RFR: 8367949: JFR: MethodTrace double-counts methods that catch their own exceptions

[Jean-Noël Rouvignac]

On Sun, 21 Dec 2025 16:22:25 GMT, Erik Gahlin <egahlin at openjdk.org> wrote:

> Could I have a review of a PR that changes how the instrumentation of the MethodTrace and MethodTiming events is implemented, so they handle exceptions in a better way? 
> 
> For constructors, the current implementation is still used in certain corner cases. A proper implementation would require data-flow analysis, but for all practical purposes this code should work fine.
> 
> Testing: jdk/jdk/jfr
> 
> Thanks
> Erik

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/Instrumentation.java line 80:

> 78:         byte[] generated = classFile.build(classModel.thisClass().asSymbol(), classBuilder -> {
> 79:             for (var ce : classModel) {
> 80:                 if (modifyClassElement(classModel,classBuilder, ce)) {

Suggestion:

                if (modifyClassElement(classModel, classBuilder, ce)) {

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/Instrumentation.java line 111:

> 109:                 Modification m = tm.modification();
> 110:                 if (m.tracing() || m.timing()) {
> 111:                     return modifyMethod(classModel,classBuilder, mm, tm);

Suggestion:

                    return modifyMethod(classModel, classBuilder, mm, tm);

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PR Review Comment: https://git.openjdk.org/jdk/pull/28947#discussion_r2646154444
PR Review Comment: https://git.openjdk.org/jdk/pull/28947#discussion_r2646154577