X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/04e1eb03b0daca6fb94a87c972da527c25db032c..8472511246c9160d4ff40ab86f635fc67c10b54a:/src/common/socket.cpp

diff --git a/src/common/socket.cpp b/src/common/socket.cpp
index 1cfac04844..545a68d54f 100644
--- a/src/common/socket.cpp
+++ b/src/common/socket.cpp
@@ -1,60 +1,125 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:       socket.cpp
+// Name:       src/common/socket.cpp
 // Purpose:    Socket handler classes
 // Authors:    Guilhem Lavaux, Guillermo Rodriguez Garcia
 // Created:    April 1997
 // Copyright:  (C) 1999-1997, Guilhem Lavaux
-//             (C) 2000-1999, Guillermo Rodriguez Garcia
+//             (C) 1999-2000, Guillermo Rodriguez Garcia
+//             (C) 2008 Vadim Zeitlin
 // RCS_ID:     $Id$
-// License:    see wxWindows license
+// Licence:    wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "socket.h"
-#endif
+// ==========================================================================
+// Declarations
+// ==========================================================================
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-#pragma hdrstop
+    #pragma hdrstop
 #endif
 
 #if wxUSE_SOCKETS
 
-/////////////////////////////////////////////////////////////////////////////
-// wxWindows headers
-/////////////////////////////////////////////////////////////////////////////
-
-#include "wx/app.h"
-#include "wx/defs.h"
-#include "wx/object.h"
-#include "wx/string.h"
-#include "wx/timer.h"
-#include "wx/utils.h"
-#include "wx/module.h"
-#include "wx/log.h"
-#include "wx/intl.h"
+#include "wx/socket.h"
 
-/////////////////////////////////////////////////////////////////////////////
-// wxSocket headers
-/////////////////////////////////////////////////////////////////////////////
+#ifndef WX_PRECOMP
+    #include "wx/object.h"
+    #include "wx/string.h"
+    #include "wx/intl.h"
+    #include "wx/log.h"
+    #include "wx/event.h"
+    #include "wx/app.h"
+    #include "wx/utils.h"
+    #include "wx/timer.h"
+    #include "wx/module.h"
+#endif
 
+#include "wx/apptrait.h"
 #include "wx/sckaddr.h"
-#include "wx/socket.h"
+#include "wx/stopwatch.h"
+#include "wx/thread.h"
+#include "wx/evtloop.h"
+#include "wx/link.h"
+
+#include "wx/private/fd.h"
+#include "wx/private/socket.h"
+
+#ifdef __UNIX__
+    #include <errno.h>
+#endif
+
+// we use MSG_NOSIGNAL to avoid getting SIGPIPE when sending data to a remote
+// host which closed the connection if it is available, otherwise we rely on
+// SO_NOSIGPIPE existency
+//
+// this should cover all the current Unix systems (Windows never sends any
+// signals anyhow) but if we find one that has neither we should explicitly
+// ignore SIGPIPE for it
+// OpenVMS has neither MSG_NOSIGNAL nor SO_NOSIGPIPE. However the socket sample
+// seems to work. Not sure if problems will show up on OpenVMS using sockets.
+#ifdef MSG_NOSIGNAL
+    #define wxSOCKET_MSG_NOSIGNAL MSG_NOSIGNAL
+#else // MSG_NOSIGNAL not available (BSD including OS X)
+    // next best possibility is to use SO_NOSIGPIPE socket option, this covers
+    // BSD systems (including OS X) -- but if we don't have it neither (AIX and
+    // old HP-UX do not), we have to fall back to the old way of simply
+    // disabling SIGPIPE temporarily, so define a class to do it in a safe way
+    #if defined(__UNIX__) && !defined(SO_NOSIGPIPE)
+    extern "C" { typedef void (*wxSigHandler_t)(int); }
+    namespace
+    {
+        class IgnoreSignal
+        {
+        public:
+            // ctor disables the given signal
+            IgnoreSignal(int sig)
+                : m_handler(signal(sig, SIG_IGN)),
+                  m_sig(sig)
+            {
+            }
+
+            // dtor restores the old handler
+            ~IgnoreSignal()
+            {
+                signal(m_sig, m_handler);
+            }
+
+        private:
+            const wxSigHandler_t m_handler;
+            const int m_sig;
+
+            wxDECLARE_NO_COPY_CLASS(IgnoreSignal);
+        };
+    } // anonymous namespace
+
+    #define wxNEEDS_IGNORE_SIGPIPE
+    #endif // Unix without SO_NOSIGPIPE
+
+    #define wxSOCKET_MSG_NOSIGNAL 0
+#endif
+
+// DLL options compatibility check:
+#include "wx/build.h"
+WX_CHECK_BUILD_OPTIONS("wxNet")
+
+// --------------------------------------------------------------------------
+// macros and constants
+// --------------------------------------------------------------------------
+
+// event
+wxDEFINE_EVENT(wxEVT_SOCKET, wxSocketEvent);
 
 // discard buffer
 #define MAX_DISCARD_SIZE (10 * 1024)
 
-// what to do within waits
-#define PROCESS_EVENTS() wxYield()
-
-// use wxPostEvent or not
-#define EXPERIMENTAL_USE_POST 1
+#define wxTRACE_Socket wxT("wxSocket")
 
-// --------------------------------------------------------------
-// ClassInfos
-// --------------------------------------------------------------
+// --------------------------------------------------------------------------
+// wxWin macros
+// --------------------------------------------------------------------------
 
 IMPLEMENT_CLASS(wxSocketBase, wxObject)
 IMPLEMENT_CLASS(wxSocketServer, wxSocketBase)
@@ -62,1069 +127,1962 @@ IMPLEMENT_CLASS(wxSocketClient, wxSocketBase)
 IMPLEMENT_CLASS(wxDatagramSocket, wxSocketBase)
 IMPLEMENT_DYNAMIC_CLASS(wxSocketEvent, wxEvent)
 
+// ----------------------------------------------------------------------------
+// private functions
+// ----------------------------------------------------------------------------
+
+namespace
+{
+
+void SetTimeValFromMS(timeval& tv, unsigned long ms)
+{
+    tv.tv_sec  = (ms / 1000);
+    tv.tv_usec = (ms % 1000) * 1000;
+}
+
+} // anonymous namespace
+
+// --------------------------------------------------------------------------
+// private classes
+// --------------------------------------------------------------------------
+
 class wxSocketState : public wxObject
 {
 public:
-  bool                     m_notify_state;
-  GSocketEventFlags        m_neededreq;
-  wxSockFlags              m_flags;
-  wxSocketBase::wxSockCbk  m_cbk;
-  char                    *m_cdata;
+    wxSocketFlags            m_flags;
+    wxSocketEventFlags       m_eventmask;
+    bool                     m_notify;
+    void                    *m_clientData;
+
+public:
+    wxSocketState() : wxObject() {}
+
+    wxDECLARE_NO_COPY_CLASS(wxSocketState);
+};
+
+// wxSocketWaitModeChanger: temporarily change the socket flags affecting its
+// wait mode
+class wxSocketWaitModeChanger
+{
+public:
+    // temporarily set the flags to include the flag value which may be either
+    // wxSOCKET_NOWAIT or wxSOCKET_WAITALL
+    wxSocketWaitModeChanger(wxSocketBase *socket, int flag)
+        : m_socket(socket),
+          m_oldflags(socket->GetFlags())
+
+    {
+        // We can be passed only wxSOCKET_WAITALL{_READ,_WRITE} or
+        // wxSOCKET_NOWAIT{_READ,_WRITE} normally.
+        wxASSERT_MSG( !(flag & wxSOCKET_WAITALL) || !(flag & wxSOCKET_NOWAIT),
+                      "not a wait flag" );
+
+        // preserve wxSOCKET_BLOCK value when switching to wxSOCKET_WAITALL
+        // mode but not when switching to wxSOCKET_NOWAIT as the latter is
+        // incompatible with wxSOCKET_BLOCK
+        if ( flag != wxSOCKET_NOWAIT )
+            flag |= m_oldflags & wxSOCKET_BLOCK;
+
+        socket->SetFlags(flag);
+    }
+
+    ~wxSocketWaitModeChanger()
+    {
+        m_socket->SetFlags(m_oldflags);
+    }
+
+private:
+    wxSocketBase * const m_socket;
+    const int m_oldflags;
+
+    wxDECLARE_NO_COPY_CLASS(wxSocketWaitModeChanger);
+};
+
+// wxSocketRead/WriteGuard are instantiated before starting reading
+// from/writing to the socket
+class wxSocketReadGuard
+{
+public:
+    wxSocketReadGuard(wxSocketBase *socket)
+        : m_socket(socket)
+    {
+        wxASSERT_MSG( !m_socket->m_reading, "read reentrancy?" );
+
+        m_socket->m_reading = true;
+    }
+
+    ~wxSocketReadGuard()
+    {
+        m_socket->m_reading = false;
+
+        // connection could have been lost while reading, in this case calling
+        // ReenableEvents() would assert and is not necessary anyhow
+        wxSocketImpl * const impl = m_socket->m_impl;
+        if ( impl && impl->m_fd != INVALID_SOCKET )
+            impl->ReenableEvents(wxSOCKET_INPUT_FLAG);
+    }
 
+private:
+    wxSocketBase * const m_socket;
+
+    wxDECLARE_NO_COPY_CLASS(wxSocketReadGuard);
+};
+
+class wxSocketWriteGuard
+{
 public:
-  wxSocketState() : wxObject() {}
+    wxSocketWriteGuard(wxSocketBase *socket)
+        : m_socket(socket)
+    {
+        wxASSERT_MSG( !m_socket->m_writing, "write reentrancy?" );
+
+        m_socket->m_writing = true;
+    }
+
+    ~wxSocketWriteGuard()
+    {
+        m_socket->m_writing = false;
+
+        wxSocketImpl * const impl = m_socket->m_impl;
+        if ( impl && impl->m_fd != INVALID_SOCKET )
+            impl->ReenableEvents(wxSOCKET_OUTPUT_FLAG);
+    }
+
+private:
+    wxSocketBase * const m_socket;
+
+    wxDECLARE_NO_COPY_CLASS(wxSocketWriteGuard);
 };
 
