event/SocketMonitor: refactor to SocketEvent

Similar to commits 1686f4e857 and
30a5dd267b

src/lib/nfs/Connection.cxx

@@ -183,17 +183,17 @@ NfsConnection::CancellableCallback::Callback(int err,
 static constexpr unsigned
 libnfs_to_events(int i) noexcept
 {
-	return ((i & POLLIN) ? SocketMonitor::READ : 0) |
-		((i & POLLOUT) ? SocketMonitor::WRITE : 0);
+	return ((i & POLLIN) ? SocketEvent::READ : 0) |
+		((i & POLLOUT) ? SocketEvent::WRITE : 0);
 }
 
 static constexpr int
 events_to_libnfs(unsigned i) noexcept
 {
-	return ((i & SocketMonitor::READ) ? POLLIN : 0) |
-		((i & SocketMonitor::WRITE) ? POLLOUT : 0) |
-		((i & SocketMonitor::HANGUP) ? POLLHUP : 0) |
-		((i & SocketMonitor::ERROR) ? POLLERR : 0);
+	return ((i & SocketEvent::READ) ? POLLIN : 0) |
+		((i & SocketEvent::WRITE) ? POLLOUT : 0) |
+		((i & SocketEvent::HANGUP) ? POLLHUP : 0) |
+		((i & SocketEvent::ERROR) ? POLLERR : 0);
 }
 
 NfsConnection::~NfsConnection() noexcept
@@ -403,8 +403,8 @@ NfsConnection::DestroyContext() noexcept
 	   new leases */
 	defer_new_lease.Cancel();
 
-	if (SocketMonitor::IsDefined())
-		SocketMonitor::Steal();
+	if (socket_event.IsDefined())
+		socket_event.Steal();
 
 	callbacks.ForEach([](CancellableCallback &c){
 			c.PrepareDestroyContext();
@@ -434,25 +434,25 @@ NfsConnection::ScheduleSocket() noexcept
 
 	const int which_events = nfs_which_events(context);
 
-	if (which_events == POLLOUT && SocketMonitor::IsDefined())
+	if (which_events == POLLOUT && socket_event.IsDefined())
 		/* kludge: if libnfs asks only for POLLOUT, it means
 		   that it is currently waiting for the connect() to
 		   finish - rpc_reconnect_requeue() may have been
 		   called from inside nfs_service(); we must now
 		   unregister the old socket and register the new one
 		   instead */
-		SocketMonitor::Steal();
+		socket_event.Steal();
 
-	if (!SocketMonitor::IsDefined()) {
+	if (!socket_event.IsDefined()) {
 		SocketDescriptor _fd(nfs_get_fd(context));
 		if (!_fd.IsDefined())
 			return;
 
 		_fd.EnableCloseOnExec();
-		SocketMonitor::Open(_fd);
+		socket_event.Open(_fd);
 	}
 
-	SocketMonitor::Schedule(libnfs_to_events(which_events));
+	socket_event.Schedule(libnfs_to_events(which_events));
 }
 
 inline int
@@ -480,16 +480,14 @@ NfsConnection::Service(unsigned flags) noexcept
 	return result;
 }
 
-bool
+void
 NfsConnection::OnSocketReady(unsigned flags) noexcept
 {
 	assert(GetEventLoop().IsInside());
 	assert(deferred_close.empty());
 
-	bool closed = false;
-
 	const bool was_mounted = mount_finished;
-	if (!mount_finished || (flags & SocketMonitor::HANGUP) != 0)
+	if (!mount_finished || (flags & SocketEvent::HANGUP) != 0)
 		/* until the mount is finished, the NFS client may use
 		   various sockets, therefore we unregister and
 		   re-register it each time */
@@ -497,7 +495,7 @@ NfsConnection::OnSocketReady(unsigned flags) noexcept
 		   which is a sure sign that libnfs will close the
 		   socket, which can lead to a race condition if
 		   epoll_ctl() is called later */
-		SocketMonitor::Steal();
+		socket_event.Steal();
 
 	const int result = Service(flags);
 
