On Thu, Jan 16, 2014 at 7:51 AM, Giovanni Piero Deretta
I think that Harmut point is that you can very well use threads for the same thing. ... The point of using fibers (i.e. M:N threading) is almost purely performance.
Again, for a large class of use cases, fibers and threads are not the same. Writing thread-safe code remains something of an art, a specialty within the already-rarefied realm of good C++ coding. With care, code review and testing, it is of course possible to produce good thread-safe code when you are writing it from scratch. But retrofitting existing single-threaded code to be thread-safe can be extremely costly. At this moment in history, we have a very large volume of existing code whose developers (perhaps unconsciously) relied on having exclusive access to certain in-process resources. Some of us do not have the option to discard it and rewrite from scratch. Yes, this is a subset of the possible use cases of the Fiber library. It is an important subset because threads provide no equivalent. Yes, I also want a Boost library that will concurrently process very large numbers of tasks, with each of a number of threads running very many fibers. I think the Fiber library gives us a foundation on which to build that support. But even with its present feature set, with Oliver responding to the community, it has great value. I feel frustrated when people dismiss the very real benefit of cooperative context switching as irrelevant to them.