RFR(S): 8241638: launcher time metrics alway report 1 on Linux when _JAVA_LAUNCHER_DEBUG set

[Henry Jen]

Based on my understanding to gethrtime(), the main benefit is not to be affected by settimeofday or adjtime. I think it is probably better to use

clock_gettime(CLOCK_MONOTONIC_RAW, ts);

which I checked seems to be available on both Linux and Mac. Haven’t test it though.

Cheers,
Henry

> On Mar 30, 2020, at 1:37 AM, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> 
> On 30/03/2020 03:41, linzang(臧琳) wrote:
>> Dear All,
>>      May I ask your help to reivew this tiny patch? Thanks.
>> 
>> 
>> 
>> BRs,
>> Lin
>> 
>> From: "linzang(臧琳)" <linzang at tencent.com>
>> Date: Thursday, March 26, 2020 at 3:13 PM
>> To: "core-libs-dev at openjdk.java.net" <core-libs-dev at openjdk.java.net>
>> Subject: RFR(S): 8241638: launcher time metrics alway report 1 on Linux when _JAVA_LAUNCHER_DEBUG set
>> 
>> Dear All,
>> May I ask your help to review this tiny fix?
>>     Bug: https://bugs.openjdk.java.net/browse/JDK-8241638
>>     Webrev: http://cr.openjdk.java.net/~lzang/8241638/webrev01/
>> Thanks!
>> 
> Using gettimeofday on non-Solaris platforms seems reasonable here. The comment in the patch suggests Linux but it's other Unix builds too. Also just a minor nit that the code in java.base uses 4-space indent, not 2. Looking at the patch makes me wondering if we should remove HAVE_GETHRTIME as it seems to be only used on Solaris and the launcher is already using #ifdef __solaris__ in several places. Henry, do you have any comments on this?
> 
> -Alan