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romanett
8e96408b2a
## Problem `FuzzCrashAssets(AflfuzzBinaryDecoder)` failed intermittently on net48 (run 38897795750, test-windows-net48 1/16, on #4815, which changes only `perf/`): > 10562496 bytes allocated for 42 input bytes, budget 8391296 bytes On .NET Framework, `FuzzOracles` measures allocations with `AppDomain.MonitoringTotalAllocatedMemorySize`. That counter covers the whole AppDomain, so it also counts other threads in the test host. Measured on net48 Release for `crash-0bdcbfafc13981ae6f665ad52cabc1cbe21b0238`: | Scenario | Bytes | |---|---| | First decode in the process (one-time XML setup) | 1,083,232 | | Later decodes, same thread or a fresh thread | 16,440 | | Same decode with one concurrent thread allocating | 10.7 to 23.8 MB (over budget) | The decoder does not have a per-thread cost, and #4812 did not regress it. The CI TRX shows that tests ran one at a time. The failure came about 2 s into the run, right after a burst of about 100 fast test cases, which fits vstest serializing results on a background thread. ## Fix `FuzzOracles.RunTarget` re-runs a target when the allocation finding comes from a counter that is not per thread (`AllocationConfirmationRuns = 2`). It reports the finding only if every run confirms it. A real over-budget decode allocates the same amount every time, while a burst on another thread rarely lines up with all three runs. This is the same approach the time oracle already uses (`TimeConfirmationRuns`). Runtimes with a per-thread counter (net8+) behave as before. `FuzzMethods` playback goes through `RunTarget` too, so it also gets the confirmation runs. ## Tests - New tests in `FuzzOraclesTests`: - A finding that every run confirms is still reported, after 3 runs on net48 and 1 run on net8+. - A finding inflated by another thread is ignored (net48 only). This test fails when the confirmation runs are set to 0. - net48 Release: Opc.Ua.Fuzzing.Tests 156/156, Opc.Ua.Encoders.Fuzz.Tests 8130/8130. - net10.0: FuzzOraclesTests pass. 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>