/*
* tclTimer.c --
*
* This file provides timer event management facilities for Tcl,
* including the "after" command.
*
* Copyright (c) 1997 by 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: tclTimer.c,v 1.31 2008/01/22 20:52:10 dgp Exp $
*/
#include "tclInt.h"
/*
* For each timer callback that's pending there is one record of the following
* type. The normal handlers (created by Tcl_CreateTimerHandler) are chained
* together in a list sorted by time (earliest event first).
*/
typedef struct TimerHandler {
Tcl_Time time; /* When timer is to fire. */
Tcl_TimerProc *proc; /* Function to call. */
ClientData clientData; /* Argument to pass to proc. */
Tcl_TimerToken token; /* Identifies handler so it can be deleted. */
struct TimerHandler *nextPtr;
/* Next event in queue, or NULL for end of
* queue. */
} TimerHandler;
/*
* The data structure below is used by the "after" command to remember the
* command to be executed later. All of the pending "after" commands for an
* interpreter are linked together in a list.
*/
typedef struct AfterInfo {
struct AfterAssocData *assocPtr;
/* Pointer to the "tclAfter" assocData for the
* interp in which command will be
* executed. */
Tcl_Obj *commandPtr; /* Command to execute. */
int id; /* Integer identifier for command; used to
* cancel it. */
Tcl_TimerToken token; /* Used to cancel the "after" command. NULL
* means that the command is run as an idle
* handler rather than as a timer handler.
* NULL means this is an "after idle" handler
* rather than a timer handler. */
struct AfterInfo *nextPtr; /* Next in list of all "after" commands for
* this interpreter. */
} AfterInfo;
/*
* One of the following structures is associated with each interpreter for
* which an "after" command has ever been invoked. A pointer to this structure
* is stored in the AssocData for the "tclAfter" key.
*/
typedef struct AfterAssocData {
Tcl_Interp *interp; /* The interpreter for which this data is
* registered. */
AfterInfo *firstAfterPtr; /* First in list of all "after" commands still
* pending for this interpreter, or NULL if
* none. */
} AfterAssocData;
/*
* There is one of the following structures for each of the handlers declared
* in a call to Tcl_DoWhenIdle. All of the currently-active handlers are
* linked together into a list.
*/
typedef struct IdleHandler {
Tcl_IdleProc (*proc); /* Function to call. */
ClientData clientData; /* Value to pass to proc. */
int generation; /* Used to distinguish older handlers from
* recently-created ones. */
struct IdleHandler *nextPtr;/* Next in list of active handlers. */
} IdleHandler;
/*
* The timer and idle queues are per-thread because they are associated with
* the notifier, which is also per-thread.
*
* All static variables used in this file are collected into a single instance
* of the following structure. For multi-threaded implementations, there is
* one instance of this structure for each thread.
*
* Notice that different structures with the same name appear in other files.
* The structure defined below is used in this file only.
*/
typedef struct ThreadSpecificData {
TimerHandler *firstTimerHandlerPtr; /* First event in queue. */
int lastTimerId; /* Timer identifier of most recently created
* timer. */
int timerPending; /* 1 if a timer event is in the queue. */
IdleHandler *idleList; /* First in list of all idle handlers. */
IdleHandler *lastIdlePtr; /* Last in list (or NULL for empty list). */
int idleGeneration; /* Used to fill in the "generation" fields of
* IdleHandler structures. Increments each
* time Tcl_DoOneEvent starts calling idle
* handlers, so that all old handlers can be
* called without calling any of the new ones
* created by old ones. */
int afterId; /* For unique identifiers of after events. */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
/*
* Helper macros for working with times. TCL_TIME_BEFORE encodes how to write
* the ordering relation on (normalized) times, and TCL_TIME_DIFF_MS computes
* the number of milliseconds difference between two times. Both macros use
* both of their arguments multiple times, so make sure they are cheap and
* side-effect free. The "prototypes" for these macros are:
*
* static int TCL_TIME_BEFORE(Tcl_Time t1, Tcl_Time t2);
* static long TCL_TIME_DIFF_MS(Tcl_Time t1, Tcl_Time t2);
*/
#define TCL_TIME_BEFORE(t1, t2) \
(((t1).sec<(t2).sec) || ((t1).sec==(t2).sec && (t1).usec<(t2).usec))
#define TCL_TIME_DIFF_MS(t1, t2) \
(1000*((Tcl_WideInt)(t1).sec - (Tcl_WideInt)(t2).sec) + \
((long)(t1).usec - (long)(t2).usec)/1000)
/*
* Prototypes for functions referenced only in this file:
*/
static void AfterCleanupProc(ClientData clientData,
Tcl_Interp *interp);
static int AfterDelay(Tcl_Interp *interp, Tcl_WideInt ms);
static void AfterProc(ClientData clientData);
static void FreeAfterPtr(AfterInfo *afterPtr);
static AfterInfo * GetAfterEvent(AfterAssocData *assocPtr,
Tcl_Obj *commandPtr);
static ThreadSpecificData *InitTimer(void);
static void TimerExitProc(ClientData clientData);
static int TimerHandlerEventProc(Tcl_Event *evPtr, int flags);
static void TimerCheckProc(ClientData clientData, int flags);
static void TimerSetupProc(ClientData clientData, int flags);
/*
*----------------------------------------------------------------------
*
* InitTimer --
*
* This function initializes the timer module.
