Hardcoded default providers for asynchronous channel and file system

[Alan Bateman]

On 08/11/2011 09:11, Jonathan Lu wrote:
>
> Hello Alan,
>
> Thanks for reminding! I've updated my patch to include 
> DefaultSelectorProvider, see the attachment.
> And I also tried to build the patched OpenJDK8 on Linux, Windows and 
> Solaris, the result seems OK.
> Could you please take a look at it?
I finally got a chance to look at this.

My only concern with is that adds quite a bit of complexity to the 
build. From a portability point of view (the original objective) then it 
means editing three additional scripts for each platform too.

What would you think about making it a lot simpler with something like:

ifneq ($(PLATFORM),windows)

$(GENSRCDIR)/sun/nio/fs/DefaultFileSystemProvider.java: \
     
$(PLATFORM_SRC)/classes/sun/nio/fs/DefaultFileSystemProvider.java.$(PLATFORM)
         $(install-file)

clean::
         $(RM) $(GENSRCDIR)/sun/nio/fs/DefaultFileSystemProvider.java

endif

One benefit of this is that it would be trivial to change in the event 
that there were separate src/linux and src/solaris directories (BTW: 
don't read anything into this comment but at some point I think we 
should re-visit the current layout).

One other comment is that you've retained the code to choose the 
SelectorProvider implementation based on the Linux kernel. I think we 
should just drop this check as it's unlikely that anyone is porting and 
target ancient 2.4 kernels now.

-Alan.