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46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
#ifndef __LIB_WAIT_H__
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#define __LIB_WAIT_H__
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#include <l4/lib/list.h>
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#include <l4/lib/spinlock.h>
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struct ktcb;
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struct waitqueue {
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struct list_head task_list;
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struct ktcb *task;
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};
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#define DECLARE_WAITQUEUE(wq, tsk) \
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struct waitqueue wq = { \
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.task_list = { &wq.task_list, &wq.task_list }, \
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.task = tsk, \
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};
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// LIST_HEAD_INIT(task_list),
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/*
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* The waitqueue spinlock ensures waiters are added and removed atomically so
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* that wake-ups and sleeps occur in sync. Otherwise, a task could try to wake
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* up a waitqueue **during when a task has decided to sleep but is not in the
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* queue yet. (** Take "during" here as a pseudo-concurrency term on UP)
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*/
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struct waitqueue_head {
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int sleepers;
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struct spinlock slock; /* Locks sleeper queue */
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struct list_head task_list; /* Sleeper queue head */
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};
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static inline void waitqueue_head_init(struct waitqueue_head *head)
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{
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memset(head, 0, sizeof(struct waitqueue_head));
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INIT_LIST_HEAD(&head->task_list);
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}
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/*
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* Used for ipc related waitqueues who have special wait queue manipulation
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* conditions.
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*/
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void wake_up(struct waitqueue_head *wqh);
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#endif /* __LIB_WAIT_H__ */
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