*
* Results:
* A pointer to the thread specific data.
*
* Side effects:
* Registers the idle and timer event sources.
*
*----------------------------------------------------------------------
*/
static ThreadSpecificData *
InitTimer(void)
{
ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
TclThreadDataKeyGet(&dataKey);
if (tsdPtr == NULL) {
tsdPtr = TCL_TSD_INIT(&dataKey);
Tcl_CreateEventSource(TimerSetupProc, TimerCheckProc, NULL);
Tcl_CreateThreadExitHandler(TimerExitProc, NULL);
}
return tsdPtr;
}
/*
*----------------------------------------------------------------------
*
* TimerExitProc --
*
* This function is call at exit or unload time to remove the timer and
* idle event sources.
*
* Results:
* None.
*
* Side effects:
* Removes the timer and idle event sources and remaining events.
*
*----------------------------------------------------------------------
*/
static void
TimerExitProc(
ClientData clientData) /* Not used. */
{
ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
TclThreadDataKeyGet(&dataKey);
Tcl_DeleteEventSource(TimerSetupProc, TimerCheckProc, NULL);
if (tsdPtr != NULL) {
register TimerHandler *timerHandlerPtr;
timerHandlerPtr = tsdPtr->firstTimerHandlerPtr;
while (timerHandlerPtr != NULL) {
tsdPtr->firstTimerHandlerPtr = timerHandlerPtr->nextPtr;
ckfree((char *) timerHandlerPtr);
timerHandlerPtr = tsdPtr->firstTimerHandlerPtr;
}
}
}
/*
*--------------------------------------------------------------
*
* Tcl_CreateTimerHandler --
*
* Arrange for a given function to be invoked at a particular time in the
* future.
*
* Results:
* The return value is a token for the timer event, which may be used to
* delete the event before it fires.
*
* Side effects:
* When milliseconds have elapsed, proc will be invoked exactly once.
*
*--------------------------------------------------------------
*/
Tcl_TimerToken
Tcl_CreateTimerHandler(
int milliseconds, /* How many milliseconds to wait before
* invoking proc. */
Tcl_TimerProc *proc, /* Function to invoke. */
ClientData clientData) /* Arbitrary data to pass to proc. */
{
Tcl_Time time;
/*
* Compute when the event should fire.
*/
Tcl_GetTime(&time);
time.sec += milliseconds/1000;
time.usec += (milliseconds%1000)*1000;
if (time.usec >= 1000000) {
time.usec -= 1000000;
time.sec += 1;
}
return TclCreateAbsoluteTimerHandler(&time, proc, clientData);
}
/*
*--------------------------------------------------------------
*
* TclCreateAbsoluteTimerHandler --
*
* Arrange for a given function to be invoked at a particular time in the
* future.
*
* Results:
* The return value is a token for the timer event, which may be used to
* delete the event before it fires.
*
* Side effects:
* When the time in timePtr has been reached, proc will be invoked
* exactly once.
*
*--------------------------------------------------------------
*/
Tcl_TimerToken
TclCreateAbsoluteTimerHandler(
Tcl_Time *timePtr,
Tcl_TimerProc *proc,
ClientData clientData)
{
register TimerHandler *timerHandlerPtr, *tPtr2, *prevPtr;
ThreadSpecificData *tsdPtr;
tsdPtr = InitTimer();
timerHandlerPtr = (TimerHandler *) ckalloc(sizeof(TimerHandler));
/*
* Fill in fields for the event.
*/
memcpy((void *)&timerHandlerPtr->time, (void *)timePtr, sizeof(Tcl_Time));
timerHandlerPtr->proc = proc;
timerHandlerPtr->clientData = clientData;
tsdPtr->lastTimerId++;
timerHandlerPtr->token = (Tcl_TimerToken) INT2PTR(tsdPtr->lastTimerId);
/*
* Add the event to the queue in the correct position
* (ordered by event firing time).
