Do not report parsing ANR error when there are no threads

CHANGELOG.md

@@ -10,6 +10,8 @@
 ### Fixes
 
 - Ensure android initialization process continues even if options configuration block throws an exception ([#3887](https://github.com/getsentry/sentry-java/pull/3887))
+- Do not report parsing ANR error when there are no threads ([#3888](https://github.com/getsentry/sentry-java/pull/3888))
+  - This should significantly reduce the number of events with message "Sentry Android SDK failed to parse system thread dump..." reported
 
 ### Dependencies
 

sentry-android-core/src/main/java/io/sentry/android/core/AnrV2Integration.java

@@ -313,8 +313,11 @@ private void reportAsSentryEvent(
         final ThreadDumpParser threadDumpParser = new ThreadDumpParser(options, isBackground);
         final List<SentryThread> threads = threadDumpParser.parse(lines);
         if (threads.isEmpty()) {
-          // if the list is empty this means our regex matching is garbage and this is still error
-          return new ParseResult(ParseResult.Type.ERROR, dump);
+          // if the list is empty this means the system failed to capture a proper thread dump of
+          // the android threads, and only contains kernel-level threads and statuses, those ANRs
+          // are not actionable and neither they are reported by Google Play Console, so we just
+          // fall back to not reporting them
+          return new ParseResult(ParseResult.Type.NO_DUMP);
         }
         return new ParseResult(ParseResult.Type.DUMP, dump, threads);
       } catch (Throwable e) {

sentry-android-core/src/test/java/io/sentry/android/core/AnrV2IntegrationTest.kt

@@ -101,7 +101,8 @@ class AnrV2IntegrationTest {
             reason: Int? = ApplicationExitInfo.REASON_ANR,
             timestamp: Long? = null,
             importance: Int? = null,
-            addTrace: Boolean = true
+            addTrace: Boolean = true,
+            addBadTrace: Boolean = false
         ) {
             val builder = ApplicationExitInfoBuilder.newBuilder()
             if (reason != null) {
@@ -117,8 +118,36 @@ class AnrV2IntegrationTest {
                 if (!addTrace) {
                     return
                 }
-                whenever(mock.traceInputStream).thenReturn(
-                    """
+                if (addBadTrace) {
+                    whenever(mock.traceInputStream).thenReturn(
+                        """
+                        Subject: Input dispatching timed out (7985007 com.example.app/com.example.app.ui.MainActivity (server) is not responding. Waited 5000ms for FocusEvent(hasFocus=false))
+                        Here are no Binder-related exception messages available.
+                        Pid(12233) have D state thread(tid:12236 name:Signal Catcher)
+
+
+                        RssHwmKb: 823716
+                        RssKb: 548348
+                        RssAnonKb: 382156
+                        RssShmemKb: 13304
+                        VmSwapKb: 82484
+
+
+                        --- CriticalEventLog ---
+                        capacity: 20
+                        timestamp_ms: 1731507490032
+                        window_ms: 300000
+
+                        ----- dumping pid: 12233 at 313446151
+                        libdebuggerd_client: unexpected registration response: 0
+
+                        ----- Waiting Channels: pid 12233 at 2024-11-13 19:48:09.980104540+0530 -----
+                        Cmd line: com.example.app:mainProcess
+                        """.trimIndent().byteInputStream()
+                    )
+                } else {
+                    whenever(mock.traceInputStream).thenReturn(
+                        """
 "main" prio=5 tid=1 Blocked
   | group="main" sCount=1 ucsCount=0 flags=1 obj=0x72a985e0 self=0xb400007cabc57380
   | sysTid=28941 nice=-10 cgrp=top-app sched=0/0 handle=0x7deceb74f8
@@ -147,8 +176,9 @@ class AnrV2IntegrationTest {
   native: #02 pc 00000000000b63b0  /apex/com.android.runtime/lib64/bionic/libc.so (__pthread_start(void*)+208) (BuildId: 01331f74b0bb2cb958bdc15282b8ec7b)
   native: #03 pc 00000000000530b8  /apex/com.android.runtime/lib64/bionic/libc.so (__start_thread+64) (BuildId: 01331f74b0bb2cb958bdc15282b8ec7b)
   (no managed stack frames)
-                    """.trimIndent().byteInputStream()
-                )
+                        """.trimIndent().byteInputStream()
+                    )
+                }
             }
             shadowActivityManager.addApplicationExitInfo(exitInfo)
         }
@@ -551,4 +581,14 @@ class AnrV2IntegrationTest {
 
         verify(fixture.hub, never()).captureEvent(any(), anyOrNull<Hint>())
     }
+
+    @Test
+    fun `when traceInputStream has bad data, does not report ANR`() {
+        val integration = fixture.getSut(tmpDir, lastReportedAnrTimestamp = oldTimestamp)
+        fixture.addAppExitInfo(timestamp = newTimestamp, addBadTrace = true)
+
+        integration.register(fixture.hub, fixture.options)
+
+        verify(fixture.hub, never()).captureEvent(any(), anyOrNull<Hint>())
+    }
 }

sentry-android-core/src/test/java/io/sentry/android/core/internal/threaddump/ThreadDumpParserTest.kt

@@ -7,6 +7,7 @@ import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertNotNull
 import kotlin.test.assertNull
+import kotlin.test.assertTrue
 
 class ThreadDumpParserTest {
 
@@ -95,4 +96,15 @@ class ThreadDumpParserTest {
         assertEquals(28, lastFrame.lineno)
         assertNull(lastFrame.isInApp)
     }
+
+    @Test
+    fun `thread dump garbage`() {
+        val lines = Lines.readLines(File("src/test/resources/thread_dump_bad_data.txt"))
+        val parser = ThreadDumpParser(
+            SentryOptions().apply { addInAppInclude("io.sentry.samples") },
+            false
+        )
+        val threads = parser.parse(lines)
+        assertTrue(threads.isEmpty())
+    }
 }