add SystemLoadWrapperSoSource

Summary:
Add new experiment flag `SOLOADER_ENABLE_SYSTEMLOAD_WRAPPER_SOSOURCE` to test the SystemLoadWrapperSoSource.
This flag would help reduce the overhead on reading the APK file. The directApk soSource needs to iterate/read the APK(zip) file to calculate the lib and dependency list.

Reviewed By: vener91

Differential Revision: D51493295

fbshipit-source-id: e1cac9e012870eb7386a4e40dec7a5cfcaecdc43

java/com/facebook/soloader/SoLoader.java

@@ -195,6 +195,13 @@ public class SoLoader {
   /** Experiment ONLY: disable the fsync job in soSource */
   public static final int SOLOADER_DISABLE_FS_SYNC_JOB = (1 << 8);
 
+  /**
+   * Experiment ONLY: use the {@link SystemLoadWrapperSoSource} to instead of the
+   * directApk/Application soSource. This could work on the apps w/o superpack or any other so file
+   * compression.
+   */
+  public static final int SOLOADER_ENABLE_SYSTEMLOAD_WRAPPER_SOSOURCE = (1 << 9);
+
   @GuardedBy("sSoSourcesLock")
   private static int sFlags;
 
@@ -336,29 +343,35 @@ private static void initSoSources(Context context, int flags) throws IOException
       sFlags = flags;
 
       ArrayList<SoSource> soSources = new ArrayList<>();
-      addSystemLibSoSource(soSources);
-
-      // We can only proceed forward if we have a Context. The prominent case
-      // where we don't have a Context is barebones dalvikvm instantiations. In
-      // that case, the caller is responsible for providing a correct LD_LIBRARY_PATH.
-
-      if (context != null) {
-        // Prepend our own SoSource for our own DSOs.
-
-        if ((flags & SOLOADER_ENABLE_EXOPACKAGE) != 0) {
-          // Even for an exopackage, there might be some native libraries
-          // packaged directly in the application (e.g. ASAN libraries alongside
-          // a wrap.sh script [1]), so make sure we can load them.
-          // [1] https://developer.android.com/ndk/guides/wrap-script
-          addApplicationSoSource(soSources, getApplicationSoSourceFlags());
-          LogUtil.d(TAG, "Adding exo package source: " + SO_STORE_NAME_MAIN);
-          soSources.add(0, new ExoSoSource(context, SO_STORE_NAME_MAIN));
-        } else {
-          if (SysUtil.isSupportedDirectLoad(context, sAppType)) {
-            addDirectApkSoSource(context, soSources);
+      final boolean isEnabledSystemLoadWrapper =
+          (flags & SOLOADER_ENABLE_SYSTEMLOAD_WRAPPER_SOSOURCE) != 0;
+      if (isEnabledSystemLoadWrapper) {
+        addSystemLoadWrapperSoSource(context, soSources);
+      } else {
+        addSystemLibSoSource(soSources);
+
+        // We can only proceed forward if we have a Context. The prominent case
+        // where we don't have a Context is barebones dalvikvm instantiations. In
+        // that case, the caller is responsible for providing a correct LD_LIBRARY_PATH.
+
+        if (context != null) {
+          // Prepend our own SoSource for our own DSOs.
+
+          if ((flags & SOLOADER_ENABLE_EXOPACKAGE) != 0) {
+            // Even for an exopackage, there might be some native libraries
+            // packaged directly in the application (e.g. ASAN libraries alongside
+            // a wrap.sh script [1]), so make sure we can load them.
+            // [1] https://developer.android.com/ndk/guides/wrap-script
+            addApplicationSoSource(soSources, getApplicationSoSourceFlags());
+            LogUtil.d(TAG, "Adding exo package source: " + SO_STORE_NAME_MAIN);
+            soSources.add(0, new ExoSoSource(context, SO_STORE_NAME_MAIN));
+          } else {
+            if (SysUtil.isSupportedDirectLoad(context, sAppType)) {
+              addDirectApkSoSource(context, soSources);
+            }
+            addApplicationSoSource(soSources, getApplicationSoSourceFlags());
+            addBackupSoSource(context, soSources, BackupSoSource.PREFER_ANDROID_LIBS_DIRECTORY);
           }
-          addApplicationSoSource(soSources, getApplicationSoSourceFlags());
-          addBackupSoSource(context, soSources, BackupSoSource.PREFER_ANDROID_LIBS_DIRECTORY);
         }
       }
 
@@ -511,6 +524,12 @@ private static void addSystemLibSoSource(ArrayList<SoSource> soSources) {
     }
   }
 
+  private static void addSystemLoadWrapperSoSource(Context context, ArrayList<SoSource> soSources) {
+    SystemLoadWrapperSoSource systemLoadWrapperSoSource = new SystemLoadWrapperSoSource();
+    LogUtil.d(TAG, "adding systemLoadWrapper source: " + systemLoadWrapperSoSource);
+    soSources.add(0, systemLoadWrapperSoSource);
+  }
+
   private static int makePrepareFlags() {
     int prepareFlags = 0;
     // ensure the write lock is being held to protect sFlags

java/com/facebook/soloader/SystemLoadWrapperSoSource.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.facebook.soloader;
+
+import android.annotation.SuppressLint;
+import android.os.StrictMode;
+import java.io.File;
+import java.io.IOException;
+import javax.annotation.Nullable;
+
+/**
+ * A {@link SoSource} that uses the system's {@code System.loadLibrary()} method to load a library
+ */
+public class SystemLoadWrapperSoSource extends SoSource {
+
+  @SuppressLint("CatchGeneralException")
+  @Override
+  public int loadLibrary(String soName, int loadFlags, StrictMode.ThreadPolicy threadPolicy)
+      throws IOException {
+    try {
+      System.loadLibrary(soName.substring("lib".length(), soName.length() - ".so".length()));
+    } catch (Exception e) {
+      LogUtil.e(SoLoader.TAG, "Error loading library: " + soName, e);
+      return LOAD_RESULT_NOT_FOUND;
+    }
+    return LOAD_RESULT_LOADED;
+  }
+
+  @Nullable
+  @Override
+  public File unpackLibrary(String soName) throws IOException {
+    return null;
+  }
+
+  @Override
+  public String getName() {
+    return "SystemLoadWrapperSoSource";
+  }
+
+  @Override
+  public String toString() {
+    return new StringBuilder()
+        .append(getName())
+        .append("[")
+        .append(SysUtil.getClassLoaderLdLoadLibrary())
+        .append("]")
+        .toString();
+  }
+}