[QA] Load lazy fields on init in the background (#3803)

* Lazy fields in SentryOptions are now loaded on init in the background
* use option's executor instead of a new thread to load fields

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- Load lazy fields on init in the background ([#3803](https://github.com/getsentry/sentry-java/pull/3803))
+- Replace setOf with HashSet.add ([#3801](https://github.com/getsentry/sentry-java/pull/3801))
+
 ## 7.16.0-alpha.1
 
 ### Features
@@ -8,7 +15,6 @@
 
 ### Fixes
 
-- Replace setOf with HashSet.add ([#3801](https://github.com/getsentry/sentry-java/pull/3801))
 - Cache parsed Dsn ([#3796](https://github.com/getsentry/sentry-java/pull/3796))
 - fix invalid profiles when the transaction name is empty ([#3747](https://github.com/getsentry/sentry-java/pull/3747))
 - Deprecate `enableTracing` option ([#3777](https://github.com/getsentry/sentry-java/pull/3777))

sentry/src/main/java/io/sentry/Sentry.java

@@ -217,6 +217,10 @@ public static void init(final @NotNull SentryOptions options) {
    * @param options options the SentryOptions
    * @param globalHubMode the globalHubMode
    */
+  @SuppressWarnings({
+    "Convert2MethodRef",
+    "FutureReturnValueIgnored"
+  }) // older AGP versions do not support method references
   private static synchronized void init(
       final @NotNull SentryOptions options, final boolean globalHubMode) {
     if (isEnabled()) {
@@ -231,6 +235,18 @@ private static synchronized void init(
       return;
     }
 
+    // load lazy fields of the options in a separate thread
+    try {
+      options.getExecutorService().submit(() -> options.loadLazyFields());
+    } catch (RejectedExecutionException e) {
+      options
+          .getLogger()
+          .log(
+              SentryLevel.DEBUG,
+              "Failed to call the executor. Lazy fields will not be loaded. Did you call Sentry.close()?",
+              e);
+    }
+
     options.getLogger().log(SentryLevel.INFO, "GlobalHubMode: '%s'", String.valueOf(globalHubMode));
     Sentry.globalHubMode = globalHubMode;
 

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

@@ -2451,6 +2451,17 @@ public void setEnableScreenTracking(final boolean enableScreenTracking) {
     this.enableScreenTracking = enableScreenTracking;
   }
 
+  /**
+   * Load the lazy fields. Useful to load in the background, so that results are already cached. DO
+   * NOT CALL THIS METHOD ON THE MAIN THREAD.
+   */
+  void loadLazyFields() {
+    getSerializer();
+    getParsedDsn();
+    getEnvelopeReader();
+    getDateProvider();
+  }
+
   /** The BeforeSend callback */
   public interface BeforeSendCallback {