WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/synch/waitq.c



#include <time/timeout.h>
#include <arch.h>
#include <context.h>
#include <adt/list.h>
 
static void waitq_sleep_timed_out(void *data);
 
/** Initialize wait queue
 *
 * Initialize wait queue.
 *

 * overlap. In that case it behaves just as though there was no
 * timeout at all.
 *
 * @param data Pointer to the thread that called waitq_sleep_timeout().
 */
void waitq_sleep_timed_out(void *data)
{
    thread_t *t = (thread_t *) data;
    waitq_t *wq;
    bool do_wakeup = false;
    DEADLOCK_PROBE_INIT(p_wqlock);

 * Sleepers are organised in a FIFO fashion in a structure called wait queue.
 *
 * This function is really basic in that other functions as waitq_sleep()
 * and all the *_timeout() functions use it.
 *
 * @param wq        Pointer to wait queue.
 * @param usec      Timeout in microseconds.
 * @param flags     Specify mode of the sleep.
 *
 * The sleep can be interrupted only if the
 * SYNCH_FLAGS_INTERRUPTIBLE bit is specified in flags.
 *
 * If usec is greater than zero, regardless of the value of the

 * the call will not return until wakeup or interruption comes.
 *
 * If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is set in flags, the
 * call will immediately return, reporting either success or failure.
 *
 * @return      Returns one of ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT,
 *          ESYNCH_INTERRUPTED, ESYNCH_OK_ATOMIC and
 *          ESYNCH_OK_BLOCKED.
 *
 * @li  ESYNCH_WOULD_BLOCK means that the sleep failed because at the time of
 *  the call there was no pending wakeup.
 *
 * @li  ESYNCH_TIMEOUT means that the sleep timed out.
 *
 * @li  ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread.
 *
 * @li  ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was
 *  a pending wakeup at the time of the call. The caller was not put
 *  asleep at all.
 *
 * @li  ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was
 *  attempted.
 */
int waitq_sleep_timeout(waitq_t *wq, uint32_t usec, int flags)
{
    ipl_t ipl;
    int rc;

            spinlock_unlock(&THREAD->lock);
            return ESYNCH_TIMEOUT;
        }
        THREAD->timeout_pending = true;
        timeout_register(&THREAD->sleep_timeout, (uint64_t) usec,
            waitq_sleep_timed_out, THREAD);
    }
 
    list_append(&THREAD->wq_link, &wq->head);
 
    /*

   
    /*
     * Lock the thread prior to removing it from the wq.
     * This is not necessary because of mutual exclusion
     * (the link belongs to the wait queue), but because
     * of synchronization with waitq_sleep_timed_out()
     * and thread_interrupt_sleep().
     *
     * In order for these two functions to work, the following
     * invariant must hold:
     *