*/
for (tPtr2 = tsdPtr->firstTimerHandlerPtr, prevPtr = NULL; tPtr2 != NULL;
prevPtr = tPtr2, tPtr2 = tPtr2->nextPtr) {
if (TCL_TIME_BEFORE(timerHandlerPtr->time, tPtr2->time)) {
break;
}
}
timerHandlerPtr->nextPtr = tPtr2;
if (prevPtr == NULL) {
tsdPtr->firstTimerHandlerPtr = timerHandlerPtr;
} else {
prevPtr->nextPtr = timerHandlerPtr;
}
TimerSetupProc(NULL, TCL_ALL_EVENTS);
return timerHandlerPtr->token;
}
/*
*--------------------------------------------------------------
*
* Tcl_DeleteTimerHandler --
*
* Delete a previously-registered timer handler.
*
* Results:
* None.
*
* Side effects:
* Destroy the timer callback identified by TimerToken, so that its
* associated function will not be called. If the callback has already
* fired, or if the given token doesn't exist, then nothing happens.
*
*--------------------------------------------------------------
*/
void
Tcl_DeleteTimerHandler(
Tcl_TimerToken token) /* Result previously returned by
* Tcl_DeleteTimerHandler. */
{
register TimerHandler *timerHandlerPtr, *prevPtr;
ThreadSpecificData *tsdPtr = InitTimer();
if (token == NULL) {
return;
}
for (timerHandlerPtr = tsdPtr->firstTimerHandlerPtr, prevPtr = NULL;
timerHandlerPtr != NULL; prevPtr = timerHandlerPtr,
timerHandlerPtr = timerHandlerPtr->nextPtr) {
if (timerHandlerPtr->token != token) {
continue;
}
if (prevPtr == NULL) {
tsdPtr->firstTimerHandlerPtr = timerHandlerPtr->nextPtr;
} else {
prevPtr->nextPtr = timerHandlerPtr->nextPtr;
}
ckfree((char *) timerHandlerPtr);
return;
}
}
/*
*----------------------------------------------------------------------
*
* TimerSetupProc --
*
* This function is called by Tcl_DoOneEvent to setup the timer event
* source for before blocking. This routine checks both the idle and
* after timer lists.
*
* Results:
* None.
*
* Side effects:
* May update the maximum notifier block time.
*
*----------------------------------------------------------------------
*/
static void
TimerSetupProc(
ClientData data, /* Not used. */
int flags) /* Event flags as passed to Tcl_DoOneEvent. */
{
Tcl_Time blockTime;
ThreadSpecificData *tsdPtr = InitTimer();
if (((flags & TCL_IDLE_EVENTS) && tsdPtr->idleList)
|| ((flags & TCL_TIMER_EVENTS) && tsdPtr->timerPending)) {
/*
* There is an idle handler or a pending timer event, so just poll.
*/
blockTime.sec = 0;
blockTime.usec = 0;
} else if ((flags & TCL_TIMER_EVENTS) && tsdPtr->firstTimerHandlerPtr) {
/*
* Compute the timeout for the next timer on the list.
*/
Tcl_GetTime(&blockTime);
blockTime.sec = tsdPtr->firstTimerHandlerPtr->time.sec - blockTime.sec;
blockTime.usec = tsdPtr->firstTimerHandlerPtr->time.usec -
blockTime.usec;
if (blockTime.usec < 0) {
blockTime.sec -= 1;
blockTime.usec += 1000000;
}
if (blockTime.sec < 0) {
blockTime.sec = 0;
blockTime.usec = 0;
}
} else {
return;
}
Tcl_SetMaxBlockTime(&blockTime);
}
/*
*----------------------------------------------------------------------
*
* TimerCheckProc --
*
* This function is called by Tcl_DoOneEvent to check the timer event
* source for events. This routine checks both the idle and after timer
* lists.
*
* Results:
* None.
*
* Side effects:
* May queue an event and update the maximum notifier block time.
*
*----------------------------------------------------------------------
*/
static void
TimerCheckProc(
ClientData data, /* Not used. */
int flags) /* Event flags as passed to Tcl_DoOneEvent. */
{
Tcl_Event *timerEvPtr;
Tcl_Time blockTime;
ThreadSpecificData *tsdPtr = InitTimer();
if ((flags & TCL_TIMER_EVENTS) && tsdPtr->firstTimerHandlerPtr) {
/*
* Compute the timeout for the next timer on the list.
*/
Tcl_GetTime(&blockTime);
blockTime.sec = tsdPtr->firstTimerHandlerPtr->time.sec - blockTime.sec;
blockTime.usec = tsdPtr->firstTimerHandlerPtr->time.usec -
blockTime.usec;
if (blockTime.usec < 0) {
blockTime.sec -= 1;
blockTime.usec += 1000000;
}
if (blockTime.sec < 0) {
blockTime.sec = 0;
blockTime.usec = 0;
}
/*
* If the first timer has expired, stick an event on the queue.
