fix(init): Reduce allocations and bytecode instructions during Sentry.init (#5135)

* fix(init): Perform less allocation/bytecode instructions in Sentry.init

* Switch new thread to executorService in AssetsModulesLoader

* activate options earlier

* changelog

* fix: Prevent SpotlightIntegration from being re-added after user removal

Use AtomicBoolean to ensure activate() only loads SpotlightIntegration
once, so users can remove it in their configuration callback without
it being re-added by the second activate() call from Sentry.init().

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: romtsn

CHANGELOG.md

@@ -34,6 +34,7 @@
 - Log an actionable error message when Relay returns HTTP 413 (Content Too Large) ([#5115](https://github.com/getsentry/sentry-java/pull/5115))
   - Also switch the client report discard reason for all HTTP 4xx/5xx errors (except 429) from `network_error` to `send_error`
 - Trim DSN string before parsing to avoid `URISyntaxException` caused by trailing whitespace ([#5113](https://github.com/getsentry/sentry-java/pull/5113))
+- Reduce allocations and bytecode instructions during `Sentry.init` ([#5135](https://github.com/getsentry/sentry-java/pull/5135))
 
 ### Dependencies
 

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

@@ -142,6 +142,7 @@ static void loadDefaultAndMetadataOptions(
 
     readDefaultOptionValues(options, finalContext, buildInfoProvider);
     AppState.getInstance().registerLifecycleObserver(options);
+    options.activate();
   }
 
   @TestOnly
@@ -200,7 +201,7 @@ static void initializeIntegrationsAndProcessors(
     final @NotNull AppStartMetrics appStartMetrics = AppStartMetrics.getInstance();
 
     if (options.getModulesLoader() instanceof NoOpModulesLoader) {
-      options.setModulesLoader(new AssetsModulesLoader(context, options.getLogger()));
+      options.setModulesLoader(new AssetsModulesLoader(context, options));
     }
     if (options.getDebugMetaLoader() instanceof NoOpDebugMetaLoader) {
       options.setDebugMetaLoader(new AssetsDebugMetaLoader(context, options.getLogger()));

sentry-android-core/src/main/java/io/sentry/android/core/internal/modules/AssetsModulesLoader.java

@@ -1,8 +1,8 @@
 package io.sentry.android.core.internal.modules;
 
 import android.content.Context;
-import io.sentry.ILogger;
 import io.sentry.SentryLevel;
+import io.sentry.SentryOptions;
 import io.sentry.android.core.ContextUtils;
 import io.sentry.internal.modules.ModulesLoader;
 import java.io.FileNotFoundException;
@@ -18,13 +18,21 @@ public final class AssetsModulesLoader extends ModulesLoader {
 
   private final @NotNull Context context;
 
-  public AssetsModulesLoader(final @NotNull Context context, final @NotNull ILogger logger) {
-    super(logger);
+  public AssetsModulesLoader(final @NotNull Context context, final @NotNull SentryOptions options) {
+    super(options.getLogger());
     this.context = ContextUtils.getApplicationContext(context);
 
     // pre-load modules on a bg thread to avoid doing so on the main thread in case of a crash/error
-    //noinspection Convert2MethodRef
-    new Thread(() -> getOrLoadModules()).start();
+    try {
+      options
+          .getExecutorService()
+          .submit(
+              () -> {
+                getOrLoadModules();
+              });
+    } catch (Throwable e) {
+      options.getLogger().log(SentryLevel.ERROR, "AssetsModulesLoader submit failed", e);
+    }
   }
 
   @Override

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

@@ -16,6 +16,7 @@ import io.sentry.DateUtils
 import io.sentry.Hint
 import io.sentry.ILogger
 import io.sentry.ISentryClient
+import io.sentry.NoOpSentryExecutorService
 import io.sentry.Sentry
 import io.sentry.Sentry.OptionsConfiguration
 import io.sentry.SentryEnvelope
@@ -528,6 +529,19 @@ class SentryAndroidTest {
     assertEquals(99, AppStartMetrics.getInstance().appStartTimeSpan.startUptimeMs)
   }
 
