[OpenSPARC-T2-SAM] / sam-t2 / devtools / v9 / man / man3 / Tcl_ExitThread.3

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.TH Tcl_Exit 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_Exit, Tcl_Finalize, Tcl_CreateExitHandler, Tcl_DeleteExitHandler, Tcl_ExitThread, Tcl_FinalizeThread, Tcl_CreateThreadExitHandler, Tcl_DeleteThreadExitHandler \- end the application or thread (and invoke exit handlers)
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
\fBTcl_Exit\fR(\fIstatus\fR)
.sp
\fBTcl_Finalize\fR()
.sp
\fBTcl_CreateExitHandler\fR(\fIproc, clientData\fR)
.sp
\fBTcl_DeleteExitHandler\fR(\fIproc, clientData\fR)
.sp
\fBTcl_ExitThread\fR(\fIstatus\fR)
.sp
\fBTcl_FinalizeThread\fR()
.sp
\fBTcl_CreateThreadExitHandler\fR(\fIproc, clientData\fR)
.sp
\fBTcl_DeleteThreadExitHandler\fR(\fIproc, clientData\fR)
.SH ARGUMENTS
.AS Tcl_ExitProc clientData
.AP int status  in
Provides information about why the application or thread exited.
Exact meaning may
be platform-specific.  0 usually means a normal exit, any nonzero value
usually means that an error occurred.
.AP Tcl_ExitProc *proc in
Procedure to invoke before exiting application.
.AP ClientData clientData in
Arbitrary one-word value to pass to \fIproc\fR.
.BE

.SH DESCRIPTION
.PP
The procedures described here provide a graceful mechanism to end the
execution of a \fBTcl\fR application. Exit handlers are invoked to cleanup the
application's state before ending the execution of \fBTcl\fR code.
.PP
Invoke \fBTcl_Exit\fR to end a \fBTcl\fR application and to exit from this
process. This procedure is invoked by the \fBexit\fR command, and can be
invoked anyplace else to terminate the application.
No-one should ever invoke the \fBexit\fR system procedure directly;  always
invoke \fBTcl_Exit\fR instead, so that it can invoke exit handlers.
Note that if other code invokes \fBexit\fR system procedure directly, or
otherwise causes the application to terminate without calling
\fBTcl_Exit\fR, the exit handlers will not be run.
\fBTcl_Exit\fR internally invokes the \fBexit\fR system call, thus it never
returns control to its caller.
.PP
\fBTcl_Finalize\fR is similar to \fBTcl_Exit\fR except that it does not
exit from the current process.
It is useful for cleaning up when a process is finished using \fBTcl\fR but
wishes to continue executing, and when \fBTcl\fR is used in a dynamically
loaded extension that is about to be unloaded.
On some systems \fBTcl\fR is automatically notified when it is being
unloaded, and it calls \fBTcl_Finalize\fR internally; on these systems it
not necessary for the caller to explicitly call \fBTcl_Finalize\fR.
However, to ensure portability, your code should always invoke
\fBTcl_Finalize\fR when \fBTcl\fR is being unloaded, to ensure that the
code will work on all platforms. \fBTcl_Finalize\fR can be safely called
more than once.
.PP
.VS
\fBTcl_ExitThread\fR is used to terminate the current thread and invoke
per-thread exit handlers.  This finalization is done by
\fBTcl_FinalizeThread\fR, which you can call if you just want to clean
up per-thread state and invoke the thread exit handlers.
\fBTcl_Finalize\fR calls \fBTcl_FinalizeThread\fR for the current
thread automatically.
.VE
.PP
\fBTcl_CreateExitHandler\fR arranges for \fIproc\fR to be invoked
by \fBTcl_Finalize\fR and \fBTcl_Exit\fR.
\fBTcl_CreateThreadExitHandler\fR arranges for \fIproc\fR to be invoked
by \fBTcl_FinalizeThread\fR and \fBTcl_ExitThread\fR.
This provides a hook for cleanup operations such as flushing buffers
and freeing global memory.
\fIProc\fR should match the type \fBTcl_ExitProc\fR:
.CS
typedef void Tcl_ExitProc(ClientData \fIclientData\fR);
.CE
The \fIclientData\fR parameter to \fIproc\fR is a
copy of the \fIclientData\fR argument given to
\fBTcl_CreateExitHandler\fR or \fBTcl_CreateThreadExitHandler\fR when
the callback
was created.  Typically, \fIclientData\fR points to a data
structure containing application-specific information about
what to do in \fIproc\fR.
.PP
\fBTcl_DeleteExitHandler\fR and \fBTcl_DeleteThreadExitHandler\fR may be
called to delete a
previously-created exit handler.  It removes the handler
indicated by \fIproc\fR and \fIclientData\fR so that no call
to \fIproc\fR will be made.  If no such handler exists then
\fBTcl_DeleteExitHandler\fR or \fBTcl_DeleteThreadExitHandler\fR does nothing.