*/
if (blockTime.sec == 0 && blockTime.usec == 0 &&
!tsdPtr->timerPending) {
tsdPtr->timerPending = 1;
timerEvPtr = (Tcl_Event *) ckalloc(sizeof(Tcl_Event));
timerEvPtr->proc = TimerHandlerEventProc;
Tcl_QueueEvent(timerEvPtr, TCL_QUEUE_TAIL);
}
}
}
/*
*----------------------------------------------------------------------
*
* TimerHandlerEventProc --
*
* This function is called by Tcl_ServiceEvent when a timer event reaches
* the front of the event queue. This function handles the event by
* invoking the callbacks for all timers that are ready.
*
* Results:
* Returns 1 if the event was handled, meaning it should be removed from
* the queue. Returns 0 if the event was not handled, meaning it should
* stay on the queue. The only time the event isn't handled is if the
* TCL_TIMER_EVENTS flag bit isn't set.
*
* Side effects:
* Whatever the timer handler callback functions do.
*
*----------------------------------------------------------------------
*/
static int
TimerHandlerEventProc(
Tcl_Event *evPtr, /* Event to service. */
int flags) /* Flags that indicate what events to handle,
* such as TCL_FILE_EVENTS. */
{
TimerHandler *timerHandlerPtr, **nextPtrPtr;
Tcl_Time time;
int currentTimerId;
ThreadSpecificData *tsdPtr = InitTimer();
/*
* Do nothing if timers aren't enabled. This leaves the event on the
* queue, so we will get to it as soon as ServiceEvents() is called with
* timers enabled.
*/
if (!(flags & TCL_TIMER_EVENTS)) {
return 0;
}
/*
* The code below is trickier than it may look, for the following reasons:
*
* 1. New handlers can get added to the list while the current one is
* being processed. If new ones get added, we don't want to process
* them during this pass through the list to avoid starving other event
* sources. This is implemented using the token number in the handler:
* new handlers will have a newer token than any of the ones currently
* on the list.
* 2. The handler can call Tcl_DoOneEvent, so we have to remove the
* handler from the list before calling it. Otherwise an infinite loop
* could result.
* 3. Tcl_DeleteTimerHandler can be called to remove an element from the
* list while a handler is executing, so the list could change
* structure during the call.
* 4. Because we only fetch the current time before entering the loop, the
* only way a new timer will even be considered runnable is if its
* expiration time is within the same millisecond as the current time.
* This is fairly likely on Windows, since it has a course granularity
* clock. Since timers are placed on the queue in time order with the
* most recently created handler appearing after earlier ones with the
* same expiration time, we don't have to worry about newer generation
* timers appearing before later ones.
*/
tsdPtr->timerPending = 0;
currentTimerId = tsdPtr->lastTimerId;
Tcl_GetTime(&time);
while (1) {
nextPtrPtr = &tsdPtr->firstTimerHandlerPtr;
timerHandlerPtr = tsdPtr->firstTimerHandlerPtr;
if (timerHandlerPtr == NULL) {
break;
}
if (TCL_TIME_BEFORE(time, timerHandlerPtr->time)) {
break;
}
/*
* Bail out if the next timer is of a newer generation.
*/
if ((currentTimerId - PTR2INT(timerHandlerPtr->token)) < 0) {
break;
}
/*
* Remove the handler from the queue before invoking it, to avoid
* potential reentrancy problems.
*/
(*nextPtrPtr) = timerHandlerPtr->nextPtr;
(*timerHandlerPtr->proc)(timerHandlerPtr->clientData);
ckfree((char *) timerHandlerPtr);
}
TimerSetupProc(NULL, TCL_TIMER_EVENTS);
return 1;
}
/*
*--------------------------------------------------------------
*
* Tcl_DoWhenIdle --
*
* Arrange for proc to be invoked the next time the system is idle (i.e.,
* just before the next time that Tcl_DoOneEvent would have to wait for
* something to happen).
*
* Results:
* None.
*
* Side effects:
* Proc will eventually be called, with clientData as argument. See the
* manual entry for details.
