Asynchronously pre-fault the native library pages.

base/android/linker/linker_jni.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is the Android-specific Chromium linker, a tiny shared library
 // implementing a custom dynamic linker that can be used to load the
 // real Chromium libraries (e.g. libcontentshell.so).
 
 // The main point of this linker is to be able to share the RELRO
 // section of libcontentshell.so (or equivalent) between the browser and
@@ skipping 591 matching lines @@
   char buffer[kMaxFilePathLengthInZip + 1];
   if (crazy_library_file_path_in_zip_file(
           lib_name_c_str, buffer, sizeof(buffer)) == CRAZY_STATUS_FAILURE) {
     LOG_ERROR("%s: Failed to get full filename for library '%s'",
               __FUNCTION__, lib_name_c_str);
     buffer[0] = '\0';
   }
   return env->NewStringUTF(buffer);
 }
 
+// Prefault the pages of a native library stored in a zip file.
+//
+// |env| is the current JNI environment handle.
+// |clazz| is the static class handle which is not used here.
+// |lib_name| is the library base name.
+// Returns true for success.
+jboolean PrefaultLibraryInZipFile(JNIEnv* env, jclass clazz,
+                                  jstring zip_filename, jstring lib_name) {
+  char path_in_zip[kMaxFilePathLengthInZip + 1];
+  crazy_status_t status;
+  String lib_name_str(env, lib_name);
+  String zip_filename_str(env, zip_filename);
+  int offset, size;
+
+  status = crazy_library_file_path_in_zip_file(lib_name_str.c_str(),
+                                               path_in_zip, 256);
+  if (status == CRAZY_STATUS_FAILURE) return false;
+  status = crazy_library_offset_size_in_zip_file(zip_filename_str.c_str(),
+                                                 path_in_zip, &offset, &size);
+  if (status == CRAZY_STATUS_FAILURE) return false;
+  status = crazy_prefault_library(zip_filename_str.c_str(), offset, size);
+  return true;
+}
+
+// Prefault the pages of a native library.
+//
+// |env| is the current JNI environment handle.
+// |clazz| is the static class handle which is not used here.
+// |lib_filename| is the library file name.
+// Returns true for success.
+jboolean PrefaultLibraryInFile(JNIEnv* env, jclass clazz,
+                               jstring lib_filename) {
+  String lib_filename_str(env, lib_filename);
+
+  return (crazy_prefault_library(lib_filename_str.c_str(), 0, -1)
+          == CRAZY_STATUS_SUCCESS);
+}
+
 // Check whether the device supports mapping the APK file with executable
 // permission.
 //
 // |env| is the current JNI environment handle.
 // |clazz| is the static class handle which is not used here.
 // |apkfile_name| is the filename of the APK.
 // Returns true if supported.
 jboolean CheckMapExecSupport(JNIEnv* env, jclass clazz, jstring apkfile_name) {
   String apkfile_name_str(env, apkfile_name);
   const char* apkfile_name_c_str = apkfile_name_str.c_str();
@@ skipping 101 matching lines @@
      "J"
      ")"
      "J",
      reinterpret_cast<void*>(&GetRandomBaseLoadAddress)},
     {"nativeGetLibraryFilePathInZipFile",
      "("
      "Ljava/lang/String;"
      ")"
      "Ljava/lang/String;",
      reinterpret_cast<void*>(&GetLibraryFilePathInZipFile)},
+    {"nativePrefaultLibraryInFile",
+     "("
+     "Ljava/lang/String;"
+     ")"
+     "Z",
+     reinterpret_cast<void*>(&PrefaultLibraryInFile)
+    },
+    {"nativePrefaultLibraryInZipFile",
+     "("
+     "Ljava/lang/String;"
+     "Ljava/lang/String;"
+     ")"
+     "Z",
+     reinterpret_cast<void*>(&PrefaultLibraryInZipFile)
+    },
     {"nativeCheckMapExecSupport",
      "("
      "Ljava/lang/String;"
      ")"
      "Z",
      reinterpret_cast<void*>(&CheckMapExecSupport)},
     {"nativeCheckLibraryIsMappableInApk",
      "("
      "Ljava/lang/String;"
      "Ljava/lang/String;"
@@ skipping 43 matching lines @@
   crazy_context_t* context = GetCrazyContext();
   crazy_context_set_java_vm(context, vm, JNI_VERSION_1_4);
 
   // Register the function that the crazy linker can call to post code
   // for later execution.
   crazy_context_set_callback_poster(context, &PostForLaterExecution, NULL);
 
   LOG_INFO("%s: Done", __FUNCTION__);
   return JNI_VERSION_1_4;
 }