电子科技女学 Software Architecture Design Pattern University af Electronic Science and Technoloryf Chim Definitions 。Concurrency -"Logically"simultaneous processing Does not imply multiple processing elements ·Parallelism -"Physically"simultaneous processing Involves multiple processing elements and/or independent device operations Both concurrency and parallelism require controlled access to shared resources,e.g.I/O devices,files,database records,in-core data structures,consoles,etc. Software Architecture and Design Pattern 5Software Architecture & Design Pattern Software Architecture and Design Pattern 5 Definitions • Concurrency - “Logically" simultaneous processing - Does not imply multiple processing elements • Parallelism - “Physically" simultaneous processing - Involves multiple processing elements and/or independent device operations Both concurrency and parallelism require controlled access to shared resources, e.g. I/O devices, files, database records, in-core data structures, consoles, etc