*
*--------------------------------------------------------------
*/
void
Tcl_DoWhenIdle(
Tcl_IdleProc *proc, /* Function to invoke. */
ClientData clientData) /* Arbitrary value to pass to proc. */
{
register IdleHandler *idlePtr;
Tcl_Time blockTime;
ThreadSpecificData *tsdPtr = InitTimer();
idlePtr = (IdleHandler *) ckalloc(sizeof(IdleHandler));
idlePtr->proc = proc;
idlePtr->clientData = clientData;
idlePtr->generation = tsdPtr->idleGeneration;
idlePtr->nextPtr = NULL;
if (tsdPtr->lastIdlePtr == NULL) {
tsdPtr->idleList = idlePtr;
} else {
tsdPtr->lastIdlePtr->nextPtr = idlePtr;
}
tsdPtr->lastIdlePtr = idlePtr;
blockTime.sec = 0;
blockTime.usec = 0;
Tcl_SetMaxBlockTime(&blockTime);
}
/*
*----------------------------------------------------------------------
*
* Tcl_CancelIdleCall --
*
* If there are any when-idle calls requested to a given function with
* given clientData, cancel all of them.
*
* Results:
* None.
*
* Side effects:
* If the proc/clientData combination were on the when-idle list, they
* are removed so that they will never be called.
*
*----------------------------------------------------------------------
*/
void
Tcl_CancelIdleCall(
Tcl_IdleProc *proc, /* Function that was previously registered. */
ClientData clientData) /* Arbitrary value to pass to proc. */
{
register IdleHandler *idlePtr, *prevPtr;
IdleHandler *nextPtr;
ThreadSpecificData *tsdPtr = InitTimer();
for (prevPtr = NULL, idlePtr = tsdPtr->idleList; idlePtr != NULL;
prevPtr = idlePtr, idlePtr = idlePtr->nextPtr) {
while ((idlePtr->proc == proc)
&& (idlePtr->clientData == clientData)) {
nextPtr = idlePtr->nextPtr;
ckfree((char *) idlePtr);
idlePtr = nextPtr;
if (prevPtr == NULL) {
tsdPtr->idleList = idlePtr;
} else {
prevPtr->nextPtr = idlePtr;
}
if (idlePtr == NULL) {
tsdPtr->lastIdlePtr = prevPtr;
return;
}
}
}
}
/*
*----------------------------------------------------------------------
*
* TclServiceIdle --
*
* This function is invoked by the notifier when it becomes idle. It will
* invoke all idle handlers that are present at the time the call is
* invoked, but not those added during idle processing.
*
* Results:
* The return value is 1 if TclServiceIdle found something to do,
* otherwise return value is 0.
*
* Side effects:
* Invokes all pending idle handlers.
*
*----------------------------------------------------------------------
*/
int
TclServiceIdle(void)
{
IdleHandler *idlePtr;
int oldGeneration;
Tcl_Time blockTime;
ThreadSpecificData *tsdPtr = InitTimer();
if (tsdPtr->idleList == NULL) {
return 0;
}
oldGeneration = tsdPtr->idleGeneration;
tsdPtr->idleGeneration++;
/*
* The code below is trickier than it may look, for the following reasons:
*
* 1. New handlers can get added to the list while the current one is
* being processed. If new ones get added, we don't want to process
* them during this pass through the list (want to check for other work
* to do first). This is implemented using the generation number in the
* handler: new handlers will have a different generation than any of
* the ones currently on the list.
* 2. The handler can call Tcl_DoOneEvent, so we have to remove the
* handler from the list before calling it. Otherwise an infinite loop
* could result.
* 3. Tcl_CancelIdleCall can be called to remove an element from the list
* while a handler is executing, so the list could change structure
* during the call.
*/
for (idlePtr = tsdPtr->idleList;
((idlePtr != NULL)
&& ((oldGeneration - idlePtr->generation) >= 0));
idlePtr = tsdPtr->idleList) {
tsdPtr->idleList = idlePtr->nextPtr;
if (tsdPtr->idleList == NULL) {
tsdPtr->lastIdlePtr = NULL;
}
(*idlePtr->proc)(idlePtr->clientData);
ckfree((char *) idlePtr);
}
if (tsdPtr->idleList) {
blockTime.sec = 0;
blockTime.usec = 0;
Tcl_SetMaxBlockTime(&blockTime);
}
return 1;
}
/*
*----------------------------------------------------------------------
*
* Tcl_AfterObjCmd --
*
* This function is invoked to process the "after" Tcl command. See the
* user documentation for details on what it does.
*
* Results:
* A standard Tcl result.
*
* Side effects:
* See the user documentation.
*
*----------------------------------------------------------------------
*/
/* ARGSUSED */
int
Tcl_AfterObjCmd(
ClientData clientData, /* Unused */
Tcl_Interp *interp, /* Current interpreter. */
int objc, /* Number of arguments. */
Tcl_Obj *CONST objv[]) /* Argument objects. */
{
Tcl_WideInt ms; /* Number of milliseconds to wait */
Tcl_Time wakeup;
AfterInfo *afterPtr;
AfterAssocData *assocPtr;
int length;
int index;
char buf[16 + TCL_INTEGER_SPACE];
static CONST char *afterSubCmds[] = {
"cancel", "idle", "info", NULL
};
enum afterSubCmds {AFTER_CANCEL, AFTER_IDLE, AFTER_INFO};
ThreadSpecificData *tsdPtr = InitTimer();
if (objc < 2) {
Tcl_WrongNumArgs(interp, 1, objv, "option ?arg arg ...?");
return TCL_ERROR;
}
/*
* Create the "after" information associated for this interpreter, if it
* doesn't already exist.
