8234805: (dc) Remove JNI upcall from DatagramChannel.receive implementation

[Alan Bateman]

On 26/11/2019 14:48, Daniel Fuchs wrote:
> Hi Alan,
>
> This looks like a nice improvement. A couple of comments:
>
> DatagramChannelImpl.java:
>
>   94     // Native buffer for socket address used by receive0
>   95     private final NativeSocketAddress socketAddress;
>
> It might be useful to add a comment to stress out that
> *all* access to socketAddress must be performed while holding
> the readLock.
Good idea, I'll do that.

>
>
>  609             int n = receive(dst, connected);
>  610             while (IOStatus.okayToRetry(n) && isOpen()) {
>
>  642                 int n = receive(dst, connected);
>  643                 while (n == IOStatus.UNAVAILABLE && isOpen()) {
>
> I was wondering: why the difference (line 610 vs line 643)?
These two methods support the socket adaptor. The first is when the 
socket is configured blocking so have to retry on EINTR. The second 
supports timed receive where the socket is configured non-blocking.

-Alan.