WebSVN – HelenOS-historic – Diff – /SPARTAN/trunk/src/synch/waitq.c



 * ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was
 * attempted.
 */
int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int nonblocking)
{
    volatile ipl_t ipl; /* must be live after context_restore() */
   
   
restart:
    ipl = interrupts_disable();
   
    /*
     * Busy waiting for a delayed timeout.
     * This is an important fix for the race condition between
     * a delayed timeout and a next call to waitq_sleep_timeout().

     * there are timeouts in progress.
     */
    spinlock_lock(&THREAD->lock);
    if (THREAD->timeout_pending) {
        spinlock_unlock(&THREAD->lock);
        interrupts_restore(ipl);       
        goto restart;
    }
    spinlock_unlock(&THREAD->lock);
   
    spinlock_lock(&wq->lock);
   
    /* checks whether to go to sleep at all */
    if (wq->missed_wakeups) {
        wq->missed_wakeups--;
        spinlock_unlock(&wq->lock);
        interrupts_restore(ipl);
        return ESYNCH_OK_ATOMIC;
    }
    else {
        if (nonblocking && (usec == 0)) {
            /* return immediatelly instead of going to sleep */
            spinlock_unlock(&wq->lock);
            interrupts_restore(ipl);
            return ESYNCH_WOULD_BLOCK;
        }
    }
 
   

            /*
             * Short emulation of scheduler() return code.
             */
            before_thread_runs();
            spinlock_unlock(&THREAD->lock);
            interrupts_restore(ipl);
            return ESYNCH_TIMEOUT;
        }
        THREAD->timeout_pending = 1;
        timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_interrupted_sleep, THREAD);
    }

    THREAD->sleep_queue = wq;
 
    spinlock_unlock(&THREAD->lock);
 
    scheduler();    /* wq->lock is released in scheduler_separated_stack() */
    interrupts_restore(ipl);
   
    return ESYNCH_OK_BLOCKED;
}
 
 

 * @param all If this is non-zero, all sleeping threads
 *        will be woken up and missed count will be zeroed.
 */
void waitq_wakeup(waitq_t *wq, int all)
{
    ipl_t ipl;
 
    ipl = interrupts_disable();
    spinlock_lock(&wq->lock);
 
    _waitq_wakeup_unsafe(wq, all);
 
    spinlock_unlock(&wq->lock);
    interrupts_restore(ipl);   
}
 
/** Internal SMP- and IRQ-unsafe version of waitq_wakeup()
 *
 * This is the internal SMP- and IRQ-unsafe version