*/
assocPtr = Tcl_GetAssocData(interp, "tclAfter", NULL);
if (assocPtr == NULL) {
assocPtr = (AfterAssocData *) ckalloc(sizeof(AfterAssocData));
assocPtr->interp = interp;
assocPtr->firstAfterPtr = NULL;
Tcl_SetAssocData(interp, "tclAfter", AfterCleanupProc,
(ClientData) assocPtr);
}
/*
* First lets see if the command was passed a number as the first argument.
*/
if (objv[1]->typePtr == &tclIntType
#ifndef NO_WIDE_TYPE
|| objv[1]->typePtr == &tclWideIntType
#endif
|| objv[1]->typePtr == &tclBignumType
|| ( Tcl_GetIndexFromObj(NULL, objv[1], afterSubCmds, "", 0,
&index) != TCL_OK )) {
index = -1;
if (Tcl_GetWideIntFromObj(NULL, objv[1], &ms) != TCL_OK) {
Tcl_AppendResult(interp, "bad argument \"",
Tcl_GetString(objv[1]),
"\": must be cancel, idle, info, or an integer",
NULL);
return TCL_ERROR;
}
}
/*
* At this point, either index = -1 and ms contains the number of ms
* to wait, or else index is the index of a subcommand.
*/
switch (index) {
case -1: {
if (ms < 0) {
ms = 0;
}
if (objc == 2) {
return AfterDelay(interp, ms);
}
afterPtr = (AfterInfo *) ckalloc((unsigned) (sizeof(AfterInfo)));
afterPtr->assocPtr = assocPtr;
if (objc == 3) {
afterPtr->commandPtr = objv[2];
} else {
afterPtr->commandPtr = Tcl_ConcatObj(objc-2, objv+2);
}
Tcl_IncrRefCount(afterPtr->commandPtr);
/*
* The variable below is used to generate unique identifiers for after
* commands. This id can wrap around, which can potentially cause
* problems. However, there are not likely to be problems in practice,
* because after commands can only be requested to about a month in
* the future, and wrap-around is unlikely to occur in less than about
* 1-10 years. Thus it's unlikely that any old ids will still be
* around when wrap-around occurs.
*/
afterPtr->id = tsdPtr->afterId;
tsdPtr->afterId += 1;
Tcl_GetTime(&wakeup);
wakeup.sec += (long)(ms / 1000);
wakeup.usec += ((long)(ms % 1000)) * 1000;
if (wakeup.usec > 1000000) {
wakeup.sec++;
wakeup.usec -= 1000000;
}
afterPtr->token = TclCreateAbsoluteTimerHandler(&wakeup, AfterProc,
(ClientData) afterPtr);
afterPtr->nextPtr = assocPtr->firstAfterPtr;
assocPtr->firstAfterPtr = afterPtr;
Tcl_SetObjResult(interp, Tcl_ObjPrintf("after#%d", afterPtr->id));
return TCL_OK;
}
case AFTER_CANCEL: {
Tcl_Obj *commandPtr;
char *command, *tempCommand;
int tempLength;
if (objc < 3) {
Tcl_WrongNumArgs(interp, 2, objv, "id|command");
return TCL_ERROR;
}
if (objc == 3) {
commandPtr = objv[2];
} else {
commandPtr = Tcl_ConcatObj(objc-2, objv+2);;
}
command = Tcl_GetStringFromObj(commandPtr, &length);
for (afterPtr = assocPtr->firstAfterPtr; afterPtr != NULL;
afterPtr = afterPtr->nextPtr) {
tempCommand = Tcl_GetStringFromObj(afterPtr->commandPtr,
&tempLength);
if ((length == tempLength)
&& (memcmp((void*) command, (void*) tempCommand,
(unsigned) length) == 0)) {
break;
}
}
if (afterPtr == NULL) {
afterPtr = GetAfterEvent(assocPtr, commandPtr);
}
if (objc != 3) {
Tcl_DecrRefCount(commandPtr);
}
if (afterPtr != NULL) {
if (afterPtr->token != NULL) {
Tcl_DeleteTimerHandler(afterPtr->token);
} else {
Tcl_CancelIdleCall(AfterProc, (ClientData) afterPtr);
}
FreeAfterPtr(afterPtr);
}
break;
}
case AFTER_IDLE:
if (objc < 3) {
