So pretty much he is saying that concurrency and parallelism aren't the same thing. (Which is kind of a 'duh' if you think about it).
Parallelism is concerned with efficiency of the algorithm in a parallel environment. His example is that quick-sort is an easily parallelized algorithm (each level of recursion is two completely independent steps). This means that at each level, you can run the independent steps at the same time, meaning that in a parallel environment, you can see a big speed improvement.
Concurrency is more dealing with the control flow of a program. Concurrency tries to manage resources in a 'nondeterministic' environment.
Pretty much, its like an OS scheduler. The OS scheduler has to manage all of its resources, like the printer or the hard drive or whatever else, between different concurrently running processes, and prevent things like race conditions or deadlock. This isn't a parallelism issue, because you can have, for example, a single threaded processor with a multi-tasking operating system.
So pretty much he is saying that concurrency and parallelism aren't the same thing. (Which is kind of a 'duh' if you think about it).
Parallelism is concerned with efficiency of the algorithm in a parallel environment. His example is that quick-sort is an easily parallelized algorithm (each level of recursion is two completely independent steps). This means that at each level, you can run the independent steps at the same time, meaning that in a parallel environment, you can see a big speed improvement.
Concurrency is more dealing with the control flow of a program. Concurrency tries to manage resources in a 'nondeterministic' environment.
Pretty much, its like an OS scheduler. The OS scheduler has to manage all of its resources, like the printer or the hard drive or whatever else, between different concurrently running processes, and prevent things like race conditions or deadlock. This isn't a parallelism issue, because you can have, for example, a single threaded processor with a multi-tasking operating system.
does that help?