RFR: 8262094: Handshake timeout scaled wrong

[Robbin Ehn]

On Mon, 22 Feb 2021 07:46:47 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Hi Robbin,
> 
> This change seems much clearer, but to be clear the actual result is the same as the "counter" tracks nanoseconds.
> 
> This counts as a trivial change IMO.
> 
> Thanks,
> David

Hi David, unfortunately I don't I agree that this is trivial:

`open/src/hotspot/os/windows/os_windows.cpp:jlong os::elapsed_frequency() {
open/src/hotspot/os/windows/os_windows.cpp-  return performance_frequency;
open/src/hotspot/os/windows/os_windows.cpp-}`

This value comes from QueryPerformanceFrequency, which depends on what resolution the Windows thinks is reasonable given what hardware support there are.

In a virtualized env. this causes a 20.000 ms timeout to timeout after 2 s for me due to low resolution (windows only).
(all other platforms hardcoded to NANASECONDS)

We have two more suspective uses here, which I have not investigated (but we have seem wired timeouts with both ZGC and G1, but I have seen non with parGC):
`open/src/hotspot/share/gc/z/zMark.cpp:      _timeout(_start.value() + TimeHelper::micros_to_counter(timeout_in_micros))`

`open/src/hotspot/share/gc/g1/g1ServiceThread.cpp:  jlong delay = TimeHelper::millis_to_counter(delay_ms);`

Thanks

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PR: https://git.openjdk.java.net/jdk/pull/2666