[NDK] Add loadNativeLibraries method to allow pre-loading .so files (#1082)

* Add loadNativeLibraries method to allow pre-loading .so files

* Update Changelog

Author: markushi

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+**Features**:
+
+- Android NDK: Add `.loadNativeLibraries()` method to allow pre-loading .so files ([#1082](https://github.com/getsentry/sentry-native/pull/1082))
+
 ## 0.7.13
 
 **Features**:

ndk/lib/api/sentry-native-ndk.api

@@ -79,5 +79,6 @@ public final class io/sentry/ndk/NdkOptions {
 public final class io/sentry/ndk/SentryNdk {
 	public static fun close ()V
 	public static fun init (Lio/sentry/ndk/NdkOptions;)V
+	public static fun loadNativeLibraries ()V
 }
 

ndk/lib/src/main/java/io/sentry/ndk/SentryNdk.java

@@ -6,16 +6,7 @@
 @ApiStatus.Internal
 public final class SentryNdk {
 
-  static {
-    // On older Android versions, it was necessary to manually call "`System.loadLibrary` on all
-    // transitive dependencies before loading [the] main library."
-    // The dependencies of `libsentry.so` are currently `lib{c,m,dl,log}.so`.
-    // See
-    // https://android.googlesource.com/platform/bionic/+/master/android-changes-for-ndk-developers.md#changes-to-library-dependency-resolution
-    System.loadLibrary("log");
-    System.loadLibrary("sentry");
-    System.loadLibrary("sentry-android");
-  }
+  private static volatile boolean nativeLibrariesLoaded;
 
   private SentryNdk() {}
 
@@ -29,11 +20,31 @@ private SentryNdk() {}
    * @param options the SentryAndroidOptions
    */
   public static void init(@NotNull final NdkOptions options) {
+    loadNativeLibraries();
     initSentryNative(options);
   }
 
   /** Closes the NDK integration */
   public static void close() {
+    loadNativeLibraries();
     shutdown();
   }
+
+  /**
+   * Loads all required native libraries. This is automatically done by {@link #init(NdkOptions)},
+   * but can be called manually in case you want to preload the libraries before calling #init.
+   */
+  public static synchronized void loadNativeLibraries() {
+    if (!nativeLibrariesLoaded) {
+      // On older Android versions, it was necessary to manually call "`System.loadLibrary` on all
+      // transitive dependencies before loading [the] main library."
+      // The dependencies of `libsentry.so` are currently `lib{c,m,dl,log}.so`.
+      // See
+      // https://android.googlesource.com/platform/bionic/+/master/android-changes-for-ndk-developers.md#changes-to-library-dependency-resolution
+      System.loadLibrary("log");
+      System.loadLibrary("sentry");
+      System.loadLibrary("sentry-android");
+      nativeLibrariesLoaded = true;
+    }
+  }
 }