perf(core): [Init Reflection 1] Probe class availability without initializing#5635
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perf(core): [Init Reflection 1] Probe class availability without initializing#5635runningcode wants to merge 3 commits into
runningcode wants to merge 3 commits into
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LoadClass.loadClass used Class.forName(name) which initializes the class. Used purely for availability probing during init, this eagerly runs unrelated static initializers (e.g. Compose's Owner, the fragment integration). Use Class.forName(name, false, classLoader) so the class is only initialized lazily on first real use. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This was referenced Jun 25, 2026
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PR Stack (Init Reflection)
Part of JAVA-587
📜 Description
LoadClass.loadClassusedClass.forName(name), which initializes the class. Since this method is used purely to probe whether an optional integration is on the classpath duringSentryAndroid.init, that eagerly runs unrelated static initializers — the customer trace showsandroidx.compose.ui.node.Owner.<clinit>andFragmentLifecycleIntegration.<clinit>executing under the availability check.This switches to
Class.forName(name, false, classLoader)so the class is loaded but only initialized lazily on first real use (e.g. when it's actually instantiated).💡 Motivation and Context
First of three stacked PRs reducing reflection cost on the init path, from the customer-provided Perfetto trace in the Reduce SDK init time [Android] project (JAVA-586 area).
💚 How did you test it?
New
LoadClassTestincluding a guard asserting that probing a class does not run its static initializer; existing init/integration tests pass unchanged.📝 Checklist
sendDefaultPIIis enabled.🔮 Next steps
PR 2 caches lookups and collapses double-probes; PR 3 gates the Compose probes behind their features.
⏱️ Pixel 3 benchmark (ART method trace → Perfetto trace_processor)
Probing a class that has a (deliberately heavy) static initializer:
Class.forName(name)Class.forName(name, false, loader)<clinit>invocations under the probeThe static initializer runs under the old probe and is entirely skipped under the new one. In the production trace this was
androidx.compose.ui.node.Owner.<clinit>andFragmentLifecycleIntegration.<clinit>running during init. (Method tracing inflates the absolute<clinit>time, so only the invocation count is reported.)