-// --------------------------------------------------------------
-// wxSocketBase ctor and dtor
-// --------------------------------------------------------------
+// ============================================================================
+// wxSocketManager
+// ============================================================================
+
+wxSocketManager *wxSocketManager::ms_manager = NULL;
+
+/* static */
+void wxSocketManager::Set(wxSocketManager *manager)
+{
+    wxASSERT_MSG( !ms_manager, "too late to set manager now" );
+
+    ms_manager = manager;
+}
+
+/* static */
+void wxSocketManager::Init()
+{
+    wxASSERT_MSG( !ms_manager, "shouldn't be initialized twice" );
+
+    /*
+        Details: Initialize() creates a hidden window as a sink for socket
+        events, such as 'read completed'. wxMSW has only one message loop
+        for the main thread. If Initialize is called in a secondary thread,
+        the socket window will be created for the secondary thread, but
+        since there is no message loop on this thread, it will never
+        receive events and all socket operations will time out.
+        BTW, the main thread must not be stopped using sleep or block
+        on a semaphore (a bad idea in any case) or socket operations
+        will time out.
+
+        On the Mac side, Initialize() stores a pointer to the CFRunLoop for
+        the main thread. Because secondary threads do not have run loops,
+        adding event notifications to the "Current" loop would have no
+        effect at all, events would never fire.
+    */
+    wxASSERT_MSG( wxIsMainThread(),
+                    "sockets must be initialized from the main thread" );
+
+    wxAppConsole * const app = wxAppConsole::GetInstance();
+    wxCHECK_RET( app, "sockets can't be initialized without wxApp" );
+
+    ms_manager = app->GetTraits()->GetSocketManager();
+}
+
+// ==========================================================================
+// wxSocketImpl
+// ==========================================================================
+
+wxSocketImpl::wxSocketImpl(wxSocketBase& wxsocket)
+    : m_wxsocket(&wxsocket)
+{
+    m_fd              = INVALID_SOCKET;
+    m_error           = wxSOCKET_NOERROR;
+    m_server          = false;
+    m_stream          = true;
+
+    SetTimeout(wxsocket.GetTimeout() * 1000);
+
+    m_establishing    = false;
+    m_reusable        = false;
+    m_broadcast       = false;
+    m_dobind          = true;
+    m_initialRecvBufferSize = -1;
+    m_initialSendBufferSize = -1;
+}
+
+wxSocketImpl::~wxSocketImpl()
+{
+    if ( m_fd != INVALID_SOCKET )
+        Shutdown();
+}
+
+bool wxSocketImpl::PreCreateCheck(const wxSockAddressImpl& addr)
+{
+    if ( m_fd != INVALID_SOCKET )
+    {
+        m_error = wxSOCKET_INVSOCK;
+        return false;
+    }
+
+    if ( !addr.IsOk() )
+    {
+        m_error = wxSOCKET_INVADDR;
+        return false;
+    }
+
+    return true;
+}
+
+void wxSocketImpl::PostCreation()
+{
+    // FreeBSD variants can't use MSG_NOSIGNAL, and instead use a socket option
+#ifdef SO_NOSIGPIPE
+    EnableSocketOption(SO_NOSIGPIPE);
+#endif
+
+    if ( m_reusable )
+        EnableSocketOption(SO_REUSEADDR);
+
+    if ( m_broadcast )
+    {
+        wxASSERT_MSG( !m_stream, "broadcasting is for datagram sockets only" );
+
+        EnableSocketOption(SO_BROADCAST);
+    }
+
+    if ( m_initialRecvBufferSize >= 0 )
+        SetSocketOption(SO_RCVBUF, m_initialRecvBufferSize);
+    if ( m_initialSendBufferSize >= 0 )
+        SetSocketOption(SO_SNDBUF, m_initialSendBufferSize);
+
+    // we always put our sockets in unblocked mode and handle blocking
+    // ourselves in DoRead/Write() if wxSOCKET_WAITALL is specified
+    UnblockAndRegisterWithEventLoop();
+}
+
+wxSocketError wxSocketImpl::UpdateLocalAddress()
+{
+    if ( !m_local.IsOk() )
+    {
+        // ensure that we have a valid object using the correct family: correct
+        // being the same one as our peer uses as we have no other way to
+        // determine it
+        m_local.Create(m_peer.GetFamily());
+    }
+
+    WX_SOCKLEN_T lenAddr = m_local.GetLen();
+    if ( getsockname(m_fd, m_local.GetWritableAddr(), &lenAddr) != 0 )
+    {
+        Close();
+        m_error = wxSOCKET_IOERR;
+        return m_error;
+    }
+
+    return wxSOCKET_NOERROR;
+}
+
+wxSocketError wxSocketImpl::CreateServer()
+{
+    if ( !PreCreateCheck(m_local) )
+        return m_error;
+
+    m_server = true;
+    m_stream = true;
+
+    // do create the socket
+    m_fd = socket(m_local.GetFamily(), SOCK_STREAM, 0);
+
+    if ( m_fd == INVALID_SOCKET )
+    {
+        m_error = wxSOCKET_IOERR;
+        return wxSOCKET_IOERR;
+    }
+
+    PostCreation();
+
+    // and then bind to and listen on it
+    //
+    // FIXME: should we test for m_dobind here?
+    if ( bind(m_fd, m_local.GetAddr(), m_local.GetLen()) != 0 )
+        m_error = wxSOCKET_IOERR;
+
+    if ( IsOk() )
+    {
+        if ( listen(m_fd, 5) != 0 )
+            m_error = wxSOCKET_IOERR;
+    }
+
+    if ( !IsOk() )
+    {
+        Close();
+        return m_error;
+    }
+
+    // finally retrieve the address we effectively bound to
+    return UpdateLocalAddress();
+}
+
+wxSocketError wxSocketImpl::CreateClient(bool wait)
+{
+    if ( !PreCreateCheck(m_peer) )
+        return m_error;
+
+    m_fd = socket(m_peer.GetFamily(), SOCK_STREAM, 0);
+
+    if ( m_fd == INVALID_SOCKET )
+    {
+        m_error = wxSOCKET_IOERR;
+        return wxSOCKET_IOERR;
+    }
+
+    PostCreation();
+
+    // If a local address has been set, then bind to it before calling connect
+    if ( m_local.IsOk() )
+    {
+        if ( bind(m_fd, m_local.GetAddr(), m_local.GetLen()) != 0 )
+        {
+            Close();
+            m_error = wxSOCKET_IOERR;
+            return m_error;
+        }
+    }
+
+    // Do connect now
+    int rc = connect(m_fd, m_peer.GetAddr(), m_peer.GetLen());
+    if ( rc == SOCKET_ERROR )
+    {
+        wxSocketError err = GetLastError();
+        if ( err == wxSOCKET_WOULDBLOCK )
+        {
+            m_establishing = true;
+
+            // block waiting for connection if we should (otherwise just return
+            // wxSOCKET_WOULDBLOCK to the caller)
+            if ( wait )
+            {
+                err = SelectWithTimeout(wxSOCKET_CONNECTION_FLAG)
+                        ? wxSOCKET_NOERROR
+                        : wxSOCKET_TIMEDOUT;
+                m_establishing = false;
+            }
+        }
+
+        m_error = err;
+    }
+    else // connected
+    {
+        m_error = wxSOCKET_NOERROR;
+    }
+
+    return m_error;
+}
+
+
+wxSocketError wxSocketImpl::CreateUDP()
+{
+    if ( !PreCreateCheck(m_local) )
+        return m_error;
+
+    m_stream = false;
+    m_server = false;
+
+    m_fd = socket(m_local.GetFamily(), SOCK_DGRAM, 0);
+
+    if ( m_fd == INVALID_SOCKET )
+    {
+        m_error = wxSOCKET_IOERR;
+        return wxSOCKET_IOERR;
+    }
+
+    PostCreation();
+
+    if ( m_dobind )
+    {
+        if ( bind(m_fd, m_local.GetAddr(), m_local.GetLen()) != 0 )
+        {
+            Close();
+            m_error = wxSOCKET_IOERR;
+            return m_error;
+        }
+
+        return UpdateLocalAddress();
+    }
+
+    return wxSOCKET_NOERROR;
+}
+
+wxSocketImpl *wxSocketImpl::Accept(wxSocketBase& wxsocket)
+{
+    wxSockAddressStorage from;
+    WX_SOCKLEN_T fromlen = sizeof(from);
+    const wxSOCKET_T fd = accept(m_fd, &from.addr, &fromlen);
+
+    // accepting is similar to reading in the sense that it resets "ready for
+    // read" flag on the socket
+    ReenableEvents(wxSOCKET_INPUT_FLAG);
+
+    if ( fd == INVALID_SOCKET )
+        return NULL;
+
+    wxSocketManager * const manager = wxSocketManager::Get();
+    if ( !manager )
+        return NULL;
+
+    wxSocketImpl * const sock = manager->CreateSocket(wxsocket);
+    if ( !sock )
+        return NULL;
+
+    sock->m_fd = fd;
+    sock->m_peer = wxSockAddressImpl(from.addr, fromlen);
+
+    sock->UnblockAndRegisterWithEventLoop();
+
+    return sock;
+}
+
+
+void wxSocketImpl::Close()
+{
+    if ( m_fd != INVALID_SOCKET )
+    {
+        DoClose();
+        m_fd = INVALID_SOCKET;
+    }
+}
+
+void wxSocketImpl::Shutdown()
+{
+    if ( m_fd != INVALID_SOCKET )
+    {
+        shutdown(m_fd, 1 /* SD_SEND */);
+        Close();
+    }
+}
+
+/*
+ *  Sets the timeout for blocking calls. Time is expressed in
+ *  milliseconds.
+ */
+void wxSocketImpl::SetTimeout(unsigned long millis)
+{
+    SetTimeValFromMS(m_timeout, millis);
+}
+
+void wxSocketImpl::NotifyOnStateChange(wxSocketNotify event)
+{
+    m_wxsocket->OnRequest(event);
+}
+
+/* Address handling */
+wxSocketError wxSocketImpl::SetLocal(const wxSockAddressImpl& local)
+{
+    /* the socket must be initialized, or it must be a server */
+    if (m_fd != INVALID_SOCKET && !m_server)
+    {
+        m_error = wxSOCKET_INVSOCK;
+        return wxSOCKET_INVSOCK;
+    }
+
+    if ( !local.IsOk() )
+    {
+        m_error = wxSOCKET_INVADDR;
+        return wxSOCKET_INVADDR;
+    }
+
+    m_local = local;
+
+    return wxSOCKET_NOERROR;
+}
+
+wxSocketError wxSocketImpl::SetPeer(const wxSockAddressImpl& peer)
+{
+    if ( !peer.IsOk() )
+    {
+        m_error = wxSOCKET_INVADDR;
+        return wxSOCKET_INVADDR;
+    }
+
+    m_peer = peer;
+
+    return wxSOCKET_NOERROR;
+}
+
+const wxSockAddressImpl& wxSocketImpl::GetLocal()
+{
+    if ( !m_local.IsOk() )
+        UpdateLocalAddress();
+
+    return m_local;
+}
+
+// ----------------------------------------------------------------------------
+// wxSocketImpl IO
+// ----------------------------------------------------------------------------
+
+// this macro wraps the given expression (normally a syscall) in a loop which
+// ignores any interruptions, i.e. reevaluates it again if it failed and errno
+// is EINTR
+#ifdef __UNIX__
+    #define DO_WHILE_EINTR( rc, syscall ) \
+        do { \
+            rc = (syscall); \
+        } \
+        while ( rc == -1 && errno == EINTR )
+#else
+    #define DO_WHILE_EINTR( rc, syscall ) rc = (syscall)
+#endif
+
+int wxSocketImpl::RecvStream(void *buffer, int size)
+{
+    int ret;
+    DO_WHILE_EINTR( ret, recv(m_fd, static_cast<char *>(buffer), size, 0) );
+
+    if ( !ret )
+    {
+        // receiving 0 bytes for a TCP socket indicates that the connection was
+        // closed by peer so shut down our end as well (for UDP sockets empty
+        // datagrams are also possible)
+        m_establishing = false;
+        NotifyOnStateChange(wxSOCKET_LOST);
+
+        Shutdown();
+
+        // do not return an error in this case however
+    }
+
+    return ret;
+}
+
+int wxSocketImpl::SendStream(const void *buffer, int size)
+{
+#ifdef wxNEEDS_IGNORE_SIGPIPE
+    IgnoreSignal ignore(SIGPIPE);
+#endif
+
+    int ret;
+    DO_WHILE_EINTR( ret, send(m_fd, static_cast<const char *>(buffer), size,
+                              wxSOCKET_MSG_NOSIGNAL) );
+
+    return ret;
+}
+
+int wxSocketImpl::RecvDgram(void *buffer, int size)
+{
+    wxSockAddressStorage from;
+    WX_SOCKLEN_T fromlen = sizeof(from);
+
+    int ret;
+    DO_WHILE_EINTR( ret, recvfrom(m_fd, static_cast<char *>(buffer), size,
+                                  0, &from.addr, &fromlen) );
+
+    if ( ret == SOCKET_ERROR )
+        return SOCKET_ERROR;
+
+    m_peer = wxSockAddressImpl(from.addr, fromlen);
+    if ( !m_peer.IsOk() )
+        return -1;
+
+    return ret;
+}
+
+int wxSocketImpl::SendDgram(const void *buffer, int size)
+{
+    if ( !m_peer.IsOk() )
+    {
+        m_error = wxSOCKET_INVADDR;
+        return -1;
+    }
+
+    int ret;
+    DO_WHILE_EINTR( ret, sendto(m_fd, static_cast<const char *>(buffer), size,
+                                0, m_peer.GetAddr(), m_peer.GetLen()) );
+
+    return ret;
+}
+
+int wxSocketImpl::Read(void *buffer, int size)
+{
+    // server sockets can't be used for IO, only to accept new connections
+    if ( m_fd == INVALID_SOCKET || m_server )
+    {
+        m_error = wxSOCKET_INVSOCK;
+        return -1;
+    }
+
+    int ret = m_stream ? RecvStream(buffer, size)
+                       : RecvDgram(buffer, size);
+
+    m_error = ret == SOCKET_ERROR ? GetLastError() : wxSOCKET_NOERROR;
+
+    return ret;
+}
+
+int wxSocketImpl::Write(const void *buffer, int size)
+{
+    if ( m_fd == INVALID_SOCKET || m_server )
+    {
+        m_error = wxSOCKET_INVSOCK;
+        return -1;
+    }
+
+    int ret = m_stream ? SendStream(buffer, size)
+                       : SendDgram(buffer, size);
+
+    m_error = ret == SOCKET_ERROR ? GetLastError() : wxSOCKET_NOERROR;
+
+    return ret;
+}
+
+// ==========================================================================
+// wxSocketBase
+// ==========================================================================
+
+// --------------------------------------------------------------------------
+// Initialization and shutdown
+// --------------------------------------------------------------------------
+
+namespace
+{
+
+// counts the number of calls to Initialize() minus the number of calls to
+// Shutdown(): we don't really need it any more but it was documented that
+// Shutdown() must be called the same number of times as Initialize() and using
+// a counter helps us to check it
+int gs_socketInitCount = 0;
+
+} // anonymous namespace
+
+bool wxSocketBase::IsInitialized()
+{
+    wxASSERT_MSG( wxIsMainThread(), "unsafe to call from other threads" );
+
+    return gs_socketInitCount != 0;
+}
+
+bool wxSocketBase::Initialize()
+{
+    wxCHECK_MSG( wxIsMainThread(), false,
+                 "must be called from the main thread" );
+
+    if ( !gs_socketInitCount )
+    {
+        wxSocketManager * const manager = wxSocketManager::Get();
+        if ( !manager || !manager->OnInit() )
+            return false;
+    }
+
+    gs_socketInitCount++;
+
+    return true;
+}
+
+void wxSocketBase::Shutdown()
+{
+    wxCHECK_RET( wxIsMainThread(), "must be called from the main thread" );
+
+    wxCHECK_RET( gs_socketInitCount > 0, "too many calls to Shutdown()" );
+
+    if ( !--gs_socketInitCount )
+    {
+        wxSocketManager * const manager = wxSocketManager::Get();
+        wxCHECK_RET( manager, "should have a socket manager" );
+
+        manager->OnExit();
+    }
+}
+
+// --------------------------------------------------------------------------
+// Ctor and dtor
+// --------------------------------------------------------------------------
+
+void wxSocketBase::Init()
+{
+    m_impl         = NULL;
+    m_type         = wxSOCKET_UNINIT;
+
+    // state
+    m_flags        = 0;
+    m_connected    =
+    m_establishing =
+    m_reading      =
+    m_writing      =
+    m_closed       = false;
+    m_lcount       = 0;
+    m_lcount_read  = 0;
+    m_lcount_write = 0;
+    m_timeout      = 600;
+    m_beingDeleted = false;
+
+    // pushback buffer
+    m_unread       = NULL;
+    m_unrd_size    = 0;
+    m_unrd_cur     = 0;
+
+    // events
+    m_id           = wxID_ANY;
+    m_handler      = NULL;
+    m_clientData   = NULL;
+    m_notify       = false;
+    m_eventmask    =
+    m_eventsgot    = 0;
+
+    // when we create the first socket in the main thread we initialize the
+    // OS-dependent socket stuff: notice that this means that the user code
+    // needs to call wxSocket::Initialize() itself if the first socket it
+    // creates is not created in the main thread
+    if ( wxIsMainThread() )
+    {
+        if ( !Initialize() )
+        {
+            wxLogError(_("Cannot initialize sockets"));
+        }
+    }
+}
+
+wxSocketBase::wxSocketBase()
+{
+    Init();
+}
+
+wxSocketBase::wxSocketBase(wxSocketFlags flags, wxSocketType type)
+{
+    Init();
+
+    SetFlags(flags);
+
+    m_type = type;
+}
+
+wxSocketBase::~wxSocketBase()
+{
+    // Shutdown and close the socket
+    if (!m_beingDeleted)
+        Close();
+
+    // Destroy the implementation object
+    delete m_impl;
+
+    // Free the pushback buffer
+    free(m_unread);
+}
+
+bool wxSocketBase::Destroy()
+{
+    // Delayed destruction: the socket will be deleted during the next idle
+    // loop iteration. This ensures that all pending events have been
+    // processed.
+    m_beingDeleted = true;
+
+    // Shutdown and close the socket
+    Close();
+
+    // Suppress events from now on
+    Notify(false);
+
+    // Schedule this object for deletion instead of destroying it right now if
+    // it can have other events pending for it and we have a way to do it.
+    //
+    // Notice that sockets used in other threads won't have any events for them
+    // and we shouldn't use delayed destruction mechanism for them as it's not
+    // MT-safe.
+    if ( wxIsMainThread() && wxTheApp )
+    {
+        wxTheApp->ScheduleForDestruction(this);
+    }
+    else // no app
+    {
+        // in wxBase we might have no app object at all, don't leak memory
+        delete this;
+    }
 
