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Diffstat (limited to 'doc/Notifier.3')
| -rw-r--r-- | doc/Notifier.3 | 30 |
1 files changed, 3 insertions, 27 deletions
diff --git a/doc/Notifier.3 b/doc/Notifier.3 index 2ea9195..3bf7c0f 100644 --- a/doc/Notifier.3 +++ b/doc/Notifier.3 @@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: Notifier.3,v 1.11 2004/10/07 15:37:44 dkf Exp $ +'\" RCS: @(#) $Id: Notifier.3,v 1.12 2004/10/07 16:05:14 dkf Exp $ '\" .so man.macros .TH Notifier 3 8.1 Tcl "Tcl Library Procedures" @@ -99,11 +99,9 @@ Procedure to invoke for each queued event in \fBTcl_DeleteEvents\fR. .AP int flags in What types of events to service. These flags are the same as those passed to \fBTcl_DoOneEvent\fR. -.VS 8.1 .AP int mode in Indicates whether events should be serviced by \fBTcl_ServiceAll\fR. Must be one of \fBTCL_SERVICE_NONE\fR or \fBTCL_SERVICE_ALL\fR. -.VE .BE .SH INTRODUCTION @@ -137,9 +135,7 @@ sources place events onto the queue so that they may be processed in order at appropriate times during the event loop. The event queue guarantees a fair discipline of event handling, so that no event source can starve the others. It also allows events to be saved for -servicing at a future time. -.VS 8.1 -Threaded applications work in a +servicing at a future time. Threaded applications work in a similar manner, except that there is a separate event queue for each thread containing a Tcl interpreter. \fBTcl_QueueEvent\fR is used (primarily @@ -171,7 +167,6 @@ The procedures \fBTcl_ServiceAll\fR, \fBTcl_ServiceEvent\fR, to help connect Tcl's event loop to an external event loop such as Motif's. .SH "NOTIFIER BASICS" -.VE .PP The easiest way to understand how the notifier works is to consider what happens when \fBTcl_DoOneEvent\fR is called. @@ -182,17 +177,13 @@ things: .IP [1] Check the event queue to see if it contains any events that can be serviced. If so, service the first possible event, remove it -.VS 8.1 from the queue, and return. It does this by calling \fBTcl_ServiceEvent\fR and passing in the \fIflags\fR argument. -.VE .IP [2] Prepare to block for an event. To do this, \fBTcl_DoOneEvent\fR invokes a \fIsetup procedure\fR in each event source. The event source will perform event-source specific initialization and -.VS 8.1 possibly call \fBTcl_SetMaxBlockTime\fR to limit how long -.VE \fBTcl_WaitForEvent\fR will block if no new events occur. .IP [3] Call \fBTcl_WaitForEvent\fR. This procedure is implemented differently @@ -258,7 +249,6 @@ request notification with a Windows event. For timer-driven event sources such as timer events or any polled event, the event source can call \fBTcl_SetMaxBlockTime\fR to force the application to wake up after a specified time even if no events have occurred. -.VS 8.1 If no event source calls \fBTcl_SetMaxBlockTime\fR then \fBTcl_WaitForEvent\fR will wait as long as necessary for an event to occur; otherwise, it will only wait as long as the shortest @@ -270,7 +260,6 @@ events already queued. If there are, it calls \fBTcl_SetMaxBlockTime\fR with a 0 block time so that \fBTcl_WaitForEvent\fR does not block if there is no new data on the X connection. -.VE The \fItimePtr\fR argument to \fBTcl_WaitForEvent\fR points to a structure that describes a time interval in seconds and microseconds: @@ -282,16 +271,13 @@ typedef struct Tcl_Time { .CE The \fIusec\fR field should be less than 1000000. .PP -.VS 8.1 Information provided to \fBTcl_SetMaxBlockTime\fR is only used for the next call to \fBTcl_WaitForEvent\fR; it is discarded after \fBTcl_WaitForEvent\fR returns. -.VE The next time an event wait is done each of the event sources' setup procedures will be called again, and they can specify new information for that event wait. .PP -.VS 8.1 If the application uses an external event loop rather than \fBTcl_DoOneEvent\fR, the event sources may need to call \fBTcl_SetMaxBlockTime\fR at other times. For example, if a new event @@ -307,7 +293,6 @@ platform-specific procedures may also be available for \fIsetupProc\fR, if there is additional information needed by \fBTcl_WaitForEvent\fR on that platform. For example, on Unix systems the \fBTcl_CreateFileHandler\fR interface can be used to wait for file events. -.VE .PP The second procedure provided by each event source is its check procedure, indicated by the \fIcheckProc\fR argument to @@ -365,10 +350,8 @@ events at the front of the queue, such as a series of Enter and Leave events synthesized during a grab or ungrab operation in Tk. .PP -.VS 8.1 When it is time to handle an event from the queue (steps 1 and 4 above) \fBTcl_ServiceEvent\fR will invoke the \fIproc\fR specified -.VE in the first queued \fBTcl_Event\fR structure. \fIProc\fR must match the following prototype: .CS @@ -380,9 +363,7 @@ The first argument to \fIproc\fR is a pointer to the event, which will be the same as the first argument to the \fBTcl_QueueEvent\fR call that added the event to the queue. The second argument to \fIproc\fR is the \fIflags\fR argument for the -.VS 8.1 current call to \fBTcl_ServiceEvent\fR; this is used by the event source -.VE to return immediately if its events are not relevant. .PP It is up to \fIproc\fR to handle the event, typically by invoking @@ -391,9 +372,7 @@ Once the event source has finished handling the event it returns 1 to indicate that the event can be removed from the queue. If for some reason the event source decides that the event cannot be handled at this time, it may return 0 to indicate that the event -.VS 8.1 should be deferred for processing later; in this case \fBTcl_ServiceEvent\fR -.VE will go on to the next event in the queue and attempt to service it. There are several reasons why an event source might defer an event. One possibility is that events of this type are excluded by the @@ -404,7 +383,6 @@ Another example of deferring events happens in Tk if \fBTk_RestrictEvents\fR has been invoked to defer certain kinds of window events. .PP -.VS 8.1 When \fIproc\fR returns 1, \fBTcl_ServiceEvent\fR will remove the event from the event queue and free its storage. Note that the storage for an event must be allocated by @@ -446,13 +424,11 @@ point to the next event in the queue. \fIcheckProc\fR, and \fIclientData\fR arguments must exactly match those provided to the \fBTcl_CreateEventSource\fR for the event source to be deleted. If no such source exists, \fBTcl_DeleteEventSource\fR has no effect. -.VE .SH "CREATING A NEW NOTIFIER" .PP The notifier consists of all the procedures described in this manual entry, plus \fBTcl_DoOneEvent\fR and \fBTcl_Sleep\fR, which are -.VS 8.1 available on all platforms, and \fBTcl_CreateFileHandler\fR and \fBTcl_DeleteFileHandler\fR, which are Unix-specific. Most of these procedures are generic, in that they are the same for all notifiers. @@ -594,7 +570,7 @@ then calls to \fBTcl_ServiceAll\fR will behave normally. mode, which should be restored when the recursive loop exits. \fBTcl_GetServiceMode\fR returns the current value of the service mode. -.VE + .SH "SEE ALSO" \fBTcl_CreateFileHandler\fR, \fBTcl_DeleteFileHandler\fR, \fBTcl_Sleep\fR, \fBTcl_DoOneEvent\fR, \fBThread(3)\fR |