* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
sigtimedwait() -> nxsig_timedwait()
sigwaitinfo() -> nxsig_waitinfo()
nanosleep() -> nxsig_nanosleep()
The internal OS versions differ from the standard application interfaces in that:
- They do not create cancellation points, and
- they do not modify the application's errno variable
Squashed commit of the following:
sched/signal: Replace all usage of sigwaitinfo(), sigtimedwait(), and nanosleep() with the OS internal counterparts nxsig_waitinfo(), nxsig_timedwait(), and nxsig_nanosleep().
sched/signal: Add nxsig_nanosleep(). This is an internal OS version of nanosleep(). It differs in that it does not set the errno varaiable and does not create a cancellation point.
sched/signal: Add nxsig_timedwait() and nxsig_waitinfo(). These are internal OS versions of sigtimedwait() and sigwaitinfo(). They differ in that they do not set the errno varaiable and they do not create cancellation points.
Xiang Xiao