Hi Ralph,
I've added an apache-log4j-interest label to the issue.
cheers,
dalibor topic
On 14.04.2021 19:00, Ralph Goers wrote:
I don’t have an account in the bug tracking system. Could someone possibly
update the issue noted below to indicate that Apache Log4j 2 would also like
that enhancement?
Thanks,
Ralph
On Apr 5, 2021, at 1:26 PM, Roger Riggs <roger.ri...@oracle.com> wrote:
Hi,
Java does not have a data type with enough resolution to hold a full nanosecond
value.
Hence the implementation of Instant holding seconds and nanos.
There is an long dormant enhancement request to return micro-seconds as a long.
8196003 <https://bugs.openjdk.java.net/browse/JDK-8196003> java.time Instant
and Duration methods for microseconds
That might be useful if the application gets enough resolution from
microseconds.
There might be some clever interpolation between System.currentTimeMillis()
and adjusting with System.nanoTime().
Though it would likely not be exactly synchronized with the values from Instant.
Regards, Roger
On 4/5/21 3:56 PM, Brian Goetz wrote:
Project Valhalla will allow Instant to be migrated to a primitive class, which
would address your problem.
On 4/2/2021 7:47 PM, Ralph Goers wrote:
Log4j 2 supports the notion of a PreciseClock - one that can be initialized to
something more precise than a millisecond. At the same time it also supports
running with no heap allocations in certain circumstances. I am in the process
of moving our master branch to require Java 11 as the minimum. In doing so I am
encountering unit test errors while verifying that logging is garbage free.
They all occur allocating an Instant.
The code we have simply does
public void init(MutableInstant mutableInstant) {
Instant instant = java.time.Clock.systemUTC().instant();
mutableInstant.initFromEpochSecond(instant.getEpochSecond(), instant.getNano());
}
In our previous tests we had thought the allocation was being eliminated due to
escape analysis since the data is being extracted from the Instant and not
passed along. However, after upgrading the Google test library and the JDK
version it appears that is not the case.
Ideally we would really like something like
public void init(MutableInstant mutableInstant) {
java.time.Clock.systemUTC().initInstant(mutableInstant);
}
where Mutable instant would implement an interface that has the two set
methods.The method would execute the same logic that is in the instant() method
but instead of creating a new Instant it would call the set methods for the
provided object.
This would allow us to either have the MutableInstants in ThreadLocals or some
other mechanism to ensure they are thread safe and have no heap allocations. As
it stands now I see no way to gain access to the higher precision clock without
memory allocation.
Do you know of another way to do this? Am I missing something?
Ralph
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