BUG#13431369 - MAIN.VARIABLES-NOTEMBEDDED CRASHES THE SERVER SPORADICALLY ON WINDOWS

On shutdown(), Windows can drop traffic still queued for sending even if that
wasn't specifically requested. As a result, fatal errors (those after
signaling which the server will drop the connection) were sometimes only
seen as "connection lost" on the client side, because the server-side
shutdown() erraneously discarded the correct error message before sending
it.

If on Windows, we now use the Windows API to access the (non-broken) equivalent
of shutdown().

Backport from trunk

include/violite.h

@@ -59,6 +59,9 @@ Vio* vio_new_win32shared_memory(HANDLE handle_file_map,
 #define HANDLE void *
 #endif /* __WIN__ */
 
+/* backport from 5.6 where it is part of PSI, not vio_*() */
+int	mysql_socket_shutdown(my_socket mysql_socket, int how);
+
 void	vio_delete(Vio* vio);
 int	vio_close(Vio* vio);
 void    vio_reset(Vio* vio, enum enum_vio_type type,

sql/mysqld.cc

@@ -1045,7 +1045,7 @@ static void close_connections(void)
   {
     if (ip_sock != INVALID_SOCKET)
     {
-      (void) shutdown(ip_sock, SHUT_RDWR);
+      (void) mysql_socket_shutdown(ip_sock, SHUT_RDWR);
       (void) closesocket(ip_sock);
       ip_sock= INVALID_SOCKET;
     }
@@ -1077,7 +1077,7 @@ static void close_connections(void)
 #ifdef HAVE_SYS_UN_H
   if (unix_sock != INVALID_SOCKET)
   {
-    (void) shutdown(unix_sock, SHUT_RDWR);
+    (void) mysql_socket_shutdown(unix_sock, SHUT_RDWR);
     (void) closesocket(unix_sock);
     (void) unlink(mysqld_unix_port);
     unix_sock= INVALID_SOCKET;
@@ -1184,14 +1184,14 @@ static void close_server_sock()
   {
     ip_sock=INVALID_SOCKET;
     DBUG_PRINT("info",("calling shutdown on TCP/IP socket"));
-    (void) shutdown(tmp_sock, SHUT_RDWR);
+    (void) mysql_socket_shutdown(tmp_sock, SHUT_RDWR);
   }
   tmp_sock=unix_sock;
   if (tmp_sock != INVALID_SOCKET)
   {
     unix_sock=INVALID_SOCKET;
     DBUG_PRINT("info",("calling shutdown on unix socket"));
-    (void) shutdown(tmp_sock, SHUT_RDWR);
+    (void) mysql_socket_shutdown(tmp_sock, SHUT_RDWR);
     (void) unlink(mysqld_unix_port);
   }
   DBUG_VOID_RETURN;
@@ -5191,7 +5191,7 @@ void handle_connections_sockets()
 	  if (req.sink)
 	    ((void (*)(int))req.sink)(req.fd);
 
-	  (void) shutdown(new_sock, SHUT_RDWR);
+	  (void) mysql_socket_shutdown(new_sock, SHUT_RDWR);
 	  (void) closesocket(new_sock);
 	  continue;
 	}
@@ -5207,7 +5207,7 @@ void handle_connections_sockets()
                   (SOCKET_SIZE_TYPE *)&dummyLen) < 0  )
       {
 	sql_perror("Error on new connection socket");
-	(void) shutdown(new_sock, SHUT_RDWR);
+	(void) mysql_socket_shutdown(new_sock, SHUT_RDWR);
 	(void) closesocket(new_sock);
 	continue;
       }
@@ -5219,7 +5219,7 @@ void handle_connections_sockets()
 
     if (!(thd= new THD))
     {
-      (void) shutdown(new_sock, SHUT_RDWR);
+      (void) mysql_socket_shutdown(new_sock, SHUT_RDWR);
       (void) closesocket(new_sock);
       continue;
     }
@@ -5238,7 +5238,7 @@ void handle_connections_sockets()
         vio_delete(vio_tmp);
       else
       {
-	(void) shutdown(new_sock, SHUT_RDWR);
+	(void) mysql_socket_shutdown(new_sock, SHUT_RDWR);
 	(void) closesocket(new_sock);
       }
       delete thd;

vio/viosocket.c

@@ -23,6 +23,11 @@
   the file descriptior.
 */
 
+#ifdef __WIN__
+  #include <winsock2.h>
+  #include <MSWSock.h>
+  #pragma comment(lib, "ws2_32.lib")
+#endif
 #include "vio_priv.h"
 
 #ifdef FIONREAD_IN_SYS_FILIO
@@ -277,6 +282,37 @@ vio_was_interrupted(Vio *vio __attribute__((unused)))
 }
 
 
+int
+mysql_socket_shutdown(my_socket mysql_socket, int how)
+{
+  int result;
+
+#ifdef __WIN__
+  static LPFN_DISCONNECTEX DisconnectEx = NULL;
+  if (DisconnectEx == NULL)
+  {
+    DWORD dwBytesReturned;
+    GUID guidDisconnectEx = WSAID_DISCONNECTEX;
+    WSAIoctl(mysql_socket, SIO_GET_EXTENSION_FUNCTION_POINTER,
+             &guidDisconnectEx, sizeof(GUID),
+             &DisconnectEx, sizeof(DisconnectEx), 
+             &dwBytesReturned, NULL, NULL);
+  }
+#endif
+
+  /* Non instrumented code */
+#ifdef __WIN__
+  if (DisconnectEx)
+    result= (DisconnectEx(mysql_socket, (LPOVERLAPPED) NULL,
+                          (DWORD) 0, (DWORD) 0) == TRUE) ? 0 : -1;
+  else
+#endif
+    result= shutdown(mysql_socket, how);
+
+  return result;
+}
+
+
 int vio_close(Vio * vio)
 {
   int r=0;
@@ -289,7 +325,7 @@ int vio_close(Vio * vio)
       vio->type == VIO_TYPE_SSL);
 
     DBUG_ASSERT(vio->sd >= 0);
-    if (shutdown(vio->sd, SHUT_RDWR))
+    if (mysql_socket_shutdown(vio->sd, SHUT_RDWR))
       r= -1;
     if (closesocket(vio->sd))
       r= -1;