Crystal: bdw-gc coroutines support

[NewsBot]

A new Crystal blog post/announcement has been posted!

Crystal uses bdw-gc and supports coroutines. Fibers is how coroutines are called here. For many years Crystal has been single-thread with fibers. Single-thread is still the default alternative. Sometime ago we added muti-thread support where each thread can run concurrently multiple fibers. This required some patches and eventual contributions to bdw-gc in order to achieve this since there was no built-in support for coroutines in the library.

The support for multi-thread coroutines was gained by allowing the user to control the stack bottom of each thread. Changing the stack bottom and the instruction pointer is what effectively gives life to the coroutines. This is, letting the program choose what portion of the program to execute next without needing to tell the OS about it. Telling the OS would be equivalent to using threads and that would be more expensive.

So Crystal, and other languages, could benefit from having a mut...

Get the full details here: bdw-gc coroutines support - The Crystal Programming Language