Tcl_WrongNumArgs(interp, 2, objv, "script script ...");
return TCL_ERROR;
}
afterPtr = (AfterInfo *) ckalloc((unsigned) (sizeof(AfterInfo)));
afterPtr->assocPtr = assocPtr;
if (objc == 3) {
afterPtr->commandPtr = objv[2];
} else {
afterPtr->commandPtr = Tcl_ConcatObj(objc-2, objv+2);
}
Tcl_IncrRefCount(afterPtr->commandPtr);
afterPtr->id = tsdPtr->afterId;
tsdPtr->afterId += 1;
afterPtr->token = NULL;
afterPtr->nextPtr = assocPtr->firstAfterPtr;
assocPtr->firstAfterPtr = afterPtr;
Tcl_DoWhenIdle(AfterProc, (ClientData) afterPtr);
Tcl_SetObjResult(interp, Tcl_ObjPrintf("after#%d", afterPtr->id));
break;
case AFTER_INFO: {
Tcl_Obj *resultListPtr;
if (objc == 2) {
for (afterPtr = assocPtr->firstAfterPtr; afterPtr != NULL;
afterPtr = afterPtr->nextPtr) {
if (assocPtr->interp == interp) {
sprintf(buf, "after#%d", afterPtr->id);
Tcl_AppendElement(interp, buf);
}
}
return TCL_OK;
}
if (objc != 3) {
Tcl_WrongNumArgs(interp, 2, objv, "?id?");
return TCL_ERROR;
}
afterPtr = GetAfterEvent(assocPtr, objv[2]);
if (afterPtr == NULL) {
Tcl_AppendResult(interp, "event \"", TclGetString(objv[2]),
"\" doesn't exist", NULL);
return TCL_ERROR;
}
resultListPtr = Tcl_NewObj();
Tcl_ListObjAppendElement(interp, resultListPtr, afterPtr->commandPtr);
Tcl_ListObjAppendElement(interp, resultListPtr, Tcl_NewStringObj(
(afterPtr->token == NULL) ? "idle" : "timer", -1));
Tcl_SetObjResult(interp, resultListPtr);
break;
}
default:
Tcl_Panic("Tcl_AfterObjCmd: bad subcommand index to afterSubCmds");
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* AfterDelay --
*
* Implements the blocking delay behaviour of [after $time]. Tricky
* because it has to take into account any time limit that has been set.
*
* Results:
* Standard Tcl result code (with error set if an error occurred due to a
* time limit being exceeded).
*
* Side effects:
* May adjust the time limit granularity marker.
*
*----------------------------------------------------------------------
*/
static int
AfterDelay(
Tcl_Interp *interp,
Tcl_WideInt ms)
{
Interp *iPtr = (Interp *) interp;
Tcl_Time endTime, now;
Tcl_WideInt diff;
Tcl_GetTime(&endTime);
endTime.sec += (long)(ms/1000);
endTime.usec += ((int)(ms%1000))*1000;
if (endTime.usec >= 1000000) {
endTime.sec++;
endTime.usec -= 1000000;
}
do {
Tcl_GetTime(&now);
if (iPtr->limit.timeEvent != NULL
&& TCL_TIME_BEFORE(iPtr->limit.time, now)) {
iPtr->limit.granularityTicker = 0;
if (Tcl_LimitCheck(interp) != TCL_OK) {
return TCL_ERROR;
}
}
if (iPtr->limit.timeEvent == NULL
|| TCL_TIME_BEFORE(endTime, iPtr->limit.time)) {
diff = TCL_TIME_DIFF_MS(endTime, now);
#ifndef TCL_WIDE_INT_IS_LONG
if (diff > LONG_MAX) {
diff = LONG_MAX;
}
#endif
if (diff > 0) {
Tcl_Sleep((long)diff);
}
} else {
diff = TCL_TIME_DIFF_MS(iPtr->limit.time, now);
#ifndef TCL_WIDE_INT_IS_LONG
if (diff > LONG_MAX) {
diff = LONG_MAX;
}
#endif
if (diff > 0) {
Tcl_Sleep((long)diff);
}
if (Tcl_LimitCheck(interp) != TCL_OK) {
return TCL_ERROR;
}
}
} while (TCL_TIME_BEFORE(now, endTime));
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* GetAfterEvent --
*
* This function parses an "after" id such as "after#4" and returns a
* pointer to the AfterInfo structure.
