Merge "Naming fix and add comments"
diff --git a/core/java/android/os/Binder.java b/core/java/android/os/Binder.java
index 44e6f1b..a83c7b3 100644
--- a/core/java/android/os/Binder.java
+++ b/core/java/android/os/Binder.java
@@ -21,7 +21,6 @@
import android.util.Slog;
import com.android.internal.util.FastPrintWriter;
-import com.android.internal.util.FunctionalUtils;
import com.android.internal.util.FunctionalUtils.ThrowingRunnable;
import com.android.internal.util.FunctionalUtils.ThrowingSupplier;
@@ -200,7 +199,7 @@
* then its own pid is returned.
*/
public static final native int getCallingPid();
-
+
/**
* Return the Linux uid assigned to the process that sent you the
* current transaction that is being processed. This uid can be used with
@@ -333,7 +332,7 @@
* it needs to.
*/
public static final native void flushPendingCommands();
-
+
/**
* Add the calling thread to the IPC thread pool. This function does
* not return until the current process is exiting.
@@ -370,7 +369,7 @@
}
}
}
-
+
/**
* Convenience method for associating a specific interface with the Binder.
* After calling, queryLocalInterface() will be implemented for you
@@ -381,7 +380,7 @@
mOwner = owner;
mDescriptor = descriptor;
}
-
+
/**
* Default implementation returns an empty interface name.
*/
@@ -406,7 +405,7 @@
public boolean isBinderAlive() {
return true;
}
-
+
/**
* Use information supplied to attachInterface() to return the
* associated IInterface if it matches the requested
@@ -607,7 +606,7 @@
}
return r;
}
-
+
/**
* Local implementation is a no-op.
*/
@@ -620,7 +619,7 @@
public boolean unlinkToDeath(DeathRecipient recipient, int flags) {
return true;
}
-
+
protected void finalize() throws Throwable {
try {
destroyBinder();
@@ -714,7 +713,15 @@
}
}
+/**
+ * Java proxy for a native IBinder object.
+ * Allocated and constructed by the native javaObjectforIBinder function. Never allocated
+ * directly from Java code.
+ */
final class BinderProxy implements IBinder {
+ // See android_util_Binder.cpp for the native half of this.
+ // TODO: Consider using NativeAllocationRegistry instead of finalization.
+
// Assume the process-wide default value when created
volatile boolean mWarnOnBlocking = Binder.sWarnOnBlocking;
@@ -773,7 +780,7 @@
reply.recycle();
}
}
-
+
public void dumpAsync(FileDescriptor fd, String[] args) throws RemoteException {
Parcel data = Parcel.obtain();
Parcel reply = Parcel.obtain();
@@ -810,7 +817,7 @@
BinderProxy() {
mSelf = new WeakReference(this);
}
-
+
@Override
protected void finalize() throws Throwable {
try {
@@ -819,9 +826,9 @@
super.finalize();
}
}
-
+
private native final void destroy();
-
+
private static final void sendDeathNotice(DeathRecipient recipient) {
if (false) Log.v("JavaBinder", "sendDeathNotice to " + recipient);
try {
@@ -832,8 +839,20 @@
exc);
}
}
-
+
+ // This WeakReference to "this" is used only by native code to "attach" to the
+ // native IBinder object.
+ // Using WeakGlobalRefs instead currently appears unsafe, in that they can yield a
+ // non-null value after the BinderProxy is enqueued for finalization.
+ // Used only once immediately after construction.
+ // TODO: Consider making the extra native-to-java call to compute this on the fly.
final private WeakReference mSelf;
+
+ // Native pointer to the wrapped native IBinder object. Counted as strong reference.
private long mObject;
+
+ // Native pointer to native DeathRecipientList. Counted as strong reference.
+ // Basically owned by the JavaProxy object. Reference counted only because DeathRecipients
+ // hold a weak reference that can be temporarily promoted.
private long mOrgue;
}
diff --git a/core/jni/android_util_Binder.cpp b/core/jni/android_util_Binder.cpp
index 5b0f776..768f53f 100644
--- a/core/jni/android_util_Binder.cpp
+++ b/core/jni/android_util_Binder.cpp
@@ -488,8 +488,8 @@
private:
JavaVM* const mVM;
- jobject mObject;
- jweak mObjectWeak; // will be a weak ref to the same VM-side DeathRecipient after binderDied()
+ jobject mObject; // Initial strong ref to Java-side DeathRecipient. Cleared on binderDied().
+ jweak mObjectWeak; // weak ref to the same Java-side DeathRecipient after binderDied().
wp<DeathRecipientList> mList;
};
@@ -561,7 +561,7 @@
env->DeleteGlobalRef((jobject)obj);
}
-static Mutex mProxyLock;
+static Mutex gProxyLock;
jobject javaObjectForIBinder(JNIEnv* env, const sp<IBinder>& val)
{
@@ -576,7 +576,7 @@
// For the rest of the function we will hold this lock, to serialize
// looking/creation/destruction of Java proxies for native Binder proxies.
- AutoMutex _l(mProxyLock);
+ AutoMutex _l(gProxyLock);
// Someone else's... do we know about it?
jobject object = (jobject)val->findObject(&gBinderProxyOffsets);
@@ -1252,7 +1252,7 @@
static void android_os_BinderProxy_destroy(JNIEnv* env, jobject obj)
{
// Don't race with construction/initialization
- AutoMutex _l(mProxyLock);
+ AutoMutex _l(gProxyLock);
IBinder* b = (IBinder*)
env->GetLongField(obj, gBinderProxyOffsets.mObject);
