Aggressively trim memory for system_process

Bug: 16978006

Don't HWUI-accelerate KeyguardScrim
Aggressively trim memory as soon as a ViewRootImpl
dies or has its visibility changed.

Change-Id: Ie1b7c9d30653456bd2e9f309128174f972999368

3 files changed, 48 insertions, 1 deletions

diff --git a/core/java/android/view/HardwareRenderer.java b/core/java/android/view/HardwareRenderer.java
index edb3798..904e33f 100644
--- a/core/java/android/view/HardwareRenderer.java
+++ b/core/java/android/view/HardwareRenderer.java
@@ -186,6 +186,18 @@ public abstract class HardwareRenderer {
         }
     }
 
+    public static boolean sTrimForeground = false;
+
+    /**
+     * Controls whether or not the hardware renderer should aggressively
+     * trim memory. Note that this must not be set for any process that
+     * uses WebView! This should be only used by system_process or similar
+     * that do not go into the background.
+     */
+    public static void enableForegroundTrimming() {
+        sTrimForeground = true;
+    }
+
     /**
      * Indicates whether hardware acceleration is available under any form for
      * the view hierarchy.
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 43ab4ef..b1d3d45 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -804,6 +804,9 @@ public final class ViewRootImpl implements ViewParent,
         if (mAppVisible != visible) {
             mAppVisible = visible;
             scheduleTraversals();
+            if (!mAppVisible) {
+                WindowManagerGlobal.trimForeground();
+            }
         }
     }
 
diff --git a/core/java/android/view/WindowManagerGlobal.java b/core/java/android/view/WindowManagerGlobal.java
index c39ec97..08160c8 100644
--- a/core/java/android/view/WindowManagerGlobal.java
+++ b/core/java/android/view/WindowManagerGlobal.java
@@ -375,6 +375,9 @@ public final class WindowManagerGlobal {
                 mDyingViews.remove(view);
             }
         }
+        if (HardwareRenderer.sTrimForeground && HardwareRenderer.isAvailable()) {
+            doTrimForeground();
+        }
     }
 
     private int findViewLocked(View view, boolean required) {
@@ -413,6 +416,35 @@ public final class WindowManagerGlobal {
             }
 
             HardwareRenderer.trimMemory(level);
+
+            if (HardwareRenderer.sTrimForeground) {
+                doTrimForeground();
+            }
+        }
+    }
+
+    public static void trimForeground() {
+        if (HardwareRenderer.sTrimForeground && HardwareRenderer.isAvailable()) {
+            WindowManagerGlobal wm = WindowManagerGlobal.getInstance();
+            wm.doTrimForeground();
+        }
+    }
+
+    private void doTrimForeground() {
+        boolean hasVisibleWindows = false;
+        synchronized (mLock) {
+            for (int i = mRoots.size() - 1; i >= 0; --i) {
+                if (mRoots.get(i).getHostVisibility() == View.VISIBLE
+                        && mRoots.get(i).mAttachInfo.mHardwareRenderer != null) {
+                    hasVisibleWindows = true;
+                } else {
+                    mRoots.get(i).destroyHardwareResources();
+                }
+            }
+        }
+        if (!hasVisibleWindows) {
+            HardwareRenderer.trimMemory(
+                    ComponentCallbacks2.TRIM_MEMORY_COMPLETE);
         }
     }
 
@@ -428,7 +460,7 @@ public final class WindowManagerGlobal {
                 for (int i = 0; i < count; i++) {
                     ViewRootImpl root = mRoots.get(i);
                     String name = getWindowName(root);
-                    pw.printf("\n\t%s", name);
+                    pw.printf("\n\t%s (visibility=%d)", name, root.getHostVisibility());
 
                     HardwareRenderer renderer =
                             root.getView().mAttachInfo.mHardwareRenderer;