Placeholder for binder freeze notification API.

Adding the placeholder APIs to validate whether this breaks existing
prebuilts.

Bug: 338097747
Change-Id: Id7357076ad98c1f220a78186fe509326047cf922
Test: m

Author: Yu-Ting Tseng

libs/binder/Binder.cpp

@@ -441,6 +441,14 @@ status_t BBinder::unlinkToDeath(
     return INVALID_OPERATION;
 }
 
+status_t BBinder::addFrozenStateChangeCallback(const wp<FrozenStateChangeCallback>&) {
+    return INVALID_OPERATION;
+}
+
+status_t BBinder::removeFrozenStateChangeCallback(const wp<FrozenStateChangeCallback>&) {
+    return INVALID_OPERATION;
+}
+
 status_t BBinder::dump(int /*fd*/, const Vector<String16>& /*args*/)
 {
     return NO_ERROR;

libs/binder/BpBinder.cpp

@@ -557,6 +557,14 @@ void BpBinder::sendObituary()
     }
 }
 
+status_t BpBinder::addFrozenStateChangeCallback(const wp<FrozenStateChangeCallback>&) {
+    return INVALID_OPERATION;
+}
+
+status_t BpBinder::removeFrozenStateChangeCallback(const wp<FrozenStateChangeCallback>&) {
+    return INVALID_OPERATION;
+}
+
 void BpBinder::reportOneDeath(const Obituary& obit)
 {
     sp<DeathRecipient> recipient = obit.recipient.promote();

libs/binder/include/binder/Binder.h

@@ -50,6 +50,13 @@ class BBinder : public IBinder {
                                                       void* cookie = nullptr, uint32_t flags = 0,
                                                       wp<DeathRecipient>* outRecipient = nullptr);
 
+    // Placeholders to test if adding virtual functions here breaks things.
+    // Will be replaced by an actual API once things are verified to work.
+    LIBBINDER_EXPORTED virtual status_t addFrozenStateChangeCallback(
+            const wp<FrozenStateChangeCallback>& callback);
+    LIBBINDER_EXPORTED virtual status_t removeFrozenStateChangeCallback(
+            const wp<FrozenStateChangeCallback>& callback);
+
     LIBBINDER_EXPORTED virtual void* attachObject(const void* objectID, void* object,
                                                   void* cleanupCookie,
                                                   object_cleanup_func func) final;

libs/binder/include/binder/BpBinder.h

@@ -66,6 +66,12 @@ class BpBinder : public IBinder {
                                                       void* cookie = nullptr, uint32_t flags = 0,
                                                       wp<DeathRecipient>* outRecipient = nullptr);
 
+    [[nodiscard]] virtual status_t addFrozenStateChangeCallback(
+            const wp<FrozenStateChangeCallback>& recipient);
+
+    [[nodiscard]] virtual status_t removeFrozenStateChangeCallback(
+            const wp<FrozenStateChangeCallback>& recipient);
+
     LIBBINDER_EXPORTED virtual void* attachObject(const void* objectID, void* object,
                                                   void* cleanupCookie,
                                                   object_cleanup_func func) final;

libs/binder/include/binder/IBinder.h

@@ -198,9 +198,14 @@ class [[clang::lto_visibility_public]] LIBBINDER_EXPORTED IBinder : public virtu
         virtual void binderDied(const wp<IBinder>& who) = 0;
     };
 
-    #if defined(__clang__)
-    #pragma clang diagnostic pop
-    #endif
+    class FrozenStateChangeCallback : public virtual RefBase {
+    public:
+        virtual void onStateChanged(const wp<IBinder>& who, bool isFrozen) = 0;
+    };
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
 
     /**
      * Register the @a recipient for a notification if this binder
@@ -249,6 +254,12 @@ class [[clang::lto_visibility_public]] LIBBINDER_EXPORTED IBinder : public virtu
                                             uint32_t flags = 0,
                                             wp<DeathRecipient>* outRecipient = nullptr) = 0;
 
+    // Placeholders. See Binder.h for details.
+    [[nodiscard]] virtual status_t addFrozenStateChangeCallback(
+            const wp<FrozenStateChangeCallback>& callback) = 0;
+    [[nodiscard]] virtual status_t removeFrozenStateChangeCallback(
+            const wp<FrozenStateChangeCallback>& callback) = 0;
+
     virtual bool            checkSubclass(const void* subclassID) const;
 
     typedef void (*object_cleanup_func)(const void* id, void* obj, void* cleanupCookie);