Extend and rename wxSocketImpl::UnblockAndRegisterWithEventLoop()

In addition to unblocking and registering the socket, also support using
this function to make the socket blocking and unregistering it from the
event loop, if its flags include wxSOCKET_BLOCK.

This was already half-done by wxMSW, which took wxSOCKET_BLOCK presence
into account in its implementation, but not by the Unix implementation.
Now do it under all platforms, as this will be useful for switching a
previously non-blocking socket to blocking mode.

Finally, rename the function to better reflect what it really does.

See #12886.

include/wx/msw/private/sockmsw.h

@@ -60,7 +60,7 @@ public:
 private:
     virtual void DoClose() wxOVERRIDE;
 
-    virtual void UnblockAndRegisterWithEventLoop() wxOVERRIDE
+    virtual void UpdateBlockingState() wxOVERRIDE
     {
         if ( GetSocketFlags() & wxSOCKET_BLOCK )
         {
@@ -74,6 +74,9 @@ private:
             // would result in data races and other unpleasantness.
             wxIoctlSocketArg_t trueArg = 1;
             ioctlsocket(m_fd, FIONBIO, &trueArg);
+
+            // Uninstall it in case it was installed before.
+            wxSocketManager::Get()->Uninstall_Callback(this);
         }
         else
         {

include/wx/private/socket.h

@@ -323,9 +323,11 @@ private:
     // called by Close() if we have a valid m_fd
     virtual void DoClose() = 0;
 
-    // put this socket into non-blocking mode and enable monitoring this socket
+    // Update the socket depending on the presence or absence of wxSOCKET_BLOCK
-    // as part of the event loop
+    // in GetSocketFlags(): if it's present, make the socket blocking and
-    virtual void UnblockAndRegisterWithEventLoop() = 0;
+    // ensure that we don't get any asynchronous event for it, otherwise put
+    // it into non-blocking mode and enable monitoring it in the event loop.
+    virtual void UpdateBlockingState() = 0;
 
     // check that the socket wasn't created yet and that the given address
     // (either m_local or m_peer depending on the socket kind) is valid and
@@ -350,7 +352,7 @@ private:
     }
 
     // apply the options to the (just created) socket and register it with the
-    // event loop by calling UnblockAndRegisterWithEventLoop()
+    // event loop by calling UpdateBlockingState()
     void PostCreation();
 
     // update local address after binding/connecting

include/wx/unix/private/sockunix.h

@@ -73,12 +73,13 @@ private:
         wxCloseSocket(m_fd);
     }
 
-    virtual void UnblockAndRegisterWithEventLoop() wxOVERRIDE
+    virtual void UpdateBlockingState() wxOVERRIDE
     {
-        int trueArg = 1;
+        // Make this int and not bool to allow passing it to ioctl().
-        ioctl(m_fd, FIONBIO, &trueArg);
+        const int isBlocking = (GetSocketFlags() & wxSOCKET_BLOCK) != 0;
+        ioctl(m_fd, FIONBIO, &isBlocking);
 
-        EnableEvents();
+        DoEnableEvents(wxSOCKET_INPUT_FLAG | wxSOCKET_OUTPUT_FLAG, !isBlocking);
     }
 
     // enable or disable notifications for socket input/output events

src/common/socket.cpp

@@ -366,9 +366,9 @@ void wxSocketImpl::PostCreation()
     if ( m_initialSendBufferSize >= 0 )
         SetSocketOption(SO_SNDBUF, m_initialSendBufferSize);
 
-    // we always put our sockets in unblocked mode and handle blocking
+    // Call this to put our socket in unblocked mode: we'll handle blocking
     // ourselves in DoRead/Write() if wxSOCKET_WAITALL is specified
-    UnblockAndRegisterWithEventLoop();
+    UpdateBlockingState();
 }
 
 wxSocketError wxSocketImpl::UpdateLocalAddress()
@@ -551,7 +551,7 @@ wxSocketImpl *wxSocketImpl::Accept(wxSocketBase& wxsocket)
     sock->m_fd = fd;
     sock->m_peer = wxSockAddressImpl(from.addr, fromlen);
 
-    sock->UnblockAndRegisterWithEventLoop();
+    sock->UpdateBlockingState();
 
     return sock;
 }