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author | Paolo Bonzini <pbonzini@redhat.com> | 2021-05-17 12:05:48 +0200 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2021-05-21 18:22:33 +0100 |
commit | 0a6f0c76a030710780ce10d6347a70f098024d21 (patch) | |
tree | 79401e5d13d95cde502761e07cf3344a0824ac1f /util | |
parent | 29a6ea24eb85d8400df1607a9e11d0ef9ec5e88d (diff) | |
download | qemu-0a6f0c76a030710780ce10d6347a70f098024d21.zip qemu-0a6f0c76a030710780ce10d6347a70f098024d21.tar.gz qemu-0a6f0c76a030710780ce10d6347a70f098024d21.tar.bz2 |
coroutine-sleep: introduce qemu_co_sleep
Allow using QemuCoSleep to sleep forever until woken by qemu_co_sleep_wake.
This makes the logic of qemu_co_sleep_ns_wakeable easy to understand.
In the future we will introduce an API that can work even if the
sleep and wake happen from different threads. For now, initializing
w->to_wake after timer_mod is fine because the timer can only fire in
the same AioContext.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210517100548.28806-7-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'util')
-rw-r--r-- | util/qemu-coroutine-sleep.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/util/qemu-coroutine-sleep.c b/util/qemu-coroutine-sleep.c index 89c3b75..571ab52 100644 --- a/util/qemu-coroutine-sleep.c +++ b/util/qemu-coroutine-sleep.c @@ -41,12 +41,9 @@ static void co_sleep_cb(void *opaque) qemu_co_sleep_wake(w); } -void coroutine_fn qemu_co_sleep_ns_wakeable(QemuCoSleep *w, - QEMUClockType type, int64_t ns) +void coroutine_fn qemu_co_sleep(QemuCoSleep *w) { Coroutine *co = qemu_coroutine_self(); - AioContext *ctx = qemu_get_current_aio_context(); - QEMUTimer ts; const char *scheduled = qatomic_cmpxchg(&co->scheduled, NULL, qemu_co_sleep_ns__scheduled); @@ -58,11 +55,26 @@ void coroutine_fn qemu_co_sleep_ns_wakeable(QemuCoSleep *w, } w->to_wake = co; - aio_timer_init(ctx, &ts, type, SCALE_NS, co_sleep_cb, w), - timer_mod(&ts, qemu_clock_get_ns(type) + ns); qemu_coroutine_yield(); - timer_del(&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); +} |