diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2018-02-03 10:39:34 -0500 |
|---|---|---|
| committer | Fam Zheng <famz@redhat.com> | 2018-02-08 09:22:03 +0800 |
| commit | 5261dd7b0106a88c9b323607136b1dfa1d7db689 (patch) | |
| tree | 6463067b5849821f9639f5a3b5bcfd70513ac57c /fsdev | |
| parent | 1a957cf9c4637abe4b7d67a91312a2565306641e (diff) | |
coroutine-lock: make qemu_co_enter_next thread-safe
qemu_co_queue_next does not need to release and re-acquire the mutex,
because the queued coroutine does not run immediately. However, this
does not hold for qemu_co_enter_next. Now that qemu_co_queue_wait
can synchronize (via QemuLockable) with code that is not running in
coroutine context, it's important that code using qemu_co_enter_next
can easily use a standardized locking idiom.
First of all, qemu_co_enter_next must use aio_co_wake to restart the
coroutine. Second, the function gains a second argument, a QemuLockable*,
and the comments of qemu_co_queue_next and qemu_co_queue_restart_all
are adjusted to clarify the difference.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180203153935.8056-5-pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Diffstat (limited to 'fsdev')
| -rw-r--r-- | fsdev/qemu-fsdev-throttle.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fsdev/qemu-fsdev-throttle.c b/fsdev/qemu-fsdev-throttle.c index 49eebb5412..1dc07fbc12 100644 --- a/fsdev/qemu-fsdev-throttle.c +++ b/fsdev/qemu-fsdev-throttle.c @@ -20,13 +20,13 @@ static void fsdev_throttle_read_timer_cb(void *opaque) { FsThrottle *fst = opaque; - qemu_co_enter_next(&fst->throttled_reqs[false]); + qemu_co_enter_next(&fst->throttled_reqs[false], NULL); } static void fsdev_throttle_write_timer_cb(void *opaque) { FsThrottle *fst = opaque; - qemu_co_enter_next(&fst->throttled_reqs[true]); + qemu_co_enter_next(&fst->throttled_reqs[true], NULL); } void fsdev_throttle_parse_opts(QemuOpts *opts, FsThrottle *fst, Error **errp) |