-wxSocketBase::wxSocketBase(wxSockFlags _flags, wxSockType _type) :
-  wxEvtHandler(),
-  m_socket(NULL), m_evt_handler(NULL), m_id(-1),
-  m_flags(_flags), m_type(_type),
-  m_neededreq(0), m_notify_state(FALSE),
-  m_connected(FALSE), m_establishing(FALSE),
-  m_reading(FALSE), m_writing(FALSE),
-  m_error(FALSE), m_lcount(0), m_timeout(600), m_states(),
-  m_unread(NULL), m_unrd_size(0), m_unrd_cur(0),
-  m_cbk(NULL), m_cdata(NULL)
-{
+    return true;
 }
 
-wxSocketBase::wxSocketBase() :
-  wxEvtHandler(),
-  m_socket(NULL), m_evt_handler(NULL), m_id(-1),
-  m_flags(NONE), m_type(SOCK_UNINIT),
-  m_neededreq(0), m_notify_state(FALSE),
-  m_connected(FALSE), m_establishing(FALSE),
-  m_reading(FALSE), m_writing(FALSE),
-  m_error(FALSE), m_lcount(0), m_timeout(600), m_states(),
-  m_unread(NULL), m_unrd_size(0), m_unrd_cur(0),
-  m_cbk(NULL), m_cdata(NULL)
+// ----------------------------------------------------------------------------
+// simple accessors
+// ----------------------------------------------------------------------------
+
+void wxSocketBase::SetError(wxSocketError error)
 {
+    m_impl->m_error = error;
 }
 
-wxSocketBase::~wxSocketBase()
+wxSocketError wxSocketBase::LastError() const
 {
-  if (m_unread)
-    free(m_unread);
-
-  // Shutdown and close the socket
-  Close();
-
-  // Destroy the GSocket object
-  if (m_socket)
-    GSocket_destroy(m_socket);
+    return m_impl->GetError();
 }
 
+// --------------------------------------------------------------------------
+// Basic IO calls
+// --------------------------------------------------------------------------
+
+// The following IO operations update m_lcount:
+// {Read, Write, ReadMsg, WriteMsg, Peek, Unread, Discard}
 bool wxSocketBase::Close()
 {
-  // Interrupt pending waits
-  InterruptAllWaits();
+    // Interrupt pending waits
+    InterruptWait();
 
-  if (m_socket)
-  {
-    // Disable callbacks
-    GSocket_UnsetCallback(m_socket, GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
-                                    GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG);
+    ShutdownOutput();
 
-    // Shutdown the connection
-    GSocket_Shutdown(m_socket);
-  }
-
-  m_connected = FALSE;              // (GRG)
-  m_establishing = FALSE;
-  return TRUE;
+    m_connected = false;
+    m_establishing = false;
+    return true;
 }
 
-// --------------------------------------------------------------
-// wxSocketBase basic IO operations
-// --------------------------------------------------------------
-
-// All IO operations {Read, Write, ReadMsg, WriteMsg, Peek,
-// Unread, Discard} update m_error and m_lcount.
-//
-// TODO: Should Connect, Accept and AcceptWith update m_error?
-
-class _wxSocketInternalTimer: public wxTimer
+void wxSocketBase::ShutdownOutput()
 {
-public:
-  int *m_state;
-  unsigned long m_new_val;
-
-  void Notify()
-  {
-    *m_state = (int)m_new_val;      // Change the value
-  }
-};
+    if ( m_impl )
+        m_impl->Shutdown();
+}
 
-wxSocketBase& wxSocketBase::Read(char* buffer, wxUint32 nbytes)
+wxSocketBase& wxSocketBase::Read(void* buffer, wxUint32 nbytes)
 {
-  // Mask read events
-  m_reading = TRUE;
-
-  m_lcount = _Read(buffer, nbytes);
-
-  // If in wxSOCKET_WAITALL mode, all bytes should have been read.
-  if (m_flags & wxSOCKET_WAITALL)
-    m_error = (m_lcount != nbytes);
-  else
-    m_error = (m_lcount == 0);
+    wxSocketReadGuard read(this);
 
-  // Allow read events from now on
-  m_reading = FALSE;
+    m_lcount_read = DoRead(buffer, nbytes);
+    m_lcount = m_lcount_read;
 
-  return *this;
+    return *this;
 }
 
-wxUint32 wxSocketBase::_Read(char* buffer, wxUint32 nbytes)
+wxUint32 wxSocketBase::DoRead(void* buffer_, wxUint32 nbytes)
 {
-  int total;
-  int ret = 1;
+    wxCHECK_MSG( m_impl, 0, "socket must be valid" );
 
-  // Try the pushback buffer first
-  total = GetPushback(buffer, nbytes, FALSE);
-  nbytes -= total;
-  buffer += total;
+    // We use pointer arithmetic here which doesn't work with void pointers.
+    char *buffer = static_cast<char *>(buffer_);
+    wxCHECK_MSG( buffer, 0, "NULL buffer" );
 
-  // If the socket is invalid or we got all the data, return now (GRG)
-  if (!m_socket || !nbytes)
-    return total;
+    // Try the push back buffer first, even before checking whether the socket
+    // is valid to allow reading previously pushed back data from an already
+    // closed socket.
+    wxUint32 total = GetPushback(buffer, nbytes, false);
+    nbytes -= total;
+    buffer += total;
 
-  // Possible combinations (they are checked in this order)
-  // wxSOCKET_NOWAIT
-  // wxSOCKET_WAITALL | wxSOCKET_BLOCK
-  // wxSOCKET_WAITALL
-  // wxSOCKET_BLOCK
-  // wxSOCKET_NONE
-  //
-  if (m_flags & wxSOCKET_NOWAIT)
-  {
-    GSocket_SetNonBlocking(m_socket, TRUE);
-    ret = GSocket_Read(m_socket, buffer, nbytes);
-    GSocket_SetNonBlocking(m_socket, FALSE);
-
-    if (ret > 0)
-      total += ret;
-  }
-  else if (m_flags & wxSOCKET_WAITALL)
-  {
-    while (ret > 0 && nbytes > 0)
-    {
-      if (!(m_flags & wxSOCKET_BLOCK) && !WaitForRead())
-          break;
-
-      ret = GSocket_Read(m_socket, buffer, nbytes);
-
-      if (ret > 0)
-      {
-        total  += ret;
-        buffer += ret;
-        nbytes -= ret;
-      }
-    }
-  }
-  else
-  {
-    if ((m_flags & wxSOCKET_BLOCK) || WaitForRead())
+    while ( nbytes )
     {
-      ret = GSocket_Read(m_socket, buffer, nbytes);
+        // our socket is non-blocking so Read() will return immediately if
+        // there is nothing to read yet and it's more efficient to try it first
+        // before entering DoWait() which is going to start dispatching GUI
+        // events and, even more importantly, we must do this under Windows
+        // where we're not going to get notifications about socket being ready
+        // for reading before we read all the existing data from it
+        const int ret = !m_impl->m_stream || m_connected
+                            ? m_impl->Read(buffer, nbytes)
+                            : 0;
+        if ( ret == -1 )
+        {
+            if ( m_impl->GetLastError() == wxSOCKET_WOULDBLOCK )
+            {
+                // if we don't want to wait, just return immediately
+                if ( m_flags & wxSOCKET_NOWAIT_READ )
+                {
+                    // this shouldn't be counted as an error in this case
+                    SetError(wxSOCKET_NOERROR);
+                    break;
+                }
+
+                // otherwise wait until the socket becomes ready for reading or
+                // an error occurs on it
+                if ( !DoWaitWithTimeout(wxSOCKET_INPUT_FLAG) )
+                {
+                    // and exit if the timeout elapsed before it did
+                    SetError(wxSOCKET_TIMEDOUT);
+                    break;
+                }
+
+                // retry reading
+                continue;
+            }
+            else // "real" error
+            {
+                SetError(wxSOCKET_IOERR);
+                break;
+            }
+        }
+        else if ( ret == 0 )
+        {
+            // for connection-oriented (e.g. TCP) sockets we can only read
+            // 0 bytes if the other end has been closed, and for connectionless
+            // ones (UDP) this flag doesn't make sense anyhow so we can set it
+            // to true too without doing any harm
+            m_closed = true;
+
+            // we're not going to read anything else and so if we haven't read
+            // anything (or not everything in wxSOCKET_WAITALL case) already,
+            // signal an error
+            if ( (m_flags & wxSOCKET_WAITALL_READ) || !total )
+                SetError(wxSOCKET_IOERR);
+            break;
+        }
 
