Quiet excessive logging of missing lambdas during preload

This patch will change the logging behavior in the Zygote such that
lambdas from the preload list that aren't found during Zygote
initialization will be counted and a summary provided at the end rather
than logging them each individually.  These missing lambdas will only be
logged for userdebug builds.

Test: Compared logs before and after
Bug: 163602260
Change-Id: I4cd11d626d7e4f365c55f8458aac20cd442638ed

core/java/com/android/internal/os/ZygoteInit.java

@@ -86,9 +86,10 @@ import java.security.Security;
  */
 public class ZygoteInit {
 
-    // TODO (chriswailes): Change this so it is set with Zygote or ZygoteSecondary as appropriate
     private static final String TAG = "Zygote";
 
+    private static final boolean LOGGING_DEBUG = Log.isLoggable(TAG, Log.DEBUG);
+
     private static final String PROPERTY_DISABLE_GRAPHICS_DRIVER_PRELOADING =
             "ro.zygote.disable_gl_preload";
 
@@ -284,6 +285,7 @@ public class ZygoteInit {
                     new BufferedReader(new InputStreamReader(is), Zygote.SOCKET_BUFFER_SIZE);
 
             int count = 0;
+            int missingLambdaCount = 0;
             String line;
             while ((line = br.readLine()) != null) {
                 // Skip comments and blank lines.
@@ -302,24 +304,33 @@ public class ZygoteInit {
                     Class.forName(line, true, null);
                     count++;
                 } catch (ClassNotFoundException e) {
-                    Log.w(TAG, "Class not found for preloading: " + line);
+                    if (line.contains("$$Lambda$")) {
+                        if (LOGGING_DEBUG) {
+                            missingLambdaCount++;
+                        }
+                    } else {
+                        Log.w(TAG, "Class not found for preloading: " + line);
+                    }
                 } catch (UnsatisfiedLinkError e) {
                     Log.w(TAG, "Problem preloading " + line + ": " + e);
                 } catch (Throwable t) {
                     Log.e(TAG, "Error preloading " + line + ".", t);
                     if (t instanceof Error) {
                         throw (Error) t;
-                    }
+                    } else if (t instanceof RuntimeException) {
-                    if (t instanceof RuntimeException) {
                         throw (RuntimeException) t;
+                    } else {
+                        throw new RuntimeException(t);
                     }
-                    throw new RuntimeException(t);
                 }
                 Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
             }
 
             Log.i(TAG, "...preloaded " + count + " classes in "
                     + (SystemClock.uptimeMillis() - startTime) + "ms.");
+            if (LOGGING_DEBUG && missingLambdaCount != 0) {
+                Log.i(TAG, "Unresolved lambda preloads: " + missingLambdaCount);
+            }
         } catch (IOException e) {
             Log.e(TAG, "Error reading " + PRELOADED_CLASSES + ".", e);
         } finally {