+  @Test
+  fun `executor service is not NoOp when AndroidConnectionStatusProvider is initialized`() {
+    var executorServiceIsNoOp = true
+    fixture.initSut(context = context) { options ->
+      options.dsn = "https://key@sentry.io/123"
+      // the config callback runs before initializeIntegrationsAndProcessors, which creates
+      // AndroidConnectionStatusProvider - so if the executor is already real here,
+      // it's guaranteed to be real when the provider calls submitSafe()
+      executorServiceIsNoOp = options.executorService is NoOpSentryExecutorService
+    }
+    assertFalse(executorServiceIsNoOp)
+  }
+
   @Test
   fun `if the config options block throws still intializes android event processors`() {
     lateinit var optionsRef: SentryOptions

sentry-android-core/src/test/java/io/sentry/android/core/internal/modules/AssetsModulesLoaderTest.kt

@@ -2,7 +2,8 @@ package io.sentry.android.core.internal.modules
 
 import android.content.Context
 import android.content.res.AssetManager
-import io.sentry.ILogger
+import io.sentry.SentryOptions
+import io.sentry.test.ImmediateExecutorService
 import java.io.FileNotFoundException
 import java.nio.charset.Charset
 import kotlin.test.Test
@@ -16,7 +17,7 @@ class AssetsModulesLoaderTest {
   class Fixture {
     val context = mock<Context>()
     val assets = mock<AssetManager>()
-    val logger = mock<ILogger>()
+    val options = SentryOptions().apply { executorService = ImmediateExecutorService() }
 
     fun getSut(
       fileName: String = "sentry-external-modules.txt",
@@ -31,7 +32,7 @@ class AssetsModulesLoaderTest {
         whenever(assets.open(fileName)).thenThrow(FileNotFoundException())
       }
       whenever(context.assets).thenReturn(assets)
-      return AssetsModulesLoader(context, logger)
+      return AssetsModulesLoader(context, options)
     }
   }
 

sentry/src/main/java/io/sentry/DuplicateEventDetectionEventProcessor.java

@@ -1,6 +1,5 @@
 package io.sentry;
 
-import io.sentry.util.Objects;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -16,7 +15,7 @@ public final class DuplicateEventDetectionEventProcessor implements EventProcess
   private final @NotNull SentryOptions options;
 
   public DuplicateEventDetectionEventProcessor(final @NotNull SentryOptions options) {
-    this.options = Objects.requireNonNull(options, "options are required");
+    this.options = options;
   }
 
   @Override

sentry/src/main/java/io/sentry/MainEventProcessor.java

@@ -8,7 +8,6 @@
 import io.sentry.protocol.SentryTransaction;
 import io.sentry.protocol.User;
 import io.sentry.util.HintUtils;
-import io.sentry.util.Objects;
 import java.io.Closeable;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -29,7 +28,7 @@ public final class MainEventProcessor implements EventProcessor, Closeable {
   private volatile @Nullable HostnameCache hostnameCache = null;
 
   public MainEventProcessor(final @NotNull SentryOptions options) {
-    this.options = Objects.requireNonNull(options, "The SentryOptions is required.");
+    this.options = options;
 
     final SentryStackTraceFactory sentryStackTraceFactory =
         new SentryStackTraceFactory(this.options);
@@ -38,17 +37,6 @@ public MainEventProcessor(final @NotNull SentryOptions options) {
     sentryThreadFactory = new SentryThreadFactory(sentryStackTraceFactory);
   }
 
-  MainEventProcessor(
-      final @NotNull SentryOptions options,
-      final @NotNull SentryThreadFactory sentryThreadFactory,
-      final @NotNull SentryExceptionFactory sentryExceptionFactory) {
-    this.options = Objects.requireNonNull(options, "The SentryOptions is required.");
-    this.sentryThreadFactory =
-        Objects.requireNonNull(sentryThreadFactory, "The SentryThreadFactory is required.");
-    this.sentryExceptionFactory =
-        Objects.requireNonNull(sentryExceptionFactory, "The SentryExceptionFactory is required.");
-  }
-
   @Override
   public @NotNull SentryEvent process(final @NotNull SentryEvent event, final @NotNull Hint hint) {
     setCommons(event);

