Library loading fallback.

base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java

Index: base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
diff --git a/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java b/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
index 2f922e045b49a910bd1dcbe62b15d7633b66c567..be01f26cd2afd3039efbdc9963ad583375425d29 100644
--- a/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
+++ b/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
@@ -12,6 +12,8 @@ import org.chromium.base.CommandLine;
 import org.chromium.base.JNINamespace;
 import org.chromium.base.TraceEvent;
 
+import javax.annotation.Nullable;
+
 /**
  * This class provides functionality to load and register the native libraries.
  * Callers are allowed to separate loading the libraries from initializing them.
@@ -53,8 +55,12 @@ public class LibraryLoader {
     private static boolean sIsUsingBrowserSharedRelros = false;
     private static boolean sLoadAtFixedAddressFailed = false;
 
-    // One-way switch becomes true if the library was loaded from the APK file
-    // directly.
+    // One-way switch becomes true if the device supports loading the Chromium
+    // library directly from the APK.
+    private static boolean sLibraryLoadFromApkSupported = false;
+
+    // One-way switch becomes true if the Chromium library was loaded from the
+    // APK file directly.
     private static boolean sLibraryWasLoadedFromApk = false;
 
     // One-way switch becomes false if the Chromium library should be loaded
@@ -168,6 +174,17 @@ public class LibraryLoader {
                 boolean useChromiumLinker = Linker.isUsed();
 
                 if (useChromiumLinker) {
+                    String apkFilename = null;
+
+                    // Check if the device supports loading a library directly from the APK file.
+                    if (context != null) {
+                        apkFilename = context.getApplicationInfo().sourceDir;
+                        sLibraryLoadFromApkSupported = Linker.checkLibraryLoadFromApkSupport(
+                                apkFilename);
+                    } else {
+                        Log.w(TAG, "loadAlreadyLocked(): null context");
+                    }
+
                     // Load libraries using the Chromium linker.
                     Linker.prepareLibraryLoad();
 
@@ -180,26 +197,39 @@ public class LibraryLoader {
                             continue;
                         }
 
-                        String zipfile = null;
-                        if (Linker.isInZipFile()) {
-                            zipfile = context.getApplicationInfo().sourceDir;
-                            sLibraryWasAlignedInApk = Linker.checkLibraryAlignedInApk(
-                                    zipfile, System.mapLibraryName(library));
-                            Log.i(TAG, "Loading " + library + " from within " + zipfile);
+                        // Determine where the library should be loaded from.
+                        String zipFilename = null;
+                        String libFilename = System.mapLibraryName(library);
+                        if (apkFilename != null && Linker.isInZipFile()) {
+                            // The library is in the APK file.
+                            if (!Linker.checkLibraryAlignedInApk(
+                                    apkFilename, System.mapLibraryName(library))) {

[Anton, 2014/10/29 13:35:35]

Replace System.mapLibraryName(library) with libFilename

[petrcermak, 2014/10/29 14:01:01]

Done.

+                                sLibraryWasAlignedInApk = false;
+                            }
+                            if (sLibraryLoadFromApkSupported && sLibraryWasAlignedInApk) {
+                                // Load directly from the APK.
+                                Log.i(TAG, "Loading " + library + " directly from within " +
+                                        apkFilename);
+                                zipFilename = apkFilename;
+                            } else {
+                                // Fallback.
+                                Log.i(TAG, "Loading " + library + " using fallback from within " +
+                                        apkFilename);
+                                libFilename = LibraryLoaderHelper.buildFallbackLibrary(
+                                        context, apkFilename, libFilename);
+                                Log.i(TAG, "Built fallback library " + libFilename);
+                            }
                         } else {
-                            Log.i(TAG, "Loading: " + library);
+                            // The library is in its own file.
+                            Log.i(TAG, "Loading " + library);
                         }
 
+                        // Load the library.
                         boolean isLoaded = false;
                         if (Linker.isUsingBrowserSharedRelros()) {
                             sIsUsingBrowserSharedRelros = true;
                             try {
-                                if (zipfile != null) {
-                                    Linker.loadLibraryInZipFile(zipfile, library);
-                                    sLibraryWasLoadedFromApk = true;
-                                } else {
-                                    Linker.loadLibrary(library);
-                                }
+                                loadLibrary(zipFilename, libFilename);
                                 isLoaded = true;
                             } catch (UnsatisfiedLinkError e) {
                                 Log.w(TAG, "Failed to load native library with shared RELRO, " +
@@ -209,12 +239,7 @@ public class LibraryLoader {
                             }
                         }
                         if (!isLoaded) {
-                            if (zipfile != null) {
-                                Linker.loadLibraryInZipFile(zipfile, library);
-                                sLibraryWasLoadedFromApk = true;
-                            } else {
-                                Linker.loadLibrary(library);
-                            }
+                            loadLibrary(zipFilename, libFilename);
                         }
                     }
 
@@ -265,6 +290,15 @@ public class LibraryLoader {
         }
     }
 
+    // Load a native shared library with the Chromium linker. If the zip file
+    // filename is not null, the library is loaded directly from the zip file.
+    private static void loadLibrary(@Nullable String zipFilename, String libFilename) {
+        if (zipFilename != null) {
+            sLibraryWasLoadedFromApk = true;
+        }
+        Linker.loadLibrary(zipFilename, libFilename);
+    }
+
     // The WebView requires the Command Line to be switched over before
     // initialization is done. This is okay in the WebView's case since the
     // JNI is already loaded by this point.