ref(android): Match MemoryLimiter app exit reason introduced in Android 37.2

Android 37.2 introduced a new ApplicationExitInfo.REASON_MEMORY_LIMITER flag. This commit updates our MemoryLimiterIntegration code to match against it (while preserving ouro previous matching logic).

No Android API guard is needed for the new flag because:

 - we already check MemoryLimiterIntegration registration against API 37; and
 - REASON_MEMORY_LIMITER is a static integer constant and will be inlined as an integer by the Java compiler (meaning we don't need extra protection for devices on 37.0 or 37.1).

Author: 0xadam-brown

CHANGELOG.md

@@ -7,6 +7,10 @@
 - Deprecate `sendDefaultPii` in favor of `dataCollection` ahead of its removal in 9.0 ([#6158](https://github.com/getsentry/sentry-java/pull/6158))
 - Make the tombstone merge time threshold configurable via `SentryAndroidOptions.setTombstoneMergeTimeThresholdMillis` and the `io.sentry.tombstone.merge-time-threshold-millis` manifest option ([#6154](https://github.com/getsentry/sentry-java/pull/6154))
 
+### Improvements
+
+- Recover Android 17 `MemoryLimiter` app exits recorded as `ApplicationExitInfo.REASON_MEMORY_LIMITER` ([#6174](https://github.com/getsentry/sentry-java/pull/6174))
+
 ## 8.58.0
 
 ### Features

sentry-android-core/src/main/java/io/sentry/android/core/MemoryLimiterIntegration.java

@@ -190,24 +190,30 @@ private MemoryLimiterPolicy(final @NotNull SentryAndroidOptions options) {
     /**
      * Returns true if the provided {@code exitInfo} looks like it came from a MemoryLimiter-induced
      * process death.
-     *
-     * <p>Criteria taken from <a
-     * href="https://developer.android.com/about/versions/17/behavior-changes-all#app-memory-limits">here</a>.
      */
     @Override
     @RequiresApi(api = Build.VERSION_CODES.R)
     public boolean matches(final @NotNull ApplicationExitInfo exitInfo) {
-      if (exitInfo.getReason() != ApplicationExitInfo.REASON_OTHER) {
-        return false;
+      final int reason = exitInfo.getReason();
+
+      // 1. Return true for explicit matches.
+      if (reason == ApplicationExitInfo.REASON_MEMORY_LIMITER) {
+        return true;
       }
 
-      final String description = exitInfo.getDescription();
-      // We match on the "MemoryLimiter:" prefix rather than the full "MemoryLimiter:AnonSwap"
-      // string mentioned in the Android 17 release notes because we want to capture any future
-      // MemoryLimiter kill reason without a code change. (MemoryLimiter source already tracks
-      // MemoryLimiter:Memory and MemoryLimiter:Swap, but for now doesn't kill the process because
-      // of them.)
-      return description != null && description.contains(MEMORY_LIMITER_DESCRIPTION_PREFIX);
+      // 2. Return true for heuristic matches based on criteria discussed here:
+      // https://developer.android.com/about/versions/17/behavior-changes-all#app-memory-limits
+      if (reason == ApplicationExitInfo.REASON_OTHER) {
+        final String description = exitInfo.getDescription();
+        // We match on the "MemoryLimiter:" prefix rather than the full "MemoryLimiter:AnonSwap"
+        // string mentioned in the Android 17 release notes because we want to capture any future
+        // MemoryLimiter kill reason without a code change. (MemoryLimiter source already tracks
+        // MemoryLimiter:Memory and MemoryLimiter:Swap, but for now doesn't kill the process because
+        // of them.)
+        return description != null && description.contains(MEMORY_LIMITER_DESCRIPTION_PREFIX);
+      }
+
+      return false;
     }
 
     @Override

sentry-android-core/src/test/java/io/sentry/android/core/MemoryLimiterIntegrationTest.kt

@@ -214,8 +214,30 @@ class MemoryLimiterIntegrationTest {
     verify(fixture.options.executorService).submit(any())
   }
 
