kkonaka@mac.com <kkonaka@mac.com> [2003-09-12 00:03]:
> int busy = 0;
> wait_queue_head_t q;
> some_resource res; /* data structure shared between processes */
>
> ssize_t my_write(struct file * file, const char * buf,
> size_t count, loff_t *ppos)
> {
> while (busy) { /* grab exclusive access */
> interruptible_sleep_on(&q);
> }
>
> <do something assuming exclusive access to resources>
>
> busy = 0; /* release exclusive access */
> wake_up_interruptible(&q);
> return retval;
> }
>
Is this code supposed to be race-condition-free and to be working on
multiprocessing environments? If so, you should consider using atomic
instructions like mutexes and semaphores....
wbr,
Lukas
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