Actor Model 102 26 Actor model is a mathematical model of concurrent computation that treats "actors"as the universal primitives of concurrent digital computation: in response to a message that it receives,an actor can make local decisions,create more actors,send more messages,and determine how to respond to the next message received. Institute of Computer Software 2022-2-27 Nanjing University
Actor Model Actor model is a mathematical model of concurrent computation that treats " actors " as the universal primitives of concurrent digital computation: in response to a message that it receives, an actor can make local decisions, create more actors, send more messages, and determine how to respond to the next message received. 2022-2-27 Institute of Computer Software Nanjing University 26
Actor Model 102 Everything is an 27 object! Philosophy:Everything is an actor! Characterized by inherent concurrency of computation within and among actors dynamic creation of actors inclusion of actor addresses in messages interaction only through direct asynchronous message passing with no restriction on message arrival order Institute of Computer Software 2022-2-27 Nanjing University
Actor Model Philosophy: Everything is an actor! Characterized by inherent concurrency of computation within and among actors dynamic creation of actors inclusion of actor addresses in messages interaction only through direct asynchronous message passing with no restriction on message arrival order 2022-2-27 Institute of Computer Software Nanjing University 27 Everything is an object!
&扇 Actor Model 102 28 An actor is a computational entity that,in response to a message it receives,can concurrently: send a finite number of messages to other actors; create a finite number of new actors; designate the behavior to be used for the next message it receives. There is no assumed sequence to the above actions and they could be carried out in parallel. Institute of Computer Software 2022-2-27 Nanjing University
Actor Model An actor is a computational entity that, in response to a message it receives, can concurrently: send a finite number of messages to other actors; create a finite number of new actors; designate the behavior to be used for the next message it receives. There is no assumed sequence to the above actions and they could be carried out in parallel. 2022-2-27 Institute of Computer Software Nanjing University 28
Actor Model 11 1 2...(mail queue n+1 n specify ~、replacement Communications among actors occur asynchronously Xn+1 create actors 1121.. (mail queue .. n n+1 Recipients of messages are identified by address,sometimes called "mailing address". ETH Chair of Software Engineering P.Eugster
2022-2-27 Institute of Computer Software Nanjing University 29 2022/2/27 Institute of Computer Software Nanjing University Communications among actors occur asynchronously Recipients of messages are identified by address, sometimes called "mailing address
&扇 Evaluation 30 Rather rudimentary mechanism Explicit message passing not unified with object/methods model ▣No inheritance Asynchronous message passing How to implement queries,i.e.,invocations with replies?Especially with FIF○？ ▣Unbounded queues? 口、 Sometimes one would like to reason about a larger code portion in sequential case Requires mechanism on top of only asynchronous invocations Institute of Computer Software 2022-2-27 Nanjing University
Evaluation Rather rudimentary mechanism Explicit message passing not unified with object/methods model No inheritance Asynchronous message passing How to implement queries, i.e., invocations with replies? Especially with FIFO? Unbounded queues? Sometimes one would like to reason about a larger code portion in sequential case Requires mechanism on top of only asynchronous invocations 2022-2-27 Institute of Computer Software Nanjing University 30