acrn-hypervisor/hypervisor/common/event.c

58 lines
1.4 KiB
C

/*
* Copyright (C) 2018 Intel Corporation. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <asm/cpu.h>
#include <schedule.h>
#include <event.h>
#include <logmsg.h>
void init_event(struct sched_event *event)
{
spinlock_init(&event->lock);
event->nqueued = 0;
event->waiting_thread = NULL;
}
void reset_event(struct sched_event *event)
{
uint64_t rflag;
spinlock_irqsave_obtain(&event->lock, &rflag);
event->nqueued = 0;
event->waiting_thread = NULL;
spinlock_irqrestore_release(&event->lock, rflag);
}
/* support exclusive waiting only */
void wait_event(struct sched_event *event)
{
uint64_t rflag;
spinlock_irqsave_obtain(&event->lock, &rflag);
ASSERT((event->waiting_thread == NULL), "only support exclusive waiting");
event->waiting_thread = sched_get_current(get_pcpu_id());
event->nqueued++;
while ((event->nqueued > 0) && (event->waiting_thread != NULL)) {
sleep_thread(event->waiting_thread);
spinlock_irqrestore_release(&event->lock, rflag);
schedule();
spinlock_irqsave_obtain(&event->lock, &rflag);
}
event->waiting_thread = NULL;
spinlock_irqrestore_release(&event->lock, rflag);
}
void signal_event(struct sched_event *event)
{
uint64_t rflag;
spinlock_irqsave_obtain(&event->lock, &rflag);
event->nqueued--;
if (event->waiting_thread != NULL) {
wake_thread(event->waiting_thread);
}
spinlock_irqrestore_release(&event->lock, rflag);
}