+  // "Explicit records" are ApplicationExitInfo instances that use
+  // ApplicationExitInfo.REASON_MEMORY_LIMITER to indicate a MemoryLimiter kill. Contrast "heuristic
+  // records" below.
   @Test
-  fun `captures exit when reason and description match exits produced by MemoryLimiter`() {
+  fun `captures exit for explicit MemoryLimiter record`() {
+    val integration = fixture.getSut(tmpDir, lastReportedTimestamp = oldTimestamp)
+    fixture.addAppExitInfo(
+      reason = ApplicationExitInfo.REASON_MEMORY_LIMITER,
+      description = null,
+      timestamp = newTimestamp,
+    )
+
+    integration.register(fixture.scopes, fixture.options)
+
+    verify(fixture.scopes).captureEvent(any(), anyOrNull<Hint>())
+  }
+
+  // "Heuristic records" are ApplicationExitInfo instances that use something other than
+  // ApplicationExitInfo.REASON_MEMORY_LIMITER to indicate a MemoryLimiter kill.
+  // (REASON_MEMORY_LIMITER wasn't introduced until 37.2.) They consist of
+  // ApplicationExitInfo.REASON_OTHER + an ApplicationExitInfo.description that contains the prefix
+  // "MemoryLimiter:".
+  @Test
+  fun `captures exit for heuristic MemoryLimiter record`() {
     val integration =
       fixture.getSut(
         memoryLimiterEnabled = true,
@@ -285,25 +307,34 @@ class MemoryLimiterIntegrationTest {
   }
 
   @Test
-  fun `ignores exit when reason does not match exits produced by MemoryLimiter`() {
+  fun `captures exit for heuristic record even if description suffix is not AnonSwap`() {
     val integration = fixture.getSut(tmpDir, lastReportedTimestamp = oldTimestamp)
     fixture.addAppExitInfo(
-      reason = ApplicationExitInfo.REASON_ANR,
-      description = MemoryLimiterIntegration.MEMORY_LIMITER_DESCRIPTION,
+      reason = ApplicationExitInfo.REASON_OTHER,
+      // Description suffix is "Memory" rather than "AnonSwap".
+      description = "MemoryLimiter:Memory",
       timestamp = newTimestamp,
     )
 
     integration.register(fixture.scopes, fixture.options)
 
-    verify(fixture.scopes, never()).captureEvent(any(), anyOrNull<Hint>())
+    verify(fixture.scopes)
+      .captureEvent(
+        check<SentryEvent> { event ->
+          assertEquals("MemoryLimiter:Memory", event.exceptions!!.single().mechanism!!.description)
+        },
+        anyOrNull<Hint>(),
+      )
   }
 
+  // "Heuristic candidates" are ApplicationExitInfo instances that may or may not be heuristic
+  // records.
   @Test
-  fun `ignores exit when description does not match exits produced by MemoryLimiter`() {
+  fun `ignores exit for heuristic candidate when reason does not match`() {
     val integration = fixture.getSut(tmpDir, lastReportedTimestamp = oldTimestamp)
     fixture.addAppExitInfo(
-      reason = ApplicationExitInfo.REASON_OTHER,
-      description = "LowSwapKiller",
+      reason = ApplicationExitInfo.REASON_ANR,
+      description = MemoryLimiterIntegration.MEMORY_LIMITER_DESCRIPTION,
       timestamp = newTimestamp,
     )
 
@@ -313,29 +344,21 @@ class MemoryLimiterIntegrationTest {
   }
 
   @Test
-  fun `captures exit for any MemoryLimiter sub-reason, not just AnonSwap`() {
+  fun `ignores exit for heuristic candidate when description does not match`() {
     val integration = fixture.getSut(tmpDir, lastReportedTimestamp = oldTimestamp)
-    // A future MemoryLimiter kill sub-reason (e.g. the memory or swap limits) still lives in the
-    // "MemoryLimiter:" namespace and must be captured, with its raw sub-reason preserved.
     fixture.addAppExitInfo(
       reason = ApplicationExitInfo.REASON_OTHER,
-      description = "MemoryLimiter:Memory",
+      description = "LowSwapKiller",
       timestamp = newTimestamp,
     )
 
     integration.register(fixture.scopes, fixture.options)
 
