE_EPOLL)
 
 #include "PollGroupEpoll.hxx"
-typedef PollResultEpoll PollResult;
 typedef PollGroupEpoll PollGroup;
 
 #else
 
 #include "PollGroupPoll.hxx"
-typedef PollResultGeneric PollResult;
 typedef PollGroupPoll     PollGroup;
 
 #endif

src/event/PollGroupEpoll.hxx

@@ -61,10 +61,12 @@ public:
 
 	PollGroupEpoll() = default;
 
-	void ReadEvents(PollResultEpoll &result, int timeout_ms) noexcept {
+	auto ReadEvents(int timeout_ms) noexcept {
+		PollResultEpoll result;
 		int ret = epoll.Wait(result.events.data(), result.events.size(),
 				     timeout_ms);
 		result.n_events = std::max(0, ret);
+		return result;
 	}
 
 	bool Add(int fd, unsigned events, void *obj) noexcept {

src/event/PollGroupPoll.cxx

@@ -71,12 +71,13 @@ PollGroupPoll::Remove(int fd) noexcept
 	return true;
 }
 
-void
-PollGroupPoll::ReadEvents(PollResultGeneric &result, int timeout_ms) noexcept
+PollResultGeneric
+PollGroupPoll::ReadEvents(int timeout_ms) noexcept
 {
 	int n = poll(poll_events.empty() ? nullptr : &poll_events[0],
 		     poll_events.size(), timeout_ms);
 
+	PollResultGeneric result;
 	for (size_t i = 0; n > 0 && i < poll_events.size(); ++i) {
 		const auto &e = poll_events[i];
 		if (e.revents != 0) {
@@ -84,4 +85,6 @@ PollGroupPoll::ReadEvents(PollResultGeneric &result, int timeout_ms) noexcept
 			--n;
 		}
 	}
+
+	return result;
 }

src/event/PollGroupPoll.hxx

@@ -50,7 +50,7 @@ public:
 	PollGroupPoll() noexcept;
 	~PollGroupPoll() noexcept;
 
-	void ReadEvents(PollResultGeneric &result, int timeout_ms) noexcept;
+	PollResultGeneric ReadEvents(int timeout_ms) noexcept;
 	bool Add(int fd, unsigned events, void *obj) noexcept;
 	bool Modify(int fd, unsigned events, void *obj) noexcept;
 	bool Remove(int fd) noexcept;

src/event/PollGroupWinSelect.cxx

@@ -115,9 +115,8 @@ PollGroupWinSelect::Remove(SOCKET fd) noexcept
 	return true;
 }
 
-void
-PollGroupWinSelect::ReadEvents(PollResultGeneric &result,
-			       int timeout_ms) noexcept
+PollResultGeneric
+PollGroupWinSelect::ReadEvents(int timeout_ms) noexcept
 {
 	bool use_sleep = event_set[EVENT_READ].IsEmpty() &&
 			 event_set[EVENT_WRITE].IsEmpty();
@@ -143,8 +142,9 @@ PollGroupWinSelect::ReadEvents(PollResultGeneric &result,
 			 except_set.GetPtr(),
 			 timeout_ms < 0 ? nullptr : &tv);
 
+	PollResultGeneric result;
 	if (ret == 0 || ret == SOCKET_ERROR)
-		return;
+		return result;
 
 	for (const auto i : read_set)
 		items[i].events |= READ;
@@ -160,4 +160,6 @@ PollGroupWinSelect::ReadEvents(PollResultGeneric &result,
 			result.Add(i.second.events, i.second.obj);
 			i.second.events = 0;
 		}
+
+	return result;
 }

src/event/PollGroupWinSelect.hxx

@@ -122,7 +122,7 @@ public:
 	PollGroupWinSelect() noexcept;
 	~PollGroupWinSelect() noexcept;
 
-	void ReadEvents(PollResultGeneric &result, int timeout_ms) noexcept;
+	PollResultGeneric ReadEvents(int timeout_ms) noexcept;
 	bool Add(SOCKET fd, unsigned events, void *obj) noexcept;
 	bool Modify(SOCKET fd, unsigned events, void *obj) noexcept;
 	bool Remove(SOCKET fd) noexcept;