/*
* 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 1.21.10.1 2010/05/21 12:18:17 nijtmans Exp $
*/
#include "tclInt.h"
/*
* 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(void)
{
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)) {
Tcl_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) /* 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) /* 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.
*/
if (tclStubs.tcl_SetTimer != tclOriginalNotifier.setTimerProc) {
tclStubs.tcl_SetTimer(timePtr);
return;
}
/*
* 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(
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, /* Passed on... */
UINT message, /* What messsage is this? */
WPARAM wParam, /* Passed on... */
LPARAM lParam) /* Passed on... */
{
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.
*/
if (tclStubs.tcl_WaitForEvent != tclOriginalNotifier.waitForEventProc) {
return tclStubs.tcl_WaitForEvent(timePtr);
}
/*
* Compute the timeout in milliseconds.
*/
if (timePtr) {
/*
* TIP #233 (Virtualized Time). Convert virtual domain delay to
* real-time.
*/
Tcl_Time myTime;
myTime.sec = timePtr->sec;
myTime.usec = timePtr->usec;
if (myTime.sec != 0 || myTime.usec != 0) {
(*tclScaleTimeProcPtr) (&myTime, tclTimeClientData);
}
timeout = myTime.sec * 1000 + myTime.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) or loop servicing asynchronous procedure calls
* queued to this thread.
*/
again:
result = MsgWaitForMultipleObjectsEx(1, &tsdPtr->event, timeout,
QS_ALLINPUT, MWMO_ALERTABLE);
if (result == WAIT_IO_COMPLETION) {
goto again;
} else if (result == WAIT_FAILED) {
status = -1;
goto end;
}
}
/*
* 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 == (DWORD)-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;
}
end:
ResetEvent(tsdPtr->event);
return status;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Sleep --
*
* Delay execution for the specified number of milliseconds.
*
* Results:
* None.
*
* Side effects:
* Time passes.
*
*----------------------------------------------------------------------
*/
void
Tcl_Sleep(
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. */
Tcl_Time vdelay; /* Time to sleep, for scaling virtual ->
* real. */
DWORD sleepTime; /* Time to sleep, real-time */
vdelay.sec = ms / 1000;
vdelay.usec = (ms % 1000) * 1000;
Tcl_GetTime(&now);
desired.sec = now.sec + vdelay.sec;
desired.usec = now.usec + vdelay.usec;
if (desired.usec > 1000000) {
++desired.sec;
desired.usec -= 1000000;
}
/*
* TIP #233: Scale delay from virtual to real-time.
*/
(*tclScaleTimeProcPtr) (&vdelay, tclTimeClientData);
sleepTime = vdelay.sec * 1000 + vdelay.usec / 1000;
for (;;) {
Sleep(sleepTime);
Tcl_GetTime(&now);
if (now.sec > desired.sec) {
break;
} else if ((now.sec == desired.sec) && (now.usec >= desired.usec)) {
break;
}
vdelay.sec = desired.sec - now.sec;
vdelay.usec = desired.usec - now.usec;
(*tclScaleTimeProcPtr) (&vdelay, tclTimeClientData);
sleepTime = vdelay.sec * 1000 + vdelay.usec / 1000;
}
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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