*
* Results:
* The return value is either a pointer to an AfterInfo structure, if one
* is found that corresponds to "cmdString" and is for interp, or NULL if
* no corresponding after event can be found.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static AfterInfo *
GetAfterEvent(
AfterAssocData *assocPtr, /* Points to "after"-related information for
* this interpreter. */
Tcl_Obj *commandPtr)
{
char *cmdString; /* Textual identifier for after event, such as
* "after#6". */
AfterInfo *afterPtr;
int id;
char *end;
cmdString = TclGetString(commandPtr);
if (strncmp(cmdString, "after#", 6) != 0) {
return NULL;
}
cmdString += 6;
id = strtoul(cmdString, &end, 10);
if ((end == cmdString) || (*end != 0)) {
return NULL;
}
for (afterPtr = assocPtr->firstAfterPtr; afterPtr != NULL;
afterPtr = afterPtr->nextPtr) {
if (afterPtr->id == id) {
return afterPtr;
}
}
return NULL;
}
/*
*----------------------------------------------------------------------
*
* AfterProc --
*
* Timer callback to execute commands registered with the "after"
* command.
*
* Results:
* None.
*
* Side effects:
* Executes whatever command was specified. If the command returns an
* error, then the command "bgerror" is invoked to process the error; if
* bgerror fails then information about the error is output on stderr.
*
*----------------------------------------------------------------------
*/
static void
AfterProc(
ClientData clientData) /* Describes command to execute. */
{
AfterInfo *afterPtr = (AfterInfo *) clientData;
AfterAssocData *assocPtr = afterPtr->assocPtr;
AfterInfo *prevPtr;
int result;
Tcl_Interp *interp;
/*
* First remove the callback from our list of callbacks; otherwise someone
* could delete the callback while it's being executed, which could cause
* a core dump.
*/
if (assocPtr->firstAfterPtr == afterPtr) {
assocPtr->firstAfterPtr = afterPtr->nextPtr;
} else {
for (prevPtr = assocPtr->firstAfterPtr; prevPtr->nextPtr != afterPtr;
prevPtr = prevPtr->nextPtr) {
/* Empty loop body. */
}
prevPtr->nextPtr = afterPtr->nextPtr;
}
/*
* Execute the callback.
*/
interp = assocPtr->interp;
Tcl_Preserve((ClientData) interp);
result = Tcl_EvalObjEx(interp, afterPtr->commandPtr, TCL_EVAL_GLOBAL);
if (result != TCL_OK) {
Tcl_AddErrorInfo(interp, "\n (\"after\" script)");
TclBackgroundException(interp, result);
}
Tcl_Release((ClientData) interp);
/*
* Free the memory for the callback.
*/
Tcl_DecrRefCount(afterPtr->commandPtr);
ckfree((char *) afterPtr);
}
/*
*----------------------------------------------------------------------
*
* FreeAfterPtr --
*
* This function removes an "after" command from the list of those that
* are pending and frees its resources. This function does *not* cancel
* the timer handler; if that's needed, the caller must do it.
*
* Results:
* None.
*
* Side effects:
* The memory associated with afterPtr is released.
*
*----------------------------------------------------------------------
*/
static void
FreeAfterPtr(
AfterInfo *afterPtr) /* Command to be deleted. */
{
AfterInfo *prevPtr;
AfterAssocData *assocPtr = afterPtr->assocPtr;
if (assocPtr->firstAfterPtr == afterPtr) {
assocPtr->firstAfterPtr = afterPtr->nextPtr;
} else {
for (prevPtr = assocPtr->firstAfterPtr; prevPtr->nextPtr != afterPtr;
prevPtr = prevPtr->nextPtr) {
/* Empty loop body. */
}
prevPtr->nextPtr = afterPtr->nextPtr;
}
Tcl_DecrRefCount(afterPtr->commandPtr);
ckfree((char *) afterPtr);
}
/*
*----------------------------------------------------------------------
*
* AfterCleanupProc --
*
* This function is invoked whenever an interpreter is deleted
* to cleanup the AssocData for "tclAfter".
*
* Results:
* None.
*
* Side effects:
* After commands are removed.
*
*----------------------------------------------------------------------
*/
/* ARGSUSED */
static void
AfterCleanupProc(
ClientData clientData, /* Points to AfterAssocData for the
* interpreter. */
Tcl_Interp *interp) /* Interpreter that is being deleted. */
{
AfterAssocData *assocPtr = (AfterAssocData *) clientData;
AfterInfo *afterPtr;
while (assocPtr->firstAfterPtr != NULL) {
afterPtr = assocPtr->firstAfterPtr;
assocPtr->firstAfterPtr = afterPtr->nextPtr;
if (afterPtr->token != NULL) {
Tcl_DeleteTimerHandler(afterPtr->token);
} else {
Tcl_CancelIdleCall(AfterProc, (ClientData) afterPtr);
}
Tcl_DecrRefCount(afterPtr->commandPtr);
ckfree((char *) afterPtr);
}
ckfree((char *) assocPtr);
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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