RFR 6307456 : UnixFileSystem_md.c use of chmod() and access() should handle EINTR signal appropriately (unix)

[David Holmes]

Hi Ivan,

This is an "ancient" bug that you are fixing. I don't think it is valid.

On 15/03/2019 3:29 am, Ivan Gerasimov wrote:
> Hello!
> 
> Not all the man pages agree that chmod, access and statvfs64 can be 
> interrupted, but at least on some platforms they are allowed to fail 
> with EINTR:  chmod(2) on MacOS, access(2) on Solaris and statvfs(3) on 
> Linux.
> 
> So, it would be more accurate to wrap these up into a RESTARTABLE loop.

When Java threads are created, or native threads attach to the VM to 
become Java threads, they all get a very specific signal-mask to block 
most (non synchronous) signals. The signals that we install handlers for 
in the VM are also configured with SA_RESTART. So unless specifically 
specified as not honouring SA_RESTART we should not need the RESTARTABLE 
loop.

So I'm not clear exactly what signals we need to be guarding against 
here, or whether this indicates some kind of (historic) mismatch between 
the library and VM code?

Thanks,
David
-----

> Also, java_io_UnixFileSystem_list was tiny-optimized to avoid 
> unnecessary reallocation.
> 
> Would you please help review the fix?
> 
> BUGURL: https://bugs.openjdk.java.net/browse/JDK-6307456
> WEBREV: http://cr.openjdk.java.net/~igerasim/6307456/00/webrev/
> 
> Thanks in advance!
>