-      if (ret > 0)
         total += ret;
+
+        // if we are happy to read something and not the entire nbytes bytes,
+        // then we're done
+        if ( !(m_flags & wxSOCKET_WAITALL_READ) )
+            break;
+
+        nbytes -= ret;
+        buffer += ret;
     }
-  }
-
-  return total;
-}
-
-wxSocketBase& wxSocketBase::ReadMsg(char* buffer, wxUint32 nbytes)
-{
-  wxUint32 len, len2, sig, total;
-  bool error;
-  int old_flags;
-  struct
-  {
-    unsigned char sig[4];
-    unsigned char len[4];
-  } msg;
-
-  // Mask read events
-  m_reading = TRUE;
-
-  total = 0;
-  error = TRUE;
-  old_flags = m_flags;
-  SetFlags((m_flags & wxSOCKET_BLOCK) | wxSOCKET_WAITALL);
-
-  if (_Read((char *)&msg, sizeof(msg)) != sizeof(msg))
-    goto exit;
-
-  sig =  (wxUint32)msg.sig[0];
-  sig |= (wxUint32)(msg.sig[1] << 8);
-  sig |= (wxUint32)(msg.sig[2] << 16);
-  sig |= (wxUint32)(msg.sig[3] << 24);
-
-  if (sig != 0xfeeddead)
-  {
-    wxLogWarning( _("wxSocket: invalid signature in ReadMsg."));
-    goto exit;
-  }
-
-  len = (wxUint32)msg.len[0];
-  len |= (wxUint32)(msg.len[1] << 8);
-  len |= (wxUint32)(msg.len[2] << 16);
-  len |= (wxUint32)(msg.len[3] << 24);
-
-  if (len > nbytes)
-  {
-    len2 = len - nbytes;
-    len = nbytes;
-  }
-  else
-    len2 = 0;
-
-  // Don't attemp to read if the msg was zero bytes long.
-  if (len)
-  {
-    total = _Read(buffer, len);
-
-    if (total != len)
-      goto exit;
-  }
-  if (len2)
-  {
-    char *discard_buffer = new char[MAX_DISCARD_SIZE];
-    long discard_len;
-
-    // NOTE: discarded bytes don't add to m_lcount.
-    do
-    {
-      discard_len = ((len2 > MAX_DISCARD_SIZE)? MAX_DISCARD_SIZE : len2);
-      discard_len = _Read(discard_buffer, (wxUint32)discard_len);
-      len2 -= (wxUint32)discard_len;
-    }
-    while ((discard_len > 0) && len2);
 
-    delete [] discard_buffer;
+    return total;
+}
 
-    if (len2 != 0)
-      goto exit;
-  }
-  if (_Read((char *)&msg, sizeof(msg)) != sizeof(msg))
-    goto exit;
+wxSocketBase& wxSocketBase::ReadMsg(void* buffer, wxUint32 nbytes)
+{
+    struct
+    {
+        unsigned char sig[4];
+        unsigned char len[4];
+    } msg;
 
-  sig = (wxUint32)msg.sig[0];
-  sig |= (wxUint32)(msg.sig[1] << 8);
-  sig |= (wxUint32)(msg.sig[2] << 16);
-  sig |= (wxUint32)(msg.sig[3] << 24);
+    wxSocketReadGuard read(this);
 
-  if (sig != 0xdeadfeed)
-  {
-    wxLogWarning( _("wxSocket: invalid signature in ReadMsg."));
-    goto exit;
-  }
+    wxSocketWaitModeChanger changeFlags(this, wxSOCKET_WAITALL_READ);
 
-  // everything was OK
-  error = FALSE;
+    bool ok = false;
+    if ( DoRead(&msg, sizeof(msg)) == sizeof(msg) )
+    {
+        wxUint32 sig = (wxUint32)msg.sig[0];
+        sig |= (wxUint32)(msg.sig[1] << 8);
+        sig |= (wxUint32)(msg.sig[2] << 16);
+        sig |= (wxUint32)(msg.sig[3] << 24);
+
+        if ( sig == 0xfeeddead )
+        {
+            wxUint32 len = (wxUint32)msg.len[0];
+            len |= (wxUint32)(msg.len[1] << 8);
+            len |= (wxUint32)(msg.len[2] << 16);
+            len |= (wxUint32)(msg.len[3] << 24);
+
+            wxUint32 len2;
+            if (len > nbytes)
+            {
+                len2 = len - nbytes;
+                len = nbytes;
+            }
+            else
+                len2 = 0;
+
+            // Don't attempt to read if the msg was zero bytes long.
+            m_lcount_read = len ? DoRead(buffer, len) : 0;
+            m_lcount = m_lcount_read;
+
+            if ( len2 )
+            {
+                char discard_buffer[MAX_DISCARD_SIZE];
+                long discard_len;
+
+                // NOTE: discarded bytes don't add to m_lcount.
+                do
+                {
+                    discard_len = len2 > MAX_DISCARD_SIZE
+                                    ? MAX_DISCARD_SIZE
+                                    : len2;
+                    discard_len = DoRead(discard_buffer, (wxUint32)discard_len);
+                    len2 -= (wxUint32)discard_len;
+                }
+                while ((discard_len > 0) && len2);
+            }
+
+            if ( !len2 && DoRead(&msg, sizeof(msg)) == sizeof(msg) )
+            {
+                sig = (wxUint32)msg.sig[0];
+                sig |= (wxUint32)(msg.sig[1] << 8);
+                sig |= (wxUint32)(msg.sig[2] << 16);
+                sig |= (wxUint32)(msg.sig[3] << 24);
+
+                if ( sig == 0xdeadfeed )
+                    ok = true;
+            }
+        }
+    }
 
-exit:
-  m_error = error;
-  m_lcount = total;
-  m_reading = FALSE;
-  SetFlags(old_flags);
+    if ( !ok )
+        SetError(wxSOCKET_IOERR);
 
-  return *this;
+    return *this;
 }
 
-wxSocketBase& wxSocketBase::Peek(char* buffer, wxUint32 nbytes)
+wxSocketBase& wxSocketBase::Peek(void* buffer, wxUint32 nbytes)
 {
-  // Mask read events
-  m_reading = TRUE;
+    wxSocketReadGuard read(this);
 
-  m_lcount = _Read(buffer, nbytes);
-  Pushback(buffer, m_lcount);
+    // Peek() should never block
+    wxSocketWaitModeChanger changeFlags(this, wxSOCKET_NOWAIT);
 
-  // If in wxSOCKET_WAITALL mode, all bytes should have been read.
-  if (m_flags & wxSOCKET_WAITALL)
-    m_error = (m_lcount != nbytes);
-  else
-    m_error = (m_lcount == 0);
+    m_lcount = DoRead(buffer, nbytes);
 
-  // Allow read events again
-  m_reading = FALSE;
+    Pushback(buffer, m_lcount);
 
-  return *this;
+    return *this;
 }
 
-wxSocketBase& wxSocketBase::Write(const char *buffer, wxUint32 nbytes)
+wxSocketBase& wxSocketBase::Write(const void *buffer, wxUint32 nbytes)
 {
-  // Mask write events
-  m_writing = TRUE;
-
-  m_lcount = _Write(buffer, nbytes);
+    wxSocketWriteGuard write(this);
 
-  // If in wxSOCKET_WAITALL mode, all bytes should have been written.
-  if (m_flags & wxSOCKET_WAITALL)
-    m_error = (m_lcount != nbytes);
-  else
-    m_error = (m_lcount == 0);
+    m_lcount_write = DoWrite(buffer, nbytes);
+    m_lcount = m_lcount_write;
 
-  // Allow write events again
-  m_writing = FALSE;
-
-  return *this;
+    return *this;
 }
 
-wxUint32 wxSocketBase::_Write(const char *buffer, wxUint32 nbytes)
+// This function is a mirror image of DoRead() except that it doesn't use the
+// push back buffer and doesn't treat 0 return value specially (normally this
+// shouldn't happen at all here), so please see comments there for explanations
+wxUint32 wxSocketBase::DoWrite(const void *buffer_, wxUint32 nbytes)
 {
-  wxUint32 total = 0;
-  int ret = 1;
-
-  // If the socket is invalid, return immediately (GRG)
-  if (!m_socket)
-    return 0;
+    wxCHECK_MSG( m_impl, 0, "socket must be valid" );
 
-  // Possible combinations (they are checked in this order)
-  // wxSOCKET_NOWAIT
-  // wxSOCKET_WAITALL | wxSOCKET_BLOCK
-  // wxSOCKET_WAITALL
-  // wxSOCKET_BLOCK
-  // wxSOCKET_NONE
-  //
-  if (m_flags & wxSOCKET_NOWAIT)
-  {
-    GSocket_SetNonBlocking(m_socket, TRUE);
-    ret = GSocket_Write(m_socket, buffer, nbytes);
-    GSocket_SetNonBlocking(m_socket, FALSE);
+    const char *buffer = static_cast<const char *>(buffer_);
+    wxCHECK_MSG( buffer, 0, "NULL buffer" );
 
-    if (ret > 0)
-      total = ret;
-  }
-  else if (m_flags & wxSOCKET_WAITALL)
-  {
-    while (ret > 0 && nbytes > 0)
+    wxUint32 total = 0;
+    while ( nbytes )
     {
-      if (!(m_flags & wxSOCKET_BLOCK) && !WaitForWrite())
-          break;
+        if ( m_impl->m_stream && !m_connected )
+        {
+            if ( (m_flags & wxSOCKET_WAITALL_WRITE) || !total )
+                SetError(wxSOCKET_IOERR);
+            break;
+        }
+
+        const int ret = m_impl->Write(buffer, nbytes);
+        if ( ret == -1 )
+        {
+            if ( m_impl->GetLastError() == wxSOCKET_WOULDBLOCK )
+            {
+                if ( m_flags & wxSOCKET_NOWAIT_WRITE )
+                    break;
+
+                if ( !DoWaitWithTimeout(wxSOCKET_OUTPUT_FLAG) )
+                {
+                    SetError(wxSOCKET_TIMEDOUT);
+                    break;
+                }
+
+                continue;
+            }
+            else // "real" error
+            {
+                SetError(wxSOCKET_IOERR);
+                break;
+            }
+        }
 
-      ret = GSocket_Write(m_socket, buffer, nbytes);
+        total += ret;
 
-      if (ret > 0)
-      {
-        total  += ret;
-        buffer += ret;
-        nbytes -= ret;
-      }
-    }
-  }
-  else
-  {
-    if ((m_flags & wxSOCKET_BLOCK) || WaitForWrite())
-    {
-      ret = GSocket_Write(m_socket, buffer, nbytes);
+        if ( !(m_flags & wxSOCKET_WAITALL_WRITE) )
+            break;
 
-      if (ret > 0)
-        total = ret;
+        nbytes -= ret;
+        buffer += ret;
     }
-  }
 
