very important bit of md spinlock

1 files changed, 79 insertions, 0 deletions

diff --git a/lib/libpthread/include/spinlock.h b/lib/libpthread/include/spinlock.h
new file mode 100644
index 00000000000..0c49f5ec5df
--- /dev/null
+++ b/lib/libpthread/include/spinlock.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by John Birrell.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Id: spinlock.h,v 1.1 1998/12/21 07:58:55 d Exp $
+ * $OpenBSD: spinlock.h,v 1.1 1998/12/21 07:58:55 d Exp $
+ *
+ * Lock definitions used in both libc and libpthread.
+ *
+ */
+
+#ifndef _SPINLOCK_H_
+#define _SPINLOCK_H_
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include "_spinlock.h"
+
+/*
+ * Lock structure with room for debugging information.
+ */
+typedef struct {
+	volatile _spinlock_lock_t access_lock;
+	volatile long	lock_owner;
+	volatile const char * fname;
+	volatile int	lineno;
+} spinlock_t;
+
+#define	_SPINLOCK_INITIALIZER	{ _SPINLOCK_UNLOCKED, 0, 0, 0 }
+
+#define _SPINUNLOCK(_lck)	(_lck)->access_lock = _SPINLOCK_UNLOCKED
+#ifdef	_LOCK_DEBUG
+#define	_SPINLOCK(_lck)		_spinlock_debug(_lck, __FILE__, __LINE__)
+#else
+#define	_SPINLOCK(_lck)		_spinlock(_lck)
+#endif
+
+/*
+ * Thread function prototype definitions:
+ */
+__BEGIN_DECLS
+void	_spinlock __P((spinlock_t *));
+void	_spinlock_debug __P((spinlock_t *, const char *, int));
+
+/* lock() functions return 0 if lock was acquired. */
+/* is_locked functions() return 1 if lock is locked. */
+int	_atomic_lock __P((volatile _spinlock_lock_t *));
+int	_atomic_is_locked __P((volatile _spinlock_lock_t *));
+int	_thread_slow_atomic_lock __P((volatile _spinlock_lock_t *));
+int	_thread_slow_atomic_is_locked __P((volatile _spinlock_lock_t *));
+__END_DECLS
+
+#endif /* _SPINLOCK_H_ */