ceph/src/boost/libs/fiber/README.md

   1 boost.fiber
   2 ===========
   3
   4 boost.fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperatively.
   5 The API contains classes and functions to manage and synchronize fibers similiar to boost.thread.
   6
   7 A fiber is able to store the current execution state, including all registers and CPU flags, the
   8 instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple
   9 execution paths running on a single thread using a sort of cooperative scheduling (threads are
  10 preemptively scheduled) - the running fiber decides explicitly when it yields to allow another fiber to
  11 run (context switching).
  12
  13 A context switch between threads costs usally thousands of CPU cycles on x86 compared to a fiber switch
  14 with less than 100 cycles. A fiber can only run on a single thread at any point in time.
  15
  16 boost.fiber requires C++11!