| I see we mostly agree, but one thing here is a glaring error : > It has the good parts of both cooperative and preemptive scheduling, but yes, it's certainly cooperative. For me, the best part of cooperative scheduling is that you can work entirely without locking shared data structures, because you get "transactions" for free. This means it's rather difficult to get data races, deadlocks, etc. Go's scheduler certainly does not give you that, trades it for spreading work over different cpus. So it has problems: 1) necessity of locking, using IPC mechanisms, ... (like preemptive schedulers, and let's face facts here : channels aren't enough in real world apps) 2) everything gets blocked by large calculations (like cooperative schedulers) 3) more generally, easy to crash by misbehaving thread due to unrestricted access shared resources (not just cpu) (like cooperative schedulers) And advantages: 1) Actually uses multiple cpu's/cores/... (like preemptive schedulers) 2) integrated event loop that scales (like cooperative schedulers) If you want to see a programming language with a "scheduler" that doesn't have the bad parts of cooperative schedulers, check out Erlang. If you attempt to crash erlang with infinite loops, bad memory allocation, ... (on a properly configured system) that just won't work, the offending threads/"goroutines" crash leaving the rest of your program running fine. The offending threads will restart if you configure them to do so (which is really easy). The same can be achieved, with much more work, on the JVM, or, also with much more work, with python's "multiprocessing" library, part of the standard library. > > On the linux scheduler with proper ulimits it's bloody hard to crash the system, for instance, forkbombs, memory bombs, ... won't do it. I hope we'll get a language where you can do that too.
> I don't understand the analogy. It is not clear what "crash" means here, and it is not clear how it would apply to a runtime environment. All that stuff, forkbombs, etc, means that you can configure the system so arbitrary code can't affect the system in those particular ways. Crash means that the system/"program" doesn't respond (in a useful manner) anymore. |