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Class interprocess_semaphore

boost::interprocess::interprocess_semaphore

Synopsis

// In header: <boost/interprocess/sync/interprocess_semaphore.hpp>


class interprocess_semaphore {
public:
  // construct/copy/destruct
  interprocess_semaphore(int);
  ~interprocess_semaphore();

  // public member functions
  void post() ;
  void wait() ;
  bool try_wait() ;
  bool timed_wait(const boost::posix_time::ptime &) ;
};

Description

Wraps a interprocess_semaphore that can be placed in shared memory and can be shared between processes. Allows timed lock tries

interprocess_semaphore public construct/copy/destruct

  1. interprocess_semaphore(int initialCount);

    Creates a interprocess_semaphore with the given initial count. interprocess_exception if there is an error.

  2. ~interprocess_semaphore();

    Destroys the interprocess_semaphore. Does not throw

interprocess_semaphore public member functions

  1. void post() ;

    Increments the interprocess_semaphore count. If there are processes/threads blocked waiting for the interprocess_semaphore, then one of these processes will return successfully from its wait function. If there is an error an interprocess_exception exception is thrown.

  2. void wait() ;

    Decrements the interprocess_semaphore. If the interprocess_semaphore value is not greater than zero, then the calling process/thread blocks until it can decrement the counter. If there is an error an interprocess_exception exception is thrown.

  3. bool try_wait() ;

    Decrements the interprocess_semaphore if the interprocess_semaphore's value is greater than zero and returns true. If the value is not greater than zero returns false. If there is an error an interprocess_exception exception is thrown.

  4. bool timed_wait(const boost::posix_time::ptime & abs_time) ;

    Decrements the interprocess_semaphore if the interprocess_semaphore's value is greater than zero and returns true. Otherwise, waits for the interprocess_semaphore to the posted or the timeout expires. If the timeout expires, the function returns false. If the interprocess_semaphore is posted the function returns true. If there is an error throws sem_exception


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