/*
* tclWinNotify.c --
*
* This file contains Windows-specific procedures for the notifier,
* which is the lowest-level part of the Tcl event loop. This file
* works together with ../generic/tclNotify.c.
*
* 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: tclWinNotify.c,v 1.11.2.1 2003/03/21 03:24:09 dgp Exp $
*/
#include <windows.h>
#include "Lang.h"
#include "tkWin.h"
#if defined(TCL_EVENT_IMPLEMENT)
/*
* The follwing static indicates whether this module has been initialized.
*/
#define INTERVAL_TIMER 1 /* Handle of interval timer. */
#define WM_WAKEUP WM_USER /* Message that is send by
* Tcl_AlertNotifier. */
/*
* The following static structure contains the state information for the
* Windows implementation of the Tcl notifier. One of these structures
* is created for each thread that is using the notifier.
*/
typedef struct ThreadSpecificData {
CRITICAL_SECTION crit; /* Monitor for this notifier. */
DWORD thread; /* Identifier for thread associated with this
* notifier. */
HANDLE event; /* Event object used to wake up the notifier
* thread. */
int pending; /* Alert message pending, this field is
* locked by the notifierMutex. */
HWND hwnd; /* Messaging window. */
int timeout; /* Current timeout value. */
int timerActive; /* 1 if interval timer is running. */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
extern TclStubs tclStubs;
extern Tcl_NotifierProcs tclOriginalNotifier;
/*
* The following static indicates the number of threads that have
* initialized notifiers. It controls the lifetime of the TclNotifier
* window class.
*
* You must hold the notifierMutex lock before accessing this variable.
*/
static int notifierCount = 0;
TCL_DECLARE_MUTEX(notifierMutex)
/*
* Static routines defined in this file.
*/
static LRESULT CALLBACK NotifierProc(HWND hwnd, UINT message,
WPARAM wParam, LPARAM lParam);
/*
*----------------------------------------------------------------------
*
* Tcl_InitNotifier --
*
* Initializes the platform specific notifier state.
*
* Results:
* Returns a handle to the notifier state for this thread..
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
ClientData
Tcl_InitNotifier()
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
WNDCLASS class;
/*
* Register Notifier window class if this is the first thread to
* use this module.
*/
Tcl_MutexLock(¬ifierMutex);
if (notifierCount == 0) {
class.style = 0;
class.cbClsExtra = 0;
class.cbWndExtra = 0;
class.hInstance = TclWinGetTclInstance();
class.hbrBackground = NULL;
class.lpszMenuName = NULL;
class.lpszClassName = "TclNotifier";
class.lpfnWndProc = NotifierProc;
class.hIcon = NULL;
class.hCursor = NULL;
if (!RegisterClassA(&class)) {
panic("Unable to register TclNotifier window class");
}
}
notifierCount++;
Tcl_MutexUnlock(¬ifierMutex);
tsdPtr->pending = 0;
tsdPtr->timerActive = 0;
InitializeCriticalSection(&tsdPtr->crit);
tsdPtr->hwnd = NULL;
tsdPtr->thread = GetCurrentThreadId();
tsdPtr->event = CreateEvent(NULL, TRUE /* manual */,
FALSE /* !signaled */, NULL);
return (ClientData) tsdPtr;
}
/*
*----------------------------------------------------------------------
*
* Tcl_FinalizeNotifier --
*
* This function is called to cleanup the notifier state before
* a thread is terminated.
*
* Results:
* None.
*
* Side effects:
* May dispose of the notifier window and class.
*
*----------------------------------------------------------------------
*/
void
Tcl_FinalizeNotifier(clientData)
ClientData clientData; /* Pointer to notifier data. */
{
ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData;
/*
* Only finalize the notifier if a notifier was installed in the
* current thread; there is a route in which this is not
* guaranteed to be true (when tclWin32Dll.c:DllMain() is called
* with the flag DLL_PROCESS_DETACH by the OS, which could be
* doing so from a thread that's never previously been involved
* with Tcl, e.g. the task manager) so this check is important.
*
* Fixes Bug #217982 reported by Hugh Vu and Gene Leache.
*/
if (tsdPtr == NULL) {
return;
}
DeleteCriticalSection(&tsdPtr->crit);
CloseHandle(tsdPtr->event);
/*
* Clean up the timer and messaging window for this thread.
*/
if (tsdPtr->hwnd) {
KillTimer(tsdPtr->hwnd, INTERVAL_TIMER);
DestroyWindow(tsdPtr->hwnd);
}
/*
* If this is the last thread to use the notifier, unregister
* the notifier window class.