-  return total;
+    return total;
 }
 
-wxSocketBase& wxSocketBase::WriteMsg(const char *buffer, wxUint32 nbytes)
+wxSocketBase& wxSocketBase::WriteMsg(const void *buffer, wxUint32 nbytes)
 {
-  wxUint32 total;
-  bool error;
-  int old_flags;
-  struct {
-    unsigned char sig[4];
-    unsigned char len[4];
-  } msg;
-
-  // Mask write events
-  m_writing = TRUE;
-
-  error = TRUE;
-  total = 0;
-  old_flags = m_flags;
-  SetFlags((m_flags & wxSOCKET_BLOCK) | wxSOCKET_WAITALL);
-
-  msg.sig[0] = (unsigned char) 0xad;
-  msg.sig[1] = (unsigned char) 0xde;
-  msg.sig[2] = (unsigned char) 0xed;
-  msg.sig[3] = (unsigned char) 0xfe;
-
-  msg.len[0] = (unsigned char) (nbytes & 0xff);
-  msg.len[1] = (unsigned char) ((nbytes >> 8) & 0xff);
-  msg.len[2] = (unsigned char) ((nbytes >> 16) & 0xff);
-  msg.len[3] = (unsigned char) ((nbytes >> 24) & 0xff);
-
-  if (_Write((char *)&msg, sizeof(msg)) < sizeof(msg))
-    goto exit;
+    struct
+    {
+        unsigned char sig[4];
+        unsigned char len[4];
+    } msg;
 
-  total = _Write(buffer, nbytes);
+    wxSocketWriteGuard write(this);
 
-  if (total < nbytes)
-    goto exit;
+    wxSocketWaitModeChanger changeFlags(this, wxSOCKET_WAITALL_WRITE);
 
-  msg.sig[0] = (unsigned char) 0xed;
-  msg.sig[1] = (unsigned char) 0xfe;
-  msg.sig[2] = (unsigned char) 0xad;
-  msg.sig[3] = (unsigned char) 0xde;
-  msg.len[0] = msg.len[1] = msg.len[2] = msg.len[3] = (char) 0;
+    msg.sig[0] = (unsigned char) 0xad;
+    msg.sig[1] = (unsigned char) 0xde;
+    msg.sig[2] = (unsigned char) 0xed;
+    msg.sig[3] = (unsigned char) 0xfe;
 
-  if ((_Write((char *)&msg, sizeof(msg))) < sizeof(msg))
-    goto exit;
+    msg.len[0] = (unsigned char) (nbytes & 0xff);
+    msg.len[1] = (unsigned char) ((nbytes >> 8) & 0xff);
+    msg.len[2] = (unsigned char) ((nbytes >> 16) & 0xff);
+    msg.len[3] = (unsigned char) ((nbytes >> 24) & 0xff);
 
-  // everything was OK
-  error = FALSE;
+    bool ok = false;
+    if ( DoWrite(&msg, sizeof(msg)) == sizeof(msg) )
+    {
+        m_lcount_write = DoWrite(buffer, nbytes);
+        m_lcount = m_lcount_write;
+        if ( m_lcount_write == nbytes )
+        {
+            msg.sig[0] = (unsigned char) 0xed;
+            msg.sig[1] = (unsigned char) 0xfe;
+            msg.sig[2] = (unsigned char) 0xad;
+            msg.sig[3] = (unsigned char) 0xde;
+            msg.len[0] =
+            msg.len[1] =
+            msg.len[2] =
+            msg.len[3] = (char) 0;
+
+            if ( DoWrite(&msg, sizeof(msg)) == sizeof(msg))
+                ok = true;
+        }
+    }
 
-exit:
-  m_error = error;
-  m_lcount = total;
-  m_writing = FALSE;
+    if ( !ok )
+        SetError(wxSOCKET_IOERR);
 
-  return *this;
+    return *this;
 }
 
-wxSocketBase& wxSocketBase::Unread(const char *buffer, wxUint32 nbytes)
+wxSocketBase& wxSocketBase::Unread(const void *buffer, wxUint32 nbytes)
 {
-  if (nbytes != 0)
-    Pushback(buffer, nbytes);
+    if (nbytes != 0)
+        Pushback(buffer, nbytes);
 
-  m_error = FALSE;
-  m_lcount = nbytes;
+    SetError(wxSOCKET_NOERROR);
+    m_lcount = nbytes;
 
-  return *this;
+    return *this;
 }
 
 wxSocketBase& wxSocketBase::Discard()
 {
-  int old_flags;
-  char *buffer = new char[MAX_DISCARD_SIZE];
-  wxUint32 ret;
-  wxUint32 total = 0;
+    char *buffer = new char[MAX_DISCARD_SIZE];
+    wxUint32 ret;
+    wxUint32 total = 0;
 
-  // Mask read events
-  m_reading = TRUE;
+    wxSocketReadGuard read(this);
 
-  old_flags = m_flags;
-  SetFlags(wxSOCKET_NOWAIT);
+    wxSocketWaitModeChanger changeFlags(this, wxSOCKET_NOWAIT);
 
-  do
-  {
-    ret = _Read(buffer, MAX_DISCARD_SIZE);
-    total += ret;
-  }
-  while (ret == MAX_DISCARD_SIZE);
-
-  delete[] buffer;
-  m_lcount = total;
-  m_error  = FALSE;
+    do
+    {
+        ret = DoRead(buffer, MAX_DISCARD_SIZE);
+        total += ret;
+    }
+    while (ret == MAX_DISCARD_SIZE);
 
-  // Allow read events again
-  m_reading = FALSE;
+    delete[] buffer;
+    m_lcount = total;
+    SetError(wxSOCKET_NOERROR);
 
-  return *this;
+    return *this;
 }
 
-// --------------------------------------------------------------
-// wxSocketBase get local or peer addresses
-// --------------------------------------------------------------
+// --------------------------------------------------------------------------
+// Wait functions
+// --------------------------------------------------------------------------
 
-bool wxSocketBase::GetPeer(wxSockAddress& addr_man) const
+/*
+    This function will check for the events specified in the flags parameter,
+    and it will return a mask indicating which operations can be performed.
+ */
+wxSocketEventFlags wxSocketImpl::Select(wxSocketEventFlags flags,
+                                        const timeval *timeout)
 {
-  GAddress *peer;
-
-  if (!m_socket)
-    return FALSE;
+    if ( m_fd == INVALID_SOCKET )
+        return (wxSOCKET_LOST_FLAG & flags);
 
-  peer = GSocket_GetPeer(m_socket);
-  addr_man.SetAddress(peer);
-  GAddress_destroy(peer);
+    struct timeval tv;
+    if ( timeout )
+        tv = *timeout;
+    else
+        tv.tv_sec = tv.tv_usec = 0;
 
-  return TRUE;
-}
+    // prepare the FD sets, passing NULL for the one(s) we don't use
+    fd_set
+        readfds, *preadfds = NULL,
+        writefds, *pwritefds = NULL,
+        exceptfds;                      // always want to know about errors
 
-bool wxSocketBase::GetLocal(wxSockAddress& addr_man) const
-{
-  GAddress *local;
+    if ( flags & wxSOCKET_INPUT_FLAG )
+        preadfds = &readfds;
 
-  if (!m_socket)
-    return FALSE;
+    if ( flags & wxSOCKET_OUTPUT_FLAG )
+        pwritefds = &writefds;
 
-  local = GSocket_GetLocal(m_socket);
-  addr_man.SetAddress(local);
-  GAddress_destroy(local);
+    // When using non-blocking connect() the client socket becomes connected
+    // (successfully or not) when it becomes writable but when using
+    // non-blocking accept() the server socket becomes connected when it
+    // becomes readable.
+    if ( flags & wxSOCKET_CONNECTION_FLAG )
+    {
+        if ( m_server )
+            preadfds = &readfds;
+        else
+            pwritefds = &writefds;
+    }
 
-  return TRUE;
-}
+    if ( preadfds )
+    {
+        wxFD_ZERO(preadfds);
+        wxFD_SET(m_fd, preadfds);
+    }
 
-// --------------------------------------------------------------
-// wxSocketBase save and restore socket state
-// --------------------------------------------------------------
+    if ( pwritefds )
+    {
+        wxFD_ZERO(pwritefds);
+        wxFD_SET(m_fd, pwritefds);
+    }
 
-void wxSocketBase::SaveState()
-{
-  wxSocketState *state;
+    wxFD_ZERO(&exceptfds);
+    wxFD_SET(m_fd, &exceptfds);
 
-  state = new wxSocketState();
+    const int rc = select(m_fd + 1, preadfds, pwritefds, &exceptfds, &tv);
 
-  state->m_notify_state = m_notify_state;
-  state->m_neededreq    = m_neededreq;
-  state->m_flags        = m_flags;
-  state->m_cbk          = m_cbk;
-  state->m_cdata        = m_cdata;
+    // check for errors first
+    if ( rc == -1 || wxFD_ISSET(m_fd, &exceptfds) )
+    {
+        m_establishing = false;
 
-  m_states.Append(state);
-}
+        return wxSOCKET_LOST_FLAG & flags;
+    }
 
-void wxSocketBase::RestoreState()
-{
-  wxNode *node;
-  wxSocketState *state;
+    if ( rc == 0 )
+        return 0;
 
-  node = m_states.Last();
-  if (!node)
-    return;
+    wxASSERT_MSG( rc == 1, "unexpected select() return value" );
 
-  state = (wxSocketState *)node->Data();
+    wxSocketEventFlags detected = 0;
+    if ( preadfds && wxFD_ISSET(m_fd, preadfds) )
+        detected |= wxSOCKET_INPUT_FLAG;
 
-  SetFlags(state->m_flags);
-  m_cbk       = state->m_cbk;
-  m_cdata     = state->m_cdata;
-  m_neededreq = state->m_neededreq;
-  Notify(state->m_notify_state);
+    if ( pwritefds && wxFD_ISSET(m_fd, pwritefds) )
+    {
+        // check for the case of non-blocking connect()
+        if ( m_establishing && !m_server )
+        {
+            int error;
+            SOCKOPTLEN_T len = sizeof(error);
+            m_establishing = false;
+            getsockopt(m_fd, SOL_SOCKET, SO_ERROR, (char*)&error, &len);
+
+            if ( error )
+                detected = wxSOCKET_LOST_FLAG;
+            else
+                detected |= wxSOCKET_CONNECTION_FLAG;
+        }
+        else // not called to get non-blocking connect() status
+        {
+            detected |= wxSOCKET_OUTPUT_FLAG;
+        }
+    }
 
-  delete node;
-  delete state;
+    return detected & flags;
 }
 
+int
+wxSocketBase::DoWait(long seconds, long milliseconds, wxSocketEventFlags flags)
+{
+    // Use either the provided timeout or the default timeout value associated
+    // with this socket.
+    //
+    // TODO: allow waiting forever, see #9443
+    const long timeout = seconds == -1 ? m_timeout * 1000
+                                       : seconds * 1000 + milliseconds;
 
-// --------------------------------------------------------------
-// wxSocketBase Wait functions
-// --------------------------------------------------------------
-
-// These WaitXXX unctions do not depend on the event system any
-// longer; instead, they poll the socket, using GSocket_Select()
-// to check for the specified combination of event flags, until
-// an event occurs or until the timeout ellapses. The polling
-// loop calls PROCESS_EVENTS(), so this won't block the GUI.
+    return DoWait(timeout, flags);
+}
 
-bool wxSocketBase::_Wait(long seconds, long milliseconds,
-                         wxSocketEventFlags flags)
+int
+wxSocketBase::DoWait(long timeout, wxSocketEventFlags flags)
 {
-  GSocketEventFlags result;
-  _wxSocketInternalTimer timer;
-  long timeout;
-  int state = -1;
-
-  // Set this to TRUE to interrupt ongoing waits
-  m_interrupt = FALSE;
+    wxCHECK_MSG( m_impl, -1, "can't wait on invalid socket" );
 
-  // Check for valid socket (GRG)
-  if (!m_socket)
-    return FALSE;
+    // we're never going to become ready in a TCP client if we're not connected
+    // any more (OTOH a server can call this to precisely wait for a connection
+    // so do wait for it in this case and UDP client is never "connected")
+    if ( !m_impl->IsServer() &&
+            m_impl->m_stream && !m_connected && !m_establishing )
+        return -1;
 
