th3or14/semaphore

Strong semaphore implementation by means of the C++14 Standard Template Library

Features

• Fairness is guaranteed by the ticket lock algorithm (i.e., FIFO order). It prevents a thread from being starved out of execution for a long time due to inability to pass through a semaphore in favor of other threads.

• Instead of just setting the initial resource count value of a counting semaphore you are allowed to adjust the limit of passing threads.

• A queue of condition variables is used for the sake of waking up one certain thread using notify_one() instead of waking up all the threads using notify_all() in case of one condition variable. Benchmarks registered performance boost against the implementation based on one condition variable. Thus it looks like using an extra queue is reasonable.

Requirements

• CMake

• A C++14 compliant compiler

Building

Use CMakeLists.txt.