@@ -509,7 +507,6 @@ NfsConnection::OnSocketReady(unsigned flags) noexcept
 	if (!was_mounted && mount_finished) {
 		if (postponed_mount_error) {
 			DestroyContext();
-			closed = true;
 			BroadcastMountError(std::move(postponed_mount_error));
 		} else if (result == 0)
 			BroadcastMountSuccess();
@@ -521,7 +518,6 @@ NfsConnection::OnSocketReady(unsigned flags) noexcept
 		BroadcastError(std::make_exception_ptr(e));
 
 		DestroyContext();
-		closed = true;
 	} else if (nfs_get_fd(context) < 0) {
 		/* this happens when rpc_reconnect_requeue() is called
 		   after the connection broke, but autoreconnect was
@@ -535,7 +531,6 @@ NfsConnection::OnSocketReady(unsigned flags) noexcept
 		BroadcastError(std::make_exception_ptr(e));
 
 		DestroyContext();
-		closed = true;
 	}
 
 	assert(context == nullptr || nfs_get_fd(context) >= 0);
@@ -547,8 +542,6 @@ NfsConnection::OnSocketReady(unsigned flags) noexcept
 
 	if (context != nullptr)
 		ScheduleSocket();
-
-	return !closed;
 }
 
 inline void

src/lib/nfs/Connection.hxx

@@ -21,7 +21,7 @@
 #define MPD_NFS_CONNECTION_HXX
 
 #include "Cancellable.hxx"
-#include "event/SocketMonitor.hxx"
+#include "event/SocketEvent.hxx"
 #include "event/TimerEvent.hxx"
 #include "event/DeferEvent.hxx"
 #include "util/Compiler.h"
@@ -40,7 +40,7 @@ class NfsLease;
 /**
  * An asynchronous connection to a NFS server.
  */
-class NfsConnection : SocketMonitor {
+class NfsConnection {
 	class CancellableCallback : public CancellablePointer<NfsCallback> {
 		NfsConnection &connection;
 
@@ -93,6 +93,7 @@ class NfsConnection : SocketMonitor {
 		void Callback(int err, void *data) noexcept;
 	};
 
+	SocketEvent socket_event;
 	DeferEvent defer_new_lease;
 	TimerEvent mount_timeout_event;
 
@@ -141,7 +142,7 @@ public:
 	gcc_nonnull_all
 	NfsConnection(EventLoop &_loop,
 		      const char *_server, const char *_export_name) noexcept
-		:SocketMonitor(_loop),
+		:socket_event(_loop, BIND_THIS_METHOD(OnSocketReady)),
 		 defer_new_lease(_loop, BIND_THIS_METHOD(RunDeferred)),
 		 mount_timeout_event(_loop, BIND_THIS_METHOD(OnMountTimeout)),
 		 server(_server), export_name(_export_name),
@@ -152,6 +153,10 @@ public:
 	 */
 	~NfsConnection() noexcept;
 
+	auto &GetEventLoop() const noexcept {
+		return socket_event.GetEventLoop();
+	}
+
 	gcc_pure
 	const char *GetServer() const noexcept {
 		return server.c_str();
@@ -162,8 +167,6 @@ public:
 		return export_name.c_str();
 	}
 
-	using SocketMonitor::GetEventLoop;
-
 	/**
 	 * Ensure that the connection is established.  The connection
 	 * is kept up while at least one #NfsLease is registered.
@@ -231,8 +234,7 @@ private:
 	 */
 	int Service(unsigned flags) noexcept;
 
-	/* virtual methods from SocketMonitor */
-	bool OnSocketReady(unsigned flags) noexcept override;
+	void OnSocketReady(unsigned flags) noexcept;
 
 	/* callback for #mount_timeout_event */
 	void OnMountTimeout() noexcept;