.PP
.VS
.PP
\fBTcl_Finalize\fR and \fBTcl_Exit\fR execute all registered exit handlers,
in reverse order from the order in which they were registered.
This matches the natural order in which extensions are loaded and unloaded;
if extension \fBA\fR loads extension \fBB\fR, it usually
unloads \fBB\fR before it itself is unloaded.
If extension \fBA\fR registers its exit handlers before loading extension
\fBB\fR, this ensures that any exit handlers for \fBB\fR will be executed
before the exit handlers for \fBA\fR.
.VE
.VS
.PP
\fBTcl_Finalize\fR and \fBTcl_Exit\fR call \fBTcl_FinalizeThread\fR 
and the thread exit handlers \fIafter\fR
the process-wide exit handlers.  This is because thread finalization shuts
down the I/O channel system, so any attempt at I/O by the global exit
handlers will vanish into the bitbucket.
.VE

.SH KEYWORDS
callback, cleanup, dynamic loading, end application, exit, unloading, thread
Commit	Line	Data
920dae64 AT	1	'\"
	2	'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
	3	'\"
	4	'\" See the file "license.terms" for information on usage and redistribution
	5	'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
	6	'\"
	7	'\" RCS: @(#) $Id: Exit.3,v 1.4 2000/07/24 00:03:02 jenglish Exp $
	8	'\"
	9	'\" The definitions below are for supplemental macros used in Tcl/Tk
	10	'\" manual entries.
	11	'\"
	12	'\" .AP type name in/out ?indent?
	13	'\" Start paragraph describing an argument to a library procedure.
	14	'\" type is type of argument (int, etc.), in/out is either "in", "out",
	15	'\" or "in/out" to describe whether procedure reads or modifies arg,
	16	'\" and indent is equivalent to second arg of .IP (shouldn't ever be
	17	'\" needed; use .AS below instead)
	18	'\"
	19	'\" .AS ?type? ?name?
	20	'\" Give maximum sizes of arguments for setting tab stops. Type and
	21	'\" name are examples of largest possible arguments that will be passed
	22	'\" to .AP later. If args are omitted, default tab stops are used.
	23	'\"
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	26	'\" enclosed in one large box.
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65	'\" the option's class in the option database.
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71	'\"
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73	.if t .wh -1.3i ^B
74	.nr ^l \n(.l
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206	.de SO
207	.SH "STANDARD OPTIONS"
208	.LP
209	.nf
210	.ta 5.5c 11c
211	.ft B
212	..
213	'\" # SE - end of list of standard options
214	.de SE
215	.fi
216	.ft R
217	.LP
218	See the \\fBoptions\\fR manual entry for details on the standard options.
219	..
220	'\" # OP - start of full description for a single option
221	.de OP
222	.LP
223	.nf
224	.ta 4c
225	Command-Line Name: \\fB\\$1\\fR
226	Database Name: \\fB\\$2\\fR
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241	..
242	.de UL
243	\\$1\l'\|0\(ul'\\$2
244	..
245	.TH Tcl_Exit 3 8.1 Tcl "Tcl Library Procedures"
246	.BS
247	.SH NAME
248	Tcl_Exit, Tcl_Finalize, Tcl_CreateExitHandler, Tcl_DeleteExitHandler, Tcl_ExitThread, Tcl_FinalizeThread, Tcl_CreateThreadExitHandler, Tcl_DeleteThreadExitHandler \- end the application or thread (and invoke exit handlers)
249	.SH SYNOPSIS
250	.nf
251	\fB#include <tcl.h>\fR
252	.sp
253	\fBTcl_Exit\fR(\fIstatus\fR)
254	.sp
255	\fBTcl_Finalize\fR()
256	.sp
257	\fBTcl_CreateExitHandler\fR(\fIproc, clientData\fR)
258	.sp
259	\fBTcl_DeleteExitHandler\fR(\fIproc, clientData\fR)
260	.sp
261	\fBTcl_ExitThread\fR(\fIstatus\fR)
262	.sp
263	\fBTcl_FinalizeThread\fR()
264	.sp
265	\fBTcl_CreateThreadExitHandler\fR(\fIproc, clientData\fR)
266	.sp
267	\fBTcl_DeleteThreadExitHandler\fR(\fIproc, clientData\fR)
268	.SH ARGUMENTS
269	.AS Tcl_ExitProc clientData
270	.AP int status in
271	Provides information about why the application or thread exited.
272	Exact meaning may
273	be platform-specific. 0 usually means a normal exit, any nonzero value
274	usually means that an error occurred.
