ACE_Future_Rep(3)

NAME

ACE_Future_Rep - ACE_Future_RepT

SYNOPSIS

#include <ace/Future.h>
template<class T>
class ACE_Future_Rep
{
  private:
    friend class ACE_Future<T>;
    int set (const T &r, ACE_Future<T> &caller);
    int get (T &value, ACE_Time_Value *tv);
    int attach (
        ACE_Future_Observer<T> *observer,
        ACE_Future<T> &caller
        );
    int detach (ACE_Future_Observer<T> *observer);
    operator T ();
    void dump (void) const;
    ACE_ALLOC_HOOK_DECLARE;
    static ACE_Future_Rep<T> *create (void);
    static ACE_Future_Rep<T> *attach (ACE_Future_Rep<T> *&rep);
    static void detach (ACE_Future_Rep<T> *&rep);
    static void assign (
        ACE_Future_Rep<T> *&rep,
        ACE_Future_Rep<T> *new_rep
        );
    int ready (void);
    T *value_;
    int ref_count_;
    typedef ACE_Future_Observer<T> OBSERVER;
    typedef ACE_Unbounded_Set<OBSERVER *> OBSERVER_COLLECTION;
    OBSERVER_COLLECTION observer_collection_;
    ACE_Condition_Thread_Mutex value_ready_;
    ACE_Thread_Mutex value_ready_mutex_;
    ACE_Future_Rep (void);
    ~ACE_Future_Rep (void);
};

DESCRIPTION

An ACE_Future_RepT object encapsules a pointer to an object of class T which is the result of an asynchronous method invocation. It is pointed to by ACE_FutureT object[s] and only accessible through them.

Encapsulate reference count and object lifetime of instances.

These methods must go after the others to work around a bug with Borland's C++ Builder...

static ACE_Future_Rep<T> *create (void);

Create a ACE_Future_RepT and initialize the reference count.

static ACE_Future_Rep<T> *attach (ACE_Future_Rep<T> *&rep);

Increase the reference count and return argument. Uses the attribute "value_ready_mutex_" to synchronize reference count updating.

Precondition (rep != 0).

static void detach (ACE_Future_Rep<T> *&rep);

Decreases the reference count and and deletes rep if there are no more references to rep.

Precondition (rep != 0)

static void assign (
    ACE_Future_Rep<T> *&rep,
    ACE_Future_Rep<T> *new_rep
    );

Decreases the rep's reference count and and deletes rep if there are no more references to rep. Then assigns new_rep to rep.

Precondition (rep != 0 && new_rep != 0)

int ready (void);

Is result available?

T *value_;

Pointer to the result.

int ref_count_;

Reference count.

typedef ACE_Future_Observer<T> OBSERVER;

typedef ACE_Unbounded_Set<OBSERVER *> OBSERVER_COLLECTION;

OBSERVER_COLLECTION observer_collection_;

Keep a list of ACE_Future_Observers unread by client's reader thread.

= Condition variable and mutex that protect the value_.

ACE_Condition_Thread_Mutex value_ready_;

ACE_Thread_Mutex value_ready_mutex_;

Constructor and destructor private.

ACE_Future_Rep (void);

~ACE_Future_Rep (void);

AUTHOR (S)

Andres Kruse [email protected], Douglas C. Schmidt [email protected], Per Andersson [email protected], and John Tucker [email protected]

LIBRARY

ace