RFR : 8195857 : Posix platforms : move os::is_headless_jre check coding to os::Posix and remove test for libmawt

[David Holmes]

Hi Matthias,

Some preliminary comments ...

On 23/01/2018 6:24 PM, Baesken, Matthias wrote:
> Hello,  I  noticed that  os::is_headless_jre()  still checks  on the Posix platforms  for libmawt  which is not present any longer.

I wonder why that comment was put in but the code not changed ...

> Additionally the  os::is_headless_jre()   function could be  put in a central place at os_posix  to avoid code duplication.

I think you could simplify further and just define in os.cpp with three 
cases: windows, OS X, posix. I normally wouldn't suggest that but given 
Windows and OS X are always false, it's quite trivial.

That said this may simplify even further because I don't know if the 
concept of a headless JRE is even meaningful anymore. This what put in 
place in 2010 to support Java SE Embedded. We had a special build 
process that would remove the library from the JRE image, then a runtime 
check os::is_headless_jre() run during argument processing, that if 
true, caused the java.awt.headless property to be set to true (unless 
already set). I don't think we can even build a "headless JRE" any more.

I'd need to do some checking but I think this may all be effectively 
dead code.

Thanks,
David
-------

> Could you please review my change .
> 
> Webrev :
> 
> http://cr.openjdk.java.net/~mbaesken/webrevs/8195857/
> 
> Bug :
> 
> https://bugs.openjdk.java.net/browse/JDK-8195857
> 
> 
> 
> Thanks, Matthias
>