cyx-6 commented on a change in pull request #51: URL: https://github.com/apache/tvm-rfcs/pull/51#discussion_r781780791
########## File path: rfcs/0051-PackedFunc-as-Object.md ########## @@ -0,0 +1,82 @@ +- Feature Name: PackedFunc as Object +- Start Date: 2022-01-01 +- RFC PR: https://github.com/apache/tvm-rfcs/pull/51/ +- GitHub Issue: TBD + +## 1. Summary + +This RFC allows developers to use `PackedFunc` as TVM objects, which completes the last missing step of TVM runtime object system. + +## 2. Motivation + +Historically, several fundamental data structures in TVM are not part of the runtime object system, namely `NDArray` (not object), `Module` (not object), `String` (not exist), `Array` (not in runtime), `Map` (not in runtime), `PackedFunc` (not yet an object). + +The rationale of the original design is mainly for simplicity, which is desirable for the usecases as a monolithic compiler. As time goes on, the community has come to realize the fact that the object system should be inclusive enough and by design allow more convenient integration with vendor libraries. Therefore, as part of the effort in TVM refactoring and TVM Unity, recent work strives to re-implement these core data structures to be consistent with the runtime object protocol with stable ABI guarantee, and thus could be passed across the DLL boundary. + +As the central piece of the TVM ecosystem, this proposal focuses on making `PackedFunc` a TVM object. By doing so, it completes the last missing piece of the object ecosystem, allows TVM containers to carry `PackedFunc`s, and enables `PackedFunc`s to be passed across the DLL boundary to bring convenience to the vendor library integration. + + +## 3. Guide-level introduction + +This is mainly a developer-facing feature, and thus there is no sensible change to the existing functionalities to the end users, who are still supposed to use the same `PackedFunc` API. + +Only one major object is introduced, `PackedFuncObj`, a TVM object in the runtime system (detailed in the next section) which is an ABI stable data structure for packed functions that could be shared across language and DLL boundary. + +To avoid API misuse from developers, the `PackedFuncObj` cannot be created or manipulated directly, and the specialization of its creation `make_object<PackedFuncObj>` will be deleted for safety. Instead, the developer-facing class `PackedFunc` remains responsible for creating and managing the object, and for properly setting its content. Review comment: Sure. Since the `PackedFuncObj` is an abstract object only, it is not allowed to be created directly, while its derived classes are allowed to do so. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
