[glib/wip/silviol/gsocket_flags: 2/2] Partially revert "GSocket: Fix race conditions on Win32 if multiple threads are waiting on condition

[Silvio Lazzeretti <silviol src gnome org>]

commit 4c3b268eb2db2bf7c2f7e48eaf2f2f5ae6505efa
Author: Silvio Lazzeretti <silviola amazon com>
Date:   Tue Dec 11 14:15:24 2018 +0100

    Partially revert "GSocket: Fix race conditions on Win32 if multiple threads are waiting on conditions for 
the same socket"
    
    This partially reverts commit 799f8dcd46fb40ea206d9f1b5468db62cc00a72e.
    This patch seems to break the writability status of the server socket: once
    somebody writes to it with success, then it reports it is not writable
    anymore. Also, when the client socket has the flag FD_CONNECT set once,
    it is never cleared and then it reports it is always writable, also when
    it is not.

 gio/gsocket.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)
---
diff --git a/gio/gsocket.c b/gio/gsocket.c
index 859e807cb..46d2e1ae1 100644
--- a/gio/gsocket.c
+++ b/gio/gsocket.c
@@ -2711,8 +2711,6 @@ g_socket_accept (GSocket       *socket,
 
   while (TRUE)
     {
-      win32_unset_event_mask (socket, FD_ACCEPT);
-
       if ((ret = accept (socket->priv->fd, NULL, 0)) < 0)
        {
          int errsv = get_socket_errno ();
@@ -2727,6 +2725,8 @@ g_socket_accept (GSocket       *socket,
               errsv == EAGAIN)
 #endif
             {
+              win32_unset_event_mask(socket, FD_ACCEPT);
+
               if (socket->priv->blocking)
                 {
                   if (!g_socket_condition_wait (socket,
@@ -2743,6 +2743,8 @@ g_socket_accept (GSocket       *socket,
       break;
     }
 
+  win32_unset_event_mask(socket, FD_ACCEPT);
+
 #ifdef G_OS_WIN32
   {
     /* The socket inherits the accepting sockets event mask and even object,
@@ -2834,8 +2836,6 @@ g_socket_connect (GSocket         *socket,
 
   while (1)
     {
-      win32_unset_event_mask (socket, FD_CONNECT);
-
       if (connect (socket->priv->fd, &buffer.sa,
                   g_socket_address_get_native_size (address)) < 0)
        {
@@ -2850,6 +2850,8 @@ g_socket_connect (GSocket         *socket,
          if (errsv == WSAEWOULDBLOCK)
 #endif
            {
+          win32_unset_event_mask(socket, FD_CONNECT);
+
              if (socket->priv->blocking)
                {
                  if (g_socket_condition_wait (socket, G_IO_OUT, cancellable, error))
@@ -2875,6 +2877,8 @@ g_socket_connect (GSocket         *socket,
       break;
     }
 
+  win32_unset_event_mask(socket, FD_CONNECT);
+
   socket->priv->connected_read = TRUE;
   socket->priv->connected_write = TRUE;
 
@@ -3068,8 +3072,6 @@ g_socket_receive_with_timeout (GSocket       *socket,
 
   while (1)
     {
-      win32_unset_event_mask (socket, FD_READ);
-
       if ((ret = recv (socket->priv->fd, buffer, size, 0)) < 0)
        {
          int errsv = get_socket_errno ();
@@ -3084,6 +3086,8 @@ g_socket_receive_with_timeout (GSocket       *socket,
               errsv == EAGAIN)
 #endif
             {
+              win32_unset_event_mask(socket, FD_READ);
+
               if (timeout != 0)
                 {
                   if (!block_on_timeout (socket, G_IO_IN, timeout, start_time,
@@ -3094,10 +3098,14 @@ g_socket_receive_with_timeout (GSocket       *socket,
                 }
             }
 
+         win32_unset_event_mask(socket, FD_READ);
+
          socket_set_error_lazy (error, errsv, _("Error receiving data: %s"));
          return -1;
        }
 
+      win32_unset_event_mask(socket, FD_READ);
+
       break;
     }
 
@@ -3263,8 +3271,6 @@ g_socket_send_with_timeout (GSocket       *socket,
 
   while (1)
     {
-      win32_unset_event_mask (socket, FD_WRITE);
-
       if ((ret = send (socket->priv->fd, (const char *)buffer, size, G_SOCKET_DEFAULT_SEND_FLAGS)) < 0)
        {
          int errsv = get_socket_errno ();
@@ -3279,6 +3285,8 @@ g_socket_send_with_timeout (GSocket       *socket,
               errsv == EAGAIN)
 #endif
             {
+              win32_unset_event_mask(socket, FD_WRITE);
+
               if (timeout != 0)
                 {
                   if (!block_on_timeout (socket, G_IO_OUT, timeout, start_time,
@@ -4755,8 +4763,6 @@ g_socket_send_message_with_timeout (GSocket                *socket,
 
     while (1)
       {
-        win32_unset_event_mask (socket, FD_WRITE);
-
        if (address)
          result = WSASendTo (socket->priv->fd,
                              bufs, num_vectors,
@@ -4778,6 +4784,8 @@ g_socket_send_message_with_timeout (GSocket                *socket,
 
            if (errsv == WSAEWOULDBLOCK)
               {
+                win32_unset_event_mask(socket, FD_WRITE);
+
                 if (timeout != 0)
                   {
                     if (!block_on_timeout (socket, G_IO_OUT, timeout,
@@ -5225,8 +5233,6 @@ g_socket_receive_message_with_timeout (GSocket                 *socket,
     /* do it */
     while (1)
       {
-        win32_unset_event_mask (socket, FD_READ);
-
        addrlen = sizeof addr;
        if (address)
          result = WSARecvFrom (socket->priv->fd,
@@ -5248,6 +5254,8 @@ g_socket_receive_message_with_timeout (GSocket                 *socket,
 
             if (errsv == WSAEWOULDBLOCK)
               {
+                win32_unset_event_mask(socket, FD_READ);
+
                 if (timeout != 0)
                   {
                     if (!block_on_timeout (socket, G_IO_IN, timeout,
@@ -5261,6 +5269,7 @@ g_socket_receive_message_with_timeout (GSocket                 *socket,
            socket_set_error_lazy (error, errsv, _("Error receiving message: %s"));
            return -1;
          }
+    win32_unset_event_mask(socket, FD_READ);
        break;
       }