b0d09be850
Looking at the implementation, it seems that operator safe_bool() and its companion, operator!(), interrogate whether the referenced fiber has or has not terminated. joinable() does not. Add more joinable() cross-references, and cross-reference joinable(), operator safe_bool() and operator!().
boost.fiber
boost.fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperativly. The API contains classes and functions to manage and synchronize fibers similiar to boost.thread.
A fiber is able to store the current execution state, including all registers and CPU flags, the instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple execution paths running on a single thread using a sort of cooperative scheduling (threads are preemptively scheduled) - the running fiber decides explicitly when its yields to allow another fiber to run (context switching).
A context switch between threads costs usally thousends of CPU cycles on x86 compared to a fiber switch with less than 100 cycles. A fiber can only run on a single thread at any point in time.
Buiding: Detailed instructions can be found at https://svn.boost.org/trac/boost/wiki/TryModBoost.
git clone http://github.com/boostorg/boost modular-boost
cd modular-boost
git submodule update --init
cd libs
git clone http://github.com/olk/boost-fiber fiber
cd ..
cmake -P forward_headers.cmake
./bootstrap.sh
cp b2 /usr/local/bin
cd libs/fiber/test
b2