Recommended books on concurrency / synchronization mechanisms
Do you guys know a more theoretical book/articles about concurrent access / sync methods? I am mostly interested of how semaphores, mutexes and other synchronization mechanisms are implemented.

I did grasp the basics of Steven's second volume of Unix Network Programming, but I feel that I need something more abstract to really get the overall picture.
Recommended books on concurrency / synchronization mechanisms
===

Do you guys know a more theoretical book/articles about concurrent access / sync methods? I am mostly interested of how semaphores, mutexes and other synchronization mechanisms are implemented.

I did grasp the basics of Steven's second volume of Unix Network Programming, but I feel that I need something more abstract to really get the overall picture.