<AWT Dev> [8u] RFR: 8196681: Java Access Bridge logging and debug flags dynamically controlled

[Zhengyu Gu]

Hi Alex,

On 9/9/19 12:29 PM, Alex Kashchenko wrote:
> Hi,
> 
> Please review the code change required to backport JDK-8196681 to 8u.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8196681
> 
> Original review thread: 
> http://mail.openjdk.java.net/pipermail/awt-dev/2018-September/014302.html
> 
> 11u changeset: 
> https://hg.openjdk.java.net/jdk-updates/jdk11u-dev/rev/af9ad0ae9039
> 
> Patch does not apply cleanly, because std::chrono is used for 
> timestamps. And this part of C++11 standard is not supported by VS2010 
> toolchain that is used for 8u windows builds. The following change 
> reimplements the same timestamps without std::chrono:
> 
> 
>   auto getTimeStamp() -> long long {
> -    using namespace std::chrono;
> -    auto timeNow = 
> duration_cast<milliseconds>(steady_clock::now().time_since_epoch());
> -
> -    return timeNow.count();
> +    LARGE_INTEGER freqLarge;
> +    ::QueryPerformanceFrequency(&freqLarge);
> +    long long freq = freqLarge.QuadPart;
> +    LARGE_INTEGER counterLarge;
> +    ::QueryPerformanceCounter(&counterLarge);
> +    long long counter = counterLarge.QuadPart;
> +    long long milliDen = 1000;
> +    long long whole = (counter / freq) * milliDen;
> +    long long part = (counter % freq) * milliDen / freq;
> +    return whole + part;
>   }
> 
Would this whole + part calculation just (counter * milliDen) / freq? or 
you are worry about overflow?

Otherwise, looks good to me.

Thanks,

-Zhengyu


> 
> Backport also depends on JDK-8077707 and JDK-8132249 (both apply 
> cleanly), "jdk8u-fix-request" label was added for them.
> 
> Backport requires CSR that was filed in JDK-8230699.
> 
> Thanks!
>