No-op VMRuntime.setThreadNiceness via ASM transform#2309
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No-op VMRuntime.setThreadNiceness via ASM transform#2309colinmarsch wants to merge 2 commits intomasterfrom
colinmarsch wants to merge 2 commits intomasterfrom
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Layoutlib's VMRuntime.setThreadNiceness calls Thread.setPosixNicenessInternal, a Dalvik-specific method that doesn't exist on the JVM, causing NoSuchMethodError at runtime. Thread niceness is irrelevant for screenshot testing, so replace the method body with a no-op return. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Do we already have an existing test for verifying this?
Exercises the real layoutlib VMRuntime through AGP's instrumentation pipeline, confirming the no-op transform prevents NoSuchMethodError on Thread.setPosixNicenessInternal. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Added an integration test in 46671bc — it exercises the real layoutlib |
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Summary
NoSuchMethodError: java.lang.Thread.setPosixNicenessInternal(int)introduced by the layoutlib bumpVMRuntime.setThreadNicenesscallsThread.setPosixNicenessInternal— a Dalvik-specific native method that doesn't exist on the JVM, crashing at runtime viaHandlerThread.run→Process.setThreadPriority→VMRuntime.setThreadNicenessThreadNicenessVisitorFactory) that replaces thesetThreadNicenessmethod body with a no-op return, since thread niceness is irrelevant for screenshot testingWhy
The recent layoutlib update added a code path that assumes Dalvik-specific JVM internals are available. Rather than patching at a higher level (e.g., no-oping
Process.setThreadPriority), this targets the exact method that calls the missing native, preserving normal behavior elsewhere.