On Thu, 26 Apr 2012 16:03:08 -0700, Ben Widawsky <ben at bwidawsk.net> wrote:
> This helps implement glClientWaitSync.
>
> Finally we can use the new timed seqno waiting function to allow
> userspace to wait on a request with a timeout. This implements that
> interface.
>
> The new ioctl is very straight forward, there is a flags field which I
> envision may be useful for various flush permutations of the command.
What are the semantics of the ioctl? A simple use case would help
specify the interface here.
In particular, I can't tell whether the return value (timeout_ns) is
meant to be the time elapsed or the time remaining. What value is
returned in the timeout if we are interrupted before the wait completes?
Would
end = gettimeofday() + timeout;
do {
ret = i915_gem_wait(handle, 0, &timeout);
} while (ret == -1 && errno == EINTR);
assert(gettimeofday() <= end);
wait forever, or until the original timeout expires?
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