-  // Check for valid timeout value
-  if (seconds != -1)
-    timeout = seconds * 1000 + milliseconds;
-  else
-    timeout = m_timeout * 1000;
+    // This can be set to true from Interrupt() to exit this function a.s.a.p.
+    m_interrupt = false;
 
-  // Activate timer
-  if (timeout)
-  {
-    timer.m_state = &state;
-    timer.m_new_val = 0;
-    timer.Start((int)timeout, TRUE);
-  }
 
-  // Active polling (without using events)
-  //
-  // NOTE: this duplicates some of the code in OnRequest (lost
-  // connection and connection establishment handling) but this
-  // doesn't hurt. It has to be here because the event might
-  // be a bit delayed, and it has to be in OnRequest as well
-  // because maybe the WaitXXX functions are not being used.
-  //
-  // Do this at least once (important if timeout == 0, when
-  // we are just polling). Also, if just polling, do not yield.
-  //
-  while (state == -1)
-  {
-    result = GSocket_Select(m_socket, flags | GSOCK_LOST_FLAG);
+    const wxMilliClock_t timeEnd = wxGetLocalTimeMillis() + timeout;
 
-    // Incoming connection (server) or connection established (client)
-    if (result & GSOCK_CONNECTION_FLAG)
+    // Get the active event loop which we'll use for the message dispatching
+    // when running in the main thread unless this was explicitly disabled by
+    // setting wxSOCKET_BLOCK flag
+    wxEventLoopBase *eventLoop;
+    if ( !(m_flags & wxSOCKET_BLOCK) && wxIsMainThread() )
     {
-      timer.Stop();
-      m_connected = TRUE;
-      m_establishing = FALSE;
-      return TRUE;
+        eventLoop = wxEventLoop::GetActive();
     }
-
-    // Data available or output buffer ready
-    if ((result & GSOCK_INPUT_FLAG) || (result & GSOCK_OUTPUT_FLAG))
+    else // in worker thread
     {
-      timer.Stop();
-      return TRUE;
+        // We never dispatch messages from threads other than the main one.
+        eventLoop = NULL;
     }
 
-    // Connection lost
-    if (result & GSOCK_LOST_FLAG)
+    // Make sure the events we're interested in are enabled before waiting for
+    // them: this is really necessary here as otherwise this could happen:
+    //  1. DoRead(wxSOCKET_WAITALL) is called
+    //  2. There is nothing to read so DoWait(wxSOCKET_INPUT_FLAG) is called
+    //  3. Some, but not all data appears, wxSocketImplUnix::OnReadWaiting()
+    //     is called and wxSOCKET_INPUT_FLAG events are disabled in it
+    //  4. Because of wxSOCKET_WAITALL we call DoWait() again but the events
+    //     are still disabled and we block forever
+    //
+    // More elegant solution would be nice but for now simply re-enabling the
+    // events here will do
+    m_impl->ReenableEvents(flags & (wxSOCKET_INPUT_FLAG | wxSOCKET_OUTPUT_FLAG));
+
+
+    // Wait until we receive the event we're waiting for or the timeout expires
+    // (but note that we always execute the loop at least once, even if timeout
+    // is 0 as this is used for polling)
+    int rc = 0;
+    for ( bool firstTime = true; !m_interrupt; firstTime = false )
     {
-      timer.Stop();
-      m_connected = FALSE;                  // (GRG)
-      m_establishing = FALSE;
-      return (flags & GSOCK_LOST_FLAG);     // (GRG) <--- Maybe here???
+        long timeLeft = wxMilliClockToLong(timeEnd - wxGetLocalTimeMillis());
+        if ( timeLeft < 0 )
+        {
+            if ( !firstTime )
+                break;   // timed out
+
+            timeLeft = 0;
+        }
+
+        wxSocketEventFlags events;
+        if ( eventLoop )
+        {
+            // reset them before starting to wait
+            m_eventsgot = 0;
+
+            eventLoop->DispatchTimeout(timeLeft);
+
+            events = m_eventsgot;
+        }
+        else // no event loop or waiting in another thread
+        {
+            // as explained below, we should always check for wxSOCKET_LOST_FLAG
+            timeval tv;
+            SetTimeValFromMS(tv, timeLeft);
+            events = m_impl->Select(flags | wxSOCKET_LOST_FLAG, &tv);
+        }
+
+        // always check for wxSOCKET_LOST_FLAG, even if flags doesn't include
+        // it, as continuing to wait for anything else after getting it is
+        // pointless
+        if ( events & wxSOCKET_LOST_FLAG )
+        {
+            m_connected = false;
+            m_establishing = false;
+            rc = -1;
+            break;
+        }
+
+        // otherwise mask out the bits we're not interested in
+        events &= flags;
+
+        // Incoming connection (server) or connection established (client)?
+        if ( events & wxSOCKET_CONNECTION_FLAG )
+        {
+            m_connected = true;
+            m_establishing = false;
+            rc = true;
+            break;
+        }
+
+        // Data available or output buffer ready?
+        if ( (events & wxSOCKET_INPUT_FLAG) || (events & wxSOCKET_OUTPUT_FLAG) )
+        {
+            rc = true;
+            break;
+        }
     }
 
-    // Wait more?
-    if ((timeout == 0) || (m_interrupt))
-      break;
-    else
-      PROCESS_EVENTS();
-  }
-
-  timer.Stop();
-  return FALSE;
+    return rc;
 }
 
 bool wxSocketBase::Wait(long seconds, long milliseconds)
 {
-  return _Wait(seconds, milliseconds, GSOCK_INPUT_FLAG |
-                                      GSOCK_OUTPUT_FLAG |
-                                      GSOCK_CONNECTION_FLAG |
-                                      GSOCK_LOST_FLAG);
+    return DoWait(seconds, milliseconds,
+                  wxSOCKET_INPUT_FLAG |
+                  wxSOCKET_OUTPUT_FLAG |
+                  wxSOCKET_CONNECTION_FLAG) != 0;
 }
 
 bool wxSocketBase::WaitForRead(long seconds, long milliseconds)
 {
-  // Check pushback buffer
-  if (m_unread)
-    return TRUE;
-
-  return _Wait(seconds, milliseconds, GSOCK_INPUT_FLAG);
+    // Check pushback buffer before entering DoWait
+    if ( m_unread )
+        return true;
+
+    // Check if the socket is not already ready for input, if it is, there is
+    // no need to start waiting for it (worse, we'll actually never get a
+    // notification about the socket becoming ready if it is already under
+    // Windows)
+    if ( m_impl->Select(wxSOCKET_INPUT_FLAG) )
+        return true;
+
+    return DoWait(seconds, milliseconds, wxSOCKET_INPUT_FLAG) != 0;
 }
 
+
 bool wxSocketBase::WaitForWrite(long seconds, long milliseconds)
 {
-  return _Wait(seconds, milliseconds, GSOCK_OUTPUT_FLAG);
+    if ( m_impl->Select(wxSOCKET_OUTPUT_FLAG) )
+        return true;
+
+    return DoWait(seconds, milliseconds, wxSOCKET_OUTPUT_FLAG) != 0;
 }
 
 bool wxSocketBase::WaitForLost(long seconds, long milliseconds)
 {
-  return _Wait(seconds, milliseconds, GSOCK_LOST_FLAG);
+    return DoWait(seconds, milliseconds, wxSOCKET_LOST_FLAG) == -1;
 }
 
-void wxSocketBase::SetTimeout(long seconds)
-{
-  m_timeout = seconds;
-
-  if (m_socket)
-    GSocket_SetTimeout(m_socket, m_timeout * 1000);
-}
+// --------------------------------------------------------------------------
+// Miscellaneous
+// --------------------------------------------------------------------------
 
-// --------------------------------------------------------------
-// wxSocketBase flags
-// --------------------------------------------------------------
+//
+// Get local or peer address
+//
 
-void wxSocketBase::SetFlags(wxSockFlags _flags)
+bool wxSocketBase::GetPeer(wxSockAddress& addr) const
 {
-  m_flags = _flags;
-}
+    wxCHECK_MSG( m_impl, false, "invalid socket" );
 
-// --------------------------------------------------------------
-// wxSocketBase callback management
-// --------------------------------------------------------------
+    const wxSockAddressImpl& peer = m_impl->GetPeer();
+    if ( !peer.IsOk() )
+        return false;
 
-wxSocketBase::wxSockCbk wxSocketBase::Callback(wxSockCbk cbk_)
-{
-  wxSockCbk old_cbk = cbk_;
+    addr.SetAddress(peer);
 
-  m_cbk = cbk_;
-  return old_cbk;
+    return true;
 }
 
-char *wxSocketBase::CallbackData(char *data)
+bool wxSocketBase::GetLocal(wxSockAddress& addr) const
 {
-  char *old_data = m_cdata;
+    wxCHECK_MSG( m_impl, false, "invalid socket" );
 
-  m_cdata = data;
-  return old_data;
-}
+    const wxSockAddressImpl& local = m_impl->GetLocal();
+    if ( !local.IsOk() )
+        return false;
 
-// --------------------------------------------------------------
-// wxSocketBase automatic notifier
-// --------------------------------------------------------------
+    addr.SetAddress(local);
 
-// All events (INPUT, OUTPUT, CONNECTION, LOST) are now always
-// internally watched; but users will only be notified of those
-// events they are interested in.
+    return true;
+}
+
+//
+// Save and restore socket state
+//
 
-static void LINKAGEMODE wx_socket_callback(GSocket * WXUNUSED(socket),
-                                           GSocketEvent event, char *cdata)
+void wxSocketBase::SaveState()
 {
-  wxSocketBase *sckobj = (wxSocketBase *)cdata;
+    wxSocketState *state;
+
+    state = new wxSocketState();
 
-  sckobj->OnRequest((wxSocketNotify)event);
+    state->m_flags      = m_flags;
+    state->m_notify     = m_notify;
+    state->m_eventmask  = m_eventmask;
+    state->m_clientData = m_clientData;
+
+    m_states.Append(state);
 }
 
-wxSocketEventFlags wxSocketBase::EventToNotify(wxSocketNotify evt)
+void wxSocketBase::RestoreState()
 {
-  switch (evt)
-  {
-    case GSOCK_INPUT:      return GSOCK_INPUT_FLAG;
-    case GSOCK_OUTPUT:     return GSOCK_OUTPUT_FLAG;
-    case GSOCK_CONNECTION: return GSOCK_CONNECTION_FLAG;
-    case GSOCK_LOST:       return GSOCK_LOST_FLAG;
-  }
-  return 0;
+    wxList::compatibility_iterator node;
+    wxSocketState *state;
+
+    node = m_states.GetLast();
+    if (!node)
+        return;
+
+    state = (wxSocketState *)node->GetData();
+
+    m_flags      = state->m_flags;
+    m_notify     = state->m_notify;
+    m_eventmask  = state->m_eventmask;
+    m_clientData = state->m_clientData;
+
+    m_states.Erase(node);
+    delete state;
 }
 
-void wxSocketBase::SetNotify(wxSocketEventFlags flags)
+//
+// Timeout and flags
+//
+
+void wxSocketBase::SetTimeout(long seconds)
 {
-  m_neededreq = flags;
+    m_timeout = seconds;
+
+    if (m_impl)
+        m_impl->SetTimeout(m_timeout * 1000);
 }
 
-void wxSocketBase::Notify(bool notify)
+void wxSocketBase::SetFlags(wxSocketFlags flags)
 {
-  m_notify_state = notify;
+    // Do some sanity checking on the flags used: not all values can be used
+    // together.
+    wxASSERT_MSG( !(flags & wxSOCKET_NOWAIT) ||
+                  !(flags & (wxSOCKET_WAITALL | wxSOCKET_BLOCK)),
+                  "Using wxSOCKET_WAITALL or wxSOCKET_BLOCK with "
+                  "wxSOCKET_NOWAIT doesn't make sense" );
+
+    m_flags = flags;
 }
 
-void wxSocketBase::OnRequest(wxSocketNotify req_evt)
+
+// --------------------------------------------------------------------------
+// Event handling
+// --------------------------------------------------------------------------
+
+void wxSocketBase::OnRequest(wxSocketNotify notification)
 {
-  wxSocketEvent event(m_id);
-  wxSocketEventFlags flag = EventToNotify(req_evt);
+    wxSocketEventFlags flag = 0;
+    switch ( notification )
+    {
+        case wxSOCKET_INPUT:
+            flag = wxSOCKET_INPUT_FLAG;
+            break;
 
