*/
#include "qemu/osdep.h"
-#include "qemu/coroutine.h"
+#include "qemu/coroutine_int.h"
#include "qemu/timer.h"
#include "block/aio.h"
-typedef struct CoSleepCB {
- QEMUTimer *ts;
+static const char *qemu_co_sleep_ns__scheduled = "qemu_co_sleep_ns";
+
+void qemu_co_sleep_wake(QemuCoSleep *w)
+{
Coroutine *co;
-} CoSleepCB;
+
+ co = w->to_wake;
+ w->to_wake = NULL;
+ if (co) {
+ /* Write of schedule protected by barrier write in aio_co_schedule */
+ const char *scheduled = qatomic_cmpxchg(&co->scheduled,
+ qemu_co_sleep_ns__scheduled, NULL);
+
+ assert(scheduled == qemu_co_sleep_ns__scheduled);
+ aio_co_wake(co);
+ }
+}
static void co_sleep_cb(void *opaque)
{
- CoSleepCB *sleep_cb = opaque;
-
- aio_co_wake(sleep_cb->co);
+ QemuCoSleep *w = opaque;
+ qemu_co_sleep_wake(w);
}
-void coroutine_fn co_aio_sleep_ns(AioContext *ctx, QEMUClockType type,
- int64_t ns)
+void coroutine_fn qemu_co_sleep(QemuCoSleep *w)
{
- CoSleepCB sleep_cb = {
- .co = qemu_coroutine_self(),
- };
- sleep_cb.ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &sleep_cb);
- timer_mod(sleep_cb.ts, qemu_clock_get_ns(type) + ns);
+ Coroutine *co = qemu_coroutine_self();
+
+ const char *scheduled = qatomic_cmpxchg(&co->scheduled, NULL,
+ qemu_co_sleep_ns__scheduled);
+ if (scheduled) {
+ fprintf(stderr,
+ "%s: Co-routine was already scheduled in '%s'\n",
+ __func__, scheduled);
+ abort();
+ }
+
+ w->to_wake = co;
qemu_coroutine_yield();
- timer_del(sleep_cb.ts);
- timer_free(sleep_cb.ts);
+
+ /* w->to_wake is cleared before resuming this coroutine. */
+ assert(w->to_wake == NULL);
+}
+
+void coroutine_fn qemu_co_sleep_ns_wakeable(QemuCoSleep *w,
+ QEMUClockType type, int64_t ns)
+{
+ AioContext *ctx = qemu_get_current_aio_context();
+ QEMUTimer ts;
+
+ aio_timer_init(ctx, &ts, type, SCALE_NS, co_sleep_cb, w);
+ timer_mod(&ts, qemu_clock_get_ns(type) + ns);
+
+ /*
+ * The timer will fire in the current AiOContext, so the callback
+ * must happen after qemu_co_sleep yields and there is no race
+ * between timer_mod and qemu_co_sleep.
+ */
+ qemu_co_sleep(w);
+ timer_del(&ts);
}