RFR(xxs): 8203680: os::stat() on Posix platform does not need to copy input path

[Thomas Stüfe]

Hi David,

thanks for the review!

new version:

http://cr.openjdk.java.net/~stuefe/webrevs/8203680-os-stat-posix-should-not-create-copy/webrev.01/webrev/

I moved the comment from os_posix.cpp to os.hpp, nothing else changed.

Yes, I'd assume stat(2) works the same on all platforms. In any case,
my patch does not change this - the code calling stat() was equal on
all posix platforms, I just removed the unnecessary argument copy.

Thanks, Thomas



On Tue, Jun 19, 2018 at 9:00 AM, David Holmes <david.holmes at oracle.com> wrote:
> Hi Thomas,
>
> Looks fine.
>
> I'd probably document the semantics for native_path in os.hpp rather than
> mentioning Posix in os_windows.cpp though.
>
> I assume the system stat function is the same on Linux, BSD, OS X, AIX and
> Solaris?
>
> Thanks,
> David
>
>
> On 18/06/2018 12:13 AM, Thomas Stüfe wrote:
>>
>> Hi,
>>
>> may I get reviews for this tiny cleanup/fix.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8203680
>> patch:
>> http://cr.openjdk.java.net/~stuefe/webrevs/8203680-os-stat-posix-should-not-create-copy/webrev.00/webrev/
>>
>> os::stat() on all Posix platforms copies the input path into a fixed
>> sized temp buffer, thereby risking truncation, only to call
>> os::native_path() which is a noop on all Posix platforms.
>>
>> This patch replaces this with a straight call to stat(2), so no
>> truncation anymore. Also, it unifies the coding in os_posix.cpp.
>>
>> Thanks, Thomas
>>
>