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committed 7696f9910a9 * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))// SPDX-License-Identifier: GPL-2.0/* * Generic wait-for-completion handler; * * It differs from semaphores in that their default case is the opposite, * wait_for_completion default blocks whereas semaphore default non-block. The * interface also makes it easy to 'complete' multiple waiting threads, * something which isn't entirely natural for semaphores. * * But more importantly, the primitive documents the usage. Semaphores would * typically be used for exclusion which gives rise to priority inversion. * Waiting for completion is a typically sync point, but not an exclusion point. *//** * complete: - signals a single thread waiting on this completion * @x: holds the state of this particular completion * * This will wake up a single thread waiting on this completion. Threads will be * awakened in the same order in which they were queued. * * See also complete_all(), wait_for_completion() and related routines. * * If this function wakes up a task, it executes a full memory barrier before * accessing the task state. */void complete(struct completion *x){ unsigned long flags; spin_lock_irqsave(&x->wait.lock, flags); if (x->done != UINT_MAX) x->done++; __wake_up_locked(&x->wait, TASK_NORMAL, 1); spin_unlock_irqrestore(&x->wait.lock, flags);}EXPORT_SYMBOL(complete);/** * complete_all: - signals all threads waiting on this completion * @x: holds the state of this particular completion * * This will wake up all threads waiting on this particular completion event. * * If this function wakes up a task, it executes a full memory barrier before * accessing the task state. * * Since complete_all() sets the completion of @x permanently to done * to allow multiple waiters to finish, a call to reinit_completion() * must be used on @x if @x is to be used again. The code must make * sure that all waiters have woken and finished before reinitializing * @x. Also note that the function completion_done() can not be used * to know if there are still waiters after complete_all() has been called. */void complete_all(struct completion *x){ unsigned long flags; spin_lock_irqsave(&x->wait.lock, flags); x->done = UINT_MAX; __wake_up_locked(&x->wait, TASK_NORMAL, 0);