3 ms·
>[Dahl and Nygaard] had a concept of timing which was implemented as a simulated time train in the way that is completely standard nowadays. That gives a framew
by zengid 8y ago
>[Dahl and Nygaard] had a concept of timing which was implemented as a simulated time train in the way that is completely standard nowadays. That gives a framework within which one could explore the meaning of real concurrency.
Could anyone comment on what that framework is in current terms? Googling 'simulated time train' doesn't really help. Thanks!
- atombender 8y agoNot sure what he means by "train", but Simula 67 included a module for performing "simulations", which was the original point of the language (Simula 1 was a simulation-specific language; Simula 67 was a general-purpose language with simulation in the standard library.) The simulation module was a framework for defining parallel processes that worked with discrete, scheduled events, a bit like actors. This was intended to model real-world problems such as traffic systems or factories, that complex interactions and dependencies. A simulation had a time axis, so it ran the processes in simulated time, instead of real time. This may be what Hoare was referring to. Further reading: http://simula67.at.ifi.uio.no/Archive/Intro-simula/intro.pdf http://simula67.at.ifi.uio.no/Archive/Intro-simula/intro.pdf http://heim.ifi.uio.no/~steinkr/papers/HiNC1-webversion-simula.pdf http://heim.ifi.uio.no/~steinkr/papers/HiNC1-webversion-simu...
- zengid 8y agoWow that is really neat. Thank you!
- carlehewitt 8y agoSimulated time is not the basis of real concurrency. Simula-67 (Dahl and Nyaaard) used co-routines in which there was no parallel execution.