Fix input channel leak.

Bug: 5156144

Input channels could leak or simply live longer than they should
in some cases.

1. Monitor channels (used by the pointer location overlay) are never
   unregistered, so they would leak.

   Added code to handle failures in the receive callback by closing
   the input channel.

2. The DragState held onto its input window and application handles
   even after the input channel was disposed.

   Added code to null these handles out when they are no longer needed.

3. Input channels previously used as input event targets would stick
   around until the targets were cleared (usually on the next
   event).

   Added code to detect when the input dispatcher is in
   an idle state and to proactively clear the targets then
   to ensure that resources are released promptly.

4. Native input window handles held onto the input channel even
   after the input window was removed from the input dispatcher.
   Consequently, the input channel would not be disposed until
   the input window handle itself was freed.  Since the input
   window handle is held from managed code, this meant that the
   window's input channel could stick around until the next GC.

   Refactored the input window handle to separate the properties
   (info) and identify (handle) state into different objects.
   Then modified the dispatcher to release the properties (info)
   when no longer needed, including the input channel.

7. The pointer location overlay does not actually use its
   standard input channel, only the monitor input channel.

   Added INPUT_FEATURE_NO_INPUT_CHANNEL to allow windows to
   request that they not be provided with an input channel
   at all.

Improved some of the error handling logic to emit the status
code as part of the exception message.

Change-Id: I01988d4391a70c6678c8b0e936ca051af680b1a5

1 files changed, 9 insertions, 4 deletions

diff --git a/services/jni/com_android_server_InputApplicationHandle.cpp b/services/jni/com_android_server_InputApplicationHandle.cpp
index 7de67d9..c76ab53 100644
--- a/services/jni/com_android_server_InputApplicationHandle.cpp
+++ b/services/jni/com_android_server_InputApplicationHandle.cpp
@@ -49,25 +49,30 @@ jobject NativeInputApplicationHandle::getInputApplicationHandleObjLocalRef(JNIEn
     return env->NewLocalRef(mObjWeak);
 }
 
-bool NativeInputApplicationHandle::update() {
+bool NativeInputApplicationHandle::updateInfo() {
     JNIEnv* env = AndroidRuntime::getJNIEnv();
     jobject obj = env->NewLocalRef(mObjWeak);
     if (!obj) {
+        releaseInfo();
         return false;
     }
 
+    if (!mInfo) {
+        mInfo = new InputApplicationInfo();
+    }
+
     jstring nameObj = jstring(env->GetObjectField(obj,
             gInputApplicationHandleClassInfo.name));
     if (nameObj) {
         const char* nameStr = env->GetStringUTFChars(nameObj, NULL);
-        name.setTo(nameStr);
+        mInfo->name.setTo(nameStr);
         env->ReleaseStringUTFChars(nameObj, nameStr);
         env->DeleteLocalRef(nameObj);
     } else {
-        name.setTo("<null>");
+        mInfo->name.setTo("<null>");
     }
 
-    dispatchingTimeout = env->GetLongField(obj,
+    mInfo->dispatchingTimeout = env->GetLongField(obj,
             gInputApplicationHandleClassInfo.dispatchingTimeoutNanos);
 
     env->DeleteLocalRef(obj);