There has been some discussion on lkml about a function that would
either down a semaphore or else abort if it couldn't get the semaphore
in a certain amount of time. Something along the lines of:
down_timeout(struct semaphore *sem, long timeout);
Does something like this exist? Does anyone have a working
implementation? Does anyone see anything obviously wrong with the
following version (that I loosely based on one by Rupert Eibauer)?
semaphore.h:
extern int __down_timeout(struct semaphore * sem, unsigned int timeout);
/* "timeout" is the number of jiffies to wait.
* Returns -ETIME if timeout period expires.
*/
static inline int down_timeout(struct semaphore * sem, unsigned int timeout)
{
int ret = down_trylock(sem);
if (!ret)
ret = __down_timeout(sem, timeout);
return ret;
}
kernel/timer.c
int __down_timeout(struct semaphore * sem, int timeout)
{
int ret;
unsigned long expire;
struct timer_list timer;
expire = jiffies + timeout;
init_timer(&timer);
timer.expires = expire;
timer.data = (unsigned long) current;
timer.function = process_timeout;
add_timer(&timer);
ret = down_interruptible(sema);
if (ret && (jiffies > expire))
ret = -ETIME;
else
del_timer_sync(&timer);
return ret;
}
Thanks,
Chris
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
