From b07595d1941a25b5f82c62f9b7099c3c77d06056 Mon Sep 17 00:00:00 2001
From: Sergio Giro <sgiro@google.com>
Date: Fri, 13 May 2016 16:34:46 +0100
Subject: [PATCH] ZygoteInit: warm up JCA providers during preload

This makes the time spent in the first call of an app to
SSLSocketFactory.getDefault() drop from ~240 ms to ~50 ms. In M
it was around ~6ms. This is due to the fact that, while instantiating
the default factory, all providers are initialized.

In order to obtain the timings above, I created an app calling
SSLSocketFactory.getDefault in onCreate and timed it
with System.currentTimeMillis() .

(cherry picked from commit 6cb7b1c4765e9bc5175056826523dbd88426e9aa)

Bug: 28545496

Change-Id: Ic5aab3ece609d9fef06fee4ccb83d8371af075b2
---
 .../com/android/internal/os/ZygoteInit.java   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/core/java/com/android/internal/os/ZygoteInit.java b/core/java/com/android/internal/os/ZygoteInit.java
index d84cb8065f95e..1440e5fb559de 100644
--- a/core/java/com/android/internal/os/ZygoteInit.java
+++ b/core/java/com/android/internal/os/ZygoteInit.java
@@ -52,6 +52,8 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.security.Security;
+import java.security.Provider;
 import java.util.ArrayList;
 
 /**
@@ -193,6 +195,7 @@ public class ZygoteInit {
         // Ask the WebViewFactory to do any initialization that must run in the zygote process,
         // for memory sharing purposes.
         WebViewFactory.prepareWebViewInZygote();
+        warmUpJcaProviders();
         Log.d(TAG, "end preload");
     }
 
@@ -213,6 +216,24 @@ public class ZygoteInit {
         Hyphenator.init();
     }
 
+    /**
+     * Warm up the providers that are already registered.
+     *
+     * By doing it here we avoid that each app does it when requesting a service from the
+     * provider for the first time.
+     */
+    private static void warmUpJcaProviders() {
+        long startTime = SystemClock.uptimeMillis();
+        Trace.traceBegin(
+                Trace.TRACE_TAG_DALVIK, "Starting warm up of JCA providers");
+        for (Provider p : Security.getProviders()) {
+            p.warmUpServiceProvision();
+        }
+        Log.i(TAG, "Warmed up JCA providers in "
+                + (SystemClock.uptimeMillis()-startTime) + "ms.");
+        Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
+    }
+
     /**
      * Performs Zygote process initialization. Loads and initializes
      * commonly used classes.