Warn only if we're tearing down "live" DeathRecipient content

If the native-side bookkeeping still has strong references to VM-side
DeathRecipient objects at the time when it's being torn down, that
suggests that the app is doing unwholesome.  Log a warning to that
effect, with the class name of the objects to try to help the developer
figure out what they're mishandling.

Fixes bug 5202777 -- in particular, it no longer logs in the
working-as-intended case following delivery of the death notices,
when we've got the existing list shell but the weak refs have properly
cleared.  Also step down from "error" to "warning" logging as befits
the nature of the actual situation now being described.

Change-Id: Ic393560824800fbd912a6e69692c65be4fcc7544
diff --git a/core/jni/android_util_Binder.cpp b/core/jni/android_util_Binder.cpp
index b8f2d6f..6b5ca50 100644
--- a/core/jni/android_util_Binder.cpp
+++ b/core/jni/android_util_Binder.cpp
@@ -39,6 +39,8 @@
 #include <binder/IServiceManager.h>
 #include <utils/threads.h>
 
+#include <ScopedUtfChars.h>
+
 #include <android_runtime/AndroidRuntime.h>
 
 //#undef LOGV
@@ -444,6 +446,25 @@
         return result;
     }
 
+    void warnIfStillLive() {
+        JNIEnv* env = javavm_to_jnienv(mVM);
+        if (mObject != NULL) {
+            // Okay, something is wrong -- we have a hard reference to a live death
+            // recipient on the VM side, but the list is being torn down.
+            jclass clazz = env->GetObjectClass(mObject);
+            jmethodID getnameMethod = env->GetMethodID(clazz, "getName", NULL);
+            jstring nameString = (jstring) env->CallObjectMethod(clazz, getnameMethod);
+            if (nameString) {
+                ScopedUtfChars nameUtf(env, nameString);
+                LOGW("BinderProxy is being destroyed but the application did not call "
+                        "unlinkToDeath to unlink all of its death recipients beforehand.  "
+                        "Releasing leaked death recipient: %s", nameUtf.c_str());
+                env->DeleteLocalRef(nameString);
+            }
+            env->DeleteLocalRef(clazz);
+        }
+    }
+
 protected:
     virtual ~JavaDeathRecipient()
     {
@@ -478,7 +499,10 @@
     // to the list are holding references on the list object.  Only when they are torn
     // down can the list header be destroyed.
     if (mList.size() > 0) {
-        LOGE("Retiring DRL %p with extant death recipients\n", this);
+        List< sp<JavaDeathRecipient> >::iterator iter;
+        for (iter = mList.begin(); iter != mList.end(); iter++) {
+            (*iter)->warnIfStillLive();
+        }
     }
 }