Hardcoded default providers for asynchronous channel and file system

[Rémi Forax]

On 11/06/2011 07:16 PM, Alan Bateman wrote:
> On 04/11/2011 08:26, Jonathan Lu wrote:
>> Hi nio-dev,
>>
>> I found some hardcoded default providers in following two classes of 
>> nio module,
>> sun/nio/ch/DefaultAsynchronousChannelProvider.java
>> sun/nio/fs/DefaultFileSystemProvider.java
>>
>> On Unix platforms, these default providers will read the value of 
>> 'os.name' and construct platform specific provider accordingly.
>> For example, sun.nio.fs.SolarisFileSystemProvider is created if 
>> os.name equals "SunOS".
>> So several lines have to be modified to these class files when I try 
>> to port OpenJDK onto a new platform other than Linux and Solaris.
>>
>> So how about change this behavior to a more flexible approach? not 
>> depending on os.name.
>>
>> I prefer to generating the providers during compiling time in 
>> makefile as what has been done for nio buffers and have already got a 
>> patch works in this way. Of course, there're also other ways to do 
>> this, such as use a predefined property or a configuration file.
>> Any other ideas?
> The other one is 
> src/solaris/classes/sun/nio/ch/DefaultSelectorProvider.java which 
> selects the /dev/poll or epoll SelectorProvider depending on whether 
> we are running on Solaris or Linux.
>
> I agree we should re-visit this. One other benefit is that it fixes 
> another issue that we have on Solaris and Linux whereby classes for 
> the other platform are compiled and end up in rt.jar. It's not  
> significant from a footprint perspective but confusing to see Solaris 
> specific classes in the Linux rt.jar (and vice versa).
>
> I think build time would be the right place to select the factory 
> class and we should avoid consulting a property or configuration file 
> at runtime. So I would suggest go ahead and publish your patch for 
> discussion here.
>
> -Alan

Hi Alan, Hi Jonathan,
I've already written a program that changes the default selector provider
by changing the property before trying to access the default file system.

I have no problem with the fact that the default provider class is hardcoded
at build time but the property should still exist,
otherwise it will break my code.

If you're curious, here is why I change the default provider:
http://weblogs.java.net/blog/forax/archive/2011/10/01/asyncswing

Rémi