RFR: 8352738: Implement JEP 520: JFR Method Timing and Tracing

[Aleksey Shipilev]

On Thu, 22 May 2025 11:33:07 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Could I have a review of this enhancement that will add tracing capabilities to JFR? There are opportunities for performance improvements in the implementation, but I would rather add them later and separately.
>> 
>> Testing: tier 1-3, test/jdk/jdk/jfr
>> 
>> Thanks
>> Erik
>
> src/hotspot/share/jfr/support/methodtracer/jfrFilter.cpp line 73:
> 
>> 71:   if (name->equals("jdk.proxy1", 10)) {
>> 72:     return false;
>> 73:   }
> 
> Curious: what's `jdk.proxy1` module?

Sounds like from here:


src/java.base/share/classes/java/lang/reflect/Proxy.java:

        private static Module getDynamicModule(ClassLoader loader) {
            return dynProxyModules.computeIfAbsent(loader, (ld, clv) -> {
                // create a dynamic module and setup module access
                String mn = "jdk.proxy" + counter.incrementAndGet();


...but that looks to me that we can have more than 10 dynamic modules, so something like `jdk.proxy20` would mismatch here.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25306#discussion_r2102340775