.. _program_listing_file_semaphore.c:

Program Listing for File semaphore.c
====================================

|exhale_lsh| :ref:`Return to documentation for file <file_semaphore.c>` (``semaphore.c``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #include <string.h>
   #include "netio/netio.h"
   
   
   static void
   check_and_trigger(struct netio_semaphore* sem)
   {
     if(sem->threshold > 0 && sem->current >= sem->threshold) {
       if(sem->cb) {
         sem->cb(sem->data);
       }
       sem->threshold = 0; // semaphores only fire once
     }
   }
   
   void netio_semaphore_init(struct netio_semaphore* sem, unsigned threshold)
   {
     memset(sem, 0, sizeof(*sem));
     sem->threshold = threshold;
     sem->current = 0;
   }
   
   
   void netio_semaphore_increment(struct netio_semaphore* sem, unsigned n)
   {
     sem->current += n;
     check_and_trigger(sem);
   }
   
   
   void netio_semphore_set_threshold(struct netio_semaphore* sem, unsigned t)
   {
     sem->threshold = t;
     check_and_trigger(sem);
   }