-  // This duplicates some code in _Wait(), but this doesn't
-  // hurt. It has to be here because we don't know whether
-  // WaitXXX will be used, and it has to be in _Wait as well
-  // because the event might be a bit delayed.
-  //
-  switch(req_evt)
-  {
-    case wxSOCKET_CONNECTION:
-      m_establishing = FALSE;
-      m_connected = TRUE;
-      break;
+        case wxSOCKET_OUTPUT:
+            flag = wxSOCKET_OUTPUT_FLAG;
+            break;
 
-    // If we are in the middle of a R/W operation, do not
-    // propagate events to users. Also, filter 'late' events
-    // which are no longer valid.
-    //
-    case wxSOCKET_INPUT:
-      if (m_reading || !GSocket_Select(m_socket, GSOCK_INPUT_FLAG))
-        return;
-      break;
+        case wxSOCKET_CONNECTION:
+            flag = wxSOCKET_CONNECTION_FLAG;
 
-    case wxSOCKET_OUTPUT:
-      if (m_writing || !GSocket_Select(m_socket, GSOCK_OUTPUT_FLAG))
-        return;
-      break;
+            // we're now successfully connected
+            m_connected = true;
+            m_establishing = false;
 
-    case wxSOCKET_LOST:
-      m_connected = FALSE;
-      m_establishing = FALSE;
-      break;
+            // error was previously set to wxSOCKET_WOULDBLOCK, but this is not
+            // the case any longer
+            SetError(wxSOCKET_NOERROR);
+            break;
 
-    default:
-      break;
-  }
+        case wxSOCKET_LOST:
+            flag = wxSOCKET_LOST_FLAG;
 
-  if (((m_neededreq & flag) == flag) && m_notify_state)
-  {
-    event.m_socket = this;
-    event.m_skevt  = req_evt;
+            // if we lost the connection the socket is now closed and not
+            // connected any more
+            m_connected = false;
+            m_closed = true;
+            break;
 
-    if (m_evt_handler)
-#if EXPERIMENTAL_USE_POST
-      wxPostEvent(m_evt_handler, event);
-#else
-      ProcessEvent(event);
-#endif
+        default:
+            wxFAIL_MSG( "unknown wxSocket notification" );
+    }
+
+    // remember the events which were generated for this socket, we're going to
+    // use this in DoWait()
+    m_eventsgot |= flag;
 
-    OldOnNotify(req_evt);
-    if (m_cbk)
-      m_cbk(*this, req_evt, m_cdata);
-  }
+    // send the wx event if enabled and we're interested in it
+    if ( m_notify && (m_eventmask & flag) && m_handler )
+    {
+        // don't generate the events when we're inside DoWait() called from our
+        // own code as we are going to consume the data that has just become
+        // available ourselves and the user code won't see it at all
+        if ( (notification == wxSOCKET_INPUT && m_reading) ||
+                (notification == wxSOCKET_OUTPUT && m_writing) )
+        {
+            return;
+        }
+
+        wxSocketEvent event(m_id);
+        event.m_event      = notification;
+        event.m_clientData = m_clientData;
+        event.SetEventObject(this);
+
+        m_handler->AddPendingEvent(event);
+    }
 }
 
-void wxSocketBase::OldOnNotify(wxSocketNotify WXUNUSED(evt))
+void wxSocketBase::Notify(bool notify)
 {
+    m_notify = notify;
 }
 
-// --------------------------------------------------------------
-// wxSocketBase set event handler
-// --------------------------------------------------------------
-
-void wxSocketBase::SetEventHandler(wxEvtHandler& h_evt, int id)
+void wxSocketBase::SetNotify(wxSocketEventFlags flags)
 {
-  m_evt_handler = &h_evt;
-  m_id = id;
+    m_eventmask = flags;
+}
 
-  SetNextHandler(&h_evt);
+void wxSocketBase::SetEventHandler(wxEvtHandler& handler, int id)
+{
+    m_handler = &handler;
+    m_id      = id;
 }
 
-// --------------------------------------------------------------
-// wxSocketBase pushback
-// --------------------------------------------------------------
+// --------------------------------------------------------------------------
+// Pushback buffer
+// --------------------------------------------------------------------------
 
-void wxSocketBase::Pushback(const char *buffer, wxUint32 size)
+void wxSocketBase::Pushback(const void *buffer, wxUint32 size)
 {
-  if (!size) return;
+    if (!size) return;
 
-  if (m_unread == NULL)
-    m_unread = (char *)malloc(size);
-  else
-  {
-    char *tmp;
+    if (m_unread == NULL)
+        m_unread = malloc(size);
+    else
+    {
+        void *tmp;
 
-    tmp = (char *)malloc(m_unrd_size + size);
-    memcpy(tmp+size, m_unread, m_unrd_size);
-    free(m_unread);
+        tmp = malloc(m_unrd_size + size);
+        memcpy((char *)tmp + size, m_unread, m_unrd_size);
+        free(m_unread);
 
-    m_unread = tmp;
-  }
+        m_unread = tmp;
+    }
 
-  m_unrd_size += size;
+    m_unrd_size += size;
 
-  memcpy(m_unread, buffer, size);
+    memcpy(m_unread, buffer, size);
 }
 
-wxUint32 wxSocketBase::GetPushback(char *buffer, wxUint32 size, bool peek)
+wxUint32 wxSocketBase::GetPushback(void *buffer, wxUint32 size, bool peek)
 {
-  if (!m_unrd_size)
-    return 0;
+    wxCHECK_MSG( buffer, 0, "NULL buffer" );
+
+    if (!m_unrd_size)
+        return 0;
 
-  if (size > (m_unrd_size-m_unrd_cur))
-    size = m_unrd_size-m_unrd_cur;
+    if (size > (m_unrd_size-m_unrd_cur))
+        size = m_unrd_size-m_unrd_cur;
 
-  memcpy(buffer, (m_unread+m_unrd_cur), size);
+    memcpy(buffer, (char *)m_unread + m_unrd_cur, size);
 
-  if (!peek)
-  {
-    m_unrd_cur += size;
-    if (m_unrd_size == m_unrd_cur)
+    if (!peek)
     {
-      free(m_unread);
-      m_unread = NULL;
-      m_unrd_size = 0;
-      m_unrd_cur  = 0;
+        m_unrd_cur += size;
+        if (m_unrd_size == m_unrd_cur)
+        {
+            free(m_unread);
+            m_unread = NULL;
+            m_unrd_size = 0;
+            m_unrd_cur  = 0;
+        }
     }
-  }
 
-  return size;
+    return size;
 }
 
-// --------------------------------------------------------------
+
+// ==========================================================================
 // wxSocketServer
-// --------------------------------------------------------------
+// ==========================================================================
 
-// --------------------------------------------------------------
-// wxSocketServer ctor and dtor
-// --------------------------------------------------------------
+// --------------------------------------------------------------------------
+// Ctor
+// --------------------------------------------------------------------------
 
-wxSocketServer::wxSocketServer(wxSockAddress& addr_man,
-                               wxSockFlags flags) :
-  wxSocketBase(flags, SOCK_SERVER)
+wxSocketServer::wxSocketServer(const wxSockAddress& addr,
+                               wxSocketFlags flags)
+              : wxSocketBase(flags, wxSOCKET_SERVER)
 {
-  // Create the socket
-  m_socket = GSocket_new();
+    wxLogTrace( wxTRACE_Socket, wxT("Opening wxSocketServer") );
+
+    wxSocketManager * const manager = wxSocketManager::Get();
+    m_impl = manager ? manager->CreateSocket(*this) : NULL;
+
+    if (!m_impl)
+    {
+        wxLogTrace( wxTRACE_Socket, wxT("*** Failed to create m_impl") );
+        return;
+    }
 
-  if (!m_socket)
-    return;
+    // Setup the socket as server
+    m_impl->SetLocal(addr.GetAddress());
+
+    if (GetFlags() & wxSOCKET_REUSEADDR) {
+        m_impl->SetReusable();
+    }
+    if (GetFlags() & wxSOCKET_BROADCAST) {
+        m_impl->SetBroadcast();
+    }
+    if (GetFlags() & wxSOCKET_NOBIND) {
+        m_impl->DontDoBind();
+    }
 
-  // Setup the socket as server
-  GSocket_SetLocal(m_socket, addr_man.GetAddress());
-  if (GSocket_SetServer(m_socket) != GSOCK_NOERROR)
-  {
-    GSocket_destroy(m_socket);
-    m_socket = NULL;
-    return;
-  }
+    if (m_impl->CreateServer() != wxSOCKET_NOERROR)
+    {
+        wxDELETE(m_impl);
 
-  GSocket_SetTimeout(m_socket, m_timeout * 1000);
-  GSocket_SetCallback(m_socket, GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
-                                GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
-                                wx_socket_callback, (char *)this);
+        wxLogTrace( wxTRACE_Socket, wxT("*** CreateServer() failed") );
+        return;
+    }
 
+    // Notice that we need a cast as wxSOCKET_T is 64 bit under Win64 and that
+    // the cast is safe because a wxSOCKET_T is a handle and so limited to 32
+    // (or, actually, even 24) bit values anyhow.
+    wxLogTrace( wxTRACE_Socket, wxT("wxSocketServer on fd %u"),
+                static_cast<unsigned>(m_impl->m_fd) );
 }
 
-// --------------------------------------------------------------
-// wxSocketServer Accept
-// --------------------------------------------------------------
+// --------------------------------------------------------------------------
+// Accept
+// --------------------------------------------------------------------------
 
 bool wxSocketServer::AcceptWith(wxSocketBase& sock, bool wait)
 {
-  GSocket *child_socket;
+    if ( !m_impl || (m_impl->m_fd == INVALID_SOCKET) || !m_impl->IsServer() )
+    {
+        wxFAIL_MSG( "can only be called for a valid server socket" );
 
-  if (!m_socket)
-    return FALSE;
+        SetError(wxSOCKET_INVSOCK);
 
-  // If wait == FALSE, then the call should be nonblocking.
-  // When we are finished, we put the socket to blocking mode
-  // again.
+        return false;
+    }
 
-  if (!wait)
-    GSocket_SetNonBlocking(m_socket, TRUE);
+    if ( wait )
+    {
+        // wait until we get a connection
+        if ( !m_impl->SelectWithTimeout(wxSOCKET_INPUT_FLAG) )
+        {
+            SetError(wxSOCKET_TIMEDOUT);
 
-  child_socket = GSocket_WaitConnection(m_socket);
+            return false;
+        }
+    }
 
-  if (!wait)
-    GSocket_SetNonBlocking(m_socket, FALSE);
+    sock.m_impl = m_impl->Accept(sock);
 
-  if (!child_socket)
-    return FALSE;
+    if ( !sock.m_impl )
+    {
+        SetError(m_impl->GetLastError());
 
-  sock.m_type = SOCK_INTERNAL;
-  sock.m_socket = child_socket;
-  sock.m_connected = TRUE;
+        return false;
+    }
 
-  GSocket_SetTimeout(sock.m_socket, sock.m_timeout * 1000);
-  GSocket_SetCallback(sock.m_socket, GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
-                                     GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
-                                     wx_socket_callback, (char *)&sock);
+    sock.m_type = wxSOCKET_BASE;
+    sock.m_connected = true;
 
-  return TRUE;
+    return true;
 }
 
 wxSocketBase *wxSocketServer::Accept(bool wait)
 {
-  wxSocketBase* sock = new wxSocketBase();
+    wxSocketBase* sock = new wxSocketBase();
 
-  sock->SetFlags((wxSockFlags)m_flags);
+    sock->SetFlags(m_flags);
 
-  if (!AcceptWith(*sock, wait))
-    return NULL;
+    if (!AcceptWith(*sock, wait))
+    {
+        sock->Destroy();
+        sock = NULL;
+    }
 
-  return sock;
+    return sock;
 }
 
 bool wxSocketServer::WaitForAccept(long seconds, long milliseconds)
 {
-  return _Wait(seconds, milliseconds, GSOCK_CONNECTION_FLAG);
+    return DoWait(seconds, milliseconds, wxSOCKET_CONNECTION_FLAG) == 1;
 }
 
