libbinder_ndk: set/getExtension (ea14ef26) · Commits · e / devices / smdk4412 / android_frameworks_native

libs/binder/ndk/ibinder.cpp

+37 −0

Original line number	Diff line number	Diff line
		@@ -589,3 +589,40 @@ void AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient* recipient) {

		recipient->decStrong(nullptr);
		}

		binder_status_t AIBinder_getExtension(AIBinder* binder, AIBinder** outExt) {
		if (binder == nullptr \|\| outExt == nullptr) {
		if (outExt != nullptr) {
		*outExt = nullptr;
		}
		return STATUS_UNEXPECTED_NULL;
		}

		sp<IBinder> ext;
		status_t res = binder->getBinder()->getExtension(&ext);

		if (res != android::OK) {
		*outExt = nullptr;
		return PruneStatusT(res);
		}

		sp<AIBinder> ret = ABpBinder::lookupOrCreateFromBinder(ext);
		if (ret != nullptr) ret->incStrong(binder);

		*outExt = ret.get();
		return STATUS_OK;
		}

		binder_status_t AIBinder_setExtension(AIBinder* binder, AIBinder* ext) {
		if (binder == nullptr \|\| ext == nullptr) {
		return STATUS_UNEXPECTED_NULL;
		}

		ABBinder* rawBinder = binder->asABBinder();
		if (rawBinder == nullptr) {
		return STATUS_INVALID_OPERATION;
		}

		rawBinder->setExtension(ext->getBinder());
		return STATUS_OK;
		}

libs/binder/ndk/include_ndk/android/binder_ibinder.h

+70 −0

Original line number	Diff line number	Diff line
		@@ -510,6 +510,76 @@ __attribute__((warn_unused_result)) AIBinder_DeathRecipient* AIBinder_DeathRecip
		void AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient* recipient) __INTRODUCED_IN(29);

		#endif //__ANDROID_API__ >= __ANDROID_API_Q__

		#if __ANDROID_API__ >= __ANDROID_API_R__

		/**
		* Gets the extension registered with AIBinder_setExtension.
		*
		* See AIBinder_setExtension.
		*
		* \param binder the object to get the extension of.
		* \param outExt the returned extension object. Will be null if there is no extension set or
		* non-null with one strong ref count.
		*
		* \return error of getting the interface (may be a transaction error if this is
		* remote binder). STATUS_UNEXPECTED_NULL if binder is null.
		*/
		binder_status_t AIBinder_getExtension(AIBinder* binder, AIBinder** outExt) __INTRODUCED_IN(30);

		/**
		* Gets the extension of a binder interface. This allows a downstream developer to add
		* an extension to an interface without modifying its interface file. This should be
		* called immediately when the object is created before it is passed to another thread.
		* No thread safety is required.
		*
		* For instance, imagine if we have this interface:
		* interface IFoo { void doFoo(); }
		*
		* A). Historical option that has proven to be BAD! Only the original
		* author of an interface should change an interface. If someone
		* downstream wants additional functionality, they should not ever
		* change the interface or use this method.
		*
		* BAD TO DO: interface IFoo { BAD TO DO
		* BAD TO DO: void doFoo(); BAD TO DO
		* BAD TO DO: + void doBar(); // adding a method BAD TO DO
		* BAD TO DO: } BAD TO DO
		*
		* B). Option that this method enables.
		* Leave the original interface unchanged (do not change IFoo!).
		* Instead, create a new interface in a downstream package:
		*
		* package com.<name>; // new functionality in a new package
		* interface IBar { void doBar(); }
		*
		* When registering the interface, add:
		* std::shared_ptr<MyFoo> foo = new MyFoo; // class in AOSP codebase
		* std::shared_ptr<MyBar> bar = new MyBar; // custom extension class
		* ... = AIBinder_setExtension(foo->asBinder().get(), bar->asBinder().get());
		* // handle error
		*
		* Then, clients of IFoo can get this extension:
		* SpAIBinder binder = ...;
		* std::shared_ptr<IFoo> foo = IFoo::fromBinder(binder); // handle if null
		* SpAIBinder barBinder;
		* ... = AIBinder_getExtension(barBinder.get());
		* // handle error
		* std::shared_ptr<IBar> bar = IBar::fromBinder(barBinder);
		* // type is checked with AIBinder_associateClass
		* // if bar is null, then there is no extension or a different
		* // type of extension
		*
		* \param binder the object to get the extension on. Must be local.
		* \param ext the extension to set (binder will hold a strong reference to this)
		*
		* \return OK on success, STATUS_INVALID_OPERATION if binder is not local, STATUS_UNEXPECTED_NULL
		* if either binder is null.
		*/
		binder_status_t AIBinder_setExtension(AIBinder* binder, AIBinder* ext) __INTRODUCED_IN(30);

		#endif //__ANDROID_API__ >= __ANDROID_API_R__

		__END_DECLS

		/** @} */

libs/binder/ndk/libbinder_ndk.map.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -101,6 +101,9 @@ LIBBINDER_NDK { # introduced=29

		LIBBINDER_NDK30 { # introduced=30
		global:
		AIBinder_getExtension;
		AIBinder_setExtension;

		AIBinder_markSystemStability; # apex
		AIBinder_markVendorStability; # vndk
		AIBinder_markVintfStability; # apex vndk