sentry/src/main/java/io/sentry/SentryExceptionFactory.java

@@ -6,7 +6,6 @@
 import io.sentry.protocol.SentryStackFrame;
 import io.sentry.protocol.SentryStackTrace;
 import io.sentry.protocol.SentryThread;
-import io.sentry.util.Objects;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
@@ -31,8 +30,7 @@ public final class SentryExceptionFactory {
    * @param sentryStackTraceFactory the sentryStackTraceFactory
    */
   public SentryExceptionFactory(final @NotNull SentryStackTraceFactory sentryStackTraceFactory) {
-    this.sentryStackTraceFactory =
-        Objects.requireNonNull(sentryStackTraceFactory, "The SentryStackTraceFactory is required.");
+    this.sentryStackTraceFactory = sentryStackTraceFactory;
   }
 
   @NotNull

sentry/src/main/java/io/sentry/SentryOptions.java

@@ -46,6 +46,7 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CopyOnWriteArraySet;
+import java.util.concurrent.atomic.AtomicBoolean;
 import javax.net.ssl.SSLSocketFactory;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
@@ -318,6 +319,12 @@ public class SentryOptions {
   /** Sentry Executor Service that sends cached events and envelopes on App. start. */
   private @NotNull ISentryExecutorService executorService = NoOpSentryExecutorService.getInstance();
 
+  /**
+   * Whether SpotlightIntegration has already been loaded via reflection. This prevents re-adding it
+   * if the user removed it in their configuration callback and activate() is called again.
+   */
+  private final @NotNull AtomicBoolean spotlightIntegrationLoaded = new AtomicBoolean(false);
+
   /** connection timeout in milliseconds. */
   private int connectionTimeoutMillis = 30_000;
 
@@ -655,6 +662,18 @@ public void activate() {
       executorService = new SentryExecutorService(this);
       executorService.prewarm();
     }
+
+    // SpotlightIntegration is loaded via reflection to allow the sentry-spotlight module
+    // to be excluded from release builds, preventing insecure HTTP URLs from appearing in APKs.
+    // Only attempt once to avoid re-adding after user removal in their configuration callback.
+    if (spotlightIntegrationLoaded.compareAndSet(false, true)) {
+      try {
+        final Class<?> clazz = Class.forName("io.sentry.spotlight.SpotlightIntegration");
+        integrations.add((Integration) clazz.getConstructor().newInstance());
+      } catch (Throwable ignored) {
+        // SpotlightIntegration not available
+      }
+    }
   }
 
   /**
@@ -3340,16 +3359,6 @@ private SentryOptions(final boolean empty) {
 
       integrations.add(new ShutdownHookIntegration());
 
-      // SpotlightIntegration is loaded via reflection to allow the sentry-spotlight module
-      // to be excluded from release builds, preventing insecure HTTP URLs from appearing in APKs
-      try {
-        final Class<?> clazz = Class.forName("io.sentry.spotlight.SpotlightIntegration");
-        final Integration spotlight = (Integration) clazz.getConstructor().newInstance();
-        integrations.add(spotlight);
-      } catch (Throwable ignored) {
-        // SpotlightIntegration not available
-      }
-
       eventProcessors.add(new MainEventProcessor(this));
       eventProcessors.add(new DuplicateEventDetectionEventProcessor(this));
 

sentry/src/main/java/io/sentry/SentryThreadFactory.java

@@ -3,7 +3,6 @@
 import io.sentry.protocol.SentryStackFrame;
 import io.sentry.protocol.SentryStackTrace;
 import io.sentry.protocol.SentryThread;
-import io.sentry.util.Objects;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -26,8 +25,7 @@ public final class SentryThreadFactory {
    * @param sentryStackTraceFactory the SentryStackTraceFactory
    */
   public SentryThreadFactory(final @NotNull SentryStackTraceFactory sentryStackTraceFactory) {
-    this.sentryStackTraceFactory =
-        Objects.requireNonNull(sentryStackTraceFactory, "The SentryStackTraceFactory is required.");
+    this.sentryStackTraceFactory = sentryStackTraceFactory;
   }
 
   /**