Fix the closure of UNIX domain UDP socket.

examples/unix_udp_test/unix_udp_test.cpp

@@ -2,9 +2,6 @@
 #include <iostream>
 
 //configuration
-#define ASCS_DELAY_CLOSE 1 //this demo not used object pool and doesn't need life cycle management,
-						   //so, define this to avoid hooks for async call (and slightly improve efficiency),
-						   //any value which is bigger than zero is okay.
 //configuration
 
 #include <ascs/ext/udp.h>

include/ascs/socket.h

@@ -385,7 +385,7 @@ protected:
 #endif
 
 	//subclass notify shutdown event
-	bool close()
+	bool close(bool use_close = false) //if not use_close, shutdown (both direction) will be used
 	{
 		scope_atomic_lock lock(start_atomic);
 		while (!lock.locked())
@@ -405,7 +405,7 @@ protected:
 		if (lowest_layer().is_open())
 		{
 			asio::error_code ec;
-			lowest_layer().shutdown(Family::socket::shutdown_both, ec);
+			use_close ? lowest_layer().close(ec) : lowest_layer().shutdown(Family::socket::shutdown_both, ec);
 
 			stat.break_time = time(nullptr);
 		}

include/ascs/udp/socket.h

@@ -90,7 +90,7 @@ public:
 	const typename Family::endpoint& get_peer_addr() const {return peer_addr;}
 
 	void disconnect() {force_shutdown();}
-	void force_shutdown() {show_info("link:", "been shutting down."); this->dispatch_strand(rw_strand, [this]() {this->shutdown();});}
+	virtual void force_shutdown() {shutdown();}
 	void graceful_shutdown() {force_shutdown();}
 
 	std::string endpoint_to_string(const asio::ip::udp::endpoint& ep) const {return ep.address().to_string() + ':' + std::to_string(ep.port());}
@@ -166,6 +166,8 @@ protected:
 	Matrix* get_matrix() {return matrix;}
 	const Matrix* get_matrix() const {return matrix;}
 
+	void shutdown(bool use_close = false) {show_info("link:", "been shutting down."); this->dispatch_strand(rw_strand, ASCS_COPY_ALL_AND_THIS() {this->close(use_close);});}
+
 	virtual bool bind(const typename Family::endpoint& local_addr) {return true;}
 
 	virtual bool do_start()
@@ -224,8 +226,6 @@ private:
 	using super::do_direct_sync_send_msg;
 #endif
 
-	void shutdown() {close();}
-
 	virtual void do_recv_msg()
 	{
 #ifdef ASCS_PASSIVE_RECV
@@ -405,6 +405,8 @@ public:
 	unix_socket_base(asio::io_context& io_context_) : super(io_context_) {}
 	unix_socket_base(Matrix& matrix_) : super(matrix_) {}
 
+	virtual void force_shutdown() {this->shutdown(true);}
+
 protected:
 	virtual bool bind(const asio::local::datagram_protocol::endpoint& local_addr)
 	{