Initial revision

1 files changed, 157 insertions, 0 deletions

diff --git a/libthreads/mig_support.c b/libthreads/mig_support.c
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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);
+}