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



 
/** Initialize wait queue
 *
 * Initialize wait queue.
 *
 * @param wq        Pointer to wait queue to be initialized.
 */
void waitq_initialize(waitq_t *wq)
{
    spinlock_initialize(&wq->lock, "waitq_lock");
    list_initialize(&wq->head);
    wq->missed_wakeups = 0;
}
 
/** Handle timeout during waitq_sleep_timeout() call
 *
 * This routine is called when waitq_sleep_timeout() times out.
 * Interrupts are disabled.
 *
 * It is supposed to try to remove 'its' thread from the wait queue;
 * it can eventually fail to achieve this goal when these two events
 * 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;

/** Interrupt sleeping thread.
 *
 * This routine attempts to interrupt a thread from its sleep in a waitqueue.
 * If the thread is not found sleeping, no action is taken.
 *
 * @param t     Thread to be interrupted.
 */
void waitq_interrupt_sleep(thread_t *t)
{
    waitq_t *wq;
    bool do_wakeup = false;

/** Prepare to sleep in a waitq.
 *
 * This function will return holding the lock of the wait queue
 * and interrupts disabled.
 *
 * @param wq        Wait queue.
 *
 * @return      Interrupt level as it existed on entry to this function.
 */
ipl_t waitq_sleep_prepare(waitq_t *wq)
{
    ipl_t ipl;
   

 *
 * This function restores interrupts to the state that existed prior
 * to the call to waitq_sleep_prepare(). If necessary, the wait queue
 * lock is released.
 *
 * @param wq        Wait queue.
 * @param rc        Return code of waitq_sleep_timeout_unsafe().
 * @param ipl       Interrupt level returned by waitq_sleep_prepare().
 */
void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl)
{
    switch (rc) {
    case ESYNCH_WOULD_BLOCK:

}
 
/** Internal implementation of waitq_sleep_timeout().
 *
 * This function implements logic of sleeping in a wait queue.
 * This call must be preceded by a call to waitq_sleep_prepare()
 * and followed by a call to waitq_sleep_finish().
 *
 * @param wq        See waitq_sleep_timeout().
 * @param usec      See waitq_sleep_timeout().
 * @param flags     See waitq_sleep_timeout().
 *
 * @return      See waitq_sleep_timeout().
 */
int waitq_sleep_timeout_unsafe(waitq_t *wq, uint32_t usec, int flags)
{
    /* checks whether to go to sleep at all */
    if (wq->missed_wakeups) {

 * wrapper meant for general use.
 *
 * Besides its 'normal' wakeup operation, it attempts to unregister possible
 * timeout.
 *
 * @param wq        Pointer to wait queue.
 * @param mode      Wakeup mode.
 */
void waitq_wakeup(waitq_t *wq, wakeup_mode_t mode)
{
    ipl_t ipl;
 

/** Internal SMP- and IRQ-unsafe version of waitq_wakeup()
 *
 * This is the internal SMP- and IRQ-unsafe version of waitq_wakeup(). It
 * assumes wq->lock is already locked and interrupts are already disabled.
 *
 * @param wq        Pointer to wait queue.
 * @param mode      If mode is WAKEUP_FIRST, then the longest waitingi
 *          thread, if any, is woken up. If mode is WAKEUP_ALL, then
 *          all waiting threads, if any, are woken up. If there are
 *          no waiting threads to be woken up, the missed wakeup is
 *          recorded in the wait queue.
 */
void _waitq_wakeup_unsafe(waitq_t *wq, wakeup_mode_t mode)
{
    thread_t *t;
    count_t count = 0;