-    verify(fixture.scopes)
-      .captureEvent(
-        check<SentryEvent> { event ->
-          assertEquals("MemoryLimiter:Memory", event.exceptions!!.single().mechanism!!.description)
-        },
-        anyOrNull<Hint>(),
-      )
+    verify(fixture.scopes, never()).captureEvent(any(), anyOrNull<Hint>())
   }
 
   @Test
-  fun `ignores exit when description mentions MemoryLimiter without the namespace delimiter`() {
+  fun `ignores exit for heuristic candidate when description mentions MemoryLimiter without the namespace delimiter`() {
     val integration = fixture.getSut(tmpDir, lastReportedTimestamp = oldTimestamp)
     // "MemoryLimiter" without the ":" delimiter is not a MemoryLimiter kill; matching requires the
     // namespace prefix so we don't over-capture unrelated REASON_OTHER exits.
@@ -351,7 +374,7 @@ class MemoryLimiterIntegrationTest {
   }
 
   @Test
-  fun `ignores exit when description is null`() {
+  fun `ignores exit for heuristic candidate when description is null`() {
     val integration = fixture.getSut(tmpDir, lastReportedTimestamp = oldTimestamp)
     fixture.addAppExitInfo(
       reason = ApplicationExitInfo.REASON_OTHER,
@@ -481,7 +504,7 @@ class MemoryLimiterIntegrationTest {
   }
 
   @Test
-  fun `dedupes MemoryLimiter exists independently of ANR exits`() {
+  fun `dedupes MemoryLimiter exits independently of ANR exits`() {
     val integration =
       fixture.getSut(
         tmpDir,

sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/MainActivity.kt

@@ -76,6 +76,7 @@ import androidx.compose.ui.draw.shadow
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
@@ -992,7 +993,7 @@ fun IntegrationsScreen() {
             tagSampleAction("memory_limiter")
             activity.startActivity(Intent(activity, MemoryLimiterActivity::class.java))
           },
-          modifier = Modifier,
+          modifier = Modifier.testTag("open_memory_limiter_demo"),
         ) {
           Text("MemoryLimiter Demo", maxLines = 2, overflow = TextOverflow.Ellipsis)
         }

sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/memory/MemoryLimiterActivity.kt

@@ -47,6 +47,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
@@ -307,13 +308,25 @@ private fun MemoryLimiterScreen(
             horizontalArrangement = Arrangement.spacedBy(12.dp),
             verticalArrangement = Arrangement.spacedBy(12.dp),
           ) {
-            Button(onClick = onStartAllocating, enabled = isSupported && !isAllocating) {
+            Button(
+              onClick = onStartAllocating,
+              enabled = isSupported && !isAllocating,
+              modifier = Modifier.testTag("memory_limiter_start_pressure"),
+            ) {
               Text("Start memory pressure")
             }
-            OutlinedButton(onClick = onReleaseBuffers, enabled = allocatedMb > 0 || isAllocating) {
+            OutlinedButton(
+              onClick = onReleaseBuffers,
+              enabled = allocatedMb > 0 || isAllocating,
+              modifier = Modifier.testTag("memory_limiter_reset_run"),
+            ) {
               Text("Reset run")
             }
-            OutlinedButton(onClick = onMoveToBackground, enabled = isSupported) {
+            OutlinedButton(
+              onClick = onMoveToBackground,
+              enabled = isSupported,
+              modifier = Modifier.testTag("memory_limiter_move_background"),
+            ) {
               Text("Move app to background")
             }
           }
@@ -431,7 +444,7 @@ private fun RuntimeCard(
   isAllocating: Boolean,
   statusLine: String,
 ) {
-  ElevatedCard {
+  ElevatedCard(modifier = Modifier.testTag("memory_limiter_runtime_card")) {
     Column(modifier = Modifier.padding(18.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
       Text(
         text = "Runtime",
@@ -445,6 +458,7 @@ private fun RuntimeCard(
       RuntimeRow(label = "Retained", value = "$allocatedMb MiB")
       HorizontalDivider()
       Text(
+        modifier = Modifier.testTag("memory_limiter_status_line"),
         text = statusLine,
         style = MaterialTheme.typography.bodyMedium,
         color = MaterialTheme.colorScheme.onSurfaceVariant,