Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libc/arch/amd64/gen/_atomic_lock.c	Lines:	0	2	0.0 %
Date:	2017-11-07	Branches:	0	0	0.0 %


/*	$OpenBSD: _atomic_lock.c,v 1.1 2017/08/15 06:13:24 guenther Exp $	*/

/* David Leonard, <d@csee.uq.edu.au>. Public domain. */

/*
 * Atomic lock for amd64 -- taken from i386 code.
 */

#include <machine/spinlock.h>

int
_atomic_lock(volatile _atomic_lock_t *lock)
{
	_atomic_lock_t old;

	/*
	 * Use the eXCHanGe instruction to swap the lock value with
	 * a local variable containing the locked state.
	 */
	old = _ATOMIC_LOCK_LOCKED;
	__asm__("xchg %0,(%2)"
		: "=r" (old)
		: "0"  (old), "r"  (lock));

	return (old != _ATOMIC_LOCK_UNLOCKED);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: _atomic_lock.c,v 1.1 2017/08/15 06:13:24 guenther Exp $ */
2
3			/* David Leonard, <d@csee.uq.edu.au>. Public domain. */
4
5			/*
6			* Atomic lock for amd64 -- taken from i386 code.
7			*/
8
9			#include <machine/spinlock.h>
10
11			int
12			_atomic_lock(volatile _atomic_lock_t *lock)
13			{
14			_atomic_lock_t old;
15
16			/*
17			* Use the eXCHanGe instruction to swap the lock value with
18			* a local variable containing the locked state.
19			*/
20			old = _ATOMIC_LOCK_LOCKED;
21			__asm__("xchg %0,(%2)"
22			: "=r" (old)
23			: "0" (old), "r" (lock));
24
25			return (old != _ATOMIC_LOCK_UNLOCKED);
26			}