perf(android): Init shake detector off the main thread#5784
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FeedbackShakeIntegration.register() resolved the accelerometer via SensorManager synchronously on the calling thread, which under auto-init is the main thread. On a Pixel 10 this first SensorManager access measured ~1.75ms, making it the single most expensive integration in the Sentry.init register loop. Submit the pre-warm init() to the executor service instead. start() already re-runs the idempotent init() on demand, so shake detection still works if an activity resumes before the warm-up completes. SentryShakeDetector's lifecycle methods are now synchronized so the executor warm-up and a main-thread start() cannot race on the sensor fields. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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requested review from
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romtsn
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July 17, 2026 15:14
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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runningcode
marked this pull request as draft
July 17, 2026 15:20
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Performance metrics 🚀
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| Revision | Plain | With Sentry | Diff |
|---|---|---|---|
| 5b1a06b | 352.27 ms | 413.70 ms | 61.43 ms |
| 2124a46 | 319.19 ms | 415.04 ms | 95.85 ms |
| ad8da22 | 314.52 ms | 352.47 ms | 37.95 ms |
| d15471f | 304.55 ms | 408.43 ms | 103.87 ms |
| 0ee65e9 | 317.37 ms | 366.50 ms | 49.13 ms |
| 2195398 | 351.77 ms | 433.22 ms | 81.45 ms |
| ee747ae | 358.21 ms | 389.41 ms | 31.20 ms |
| abfcc92 | 309.54 ms | 380.32 ms | 70.78 ms |
| 8558cac | 306.16 ms | 355.24 ms | 49.09 ms |
| d15471f | 310.26 ms | 377.04 ms | 66.78 ms |
App size
| Revision | Plain | With Sentry | Diff |
|---|---|---|---|
| 5b1a06b | 0 B | 0 B | 0 B |
| 2124a46 | 1.58 MiB | 2.12 MiB | 551.51 KiB |
| ad8da22 | 1.58 MiB | 2.29 MiB | 719.83 KiB |
| d15471f | 1.58 MiB | 2.13 MiB | 559.54 KiB |
| 0ee65e9 | 0 B | 0 B | 0 B |
| 2195398 | 0 B | 0 B | 0 B |
| ee747ae | 1.58 MiB | 2.10 MiB | 530.95 KiB |
| abfcc92 | 1.58 MiB | 2.13 MiB | 557.31 KiB |
| 8558cac | 0 B | 0 B | 0 B |
| d15471f | 1.58 MiB | 2.13 MiB | 559.54 KiB |
runningcode
marked this pull request as ready for review
July 20, 2026 07:09
romtsn
approved these changes
Jul 20, 2026
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I think the bot comment needs addressing but LGTM otherwise, pre-approving
…618) A warm-up init submitted to the executor could be drained after the integration's close() ran, since integrations shut down before the executor. That re-resolved the sensor and leaked a HandlerThread. Guard init()/start() with a closed latch so a late warm-up is a no-op. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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The closed latch added to neutralize a warm-up drained after close() was permanent, so re-registering the same integration (e.g. a second Sentry.init reusing the same options) left shake detection off with no recovery. register() now re-arms the detector via reopen(), which the stale-warm-up path (init()) deliberately does not, preserving the drain-after-close guard. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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reviewed
Jul 21, 2026
runningcode
enabled auto-merge (squash)
July 21, 2026 12:29
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Summary
FeedbackShakeIntegration.register()resolved the accelerometer viaSensorManagersynchronously on the calling thread — the main thread under auto-init. On a Pixel 10 (Android 17, release build) this firstSensorManageraccess measured ~1.75 ms, making it the single most expensive integration in theSentry.initregister loop (the loop total was ~5.1 ms).This moves the pre-warm
shakeDetector.init(...)ontooptions.getExecutorService().SentryShakeDetector.start()already re-runs the idempotentinit()on demand, so shake detection still works if an activity resumes before the warm-up finishes.SentryShakeDetector's lifecycle methods (init/start/stop/close) are nowsynchronizedso the executor warm-up and a main-threadstart()cannot race on the sensor fields.Measurement (Pixel 10, release, median of 10 cold starts)
FeedbackShakeIntegration.register()Follow-up to JAVA-618. Companion PR defers the other big synchronous item (NDK init).