Rev 2310	Rev 2909
Line 52...	Line 52...
52	#include <time/timeout.h>	52	#include <time/timeout.h>
53	#include <arch.h>	53	#include <arch.h>
54	#include <context.h>	54	#include <context.h>
55	#include <adt/list.h>	55	#include <adt/list.h>
56		56
57	static void waitq_timeouted_sleep(void *data);	57	static void waitq_sleep_timed_out(void *data);
58		58
59	/** Initialize wait queue	59	/** Initialize wait queue
60	*	60	*
61	* Initialize wait queue.	61	* Initialize wait queue.
62	*	62	*
Line 79...	Line 79...
79	* overlap. In that case it behaves just as though there was no	79	* overlap. In that case it behaves just as though there was no
80	* timeout at all.	80	* timeout at all.
81	*	81	*
82	* @param data Pointer to the thread that called waitq_sleep_timeout().	82	* @param data Pointer to the thread that called waitq_sleep_timeout().
83	*/	83	*/
84	void waitq_timeouted_sleep(void *data)	84	void waitq_sleep_timed_out(void *data)
85	{	85	{
86	thread_t t = (thread_t ) data;	86	thread_t t = (thread_t ) data;
87	waitq_t *wq;	87	waitq_t *wq;
88	bool do_wakeup = false;	88	bool do_wakeup = false;
89	DEADLOCK_PROBE_INIT(p_wqlock);	89	DEADLOCK_PROBE_INIT(p_wqlock);
Line 181...	Line 181...
181	* Sleepers are organised in a FIFO fashion in a structure called wait queue.	181	* Sleepers are organised in a FIFO fashion in a structure called wait queue.
182	*	182	*
183	* This function is really basic in that other functions as waitq_sleep()	183	* This function is really basic in that other functions as waitq_sleep()
184	* and all the *_timeout() functions use it.	184	* and all the *_timeout() functions use it.
185	*	185	*
186	* @param wq Pointer to wait queue.	186	* @param wq Pointer to wait queue.
187	* @param usec Timeout in microseconds.	187	* @param usec Timeout in microseconds.
188	* @param flags Specify mode of the sleep.	188	* @param flags Specify mode of the sleep.
189	*	189	*
190	* The sleep can be interrupted only if the	190	* The sleep can be interrupted only if the
191	* SYNCH_FLAGS_INTERRUPTIBLE bit is specified in flags.	191	* SYNCH_FLAGS_INTERRUPTIBLE bit is specified in flags.
192	*	192	*
193	* If usec is greater than zero, regardless of the value of the	193	* If usec is greater than zero, regardless of the value of the
Line 198...	Line 198...
198	* the call will not return until wakeup or interruption comes.	198	* the call will not return until wakeup or interruption comes.
199	*	199	*
200	* If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is set in flags, the	200	* If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is set in flags, the
201	* call will immediately return, reporting either success or failure.	201	* call will immediately return, reporting either success or failure.
202	*	202	*
203	* @return One of: ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT, ESYNCH_INTERRUPTED,	203	* @return Returns one of ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT,
204	* ESYNCH_OK_ATOMIC, ESYNCH_OK_BLOCKED.	204	* ESYNCH_INTERRUPTED, ESYNCH_OK_ATOMIC and
-		205	* ESYNCH_OK_BLOCKED.
205	*	206	*
206	* @li ESYNCH_WOULD_BLOCK means that the sleep failed because at the time of the	207	* @li ESYNCH_WOULD_BLOCK means that the sleep failed because at the time of
207	* call there was no pending wakeup.	208	* the call there was no pending wakeup.
208	*	209	*
209	* @li ESYNCH_TIMEOUT means that the sleep timed out.	210	* @li ESYNCH_TIMEOUT means that the sleep timed out.
210	*	211	*
211	* @li ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread.	212	* @li ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread.
212	*	213	*
213	* @li ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was	214	* @li ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was
214	* a pending wakeup at the time of the call. The caller was not put	215	* a pending wakeup at the time of the call. The caller was not put
215	* asleep at all.	216	* asleep at all.
216	*	217	*
217	* @li ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was	218	* @li ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was
218	* attempted.	219	* attempted.
219	*/	220	*/
220	int waitq_sleep_timeout(waitq_t *wq, uint32_t usec, int flags)	221	int waitq_sleep_timeout(waitq_t *wq, uint32_t usec, int flags)
221	{	222	{
222	ipl_t ipl;	223	ipl_t ipl;
223	int rc;	224	int rc;
Line 353...	Line 354...
353	spinlock_unlock(&THREAD->lock);	354	spinlock_unlock(&THREAD->lock);
354	return ESYNCH_TIMEOUT;	355	return ESYNCH_TIMEOUT;
355	}	356	}
356	THREAD->timeout_pending = true;	357	THREAD->timeout_pending = true;
357	timeout_register(&THREAD->sleep_timeout, (uint64_t) usec,	358	timeout_register(&THREAD->sleep_timeout, (uint64_t) usec,
358	waitq_timeouted_sleep, THREAD);	359	waitq_sleep_timed_out, THREAD);
359	}	360	}
360		361
361	list_append(&THREAD->wq_link, &wq->head);	362	list_append(&THREAD->wq_link, &wq->head);
362		363
363	/*	364	/*
Line 429...	Line 430...
429		430
430	/*	431	/*
431	* Lock the thread prior to removing it from the wq.	432	* Lock the thread prior to removing it from the wq.
432	* This is not necessary because of mutual exclusion	433	* This is not necessary because of mutual exclusion
433	* (the link belongs to the wait queue), but because	434	* (the link belongs to the wait queue), but because
434	* of synchronization with waitq_timeouted_sleep()	435	* of synchronization with waitq_sleep_timed_out()
435	* and thread_interrupt_sleep().	436	* and thread_interrupt_sleep().
436	*	437	*
437	* In order for these two functions to work, the following	438	* In order for these two functions to work, the following
438	* invariant must hold:	439	* invariant must hold:
439	*	440	*

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/synch/waitq.c – Rev 2310 → 2909