Preload with RELRO sharing in the WebView zygote.
Now that the WebView zygote is a child of the system zygote it has the
smae address space layout and can use the existing WebView native
library RELRO file.
Preload the native library using the RELRO file in the zygote, to share
this data with applications which are using WebView. This can save up to
1-2MB of dirty memory, replacing it with clean pages that are shared
with more processes and thus have a smaller impact on PSS.
Bug: 63749735
Test: CtsWebkitTests
Change-Id: I7ce670f5fcddae9e98631e21329840ef3ad52f9a
diff --git a/core/java/android/os/ZygoteProcess.java b/core/java/android/os/ZygoteProcess.java
index 57418c8..ca4c796 100644
--- a/core/java/android/os/ZygoteProcess.java
+++ b/core/java/android/os/ZygoteProcess.java
@@ -493,11 +493,12 @@
* Instructs the zygote to pre-load the classes and native libraries at the given paths
* for the specified abi. Not all zygotes support this function.
*/
- public boolean preloadPackageForAbi(String packagePath, String libsPath, String cacheKey,
- String abi) throws ZygoteStartFailedEx, IOException {
+ public boolean preloadPackageForAbi(String packagePath, String libsPath, String libFileName,
+ String cacheKey, String abi) throws ZygoteStartFailedEx,
+ IOException {
synchronized(mLock) {
ZygoteState state = openZygoteSocketIfNeeded(abi);
- state.writer.write("4");
+ state.writer.write("5");
state.writer.newLine();
state.writer.write("--preload-package");
@@ -509,6 +510,9 @@
state.writer.write(libsPath);
state.writer.newLine();
+ state.writer.write(libFileName);
+ state.writer.newLine();
+
state.writer.write(cacheKey);
state.writer.newLine();
diff --git a/core/java/android/webkit/WebViewZygote.java b/core/java/android/webkit/WebViewZygote.java
index 63fbef3..4167ad4 100644
--- a/core/java/android/webkit/WebViewZygote.java
+++ b/core/java/android/webkit/WebViewZygote.java
@@ -169,6 +169,8 @@
final String zip = (zipPaths.size() == 1) ? zipPaths.get(0) :
TextUtils.join(File.pathSeparator, zipPaths);
+ String libFileName = WebViewFactory.getWebViewLibrary(sPackage.applicationInfo);
+
// In the case where the ApplicationInfo has been modified by the stub WebView,
// we need to use the original ApplicationInfo to determine what the original classpath
// would have been to use as a cache key.
@@ -179,7 +181,7 @@
ZygoteProcess.waitForConnectionToZygote(sZygote.getPrimarySocketAddress());
Log.d(LOGTAG, "Preloading package " + zip + " " + librarySearchPath);
- sZygote.preloadPackageForAbi(zip, librarySearchPath, cacheKey,
+ sZygote.preloadPackageForAbi(zip, librarySearchPath, libFileName, cacheKey,
Build.SUPPORTED_ABIS[0]);
} catch (Exception e) {
Log.e(LOGTAG, "Error connecting to webview zygote", e);
diff --git a/core/java/com/android/internal/os/WebViewZygoteInit.java b/core/java/com/android/internal/os/WebViewZygoteInit.java
index 32b580c..9f2434e 100644
--- a/core/java/com/android/internal/os/WebViewZygoteInit.java
+++ b/core/java/com/android/internal/os/WebViewZygoteInit.java
@@ -27,6 +27,7 @@
import android.util.Log;
import android.webkit.WebViewFactory;
import android.webkit.WebViewFactoryProvider;
+import android.webkit.WebViewLibraryLoader;
import java.io.DataOutputStream;
import java.io.File;
@@ -71,7 +72,8 @@
}
@Override
- protected void handlePreloadPackage(String packagePath, String libsPath, String cacheKey) {
+ protected void handlePreloadPackage(String packagePath, String libsPath, String libFileName,
+ String cacheKey) {
Log.i(TAG, "Beginning package preload");
// Ask ApplicationLoaders to create and cache a classloader for the WebView APK so that
// our children will reuse the same classloader instead of creating their own.
@@ -80,6 +82,10 @@
ClassLoader loader = ApplicationLoaders.getDefault().createAndCacheWebViewClassLoader(
packagePath, libsPath, cacheKey);
+ // Load the native library using WebViewLibraryLoader to share the RELRO data with other
+ // processes.
+ WebViewLibraryLoader.loadNativeLibrary(loader, libFileName);
+
// Add the APK to the Zygote's list of allowed files for children.
String[] packageList = TextUtils.split(packagePath, File.pathSeparator);
for (String packageEntry : packageList) {
diff --git a/core/java/com/android/internal/os/ZygoteConnection.java b/core/java/com/android/internal/os/ZygoteConnection.java
index a32fb43..cd83c57 100644
--- a/core/java/com/android/internal/os/ZygoteConnection.java
+++ b/core/java/com/android/internal/os/ZygoteConnection.java
@@ -155,7 +155,7 @@
if (parsedArgs.preloadPackage != null) {
handlePreloadPackage(parsedArgs.preloadPackage, parsedArgs.preloadPackageLibs,
- parsedArgs.preloadPackageCacheKey);
+ parsedArgs.preloadPackageLibFileName, parsedArgs.preloadPackageCacheKey);
return null;
}
@@ -290,7 +290,8 @@
return mSocketOutStream;
}
- protected void handlePreloadPackage(String packagePath, String libsPath, String cacheKey) {
+ protected void handlePreloadPackage(String packagePath, String libsPath, String libFileName,
+ String cacheKey) {
throw new RuntimeException("Zyogte does not support package preloading");
}
@@ -402,10 +403,24 @@
String appDataDir;
/**
- * Whether to preload a package, with the package path in the remainingArgs.
+ * The APK path of the package to preload, when using --preload-package.
*/
String preloadPackage;
+
+ /**
+ * The native library path of the package to preload, when using --preload-package.
+ */
String preloadPackageLibs;
+
+ /**
+ * The filename of the native library to preload, when using --preload-package.
+ */
+ String preloadPackageLibFileName;
+
+ /**
+ * The cache key under which to enter the preloaded package into the classloader cache,
+ * when using --preload-package.
+ */
String preloadPackageCacheKey;
/**
@@ -571,6 +586,7 @@
} else if (arg.equals("--preload-package")) {
preloadPackage = args[++curArg];
preloadPackageLibs = args[++curArg];
+ preloadPackageLibFileName = args[++curArg];
preloadPackageCacheKey = args[++curArg];
} else if (arg.equals("--preload-default")) {
preloadDefault = true;