*/
Tcl_MutexLock(¬ifierMutex);
notifierCount--;
if (notifierCount == 0) {
UnregisterClassA("TclNotifier", TclWinGetTclInstance());
}
Tcl_MutexUnlock(¬ifierMutex);
}
/*
*----------------------------------------------------------------------
*
* Tcl_AlertNotifier --
*
* Wake up the specified notifier from any thread. This routine
* is called by the platform independent notifier code whenever
* the Tcl_ThreadAlert routine is called. This routine is
* guaranteed not to be called on a given notifier after
* Tcl_FinalizeNotifier is called for that notifier. This routine
* is typically called from a thread other than the notifier's
* thread.
*
* Results:
* None.
*
* Side effects:
* Sends a message to the messaging window for the notifier
* if there isn't already one pending.
*
*----------------------------------------------------------------------
*/
void
Tcl_AlertNotifier(clientData)
ClientData clientData; /* Pointer to thread data. */
{
ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData;
/*
* Note that we do not need to lock around access to the hwnd
* because the race condition has no effect since any race condition
* implies that the notifier thread is already awake.
*/
if (tsdPtr->hwnd) {
/*
* We do need to lock around access to the pending flag.
*/
EnterCriticalSection(&tsdPtr->crit);
if (!tsdPtr->pending) {
PostMessage(tsdPtr->hwnd, WM_WAKEUP, 0, 0);
}
tsdPtr->pending = 1;
LeaveCriticalSection(&tsdPtr->crit);
} else {
SetEvent(tsdPtr->event);
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetTimer --
*
* This procedure sets the current notifier timer value. The
* notifier will ensure that Tcl_ServiceAll() is called after
* the specified interval, even if no events have occurred.
*
* Results:
* None.
*
* Side effects:
* Replaces any previous timer.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetTimer(
Tcl_Time *timePtr) /* Maximum block time, or NULL. */
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
UINT timeout;
/*
* Allow the notifier to be hooked. This may not make sense
* on Windows, but mirrors the UNIX hook.
*/
#ifndef _LANG
if (tclStubs.tcl_SetTimer != tclOriginalNotifier.setTimerProc) {
tclStubs.tcl_SetTimer(timePtr);
return;
}
#endif
/*
* We only need to set up an interval timer if we're being called
* from an external event loop. If we don't have a window handle
* then we just return immediately and let Tcl_WaitForEvent handle
* timeouts.
*/
if (!tsdPtr->hwnd) {
return;
}
if (!timePtr) {
timeout = 0;
} else {
/*
* Make sure we pass a non-zero value into the timeout argument.
* Windows seems to get confused by zero length timers.
*/
timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
if (timeout == 0) {
timeout = 1;
}
}
tsdPtr->timeout = timeout;
if (timeout != 0) {
tsdPtr->timerActive = 1;
SetTimer(tsdPtr->hwnd, INTERVAL_TIMER,
(unsigned long) tsdPtr->timeout, NULL);
} else {
tsdPtr->timerActive = 0;
KillTimer(tsdPtr->hwnd, INTERVAL_TIMER);
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_ServiceModeHook --
*
* This function is invoked whenever the service mode changes.
*
* Results:
* None.
*
* Side effects:
* If this is the first time the notifier is set into
* TCL_SERVICE_ALL, then the communication window is created.
*
*----------------------------------------------------------------------
*/
void
Tcl_ServiceModeHook(mode)
int mode; /* Either TCL_SERVICE_ALL, or
* TCL_SERVICE_NONE. */
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
/*
* If this is the first time that the notifier has been used from a
* modal loop, then create a communication window. Note that after
* this point, the application needs to service events in a timely
* fashion or Windows will hang waiting for the window to respond
* to synchronous system messages. At some point, we may want to
* consider destroying the window if we leave the modal loop, but
* for now we'll leave it around.
*/
if (mode == TCL_SERVICE_ALL && !tsdPtr->hwnd) {
tsdPtr->hwnd = CreateWindowA("TclNotifier", "TclNotifier", WS_TILED,
0, 0, 0, 0, NULL, NULL, TclWinGetTclInstance(), NULL);
/*
* Send an initial message to the window to ensure that we wake up the
* notifier once we get into the modal loop. This will force the
* notifier to recompute the timeout value and schedule a timer
* if one is needed.
