If multiple threads call kevent() to get AIO events on same kqueue fd,
it is possible that a single AIO event will be reported to multiple threads, it is not threading friendly, and the existing API can not control this behavior. Allocate a kevent flags field sigev_notify_kevent_flags for AIO event notification in sigevent, and allow user to pass EV_CLEAR, EV_DISPATCH or EV_ONESHOT to AIO kernel code, user can control whether the event should be cleared once it is retrieved by a thread. This change should be comptaible with existing application, because the field should have already been zero-filled, and no additional action will be taken by kernel. PR: kern/156567
This commit is contained in:
parent
1db689c583
commit
fde809356a
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=230857
@ -1524,6 +1524,7 @@ aio_aqueue(struct thread *td, struct aiocb *job, struct aioliojob *lj,
|
||||
int error;
|
||||
int fd, kqfd;
|
||||
int jid;
|
||||
u_short evflags;
|
||||
|
||||
if (p->p_aioinfo == NULL)
|
||||
aio_init_aioinfo(p);
|
||||
@ -1646,10 +1647,15 @@ aio_aqueue(struct thread *td, struct aiocb *job, struct aioliojob *lj,
|
||||
|
||||
if (aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_KEVENT)
|
||||
goto no_kqueue;
|
||||
evflags = aiocbe->uaiocb.aio_sigevent.sigev_notify_kevent_flags;
|
||||
if ((evflags & ~(EV_CLEAR | EV_DISPATCH | EV_ONESHOT)) != 0) {
|
||||
error = EINVAL;
|
||||
goto aqueue_fail;
|
||||
}
|
||||
kqfd = aiocbe->uaiocb.aio_sigevent.sigev_notify_kqueue;
|
||||
kev.ident = (uintptr_t)aiocbe->uuaiocb;
|
||||
kev.filter = EVFILT_AIO;
|
||||
kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1;
|
||||
kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1 | evflags;
|
||||
kev.data = (intptr_t)aiocbe;
|
||||
kev.udata = aiocbe->uaiocb.aio_sigevent.sigev_value.sival_ptr;
|
||||
error = kqfd_register(kqfd, &kev, td, 1);
|
||||
|
@ -169,12 +169,14 @@ struct sigevent {
|
||||
void (*_function)(union sigval);
|
||||
void *_attribute; /* pthread_attr_t * */
|
||||
} _sigev_thread;
|
||||
unsigned short _kevent_flags;
|
||||
long __spare__[8];
|
||||
} _sigev_un;
|
||||
};
|
||||
|
||||
#if __BSD_VISIBLE
|
||||
#define sigev_notify_kqueue sigev_signo
|
||||
#define sigev_notify_kevent_flags _sigev_un._kevent_flags
|
||||
#define sigev_notify_thread_id _sigev_un._threadid
|
||||
#endif
|
||||
#define sigev_notify_function _sigev_un._sigev_thread._function
|
||||
|
Loading…
Reference in New Issue
Block a user