event/SocketMonitor: add assertions

src/event/SocketMonitor.cxx

@@ -138,6 +138,8 @@ SocketMonitor::Close()
 SocketMonitor::ssize_t
 SocketMonitor::Read(void *data, size_t length)
 {
+	assert(IsDefined());
+
 	int flags = 0;
 #ifdef MSG_DONTWAIT
 	flags |= MSG_DONTWAIT;
@@ -149,6 +151,8 @@ SocketMonitor::Read(void *data, size_t length)
 SocketMonitor::ssize_t
 SocketMonitor::Write(const void *data, size_t length)
 {
+	assert(IsDefined());
+
 	int flags = 0;
 #ifdef MSG_NOSIGNAL
 	flags |= MSG_NOSIGNAL;
@@ -163,5 +167,7 @@ SocketMonitor::Write(const void *data, size_t length)
 void
 SocketMonitor::CommitEventFlags()
 {
+	assert(IsDefined());
+
 	loop.WakeUp();
 }

src/event/SocketMonitor.hxx

@@ -87,6 +87,8 @@ public:
 	void Close();
 
 	void Schedule(unsigned flags) {
+		assert(IsDefined());
+
 		poll.events = flags;
 		poll.revents &= flags;
 		CommitEventFlags();
@@ -137,10 +139,14 @@ private:
 	void CommitEventFlags();
 
 	bool Check() const {
+		assert(IsDefined());
+
 		return (poll.revents & poll.events) != 0;
 	}
 
 	void Dispatch() {
+		assert(IsDefined());
+
 		OnSocketReady(poll.revents & poll.events);
 	}
 };