Merge "Allow equality checking and hash for HIDL interface proxies."

core/java/android/os/HidlSupport.java

@@ -156,4 +156,27 @@ public class HidlSupport {
         // Should not reach here.
         throw new UnsupportedOperationException();
     }
+
+    /**
+     * Test that two interfaces are equal. This is the Java equivalent to C++
+     * interfacesEqual function.
+     * This essentially calls .equals on the internal binder objects (via Binder()).
+     * - If both interfaces are proxies, asBinder() returns a {@link HwRemoteBinder}
+     *   object, and they are compared in {@link HwRemoteBinder#equals}.
+     * - If both interfaces are stubs, asBinder() returns the object itself. By default,
+     *   auto-generated IFoo.Stub does not override equals(), but an implementation can
+     *   optionally override it, and {@code interfacesEqual} will use it here.
+     */
+    public static boolean interfacesEqual(IHwInterface lft, Object rgt) {
+        if (lft == rgt) {
+            return true;
+        }
+        if (lft == null || rgt == null) {
+            return false;
+        }
+        if (!(rgt instanceof IHwInterface)) {
+            return false;
+        }
+        return Objects.equals(lft.asBinder(), ((IHwInterface) rgt).asBinder());
+    }
 }

core/java/android/os/HwRemoteBinder.java

@@ -63,4 +63,9 @@ public class HwRemoteBinder implements IHwBinder {
     }
 
     private long mNativeContext;
+
+    @Override
+    public final native boolean equals(Object other);
+    @Override
+    public final native int hashCode();
 }

core/jni/android_os_HwRemoteBinder.cpp

@@ -22,9 +22,13 @@
 
 #include "android_os_HwParcel.h"
 
-#include <nativehelper/JNIHelp.h>
+#include <android/hidl/base/1.0/IBase.h>
+#include <android/hidl/base/1.0/BpHwBase.h>
+#include <android/hidl/base/1.0/BnHwBase.h>
 #include <android_runtime/AndroidRuntime.h>
 #include <hidl/Status.h>
+#include <hidl/HidlTransportSupport.h>
+#include <nativehelper/JNIHelp.h>
 #include <nativehelper/ScopedUtfChars.h>
 #include <nativehelper/ScopedLocalRef.h>
 
@@ -413,6 +417,44 @@ static jboolean JHwRemoteBinder_unlinkToDeath(JNIEnv* env, jobject thiz,
     return res;
 }
 
+static sp<hidl::base::V1_0::IBase> toIBase(JNIEnv* env, jclass hwRemoteBinderClazz, jobject jbinder)
+{
+    if (jbinder == nullptr) {
+        return nullptr;
+    }
+    if (!env->IsInstanceOf(jbinder, hwRemoteBinderClazz)) {
+        return nullptr;
+    }
+    sp<JHwRemoteBinder> context = JHwRemoteBinder::GetNativeContext(env, jbinder);
+    sp<hardware::IBinder> cbinder = context->getBinder();
+    return hardware::fromBinder<hidl::base::V1_0::IBase, hidl::base::V1_0::BpHwBase,
+                                hidl::base::V1_0::BnHwBase>(cbinder);
+}
+
+// equals iff other is also a non-null android.os.HwRemoteBinder object
+// and getBinder() returns the same object.
+// In particular, if other is an android.os.HwBinder object (for stubs) then
+// it returns false.
+static jboolean JHwRemoteBinder_equals(JNIEnv* env, jobject thiz, jobject other)
+{
+    if (env->IsSameObject(thiz, other)) {
+        return true;
+    }
+    if (other == NULL) {
+        return false;
+    }
+
+    ScopedLocalRef<jclass> clazz(env, FindClassOrDie(env, CLASS_PATH));
+
+    return hardware::interfacesEqual(toIBase(env, clazz.get(), thiz), toIBase(env, clazz.get(), other));
+}
+
+static jint JHwRemoteBinder_hashCode(JNIEnv* env, jobject thiz) {
+    jlong longHash = reinterpret_cast<jlong>(
+            JHwRemoteBinder::GetNativeContext(env, thiz)->getBinder().get());
+    return static_cast<jint>(longHash ^ (longHash >> 32)); // See Long.hashCode()
+}
+
 static JNINativeMethod gMethods[] = {
     { "native_init", "()J", (void *)JHwRemoteBinder_native_init },
 
@@ -430,6 +472,11 @@ static JNINativeMethod gMethods[] = {
     {"unlinkToDeath",
         "(Landroid/os/IHwBinder$DeathRecipient;)Z",
         (void*)JHwRemoteBinder_unlinkToDeath},
+
+    {"equals", "(Ljava/lang/Object;)Z",
+        (void*)JHwRemoteBinder_equals},
+
+    {"hashCode", "()I", (void*)JHwRemoteBinder_hashCode},
 };
 
 namespace android {