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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 const char *qemu_co_sleep_ns__scheduled = "qemu_co_sleep_ns";
struct QemuCoSleepState {
Coroutine *co;
QEMUTimer *ts;
QemuCoSleepState **user_state_pointer;
};
void qemu_co_sleep_wake(QemuCoSleepState *sleep_state)
{
/* Write of schedule protected by barrier write in aio_co_schedule */
const char *scheduled = atomic_cmpxchg(&sleep_state->co->scheduled,
qemu_co_sleep_ns__scheduled, NULL);
assert(scheduled == qemu_co_sleep_ns__scheduled);
if (sleep_state->user_state_pointer) {
*sleep_state->user_state_pointer = NULL;
}
timer_del(sleep_state->ts);
aio_co_wake(sleep_state->co);
}
static void co_sleep_cb(void *opaque)
{
qemu_co_sleep_wake(opaque);
}
void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns,
QemuCoSleepState **sleep_state)
{
AioContext *ctx = qemu_get_current_aio_context();
QemuCoSleepState state = {
.co = qemu_coroutine_self(),
.ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &state),
.user_state_pointer = sleep_state,
};
const char *scheduled = atomic_cmpxchg(&state.co->scheduled, NULL,
qemu_co_sleep_ns__scheduled);
if (scheduled) {
fprintf(stderr,
"%s: Co-routine was already scheduled in '%s'\n",
__func__, scheduled);
abort();
}
if (sleep_state) {
*sleep_state = &state;
}
timer_mod(state.ts, qemu_clock_get_ns(type) + ns);
qemu_coroutine_yield();
if (sleep_state) {
/*
* Note that *sleep_state is cleared during qemu_co_sleep_wake
* before resuming this coroutine.
*/
assert(*sleep_state == NULL);
}
timer_free(state.ts);
}
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