Operating Systems: Three Easy Pieces
Remzi H. Arpaci-Dusseau and Andrea C. Arpaci-Dusseau
August, 2018 (Version 1.00)
A book covering the fundamentals of operating systems, including virtualization of the CPU and memory, threads and concurrency, and file and storage systems. Written by professors active in the field for 25 years, this text has been developed in the classrooms of the University of Wisconsin-Madison, and has been used in the instruction of thousands of students.
The official web page is here
and there you can get all chapters in PDF for free
Why posting that?
well, always good to have some good reference on some principles
here the middle part about Concurrency is very interesting
especially when you connect it to what we have in AS3 with the
Worker (which use POSIX Threads)