275	.AP Tcl_ExitProc *proc in
276	Procedure to invoke before exiting application.
277	.AP ClientData clientData in
278	Arbitrary one-word value to pass to \fIproc\fR.
279	.BE
280
281	.SH DESCRIPTION
282	.PP
283	The procedures described here provide a graceful mechanism to end the
284	execution of a \fBTcl\fR application. Exit handlers are invoked to cleanup the
285	application's state before ending the execution of \fBTcl\fR code.
286	.PP
287	Invoke \fBTcl_Exit\fR to end a \fBTcl\fR application and to exit from this
288	process. This procedure is invoked by the \fBexit\fR command, and can be
289	invoked anyplace else to terminate the application.
290	No-one should ever invoke the \fBexit\fR system procedure directly; always
291	invoke \fBTcl_Exit\fR instead, so that it can invoke exit handlers.
292	Note that if other code invokes \fBexit\fR system procedure directly, or
293	otherwise causes the application to terminate without calling
294	\fBTcl_Exit\fR, the exit handlers will not be run.
295	\fBTcl_Exit\fR internally invokes the \fBexit\fR system call, thus it never
296	returns control to its caller.
297	.PP
298	\fBTcl_Finalize\fR is similar to \fBTcl_Exit\fR except that it does not
299	exit from the current process.
300	It is useful for cleaning up when a process is finished using \fBTcl\fR but
301	wishes to continue executing, and when \fBTcl\fR is used in a dynamically
302	loaded extension that is about to be unloaded.
303	On some systems \fBTcl\fR is automatically notified when it is being
304	unloaded, and it calls \fBTcl_Finalize\fR internally; on these systems it
305	not necessary for the caller to explicitly call \fBTcl_Finalize\fR.
306	However, to ensure portability, your code should always invoke
307	\fBTcl_Finalize\fR when \fBTcl\fR is being unloaded, to ensure that the
308	code will work on all platforms. \fBTcl_Finalize\fR can be safely called
309	more than once.
310	.PP
311	.VS
312	\fBTcl_ExitThread\fR is used to terminate the current thread and invoke
313	per-thread exit handlers. This finalization is done by
314	\fBTcl_FinalizeThread\fR, which you can call if you just want to clean
315	up per-thread state and invoke the thread exit handlers.
316	\fBTcl_Finalize\fR calls \fBTcl_FinalizeThread\fR for the current
317	thread automatically.
318	.VE
319	.PP
320	\fBTcl_CreateExitHandler\fR arranges for \fIproc\fR to be invoked
321	by \fBTcl_Finalize\fR and \fBTcl_Exit\fR.
322	\fBTcl_CreateThreadExitHandler\fR arranges for \fIproc\fR to be invoked
323	by \fBTcl_FinalizeThread\fR and \fBTcl_ExitThread\fR.
324	This provides a hook for cleanup operations such as flushing buffers
325	and freeing global memory.
326	\fIProc\fR should match the type \fBTcl_ExitProc\fR:
327	.CS
328	typedef void Tcl_ExitProc(ClientData \fIclientData\fR);
329	.CE
330	The \fIclientData\fR parameter to \fIproc\fR is a
331	copy of the \fIclientData\fR argument given to
332	\fBTcl_CreateExitHandler\fR or \fBTcl_CreateThreadExitHandler\fR when
333	the callback
334	was created. Typically, \fIclientData\fR points to a data
335	structure containing application-specific information about
336	what to do in \fIproc\fR.
337	.PP
338	\fBTcl_DeleteExitHandler\fR and \fBTcl_DeleteThreadExitHandler\fR may be
339	called to delete a
340	previously-created exit handler. It removes the handler
341	indicated by \fIproc\fR and \fIclientData\fR so that no call
342	to \fIproc\fR will be made. If no such handler exists then
343	\fBTcl_DeleteExitHandler\fR or \fBTcl_DeleteThreadExitHandler\fR does nothing.
344	.PP
345	.VS
346	.PP
347	\fBTcl_Finalize\fR and \fBTcl_Exit\fR execute all registered exit handlers,
348	in reverse order from the order in which they were registered.
349	This matches the natural order in which extensions are loaded and unloaded;
350	if extension \fBA\fR loads extension \fBB\fR, it usually
351	unloads \fBB\fR before it itself is unloaded.
352	If extension \fBA\fR registers its exit handlers before loading extension
353	\fBB\fR, this ensures that any exit handlers for \fBB\fR will be executed
354	before the exit handlers for \fBA\fR.
355	.VE
356	.VS
357	.PP
358	\fBTcl_Finalize\fR and \fBTcl_Exit\fR call \fBTcl_FinalizeThread\fR
359	and the thread exit handlers \fIafter\fR
360	the process-wide exit handlers. This is because thread finalization shuts
361	down the I/O channel system, so any attempt at I/O by the global exit
362	handlers will vanish into the bitbucket.
363	.VE
364
365	.SH KEYWORDS
366	callback, cleanup, dynamic loading, end application, exit, unloading, thread