Rev 405	Rev 413
Line 135...	Line 135...
135	* ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was	135	* ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was
136	* attempted.	136	* attempted.
137	*/	137	*/
138	int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int nonblocking)	138	int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int nonblocking)
139	{	139	{
140	volatile pri_t pri; /* must be live after context_restore() */	140	volatile ipl_t ipl; /* must be live after context_restore() */
141		141
142		142
143	restart:	143	restart:
144	pri = cpu_priority_high();	144	ipl = interrupts_disable();
145		145
146	/*	146	/*
147	* Busy waiting for a delayed timeout.	147	* Busy waiting for a delayed timeout.
148	* This is an important fix for the race condition between	148	* This is an important fix for the race condition between
149	* a delayed timeout and a next call to waitq_sleep_timeout().	149	* a delayed timeout and a next call to waitq_sleep_timeout().
Line 151...	Line 151...
151	* there are timeouts in progress.	151	* there are timeouts in progress.
152	*/	152	*/
153	spinlock_lock(&THREAD->lock);	153	spinlock_lock(&THREAD->lock);
154	if (THREAD->timeout_pending) {	154	if (THREAD->timeout_pending) {
155	spinlock_unlock(&THREAD->lock);	155	spinlock_unlock(&THREAD->lock);
156	cpu_priority_restore(pri);	156	interrupts_restore(ipl);
157	goto restart;	157	goto restart;
158	}	158	}
159	spinlock_unlock(&THREAD->lock);	159	spinlock_unlock(&THREAD->lock);
160		160
161	spinlock_lock(&wq->lock);	161	spinlock_lock(&wq->lock);
162		162
163	/* checks whether to go to sleep at all */	163	/* checks whether to go to sleep at all */
164	if (wq->missed_wakeups) {	164	if (wq->missed_wakeups) {
165	wq->missed_wakeups--;	165	wq->missed_wakeups--;
166	spinlock_unlock(&wq->lock);	166	spinlock_unlock(&wq->lock);
167	cpu_priority_restore(pri);	167	interrupts_restore(ipl);
168	return ESYNCH_OK_ATOMIC;	168	return ESYNCH_OK_ATOMIC;
169	}	169	}
170	else {	170	else {
171	if (nonblocking && (usec == 0)) {	171	if (nonblocking && (usec == 0)) {
172	/* return immediatelly instead of going to sleep */	172	/* return immediatelly instead of going to sleep */
173	spinlock_unlock(&wq->lock);	173	spinlock_unlock(&wq->lock);
174	cpu_priority_restore(pri);	174	interrupts_restore(ipl);
175	return ESYNCH_WOULD_BLOCK;	175	return ESYNCH_WOULD_BLOCK;
176	}	176	}
177	}	177	}
178		178
179		179
Line 187...	Line 187...
187	/*	187	/*
188	* Short emulation of scheduler() return code.	188	* Short emulation of scheduler() return code.
189	*/	189	*/
190	before_thread_runs();	190	before_thread_runs();
191	spinlock_unlock(&THREAD->lock);	191	spinlock_unlock(&THREAD->lock);
192	cpu_priority_restore(pri);	192	interrupts_restore(ipl);
193	return ESYNCH_TIMEOUT;	193	return ESYNCH_TIMEOUT;
194	}	194	}
195	THREAD->timeout_pending = 1;	195	THREAD->timeout_pending = 1;
196	timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_interrupted_sleep, THREAD);	196	timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_interrupted_sleep, THREAD);
197	}	197	}
Line 205...	Line 205...
205	THREAD->sleep_queue = wq;	205	THREAD->sleep_queue = wq;
206		206
207	spinlock_unlock(&THREAD->lock);	207	spinlock_unlock(&THREAD->lock);
208		208
209	scheduler(); /* wq->lock is released in scheduler_separated_stack() */	209	scheduler(); /* wq->lock is released in scheduler_separated_stack() */
210	cpu_priority_restore(pri);	210	interrupts_restore(ipl);
211		211
212	return ESYNCH_OK_BLOCKED;	212	return ESYNCH_OK_BLOCKED;
213	}	213	}
214		214
215		215
Line 226...	Line 226...
226	* @param all If this is non-zero, all sleeping threads	226	* @param all If this is non-zero, all sleeping threads
227	* will be woken up and missed count will be zeroed.	227	* will be woken up and missed count will be zeroed.
228	*/	228	*/
229	void waitq_wakeup(waitq_t *wq, int all)	229	void waitq_wakeup(waitq_t *wq, int all)
230	{	230	{
231	pri_t pri;	231	ipl_t ipl;
232		232
233	pri = cpu_priority_high();	233	ipl = interrupts_disable();
234	spinlock_lock(&wq->lock);	234	spinlock_lock(&wq->lock);
235		235
236	_waitq_wakeup_unsafe(wq, all);	236	_waitq_wakeup_unsafe(wq, all);
237		237
238	spinlock_unlock(&wq->lock);	238	spinlock_unlock(&wq->lock);
239	cpu_priority_restore(pri);	239	interrupts_restore(ipl);
240	}	240	}
241		241
242	/** Internal SMP- and IRQ-unsafe version of waitq_wakeup()	242	/** Internal SMP- and IRQ-unsafe version of waitq_wakeup()
243	*	243	*
244	* This is the internal SMP- and IRQ-unsafe version	244	* This is the internal SMP- and IRQ-unsafe version

Subversion Repositories HelenOS-historic

(root)/SPARTAN/trunk/src/synch/waitq.c – Rev 405 → 413