From 0fd6748bf61c911a2072d4d02aa0b37d025572a2 Mon Sep 17 00:00:00 2001
From: Tiger Huang <tigerhuang@google.com>
Date: Wed, 15 Apr 2020 22:16:13 +0800
Subject: [PATCH] Add logs that indicate why a surface is invalid

This helps us to debug.

Bug: 154056280
Test: Locally make leashes invalid and check the log format.
Change-Id: Idcde497ffee1f10a4289520e154aa8b39eed1f78
---
 core/java/android/view/SurfaceControl.java    | 28 +++++++++++++++++--
 .../server/wm/WindowManagerService.java       | 13 +++++++--
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/core/java/android/view/SurfaceControl.java b/core/java/android/view/SurfaceControl.java
index 1086774fc8ff5..76ed37c51bfe7 100644
--- a/core/java/android/view/SurfaceControl.java
+++ b/core/java/android/view/SurfaceControl.java
@@ -228,6 +228,7 @@ public final class SurfaceControl implements Parcelable {
      */
     public long mNativeObject;
     private long mNativeHandle;
+    private Throwable mReleaseStack = null;
 
     // TODO: Move this to native.
     private final Object mSizeLock = new Object();
@@ -426,11 +427,18 @@ public final class SurfaceControl implements Parcelable {
         if (mNativeObject != 0) {
             release();
         }
-      	if (nativeObject != 0) {
+        if (nativeObject != 0) {
             mCloseGuard.open("release");
         }
         mNativeObject = nativeObject;
         mNativeHandle = mNativeObject != 0 ? nativeGetHandle(nativeObject) : 0;
+        if (mNativeObject == 0) {
+            if (Build.IS_DEBUGGABLE) {
+                mReleaseStack = new Throwable("assigned zero nativeObject here");
+            }
+        } else {
+            mReleaseStack = null;
+        }
     }
 
     /**
@@ -989,10 +997,21 @@ public final class SurfaceControl implements Parcelable {
             nativeRelease(mNativeObject);
             mNativeObject = 0;
             mNativeHandle = 0;
+            if (Build.IS_DEBUGGABLE) {
+                mReleaseStack = new Throwable("released here");
+            }
             mCloseGuard.close();
         }
     }
 
+    /**
+     * Returns the call stack that assigned mNativeObject to zero.
+     * @hide
+     */
+    public Throwable getReleaseStack() {
+        return mReleaseStack;
+    }
+
     /**
      * Disconnect any client still connected to the surface.
      * @hide
@@ -1004,8 +1023,11 @@ public final class SurfaceControl implements Parcelable {
     }
 
     private void checkNotReleased() {
-        if (mNativeObject == 0) throw new NullPointerException(
-                "mNativeObject is null. Have you called release() already?");
+        if (mNativeObject == 0) {
+            Log.wtf(TAG, "Invalid " + this + " caused by:", mReleaseStack);
+            throw new NullPointerException(
+                "mNativeObject of " + this + " is null. Have you called release() already?");
+        }
     }
 
     /**
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 9d879765f8df8..181c2fd753720 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -2445,8 +2445,17 @@ public class WindowManagerService extends IWindowManager.Stub
             if (controls != null) {
                 final int length = Math.min(controls.length, outControls.length);
                 for (int i = 0; i < length; i++) {
-                    outControls[i] = win.isClientLocal()
-                            ? new InsetsSourceControl(controls[i]) : controls[i];
+                    final InsetsSourceControl control = controls[i];
+
+                    // Check if we are sending invalid leashes.
+                    final SurfaceControl leash = control != null ? control.getLeash() : null;
+                    if (leash != null && !leash.isValid()) {
+                        Slog.wtf(TAG, leash + " is not valid before sending to " + win,
+                                leash.getReleaseStack());
+                    }
+
+                    outControls[i] = win.isClientLocal() && control != null
+                            ? new InsetsSourceControl(control) : control;
                 }
             }
         }