/*
 * tclWinSock.c --
 *
 *	This file contains Windows-specific socket related code.
 *
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclWinSock.c,v 1.52 2006/03/10 17:34:35 vasiljevic Exp $
 */

#include "tclWinInt.h"

/*
 * Make sure to remove the redirection defines set in tclWinPort.h that is in
 * use in other sections of the core, except for us.

static DWORD WINAPI	SocketThread(LPVOID arg);
static void		TcpThreadActionProc(ClientData instanceData,
			    int action);

static Tcl_EventCheckProc	SocketCheckProc;
static Tcl_EventProc		SocketEventProc;
static Tcl_EventSetupProc	SocketSetupProc;

static Tcl_DriverBlockModeProc	TcpBlockProc;
static Tcl_DriverCloseProc	TcpCloseProc;
static Tcl_DriverSetOptionProc	TcpSetOptionProc;
static Tcl_DriverGetOptionProc	TcpGetOptionProc;
static Tcl_DriverInputProc	TcpInputProc;
static Tcl_DriverOutputProc	TcpOutputProc;
static Tcl_DriverWatchProc	TcpWatchProc;

 *
 * InitSockets --
 *
 *	Initialize the socket module. Attempts to load the wsock32.dll library
 *	and set up the winSock function table. If successful, registers the
 *	event window for the socket notifier code.
 *
 *	Assumes socketMutex is held.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Dynamically loads wsock32.dll, and registers a new window class and
 *	creates a window for use in asynchronous socket notification.

    /*
     * Check for per-thread initialization.
     */

    if (tsdPtr == NULL) {
	tsdPtr = TCL_TSD_INIT(&dataKey);
	tsdPtr->socketList = NULL;
	tsdPtr->hwnd       = NULL;

	tsdPtr->threadId   = Tcl_GetCurrentThread();

	tsdPtr->readyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
	if (tsdPtr->readyEvent == NULL) {
	    goto unloadLibrary;
	}
	tsdPtr->socketListLock = CreateEvent(NULL, FALSE, TRUE, NULL);
	if (tsdPtr->socketListLock == NULL) {
	    goto unloadLibrary;
	}
	tsdPtr->socketThread = CreateThread(NULL, 256, SocketThread,
		tsdPtr, 0, &id);


	if (tsdPtr->socketThread == NULL) {
	    goto unloadLibrary;
	}

	SetThreadPriority(tsdPtr->socketThread, THREAD_PRIORITY_HIGHEST);

	/*
	 * Wait for the thread to signal when the window has
	 * been created and if it is ready to go.
	 */

	WaitForSingleObject(tsdPtr->readyEvent, INFINITE);



	if (tsdPtr->hwnd == NULL) {
	    goto unloadLibrary; /* Trouble creating the window */
	}

	Tcl_CreateEventSource(SocketSetupProc, SocketCheckProc, NULL);

    }
    return;

  unloadLibrary:

    TclpFinalizeSockets();

    FreeLibrary(winSock.hModule);
    winSock.hModule = NULL;
    return;
}

/*
 *----------------------------------------------------------------------

    /* ARGSUSED */
static void
SocketExitHandler(
    ClientData clientData)		/* Not used. */
{
    Tcl_MutexLock(&socketMutex);
    if (winSock.hModule) {

	/*
	 * Make sure the socket event handling window is cleaned-up for, at
	 * most, this thread.
	 */

	TclpFinalizeSockets();
	UnregisterClass("TclSocket", TclWinGetTclInstance());
	winSock.WSACleanup();
	FreeLibrary(winSock.hModule);
	winSock.hModule = NULL;
    }
    initialized = 0;
    Tcl_MutexUnlock(&socketMutex);
}

/*
 *----------------------------------------------------------------------
 *
 * TclpFinalizeSockets --
 *
 *	This function is called from Tcl_FinalizeThread to finalize
 *	the platform specific socket subsystem.
 *	Also, it may be called from within this module to cleanup
 *	the state if unable to initialize the sockets subsystem.

 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Deletes the event source and destroys the socket thread.
 *
 *----------------------------------------------------------------------
 */


void
TclpFinalizeSockets()

{
    ThreadSpecificData *tsdPtr;


    tsdPtr = (ThreadSpecificData *)TclThreadDataKeyGet(&dataKey);
    if (tsdPtr != NULL) {


	if (tsdPtr->socketThread != NULL) {
	    if (tsdPtr->hwnd != NULL) {
		PostMessage(tsdPtr->hwnd, SOCKET_TERMINATE, 0, 0);

		/*
		 * Wait for the thread to exit. This ensures that we are
		 * completely cleaned up before we leave this function.


		 */

		WaitForSingleObject(tsdPtr->readyEvent, INFINITE);
		tsdPtr->hwnd = NULL;
	    }
	    CloseHandle(tsdPtr->socketThread);
	    tsdPtr->socketThread = NULL;
	}
	if (tsdPtr->readyEvent != NULL) {
	    CloseHandle(tsdPtr->readyEvent);
	    tsdPtr->readyEvent = NULL;
	}
	if (tsdPtr->socketListLock != NULL) {
	    CloseHandle(tsdPtr->socketListLock);
	    tsdPtr->socketListLock = NULL;
	}

	Tcl_DeleteEventSource(SocketSetupProc, SocketCheckProc, NULL);
    }
}

/*
 *----------------------------------------------------------------------
 *

static DWORD WINAPI
SocketThread(
    LPVOID arg)
{
    MSG msg;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)(arg);

    /*
     * Create a dummy window receiving socket events.
     */

    tsdPtr->hwnd = CreateWindow("TclSocket", "TclSocket",
	    WS_TILED, 0, 0, 0, 0, NULL, NULL, windowClass.hInstance, arg);

    /*

     * Signalize thread creator that we are done creating the window.
     */

    SetEvent(tsdPtr->readyEvent);

    /*
     * If unable to create the window, exit this thread immediately.
     */

    if (tsdPtr->hwnd == NULL) {
	return 1;
    }

    /*
     * Process all messages on the socket window until WM_QUIT.
     * This threads exits only when instructed to do so by the
     * call to PostMessage(SOCKET_TERMINATE) in TclpFinalizeSockets().
     */

    while (GetMessage(&msg, NULL, 0, 0) > 0) {
	DispatchMessage(&msg);
    }

    /*
     * This releases waiters on thread exit in TclpFinalizeSockets()
     */

    SetEvent(tsdPtr->readyEvent);

    return msg.wParam;
}


/*
 *----------------------------------------------------------------------
 *

	SetEvent(tsdPtr->socketListLock);

	notifyCmd = SELECT;
    } else {
	SocketInfo **nextPtrPtr;
	int removed = 0;

	tsdPtr = TCL_TSD_INIT(&dataKey);

	/*
	 * TIP #218, Bugfix: All access to socketList has to be protected by
	 * the lock.
	 */

	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	for (nextPtrPtr = &(tsdPtr->socketList); (*nextPtrPtr) != NULL;
		nextPtrPtr = &((*nextPtrPtr)->nextPtr)) {
	    if ((*nextPtrPtr) == infoPtr) {
		(*nextPtrPtr) = infoPtr->nextPtr;
		removed = 1;
		break;
	    }
	}
	SetEvent(tsdPtr->socketListLock);