WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/synch/rwlock.c



 * 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.
 */
 
/** @addtogroup sync
 * @{
 */
 
/**
 * @file

 *
 * A reader/writer lock can be held by multiple readers at a time.
 * Or it can be exclusively held by a sole writer at a time.
 *
 * These locks are not recursive.
 * Because a technique called direct hand-off is used and because
 * waiting takes place in a single wait queue, neither readers
 * nor writers will suffer starvation.
 *
 * If there is a writer followed by a reader waiting for the rwlock
 * and the writer times out, all leading readers are automatically woken up
 * and allowed in.

void release_spinlock(void *arg)
{
    spinlock_unlock((spinlock_t *) arg);
}
 
/** @}
 */
 

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/synch/rwlock.c – Rev 1702 → 1757

Rev 1702		Rev 1757
Line 24...		Line 24...
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup sync	29	/** @addtogroup sync
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
Line 36...		Line 36...
36	*	36	*
37	* A reader/writer lock can be held by multiple readers at a time.	37	* A reader/writer lock can be held by multiple readers at a time.
38	* Or it can be exclusively held by a sole writer at a time.	38	* Or it can be exclusively held by a sole writer at a time.
39	*	39	*
40	* These locks are not recursive.	40	* These locks are not recursive.
41	* Because technique called direct hand-off is used, neither readers	41	* Because a technique called direct hand-off is used and because
-		42	* waiting takes place in a single wait queue, neither readers
42	* nor writers will suffer starvation.	43	* nor writers will suffer starvation.
43	*	44	*
44	* If there is a writer followed by a reader waiting for the rwlock	45	* If there is a writer followed by a reader waiting for the rwlock
45	* and the writer times out, all leading readers are automatically woken up	46	* and the writer times out, all leading readers are automatically woken up
46	* and allowed in.	47	* and allowed in.
Line 382...		Line 383...
382	void release_spinlock(void *arg)	383	void release_spinlock(void *arg)
383	{	384	{
384	spinlock_unlock((spinlock_t *) arg);	385	spinlock_unlock((spinlock_t *) arg);
385	}	386	}
386		387
387	/** @}	388	/** @}
388	*/	389	*/
389		-