Retry native library load if tracing before SoLoader initialized

Reviewed By: johnbillings3

Differential Revision: D19083419

fbshipit-source-id: 01d1fa2a6e61911312d3ff3481f9c33637d59083

java/com/facebook/soloader/SoLoader.java

@@ -91,7 +91,7 @@ public class SoLoader {
   @Nullable
   private static SoSource[] sSoSources = null;
 
-  private static int sSoSourcesVersion = 0;
+  private static volatile int sSoSourcesVersion = 0;
 
   /** A backup SoSources to try if a lib file is corrupted */
   @GuardedBy("sSoSourcesLock")
@@ -866,6 +866,10 @@ private static void assertInitialized() {
     }
   }
 
+  public static int getSoSourcesVersion() {
+    return sSoSourcesVersion;
+  }
+
   /**
    * Add a new source of native libraries. SoLoader consults the new source before any
    * currently-installed source.