Merge "Remove unnecessary explicit GC in ZygoteInit."

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

@@ -86,12 +86,6 @@ public class ZygoteInit {
      */
     private static Resources mResources;
 
-    /**
-     * The number of times that the main Zygote loop
-     * should run before calling gc() again.
-     */
-    static final int GC_LOOP_COUNT = 10;
-
     /**
      * The name of a resource file that contains classes to preload.
      */
@@ -286,11 +280,6 @@ public class ZygoteInit {
             float defaultUtilization = runtime.getTargetHeapUtilization();
             runtime.setTargetHeapUtilization(0.8f);
 
-            // Start with a clean slate.
-            System.gc();
-            runtime.runFinalizationSync();
-            Debug.startAllocCounting();
-
             try {
                 BufferedReader br
                     = new BufferedReader(new InputStreamReader(is), 256);
@@ -309,15 +298,6 @@ public class ZygoteInit {
                             Log.v(TAG, "Preloading " + line + "...");
                         }
                         Class.forName(line);
-                        if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) {
-                            if (false) {
-                                Log.v(TAG,
-                                    " GC at " + Debug.getGlobalAllocSize());
-                            }
-                            System.gc();
-                            runtime.runFinalizationSync();
-                            Debug.resetGlobalAllocSize();
-                        }
                         count++;
                     } catch (ClassNotFoundException e) {
                         Log.w(TAG, "Class not found for preloading: " + line);
@@ -347,8 +327,6 @@ public class ZygoteInit {
                 // Fill in dex caches with classes, fields, and methods brought in by preloading.
                 runtime.preloadDexCaches();
 
-                Debug.stopAllocCounting();
-
                 // Bring back root. We'll need it later.
                 setEffectiveUser(ROOT_UID);
                 setEffectiveGroup(ROOT_GID);
@@ -366,10 +344,7 @@ public class ZygoteInit {
     private static void preloadResources() {
         final VMRuntime runtime = VMRuntime.getRuntime();
 
-        Debug.startAllocCounting();
         try {
-            System.gc();
-            runtime.runFinalizationSync();
             mResources = Resources.getSystem();
             mResources.startPreloading();
             if (PRELOAD_RESOURCES) {
@@ -394,22 +369,12 @@ public class ZygoteInit {
             mResources.finishPreloading();
         } catch (RuntimeException e) {
             Log.w(TAG, "Failure preloading resources", e);
-        } finally {
-            Debug.stopAllocCounting();
         }
     }
 
     private static int preloadColorStateLists(VMRuntime runtime, TypedArray ar) {
         int N = ar.length();
         for (int i=0; i<N; i++) {
-            if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) {
-                if (false) {
-                    Log.v(TAG, " GC at " + Debug.getGlobalAllocSize());
-                }
-                System.gc();
-                runtime.runFinalizationSync();
-                Debug.resetGlobalAllocSize();
-            }
             int id = ar.getResourceId(i, 0);
             if (false) {
                 Log.v(TAG, "Preloading resource #" + Integer.toHexString(id));
@@ -430,14 +395,6 @@ public class ZygoteInit {
     private static int preloadDrawables(VMRuntime runtime, TypedArray ar) {
         int N = ar.length();
         for (int i=0; i<N; i++) {
-            if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) {
-                if (false) {
-                    Log.v(TAG, " GC at " + Debug.getGlobalAllocSize());
-                }
-                System.gc();
-                runtime.runFinalizationSync();
-                Debug.resetGlobalAllocSize();
-            }
             int id = ar.getResourceId(i, 0);
             if (false) {
                 Log.v(TAG, "Preloading resource #" + Integer.toHexString(id));
@@ -459,7 +416,7 @@ public class ZygoteInit {
      * softly- and final-reachable objects, along with any other garbage.
      * This is only useful just before a fork().
      */
-    /*package*/ static void gc() {
+    /*package*/ static void gcAndFinalize() {
         final VMRuntime runtime = VMRuntime.getRuntime();
 
         /* runFinalizationSync() lets finalizers be called in Zygote,
@@ -468,9 +425,6 @@ public class ZygoteInit {
         System.gc();
         runtime.runFinalizationSync();
         System.gc();
-        runtime.runFinalizationSync();
-        System.gc();
-        runtime.runFinalizationSync();
     }
 
     /**
@@ -613,7 +567,7 @@ public class ZygoteInit {
             SamplingProfilerIntegration.writeZygoteSnapshot();
 
             // Do an initial gc to clean up after startup
-            gc();
+            gcAndFinalize();
 
             // Disable tracing so that forked processes do not inherit stale tracing tags from
             // Zygote.
@@ -682,27 +636,9 @@ public class ZygoteInit {
         fds.add(sServerSocket.getFileDescriptor());
         peers.add(null);
 
-        int loopCount = GC_LOOP_COUNT;
         while (true) {
             int index;
 
-            /*
-             * Call gc() before we block in select().
-             * It's work that has to be done anyway, and it's better
-             * to avoid making every child do it.  It will also
-             * madvise() any free memory as a side-effect.
-             *
-             * Don't call it every time, because walking the entire
-             * heap is a lot of overhead to free a few hundred bytes.
-             */
-            if (loopCount <= 0) {
-                gc();
-                loopCount = GC_LOOP_COUNT;
-            } else {
-                loopCount--;
-            }
-
-
             try {
                 fdArray = fds.toArray(fdArray);
                 index = selectReadable(fdArray);