Fix crash for 4.1 devices

Summary:
4.1 devices are crashing pretty bad i.e. right after login is complete, making app pretty useless.

Following a lead on what could be going on here.

Reviewed By: oprisnik

Differential Revision: D20577707

fbshipit-source-id: 29aafcc26230904a487d1f8595d1b222744f721f

java/com/facebook/soloader/NativeLoaderToSoLoaderDelegate.java

@@ -22,8 +22,11 @@
 /** Class that connects SoLoader to NativeLoader */
 public class NativeLoaderToSoLoaderDelegate implements NativeLoaderDelegate {
   @Override
-  public boolean loadLibrary(final String shortName) {
-    return SoLoader.loadLibrary(shortName);
+  public boolean loadLibrary(String shortName, int flags) {
+    int soLoaderFlags = 0;
+    soLoaderFlags |=
+        ((flags & SKIP_MERGED_JNI_ONLOAD) != 0) ? SoLoader.SOLOADER_SKIP_MERGED_JNI_ONLOAD : 0;
+    return SoLoader.loadLibrary(shortName, soLoaderFlags);
   }
 
   @Override

java/com/facebook/soloader/nativeloader/NativeLoader.java

@@ -26,14 +26,20 @@ public class NativeLoader {
   /** Blocked default constructor */
   private NativeLoader() {}
 
+  public static boolean loadLibrary(String shortName) {
+    return loadLibrary(shortName, 0);
+  }
+
   /**
-   * Load a shared library, initializing any JNI binding it contains.
+   * Load a shared library, initializing any JNI binding it contains. Depending upon underlying
+   * loader, behavior can be customized based on passed in flag
    *
    * @param shortName Name of library to find, without "lib" prefix or ".so" suffix
+   * @param flags 0 for default behavior, otherwise NativeLoaderDelegate defines other behaviors.
    * @return Whether the library was loaded as a result of this call (true), or was already loaded
    *     through a previous call (false).
    */
-  public static boolean loadLibrary(String shortName) {
+  public static boolean loadLibrary(String shortName, int flags) {
     synchronized (NativeLoader.class) {
       if (sDelegate == null) {
         throw new IllegalStateException(
@@ -42,8 +48,7 @@ public static boolean loadLibrary(String shortName) {
                 + "NativeLoader.init(new SystemDelegate()).");
       }
     }
-
-    return sDelegate.loadLibrary(shortName);
+    return sDelegate.loadLibrary(shortName, flags);
   }
 
   /**

java/com/facebook/soloader/nativeloader/NativeLoaderDelegate.java

@@ -20,8 +20,15 @@
 
 /** Interface used to connect chosen loader of native libraries to NativeLoader */
 public interface NativeLoaderDelegate {
-  /** @see com.facebook.soloader.nativeloader.NativeLoader#loadLibrary(String) */
-  boolean loadLibrary(String shortName);
+  /**
+   * Skip calling JNI_OnLoad if the library is merged. This is necessary for libraries that don't
+   * define JNI_OnLoad and are only loaded for their side effects (like static constructors
+   * registering callbacks). DO NOT use this to allow implicit JNI registration (by naming your
+   * methods Java_com_facebook_whatever) because that is buggy on Android.
+   */
+  int SKIP_MERGED_JNI_ONLOAD = 1;
+  /** @see com.facebook.soloader.nativeloader.NativeLoader#loadLibrary(String, int) */
+  boolean loadLibrary(String shortName, int flags);
   /** @see com.facebook.soloader.nativeloader.NativeLoader#getLibraryPath(String) */
   String getLibraryPath(String libName) throws IOException;
   /** @see com.facebook.soloader.nativeloader.NativeLoader#getSoSourcesVersion() */

java/com/facebook/soloader/nativeloader/SystemDelegate.java

@@ -19,7 +19,8 @@
 /** Class which connects system's native library loader to NativeLoader */
 public class SystemDelegate implements NativeLoaderDelegate {
   @Override
-  public boolean loadLibrary(final String shortName) {
+  public boolean loadLibrary(String shortName, int flags) {
+    // System.loadLibrary don't support flags so ignore them.
     System.loadLibrary(shortName);
     // System.loadLibrary doesn't indicate whether this was a first-time load,
     // so let's just always assume it was.