qemu/util/qemu-coroutine-sleep.c

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/*
* QEMU coroutine sleep
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu/coroutine.h"
#include "qemu/coroutine_int.h"
#include "qemu/timer.h"
#include "block/aio.h"
static void co_sleep_cb(void *opaque)
{
Coroutine *co = opaque;
/* Write of schedule protected by barrier write in aio_co_schedule */
atomic_set(&co->scheduled, NULL);
aio_co_wake(co);
}
void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns)
{
AioContext *ctx = qemu_get_current_aio_context();
QEMUTimer *ts;
Coroutine *co = qemu_coroutine_self();
const char *scheduled = atomic_cmpxchg(&co->scheduled, NULL, __func__);
if (scheduled) {
fprintf(stderr,
"%s: Co-routine was already scheduled in '%s'\n",
__func__, scheduled);
abort();
}
ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, co);
timer_mod(ts, qemu_clock_get_ns(type) + ns);
qemu_coroutine_yield();
timer_del(ts);
timer_free(ts);
}