fix(replay): Post checkCanRecord to main thread to prevent deadlock by romtsn · Pull Request #5837 · getsentry/sentry-java

romtsn · 2026-07-24T15:38:44Z

Summary

onScreenshotRecorded can run on the replay executor thread (PixelCopy masked-capture and emit paths). checkCanRecord() → pauseInternal() acquires lifecycleLock — if another thread holds that lock and submits to the same single-threaded executor, we deadlock.
Post checkCanRecord() to the main looper so it never runs on the executor thread.

This was a pre-existing issue introduced with SurfaceView capturing (masked-capture path calls onScreenshotRecorded from executor at PixelCopyStrategy.kt:209), and is also relevant for PR #5808 which adds the emitLastScreenshot executor path.

Test plan

Existing onScreenshotRecorded pauses replay when rate-limited for sessions test updated to idle looper
./gradlew :sentry-android-replay:testReleaseUnitTest --tests="*ReplayIntegrationTest*" passes

🤖 Generated with Claude Code

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

sentry · 2026-07-24T15:43:17Z

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.50.0 (1)	release

⚙️ sentry-android Build Distribution Settings

github-actions · 2026-07-24T15:46:50Z

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	330.83 ms	374.53 ms	43.70 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`05aa61d`	326.06 ms	385.46 ms	59.40 ms
`bb0ff41`	315.84 ms	350.76 ms	34.92 ms
`806307f`	357.85 ms	424.64 ms	66.79 ms
`d501a7e`	307.33 ms	341.94 ms	34.61 ms
`0ee65e9`	321.06 ms	361.24 ms	40.18 ms
`ed33deb`	334.19 ms	362.30 ms	28.11 ms
`9fbb112`	401.87 ms	515.87 ms	114.00 ms
`b8bd880`	314.56 ms	336.50 ms	21.94 ms
`5b1a06b`	315.40 ms	353.33 ms	37.94 ms
`6edfca2`	316.43 ms	398.90 ms	82.46 ms

App size

Revision	Plain	With Sentry	Diff
`05aa61d`	0 B	0 B	0 B
`bb0ff41`	0 B	0 B	0 B
`806307f`	1.58 MiB	2.10 MiB	533.42 KiB
`d501a7e`	0 B	0 B	0 B
`0ee65e9`	0 B	0 B	0 B
`ed33deb`	1.58 MiB	2.13 MiB	559.52 KiB
`9fbb112`	1.58 MiB	2.11 MiB	539.18 KiB
`b8bd880`	1.58 MiB	2.29 MiB	722.92 KiB
`5b1a06b`	0 B	0 B	0 B
`6edfca2`	1.58 MiB	2.13 MiB	559.07 KiB

Previous results on branch: rz/fix/replay-checkcanrecord-deadlock

Startup times

Revision	Plain	With Sentry	Diff
`ba152d2`	346.75 ms	440.34 ms	93.59 ms
`03ae43b`	327.07 ms	408.58 ms	81.52 ms
`33731c0`	351.60 ms	422.48 ms	70.88 ms
`ace2fbf`	318.04 ms	367.28 ms	49.24 ms
`1922e86`	319.80 ms	359.07 ms	39.27 ms

App size

Revision	Plain	With Sentry	Diff
`ba152d2`	0 B	0 B	0 B
`03ae43b`	0 B	0 B	0 B
`33731c0`	0 B	0 B	0 B
`ace2fbf`	0 B	0 B	0 B
`1922e86`	0 B	0 B	0 B

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cursor

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

Want reviews to match your repository better? Bugbot Learning can learn team-specific rules from PR activity. A team admin can enable Learning in the Cursor dashboard.

^{Reviewed by Cursor Bugbot for commit dabe4b2. Configure here.}

onScreenshotRecorded can run on the replay executor thread (PixelCopy masked-capture and emit paths). checkCanRecord -> pauseInternal acquires lifecycleLock — if another thread holds that lock and submits to the same single-threaded executor, we deadlock. When not already on the main thread, post checkCanRecord to the main looper so it never runs on the executor. On main thread, call directly to preserve existing synchronous behavior. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Holding lifecycleLock while calling awaitTermination() deadlocks if any executor task tries to acquire the same lock. Move shutdown after the lock is released to cut this edge. Ref: #5847 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

0xadam-brown

Thanks for the update 💯

Up to you whether you think it worthwhile to add tests to ReplayIntegrationTest verifying that we shutdown outside the lifecycleLock, and that we don't deadlock when invoking onScreenshotRecorded() from the replay executor path while lifecycleLock is held. Otherwise lgtm.

