Question

Where can I find the code for wait_event_interruptible in Kernel tree.
What I can find is wait_event_interruptible is defined as __wait_event_interruptible in . But I am unable to find the code .
Please help me out.

Consider a process which has gone to sleep by wait_event_interruptible. Suppose if there is an interrupt now and the interrupt handler wakes(wake_up_event_interruptible) up the sleeping process. For the process to wake up successfully should the condition given in wait_event_interruptible be true ?

Thanks

Answer 1

It’s in include/linux/wait.h:

#define wait_event_interruptible(wq, condition)               \
({                                                            \
    int __ret = 0;                                            \
    if (!(condition))                                         \
        __wait_event_interruptible(wq, condition, __ret);     \
    __ret;                                                    \
})

…

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