-// --------------------------------------------------------------
-// wxSocketClient
-// --------------------------------------------------------------
+wxSOCKET_T wxSocketBase::GetSocket() const
+{
+    wxASSERT_MSG( m_impl, wxS("Socket not initialised") );
+
+    return m_impl->m_fd;
+}
+
+
+bool wxSocketBase::GetOption(int level, int optname, void *optval, int *optlen)
+{
+    wxASSERT_MSG( m_impl, wxT("Socket not initialised") );
+
+    SOCKOPTLEN_T lenreal = *optlen;
+    if ( getsockopt(m_impl->m_fd, level, optname,
+                    static_cast<char *>(optval), &lenreal) != 0 )
+        return false;
+
+    *optlen = lenreal;
 
-// --------------------------------------------------------------
-// wxSocketClient ctor and dtor
-// --------------------------------------------------------------
+    return true;
+}
+
+bool
+wxSocketBase::SetOption(int level, int optname, const void *optval, int optlen)
+{
+    wxASSERT_MSG( m_impl, wxT("Socket not initialised") );
+
+    return setsockopt(m_impl->m_fd, level, optname,
+                      static_cast<const char *>(optval), optlen) == 0;
+}
 
-wxSocketClient::wxSocketClient(wxSockFlags _flags) :
-  wxSocketBase(_flags, SOCK_CLIENT)
+bool wxSocketBase::SetLocal(const wxIPV4address& local)
 {
+    m_localAddress = local;
+
+    return true;
 }
 
-wxSocketClient::~wxSocketClient()
+// ==========================================================================
+// wxSocketClient
+// ==========================================================================
+
+// --------------------------------------------------------------------------
+// Ctor and dtor
+// --------------------------------------------------------------------------
+
+wxSocketClient::wxSocketClient(wxSocketFlags flags)
+              : wxSocketBase(flags, wxSOCKET_CLIENT)
 {
+    m_initialRecvBufferSize =
+    m_initialSendBufferSize = -1;
 }
 
-// --------------------------------------------------------------
-// wxSocketClient Connect functions
-// --------------------------------------------------------------
+// --------------------------------------------------------------------------
+// Connect
+// --------------------------------------------------------------------------
 
-bool wxSocketClient::Connect(wxSockAddress& addr_man, bool wait)
+bool wxSocketClient::DoConnect(const wxSockAddress& remote,
+                               const wxSockAddress* local,
+                               bool wait)
 {
-  GSocketError err;
+    if ( m_impl )
+    {
+        // Shutdown and destroy the old socket
+        Close();
+        delete m_impl;
+    }
 
-  if (m_socket)         // (GRG)
-  {
-    // Shutdown and destroy the socket
-    Close();
-    GSocket_destroy(m_socket);
-  }
+    m_connected = false;
+    m_establishing = false;
 
-  m_socket = GSocket_new();
-  m_connected = FALSE;
-  m_establishing = FALSE;
+    // Create and set up the new one
+    wxSocketManager * const manager = wxSocketManager::Get();
+    m_impl = manager ? manager->CreateSocket(*this) : NULL;
+    if ( !m_impl )
+        return false;
 
-  if (!m_socket)
-    return FALSE;
+    // Reuse makes sense for clients too, if we are trying to rebind to the same port
+    if (GetFlags() & wxSOCKET_REUSEADDR)
+        m_impl->SetReusable();
+    if (GetFlags() & wxSOCKET_BROADCAST)
+        m_impl->SetBroadcast();
+    if (GetFlags() & wxSOCKET_NOBIND)
+        m_impl->DontDoBind();
 
-  GSocket_SetTimeout(m_socket, m_timeout * 1000);
-  GSocket_SetCallback(m_socket, GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
-                                GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
-                                wx_socket_callback, (char *)this);
+    // Bind to the local IP address and port, when provided or if one had been
+    // set before
+    if ( !local && m_localAddress.GetAddress().IsOk() )
+        local = &m_localAddress;
 
-  // If wait == FALSE, then the call should be nonblocking.
-  // When we are finished, we put the socket to blocking mode
-  // again.
+    if ( local )
+        m_impl->SetLocal(local->GetAddress());
 
-  if (!wait)
-    GSocket_SetNonBlocking(m_socket, TRUE);
+    m_impl->SetInitialSocketBuffers(m_initialRecvBufferSize, m_initialSendBufferSize);
 
-  GSocket_SetPeer(m_socket, addr_man.GetAddress());
-  err = GSocket_Connect(m_socket, GSOCK_STREAMED);
+    m_impl->SetPeer(remote.GetAddress());
 
-  if (!wait)
-    GSocket_SetNonBlocking(m_socket, FALSE);
+    // Finally do create the socket and connect to the peer
+    const wxSocketError err = m_impl->CreateClient(wait);
 
-  if (err != GSOCK_NOERROR)
-  {
-    if (err == GSOCK_WOULDBLOCK)
-      m_establishing = TRUE;
+    if ( err != wxSOCKET_NOERROR )
+    {
+        if ( err == wxSOCKET_WOULDBLOCK )
+        {
+            wxASSERT_MSG( !wait, "shouldn't get this for blocking connect" );
+
+            m_establishing = true;
+        }
+
+        return false;
+    }
 
-    return FALSE;
-  }
+    m_connected = true;
+    return true;
+}
+
+bool wxSocketClient::Connect(const wxSockAddress& remote, bool wait)
+{
+    return DoConnect(remote, NULL, wait);
+}
 
-  m_connected = TRUE;
-  return TRUE;
+bool wxSocketClient::Connect(const wxSockAddress& remote,
+                             const wxSockAddress& local,
+                             bool wait)
+{
+    return DoConnect(remote, &local, wait);
 }
 
 bool wxSocketClient::WaitOnConnect(long seconds, long milliseconds)
 {
-  if (m_connected)                      // Already connected
-    return TRUE;
+    if ( m_connected )
+    {
+        // this happens if the initial attempt to connect succeeded without
+        // blocking
+        return true;
+    }
 
-  if (!m_establishing || !m_socket)     // No connection in progress
-    return FALSE;
+    wxCHECK_MSG( m_establishing && m_impl, false,
+                 "No connection establishment attempt in progress" );
 
-  return _Wait(seconds, milliseconds, GSOCK_CONNECTION_FLAG);
+    // notice that we return true even if DoWait() returned -1, i.e. if an
+    // error occurred and connection was lost: this is intentional as we should
+    // return false only if timeout expired without anything happening
+    return DoWait(seconds, milliseconds, wxSOCKET_CONNECTION_FLAG) != 0;
 }
 
-// --------------------------------------------------------------
+// ==========================================================================
 // wxDatagramSocket
-// --------------------------------------------------------------
-
-/* NOTE: experimental stuff - might change */
+// ==========================================================================
 
-wxDatagramSocket::wxDatagramSocket( wxSockAddress& addr, wxSockFlags flags )
-                : wxSocketBase( flags, SOCK_DATAGRAM )
+wxDatagramSocket::wxDatagramSocket( const wxSockAddress& addr,
+                                    wxSocketFlags flags )
+                : wxSocketBase( flags, wxSOCKET_DATAGRAM )
 {
-  // Create the socket
-  m_socket = GSocket_new();
+    // Create the socket
+    wxSocketManager * const manager = wxSocketManager::Get();
+    m_impl = manager ? manager->CreateSocket(*this) : NULL;
 
-  if(!m_socket)
-    return;
+    if (!m_impl)
+        return;
 
-  // Setup the socket as non connection oriented
-  GSocket_SetLocal(m_socket, addr.GetAddress());
-  if( GSocket_SetNonOriented(m_socket) != GSOCK_NOERROR )
-  {
-    GSocket_destroy(m_socket);
-    m_socket = NULL;
-    return;
-  }
+    // Setup the socket as non connection oriented
+    m_impl->SetLocal(addr.GetAddress());
+    if (flags & wxSOCKET_REUSEADDR)
+    {
+        m_impl->SetReusable();
+    }
+    if (GetFlags() & wxSOCKET_BROADCAST)
+    {
+        m_impl->SetBroadcast();
+    }
+    if (GetFlags() & wxSOCKET_NOBIND)
+    {
+        m_impl->DontDoBind();
+    }
 
-  // Initialize all stuff
-  m_connected = FALSE;
-  m_establishing = FALSE;
-  GSocket_SetTimeout( m_socket, m_timeout );
-  GSocket_SetCallback( m_socket, GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
-                                 GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
-                                 wx_socket_callback, (char*)this );
+    if ( m_impl->CreateUDP() != wxSOCKET_NOERROR )
+    {
+        wxDELETE(m_impl);
+        return;
+    }
 
+    // Initialize all stuff
+    m_connected = false;
+    m_establishing = false;
 }
 
 wxDatagramSocket& wxDatagramSocket::RecvFrom( wxSockAddress& addr,
-                                              char* buf,
+                                              void* buf,
                                               wxUint32 nBytes )
 {
     Read(buf, nBytes);
@@ -1132,53 +2090,58 @@ wxDatagramSocket& wxDatagramSocket::RecvFrom( wxSockAddress& addr,
     return (*this);
 }
 
-wxDatagramSocket& wxDatagramSocket::SendTo( wxSockAddress& addr,
-                                            const char* buf,
+wxDatagramSocket& wxDatagramSocket::SendTo( const wxSockAddress& addr,
+                                            const void* buf,
                                             wxUint32 nBytes )
 {
-    GSocket_SetPeer(m_socket, addr.GetAddress());
+    wxASSERT_MSG( m_impl, wxT("Socket not initialised") );
+
+    m_impl->SetPeer(addr.GetAddress());
     Write(buf, nBytes);
     return (*this);
 }
 
-// --------------------------------------------------------------
-// wxSocketEvent
-// --------------------------------------------------------------
-
-// XXX: Should be moved to event.cpp ?
-
-wxSocketEvent::wxSocketEvent(int id)
-  : wxEvent(id)
-{
-  wxEventType type = (wxEventType)wxEVT_SOCKET;
-
-  SetEventType(type);
-}
-
-void wxSocketEvent::CopyObject(wxObject& obj_d) const
-{
-  wxSocketEvent *event = (wxSocketEvent *)&obj_d;
-
-  wxEvent::CopyObject(obj_d);
-
-  event->m_skevt = m_skevt;
-  event->m_socket = m_socket;
-}
-
-// --------------------------------------------------------------------------
+// ==========================================================================
 // wxSocketModule
-// --------------------------------------------------------------------------
+// ==========================================================================
 
-class WXDLLEXPORT wxSocketModule: public wxModule
+class wxSocketModule : public wxModule
 {
-  DECLARE_DYNAMIC_CLASS(wxSocketModule)
-
 public:
-  bool OnInit() { return GSocket_Init(); }
-  void OnExit() { GSocket_Cleanup(); }
+    virtual bool OnInit()
+    {
+        // wxSocketBase will call Initialize() itself only if sockets are
+        // really used, don't do it from here
+        return true;
+    }
+
+    virtual void OnExit()
+    {
+        if ( wxSocketBase::IsInitialized() )
+            wxSocketBase::Shutdown();
+    }
+
+private:
+    DECLARE_DYNAMIC_CLASS(wxSocketModule)
 };
 
 IMPLEMENT_DYNAMIC_CLASS(wxSocketModule, wxModule)
 
+#if defined(wxUSE_SELECT_DISPATCHER) && wxUSE_SELECT_DISPATCHER
+// NOTE: we need to force linking against socketiohandler.cpp otherwise in
+//       static builds of wxWidgets the ManagerSetter::ManagerSetter ctor
+//       contained there wouldn't be ever called
+wxFORCE_LINK_MODULE( socketiohandler )
+#endif
+
+// same for ManagerSetter in the MSW file
+#ifdef __WINDOWS__
+    wxFORCE_LINK_MODULE( mswsocket )
+#endif
+
+// and for OSXManagerSetter in the OS X one
+#ifdef __WXOSX__
+    wxFORCE_LINK_MODULE( osxsocket )
 #endif
-  // wxUSE_SOCKETS
+
+#endif // wxUSE_SOCKETS