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/*
* Mach Operating System
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* HISTORY
* $Log: mig_support.c,v $
* Revision 2.6 91/05/14 17:57:41 mrt
* Correcting copyright
*
* Revision 2.5 91/02/14 14:20:30 mrt
* Added new Mach copyright
* [91/02/13 12:41:26 mrt]
*
* Revision 2.4 90/08/07 14:31:41 rpd
* Removed RCS keyword nonsense.
*
* Revision 2.3 90/08/07 14:27:48 rpd
* When we recycle the global reply port by giving it to the first
* cthread, clear the global reply port. This will take care of
* someone accidently calling this twice.
* [90/08/07 rwd]
*
* Revision 2.2 90/06/02 15:14:04 rpd
* Converted to new IPC.
* [90/03/20 20:56:50 rpd]
*
* Revision 2.1 89/08/03 17:09:50 rwd
* Created.
*
* 18-Jan-89 David Golub (dbg) at Carnegie-Mellon University
* Replaced task_data() by thread_reply().
*
*
* 27-Aug-87 Eric Cooper (ecc) at Carnegie Mellon University
* Changed mig_support.c to avoid deadlock that can occur
* if tracing is turned on during calls to mig_get_reply_port().
*
* 10-Aug-87 Eric Cooper (ecc) at Carnegie Mellon University
* Changed mig_support.c to use MACH_CALL.
* Changed "is_init" to "multithreaded" and reversed its sense.
*
* 30-Jul-87 Mary Thompson (mrt) at Carnegie Mellon University
* Created.
*/
/*
* File: mig_support.c
* Author: Mary R. Thompson, Carnegie Mellon University
* Date: July, 1987
*
* Routines to set and deallocate the mig reply port for the current thread.
* Called from mig-generated interfaces.
*
*/
#include <mach/mach.h>
#include <cthreads.h>
#include "cthread_internals.h"
private boolean_t multithreaded = FALSE;
/* use a global reply port before becoming multi-threaded */
private mach_port_t mig_reply_port = MACH_PORT_NULL;
/*
* Called by mach_init with 0 before cthread_init is
* called and again with initial cproc at end of cthread_init.
*/
void
mig_init(initial)
register cproc_t initial;
{
if (initial == NO_CPROC) {
/* called from mach_init before cthread_init,
possibly after a fork. clear global reply port. */
multithreaded = FALSE;
mig_reply_port = MACH_PORT_NULL;
} else {
/* recycle global reply port as this cthread's reply port */
multithreaded = TRUE;
initial->reply_port = mig_reply_port;
mig_reply_port = MACH_PORT_NULL;
}
}
/*
* Called by mig interface code whenever a reply port is needed.
*/
mach_port_t
mig_get_reply_port()
{
register mach_port_t reply_port;
if (multithreaded) {
register cproc_t self;
self = cproc_self();
ASSERT(self != NO_CPROC);
if ((reply_port = self->reply_port) == MACH_PORT_NULL)
self->reply_port = reply_port = mach_reply_port();
} else {
if ((reply_port = mig_reply_port) == MACH_PORT_NULL)
mig_reply_port = reply_port = mach_reply_port();
}
return reply_port;
}
/*
* Called by mig interface code after a timeout on the reply port.
* May also be called by user.
*/
void
mig_dealloc_reply_port()
{
register mach_port_t reply_port;
if (multithreaded) {
register cproc_t self;
self = cproc_self();
ASSERT(self != NO_CPROC);
reply_port = self->reply_port;
self->reply_port = MACH_PORT_NULL;
} else {
reply_port = mig_reply_port;
mig_reply_port = MACH_PORT_NULL;
}
(void) mach_port_mod_refs(mach_task_self(), reply_port,
MACH_PORT_RIGHT_RECEIVE, -1);
}
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