fix(replay): Dispatch session-deadline stop off the replay worker thread (DART-323)

When a session replay reaches its duration deadline, the stop was invoked
inline from the replay worker thread inside the frame-processing task. Because
ReplayExecutorService.submit() runs tasks synchronously when already on that
thread, stop() encoded the final segment and deleted the replay cache while
holding the replay lifecycle lock. A foreground start() on the main thread then
parked on that lock long enough to trigger a background ANR.

Dispatch the deadline stop through options.executorService so the segment
encoding is enqueued asynchronously and the lifecycle lock is only held for the
fast state transition, matching the existing timer-executor stop path.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: runningcode

sentry-android-replay/src/main/java/io/sentry/android/replay/capture/SessionCaptureStrategy.kt

@@ -10,6 +10,7 @@ import io.sentry.android.replay.ReplayCache
 import io.sentry.android.replay.ScreenshotRecorderConfig
 import io.sentry.android.replay.capture.CaptureStrategy.ReplaySegment
 import io.sentry.android.replay.util.ReplayRunnable
+import io.sentry.android.replay.util.submitSafely
 import io.sentry.protocol.SentryId
 import io.sentry.transport.ICurrentDateProvider
 import io.sentry.util.FileUtils
@@ -134,8 +135,13 @@ internal class SessionCaptureStrategy(
         }
 
         if ((now - replayStartTimestamp.get() >= options.sessionReplay.sessionDuration)) {
-          options.replayController.stop()
           options.logger.log(INFO, "Session replay deadline exceeded (1h), stopping recording")
+          // dispatch off the replay worker thread, otherwise stop() would run the final segment
+          // encoding synchronously while holding the replay lifecycle lock, blocking a foreground
+          // start() on the main thread (ANR)
+          options.executorService.submitSafely(options, "$TAG.stop") {
+            options.replayController.stop()
+          }
         }
       }
     )

sentry-android-replay/src/test/java/io/sentry/android/replay/capture/SessionCaptureStrategyTest.kt

@@ -29,6 +29,8 @@ import io.sentry.protocol.SentryId
 import io.sentry.rrweb.RRWebBreadcrumbEvent
 import io.sentry.rrweb.RRWebMetaEvent
 import io.sentry.rrweb.RRWebOptionsEvent
+import io.sentry.test.DeferredExecutorService
+import io.sentry.test.ImmediateExecutorService
 import io.sentry.transport.CurrentDateProvider
 import io.sentry.transport.ICurrentDateProvider
 import java.io.File
@@ -66,6 +68,7 @@ class SessionCaptureStrategyTest {
         setReplayController(
           mock { on { breadcrumbConverter }.thenReturn(DefaultReplayBreadcrumbConverter()) }
         )
+        executorService = ImmediateExecutorService()
       }
     val scope = Scope(options)
     val scopes =
@@ -291,6 +294,35 @@ class SessionCaptureStrategyTest {
     verify(fixture.options.replayController).stop()
   }
 
+  @Test
+  fun `onScreenshotRecorded dispatches deadline stop off the calling thread`() {
+    val deferredExecutor = DeferredExecutorService()
+    fixture.options.executorService = deferredExecutor
+    var count = 0
+    val strategy =
+      fixture.getSut(
+        dateProvider = {
+          if (count++ == 2) {
+            System.currentTimeMillis() + (fixture.options.sessionReplay.sessionDuration * 2)
+          } else {
+            System.currentTimeMillis()
+          }
+        }
+      )
+    strategy.start()
+    strategy.onConfigurationChanged(mock<ScreenshotRecorderConfig>())
+
+    strategy.onScreenshotRecorded(mock<Bitmap>()) {}
+
+    // stop must not run inline on the caller (replay worker) thread, otherwise it would encode the
+    // final segment while holding the lifecycle lock and block a foreground start() (ANR)
+    verify(fixture.options.replayController, never()).stop()
+
+    deferredExecutor.runAll()
+
+    verify(fixture.options.replayController).stop()
+  }
+
   @Test
   fun `onConfigurationChanged creates new segment and updates config`() {
     val strategy = fixture.getSut()