Verifies close() completes when an executor task is waiting on lifecycleLock, ensuring shutdown happens outside the lock. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

romtsn requested review from 0xadam-brown, adinauer, markushi and runningcode as code owners July 24, 2026 15:38

romtsn added a commit that referenced this pull request Jul 24, 2026

changelog: Add entry for checkCanRecord deadlock fix (#5837)

a4cab2c

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cursor Bot reviewed Jul 24, 2026

View reviewed changes

Comment thread CHANGELOG.md Outdated

romtsn added a commit that referenced this pull request Jul 24, 2026

changelog: Add entry for checkCanRecord deadlock fix (#5837)

0f1e537

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

romtsn force-pushed the rz/fix/replay-checkcanrecord-deadlock branch 2 times, most recently from feca2f0 to dabe4b2 Compare July 27, 2026 08:16

cursor Bot reviewed Jul 27, 2026

View reviewed changes

Comment thread sentry-android-replay/src/main/java/io/sentry/android/replay/ReplayIntegration.kt Outdated

romtsn force-pushed the rz/fix/replay-checkcanrecord-deadlock branch 2 times, most recently from 4c69937 to 70a764b Compare July 27, 2026 08:23

sentry-junior Bot mentioned this pull request Jul 27, 2026

ci(warden): Drop anthropic model pin so CI inherits org default #5839

Merged

8 tasks

romtsn force-pushed the rz/fix/replay-checkcanrecord-deadlock branch from 7c64d39 to 4af06f2 Compare July 27, 2026 11:10

Merge branch 'main' into rz/fix/replay-checkcanrecord-deadlock

c181555

0xadam-brown reviewed Jul 27, 2026

View reviewed changes

Comment thread sentry-android-replay/src/main/java/io/sentry/android/replay/ReplayIntegration.kt

Comment thread sentry-android-replay/src/main/java/io/sentry/android/replay/ReplayIntegration.kt

romtsn mentioned this pull request Jul 27, 2026

fix(replay): Don't let a wedged video encoder freeze the app #5842

Open

5 tasks

fix test

6257cfc

romtsn mentioned this pull request Jul 28, 2026

refactor(replay): Consider thread confinement for lifecycle state to eliminate lifecycleLock #5847

Open

romtsn and others added 2 commits July 28, 2026 10:45

chore: Drop ponytail prefix from comment

8ab3ef2

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

0xadam-brown approved these changes Jul 28, 2026

View reviewed changes

test(replay): Add deadlock test for close() with blocked executor task

bd2c815

Verifies close() completes when an executor task is waiting on lifecycleLock, ensuring shutdown happens outside the lock. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

romtsn enabled auto-merge (squash) July 28, 2026 20:48

romtsn merged commit a30048b into main Jul 28, 2026
71 checks passed

romtsn deleted the rz/fix/replay-checkcanrecord-deadlock branch July 28, 2026 20:51

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

fix(replay): Post checkCanRecord to main thread to prevent deadlock - #5837

fix(replay): Post checkCanRecord to main thread to prevent deadlock#5837
romtsn merged 6 commits into
mainfrom
rz/fix/replay-checkcanrecord-deadlock

romtsn commented Jul 24, 2026

Uh oh!

Uh oh!

sentry Bot commented Jul 24, 2026 •

edited

Loading

Uh oh!

github-actions Bot commented Jul 24, 2026 •

edited

Loading

Baseline results on branch: main

Startup times

App size

Previous results on branch: rz/fix/replay-checkcanrecord-deadlock

Startup times

App size

Uh oh!

cursor Bot left a comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

0xadam-brown left a comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Uh oh!

Uh oh!

Conversation

romtsn commented Jul 24, 2026

Summary

Test plan

Uh oh!

Uh oh!

sentry Bot commented Jul 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

📲 Install Builds

Android

Uh oh!

github-actions Bot commented Jul 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Performance metrics 🚀

Baseline results on branch: main

Startup times

App size

Previous results on branch: rz/fix/replay-checkcanrecord-deadlock

Startup times

App size

Uh oh!

cursor Bot left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

0xadam-brown left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

sentry Bot commented Jul 24, 2026 •

edited

Loading

github-actions Bot commented Jul 24, 2026 •

edited

Loading