entered into RCS

1 files changed, 83 insertions, 0 deletions

diff --git a/libthreads/sync.c b/libthreads/sync.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:	sync.c,v $
+ * Revision 2.7  92/03/06  14:09:59  rpd
+ * 	Replaced swtch_pri with yield.
+ * 	[92/03/06            rpd]
+ * 
+ * Revision 2.6  91/05/14  17:59:54  mrt
+ * 	Correcting copyright
+ * 
+ * Revision 2.5  91/02/14  14:21:38  mrt
+ * 	Added new Mach copyright
+ * 	[91/02/13  12:41:42  mrt]
+ * 
+ * Revision 2.4  90/11/05  14:38:08  rpd
+ * 	Fix casting.  Use new macros.
+ * 	[90/10/31            rwd]
+ * 
+ * Revision 2.3  90/08/07  14:31:50  rpd
+ * 	Removed RCS keyword nonsense.
+ * 
+ * Revision 2.2  89/12/08  19:55:01  rwd
+ * 	Changed spin_lock to spin_lock_solid to optimize.
+ * 	[89/11/13            rwd]
+ * 	Added copyright.  Move mutexes to cproc.c.  Spin locks are now
+ * 	old mutexes.
+ * 	[89/10/23            rwd]
+ * 
+ */
+/*
+ * sync.c
+ *
+ * Spin locks
+ */
+
+#include <cthreads.h>
+#include "cthread_internals.h"
+
+/*
+ * Spin locks.
+ * Use test and test-and-set logic on all architectures.
+ */
+
+int cthread_spin_count=0;
+
+void
+spin_lock_solid(p)
+	register spin_lock_t *p;
+{
+	while (spin_lock_locked(p) || !spin_try_lock(p)) {
+#ifdef STATISTICS
+		cthread_spin_count++;
+#endif
+#ifdef SPIN_RESCHED
+		yield();
+#endif
+	}
+}