CoolEagle

I got a little bit confusion that wait_event_interruptible is not a funciton, but a Macro.

wait_event_interruptible is often used like the following:

if (wait_event_interruptible(*(sk->sk_sleep),
(sk->sk_state != TCP_SYN_SENT)))

if (wait_event_interruptible(self->query_wait,
(self->iriap == NULL)))


How come it can work well?!

It will be like this when compiling.

if ( wait_event_interruptible is expanded as the following code )


In Linux source code, we can see:
#define wait_event_interruptible(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) \
__wait_event_interruptible(wq, condition, __ret); \
__ret; \
})

#define __wait_event_interruptible_timeout(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (; { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (!signal_pending(current)) { \
ret = schedule_timeout(ret); \
if (!ret) \
break; \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)

CoolEagle

No one help me. so sad

CoolEagle

On one konws....