*/
Tcl_AlertNotifier((ClientData)tsdPtr);
}
}
/*
*----------------------------------------------------------------------
*
* NotifierProc --
*
* This procedure is invoked by Windows to process events on
* the notifier window. Messages will be sent to this window
* in response to external timer events or calls to
* TclpAlertTsdPtr->
*
* Results:
* A standard windows result.
*
* Side effects:
* Services any pending events.
*
*----------------------------------------------------------------------
*/
static LRESULT CALLBACK
NotifierProc(
HWND hwnd,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
if (message == WM_WAKEUP) {
EnterCriticalSection(&tsdPtr->crit);
tsdPtr->pending = 0;
LeaveCriticalSection(&tsdPtr->crit);
} else if (message != WM_TIMER) {
return DefWindowProc(hwnd, message, wParam, lParam);
}
/*
* Process all of the runnable events.
*/
Tcl_ServiceAll();
return 0;
}
/*
*----------------------------------------------------------------------
*
* Tcl_WaitForEvent --
*
* This function is called by Tcl_DoOneEvent to wait for new
* events on the message queue. If the block time is 0, then
* Tcl_WaitForEvent just polls the event queue without blocking.
*
* Results:
* Returns -1 if a WM_QUIT message is detected, returns 1 if
* a message was dispatched, otherwise returns 0.
*
* Side effects:
* Dispatches a message to a window procedure, which could do
* anything.
*
*----------------------------------------------------------------------
*/
int
Tcl_WaitForEvent(
Tcl_Time *timePtr) /* Maximum block time, or NULL. */
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
MSG msg;
DWORD timeout, result;
int status;
/*
* Allow the notifier to be hooked. This may not make
* sense on windows, but mirrors the UNIX hook.
*/
#ifndef _LANG
if (tclStubs.tcl_WaitForEvent != tclOriginalNotifier.waitForEventProc) {
return tclStubs.tcl_WaitForEvent(timePtr);
}
#endif
/*
* Compute the timeout in milliseconds.
*/
if (timePtr) {
timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
} else {
timeout = INFINITE;
}
/*
* Check to see if there are any messages in the queue before waiting
* because MsgWaitForMultipleObjects will not wake up if there are events
* currently sitting in the queue.
*/
if (!PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
/*
* Wait for something to happen (a signal from another thread, a
* message, or timeout).
*/
result = MsgWaitForMultipleObjects(1, &tsdPtr->event, FALSE, timeout,
QS_ALLINPUT);
}
/*
* Check to see if there are any messages to process.
*/
if (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
/*
* Retrieve and dispatch the first message.
*/
result = GetMessage(&msg, NULL, 0, 0);
if (result == 0) {
/*
* We received a request to exit this thread (WM_QUIT), so
* propagate the quit message and start unwinding.
*/
PostQuitMessage((int) msg.wParam);
status = -1;
} else if (result == -1) {
/*
* We got an error from the system. I have no idea why this would
* happen, so we'll just unwind.
*/
status = -1;
} else {
TranslateMessage(&msg);
DispatchMessage(&msg);
status = 1;
}
} else {
status = 0;
}
ResetEvent(tsdPtr->event);
return status;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Sleep --
*
* Delay execution for the specified number of milliseconds.
*
* Results:
* None.
*
* Side effects:
* Time passes.
*
*----------------------------------------------------------------------
*/
void
Tcl_Sleep(ms)
int ms; /* Number of milliseconds to sleep. */
{
/*
* Simply calling 'Sleep' for the requisite number of milliseconds
* can make the process appear to wake up early because it isn't
* synchronized with the CPU performance counter that is used in
* tclWinTime.c. This behavior is probably benign, but messes
* up some of the corner cases in the test suite. We get around
* this problem by repeating the 'Sleep' call as many times
* as necessary to make the clock advance by the requisite amount.
*/
Tcl_Time now; /* Current wall clock time */
Tcl_Time desired; /* Desired wakeup time */
DWORD sleepTime = ms; /* Time to sleep */
Tcl_GetTime( &now );
desired.sec = now.sec + ( ms / 1000 );
desired.usec = now.usec + 1000 * ( ms % 1000 );
if ( desired.usec > 1000000 ) {
++desired.sec;
desired.usec -= 1000000;
}
for ( ; ; ) {
Sleep( sleepTime );
Tcl_GetTime( &now );
if ( now.sec > desired.sec ) {
break;
} else if ( ( now.sec == desired.sec )
&& ( now.usec >= desired.usec ) ) {
break;
}
sleepTime = ( ( 1000 * ( desired.sec - now.sec ) )
+ ( ( desired.usec - now.usec ) / 1000 ) );
}
}
#endif