Rev 2909	Rev 2914
Line 58...	Line 58...
58		58
59	/** Initialize wait queue	59	/** Initialize wait queue
60	*	60	*
61	* Initialize wait queue.	61	* Initialize wait queue.
62	*	62	*
63	* @param wq Pointer to wait queue to be initialized.	63	* @param wq Pointer to wait queue to be initialized.
64	*/	64	*/
65	void waitq_initialize(waitq_t *wq)	65	void waitq_initialize(waitq_t *wq)
66	{	66	{
67	spinlock_initialize(&wq->lock, "waitq_lock");	67	spinlock_initialize(&wq->lock, "waitq_lock");
68	list_initialize(&wq->head);	68	list_initialize(&wq->head);
69	wq->missed_wakeups = 0;	69	wq->missed_wakeups = 0;
70	}	70	}
71		71
72	/** Handle timeout during waitq_sleep_timeout() call	72	/** Handle timeout during waitq_sleep_timeout() call
73	*	73	*
74	* This routine is called when waitq_sleep_timeout() timeouts.	74	* This routine is called when waitq_sleep_timeout() times out.
75	* Interrupts are disabled.	75	* Interrupts are disabled.
76	*	76	*
77	* It is supposed to try to remove 'its' thread from the wait queue;	77	* It is supposed to try to remove 'its' thread from the wait queue;
78	* it can eventually fail to achieve this goal when these two events	78	* it can eventually fail to achieve this goal when these two events
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_sleep_timed_out(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;
Line 121...	Line 121...
121	/** Interrupt sleeping thread.	121	/** Interrupt sleeping thread.
122	*	122	*
123	* This routine attempts to interrupt a thread from its sleep in a waitqueue.	123	* This routine attempts to interrupt a thread from its sleep in a waitqueue.
124	* If the thread is not found sleeping, no action is taken.	124	* If the thread is not found sleeping, no action is taken.
125	*	125	*
126	* @param t Thread to be interrupted.	126	* @param t Thread to be interrupted.
127	*/	127	*/
128	void waitq_interrupt_sleep(thread_t *t)	128	void waitq_interrupt_sleep(thread_t *t)
129	{	129	{
130	waitq_t *wq;	130	waitq_t *wq;
131	bool do_wakeup = false;	131	bool do_wakeup = false;
Line 232...	Line 232...
232	/** Prepare to sleep in a waitq.	232	/** Prepare to sleep in a waitq.
233	*	233	*
234	* This function will return holding the lock of the wait queue	234	* This function will return holding the lock of the wait queue
235	* and interrupts disabled.	235	* and interrupts disabled.
236	*	236	*
237	* @param wq Wait queue.	237	* @param wq Wait queue.
238	*	238	*
239	* @return Interrupt level as it existed on entry to this function.	239	* @return Interrupt level as it existed on entry to this function.
240	*/	240	*/
241	ipl_t waitq_sleep_prepare(waitq_t *wq)	241	ipl_t waitq_sleep_prepare(waitq_t *wq)
242	{	242	{
243	ipl_t ipl;	243	ipl_t ipl;
244		244
Line 270...	Line 270...
270	*	270	*
271	* This function restores interrupts to the state that existed prior	271	* This function restores interrupts to the state that existed prior
272	* to the call to waitq_sleep_prepare(). If necessary, the wait queue	272	* to the call to waitq_sleep_prepare(). If necessary, the wait queue
273	* lock is released.	273	* lock is released.
274	*	274	*
275	* @param wq Wait queue.	275	* @param wq Wait queue.
276	* @param rc Return code of waitq_sleep_timeout_unsafe().	276	* @param rc Return code of waitq_sleep_timeout_unsafe().
277	* @param ipl Interrupt level returned by waitq_sleep_prepare().	277	* @param ipl Interrupt level returned by waitq_sleep_prepare().
278	*/	278	*/
279	void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl)	279	void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl)
280	{	280	{
281	switch (rc) {	281	switch (rc) {
282	case ESYNCH_WOULD_BLOCK:	282	case ESYNCH_WOULD_BLOCK:
Line 290...	Line 290...
290	}	290	}
291		291
292	/** Internal implementation of waitq_sleep_timeout().	292	/** Internal implementation of waitq_sleep_timeout().
293	*	293	*
294	* This function implements logic of sleeping in a wait queue.	294	* This function implements logic of sleeping in a wait queue.
295	* This call must be preceeded by a call to waitq_sleep_prepare()	295	* This call must be preceded by a call to waitq_sleep_prepare()
296	* and followed by a call to waitq_slee_finish().	296	* and followed by a call to waitq_sleep_finish().
297	*	297	*
298	* @param wq See waitq_sleep_timeout().	298	* @param wq See waitq_sleep_timeout().
299	* @param usec See waitq_sleep_timeout().	299	* @param usec See waitq_sleep_timeout().
300	* @param flags See waitq_sleep_timeout().	300	* @param flags See waitq_sleep_timeout().
301	*	301	*
302	* @return See waitq_sleep_timeout().	302	* @return See waitq_sleep_timeout().
303	*/	303	*/
304	int waitq_sleep_timeout_unsafe(waitq_t *wq, uint32_t usec, int flags)	304	int waitq_sleep_timeout_unsafe(waitq_t *wq, uint32_t usec, int flags)
305	{	305	{
306	/* checks whether to go to sleep at all */	306	/* checks whether to go to sleep at all */
307	if (wq->missed_wakeups) {	307	if (wq->missed_wakeups) {
Line 382...	Line 382...
382	* wrapper meant for general use.	382	* wrapper meant for general use.
383	*	383	*
384	* Besides its 'normal' wakeup operation, it attempts to unregister possible	384	* Besides its 'normal' wakeup operation, it attempts to unregister possible
385	* timeout.	385	* timeout.
386	*	386	*
387	* @param wq Pointer to wait queue.	387	* @param wq Pointer to wait queue.
388	* @param mode Wakeup mode.	388	* @param mode Wakeup mode.
389	*/	389	*/
390	void waitq_wakeup(waitq_t *wq, wakeup_mode_t mode)	390	void waitq_wakeup(waitq_t *wq, wakeup_mode_t mode)
391	{	391	{
392	ipl_t ipl;	392	ipl_t ipl;
393		393
Line 403...	Line 403...
403	/** Internal SMP- and IRQ-unsafe version of waitq_wakeup()	403	/** Internal SMP- and IRQ-unsafe version of waitq_wakeup()
404	*	404	*
405	* This is the internal SMP- and IRQ-unsafe version of waitq_wakeup(). It	405	* This is the internal SMP- and IRQ-unsafe version of waitq_wakeup(). It
406	* assumes wq->lock is already locked and interrupts are already disabled.	406	* assumes wq->lock is already locked and interrupts are already disabled.
407	*	407	*
408	* @param wq Pointer to wait queue.	408	* @param wq Pointer to wait queue.
409	* @param mode If mode is WAKEUP_FIRST, then the longest waiting thread,	409	* @param mode If mode is WAKEUP_FIRST, then the longest waitingi
410	* if any, is woken up. If mode is WAKEUP_ALL, then all	410	* thread, if any, is woken up. If mode is WAKEUP_ALL, then
411	* waiting threads, if any, are woken up. If there are no	411	* all waiting threads, if any, are woken up. If there are
412	* waiting threads to be woken up, the missed wakeup is	412	* no waiting threads to be woken up, the missed wakeup is
413	* recorded in the wait queue.	413	* recorded in the wait queue.
414	*/	414	*/
415	void _waitq_wakeup_unsafe(waitq_t *wq, wakeup_mode_t mode)	415	void _waitq_wakeup_unsafe(waitq_t *wq, wakeup_mode_t mode)
416	{	416	{
417	thread_t *t;	417	thread_t *t;
418	count_t count = 0;	418	count_t count = 0;

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/synch/waitq.c – Rev 2909 → 2914