net: encapsulate fdwatch backend metadata

src/db/NetBase.cpp

@@ -37,6 +37,10 @@ bool CNetPoller::Create()
 		return false;
 	}
 
+	sys_log(0, "[STARTUP] fdwatch backend=%s descriptor_limit=%d",
+		fdwatch_backend_name(fdwatch_get_backend(m_fdWatcher)),
+		fdwatch_get_descriptor_limit(m_fdWatcher));
+
 	return true;
 }
 

src/game/main.cpp

@@ -602,6 +602,16 @@ int start(int argc, char **argv)
 	
 	main_fdw = fdwatch_new(4096);
 
+	if (!main_fdw)
+	{
+		sys_err("fdwatch_new failed");
+		return 0;
+	}
+
+	sys_log(0, "[STARTUP] fdwatch backend=%s descriptor_limit=%d",
+		fdwatch_backend_name(fdwatch_get_backend(main_fdw)),
+		fdwatch_get_descriptor_limit(main_fdw));
+
 	if ((tcp_socket = socket_tcp_bind(g_szPublicIP, mother_port)) == INVALID_SOCKET)
 	{
 		perror("socket_tcp_bind: tcp_socket");

src/libthecore/fdwatch.h

@@ -1,74 +1,22 @@
 #pragma once
 
-#ifndef __USE_SELECT__
+typedef struct fdwatch		FDWATCH;
+typedef struct fdwatch *	LPFDWATCH;
 
-    typedef struct fdwatch		FDWATCH;
-    typedef struct fdwatch *	LPFDWATCH;
-
-    enum EFdwatch
-    {
+enum EFdwatch
+{
 	FDW_NONE			= 0,
 	FDW_READ			= 1,
 	FDW_WRITE			= 2,
 	FDW_WRITE_ONESHOT	= 4,
 	FDW_EOF				= 8,
-    };
-
-    typedef struct kevent	KEVENT;
-    typedef struct kevent *	LPKEVENT;
-    typedef int				KQUEUE;
-
-    struct fdwatch
-    {
-		KQUEUE		kq;
-
-		int		nfiles;
-
-		LPKEVENT	kqevents;
-		int		nkqevents;
-
-		LPKEVENT	kqrevents;
-		int *		fd_event_idx;
-
-		void **		fd_data;
-		int *		fd_rw;
-    };
-
-#else
-
-    typedef struct fdwatch		FDWATCH;
-    typedef struct fdwatch *	LPFDWATCH;
-
-    enum EFdwatch
-    {
-		FDW_NONE			= 0,
-		FDW_READ			= 1,
-		FDW_WRITE			= 2,
-		FDW_WRITE_ONESHOT	= 4,
-		FDW_EOF				= 8,
-    };
-
-    struct fdwatch
-    {
-		fd_set rfd_set;
-		fd_set wfd_set;
-
-		socket_t* select_fds;
-		int* select_rfdidx;
-
-		int nselect_fds;
-
-		fd_set working_rfd_set;
-		fd_set working_wfd_set;
-
-		int nfiles;
-
-		void** fd_data;
-		int* fd_rw;
-    };
-
-#endif // WIN32
+};
 
+enum EFdwatchBackend
+{
+	FDWATCH_BACKEND_KQUEUE = 0,
+	FDWATCH_BACKEND_SELECT = 1,
+};
 
 LPFDWATCH		fdwatch_new(int nfiles);
 void			fdwatch_clear_fd(LPFDWATCH fdw, socket_t fd);
@@ -82,4 +30,6 @@ void *		fdwatch_get_client_data(LPFDWATCH fdw, unsigned int event_idx);
 void			fdwatch_del_fd(LPFDWATCH fdw, socket_t fd);
 int				fdwatch_get_buffer_size(LPFDWATCH fdw, socket_t fd);
 int				fdwatch_get_ident(LPFDWATCH fdw, unsigned int event_idx);
-
+EFdwatchBackend	fdwatch_get_backend(LPFDWATCH fdw);
+const char *	fdwatch_backend_name(EFdwatchBackend backend);
+int				fdwatch_get_descriptor_limit(LPFDWATCH fdw);

tests/smoke_auth.cpp

@@ -1,3 +1,4 @@
+#include <algorithm>
 #include <array>
 #include <cstdint>
 #include <cstring>
@@ -289,6 +290,24 @@ void TestFdwatchReadAndOneshotWrite()
 	close(sockets[0]);
 	close(sockets[1]);
 }
+
+void TestFdwatchBackendMetadata()
+{
+	LPFDWATCH fdw = fdwatch_new(4096);
+	Expect(fdw != nullptr, "fdwatch_new for backend metadata failed");
+
+#ifdef __USE_SELECT__
+	Expect(fdwatch_get_backend(fdw) == FDWATCH_BACKEND_SELECT, "Expected select backend");
+	Expect(std::strcmp(fdwatch_backend_name(fdwatch_get_backend(fdw)), "select") == 0, "Unexpected select backend name");
+	Expect(fdwatch_get_descriptor_limit(fdw) == std::min(4096, static_cast<int>(FD_SETSIZE)), "Unexpected select descriptor limit");
+#else
+	Expect(fdwatch_get_backend(fdw) == FDWATCH_BACKEND_KQUEUE, "Expected kqueue backend");
+	Expect(std::strcmp(fdwatch_backend_name(fdwatch_get_backend(fdw)), "kqueue") == 0, "Unexpected kqueue backend name");
+	Expect(fdwatch_get_descriptor_limit(fdw) == 4096, "Unexpected kqueue descriptor limit");
+#endif
+
+	fdwatch_delete(fdw);
+}
 }
 
 int main()
@@ -298,6 +317,7 @@ int main()
 		TestPacketLayouts();
 		TestSecureCipherRoundTrip();
 		TestSocketAuthWireFlow();
+		TestFdwatchBackendMetadata();
 		TestFdwatchReadAndOneshotWrite();
 		std::cout << "metin smoke tests passed\n";
 		return 0;