64 lines
1.6 KiB
C
64 lines
1.6 KiB
C
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/* See the end of this file for copyright, license, and warranty information. */
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#include <arch-generic/do_switch.h>
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#include <ardix/list.h>
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#include <ardix/malloc.h>
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#include <ardix/mutex.h>
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#include <ardix/sched.h>
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#include <ardix/util.h>
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#include <errno.h>
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#include <stddef.h>
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void mutex_lock(struct mutex *mutex)
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{
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if (mutex_trylock(mutex) != 0) {
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struct mutex_wait *entry = malloc(sizeof(*entry));
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if (entry == NULL) {
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_spin_lock(&mutex->lock); /* fall back to spinning */
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return;
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}
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spin_lock(&mutex->wait_queue_lock);
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entry->task = current;
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list_insert(&mutex->wait_queue, &entry->link);
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spin_unlock(&mutex->wait_queue_lock);
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yield(TASK_LOCKWAIT);
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}
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}
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void mutex_unlock(struct mutex *mutex)
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{
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struct mutex_wait *waiter = NULL;
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spin_lock(&mutex->wait_queue_lock);
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if (!list_is_empty(&mutex->wait_queue)) {
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waiter = list_first_entry(&mutex->wait_queue, struct mutex_wait, link);
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list_delete(&waiter->link);
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}
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spin_unlock(&mutex->wait_queue_lock);
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if (waiter != NULL) {
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struct task *task = waiter->task;
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free(waiter);
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current->state = TASK_QUEUE;
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do_switch(current, task);
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} else {
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_mutex_unlock(&mutex->lock);
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}
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}
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/*
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* This file is part of Ardix.
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* Copyright (c) 2021 Felix Kopp <owo@fef.moe>.
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*
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* Ardix is non-violent software: you may only use, redistribute,
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* and/or modify it under the terms of the CNPLv6+ as found in
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* the LICENSE file in the source code root directory or at
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* <https://git.pixie.town/thufie/CNPL>.
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*
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* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
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* permitted by applicable law. See the CNPLv6+ for details.
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*/
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