## NAME

ACE_Token_Manager - Manages all tokens in a process space.

## SYNOPSIS

    #include <ace/Token_Manager.h>

    class ACE_Token_Manager : public ACE_Cleanup
    {
      public:
        ACE_Token_Manager (void);
        virtual ~ACE_Token_Manager (void);
        static ACE_Token_Manager *instance (void);
        void instance (ACE_Token_Manager *);
        void get_token (ACE_Token_Proxy *, const ASYS_TCHAR *token_name);
        int check_deadlock (ACE_Token_Proxy *proxy);
        int check_deadlock (ACE_Tokens *token, ACE_Token_Proxy *proxy);
        void release_token (ACE_Tokens *&token);
        ACE_TOKEN_CONST::MUTEX &mutex (void);
        void dump (void) const;
        void debug (int d);
      private:
        int debug_;
        static ACE_Token_Manager *token_manager_;
        ACE_Tokens *token_waiting_for (const ASYS_TCHAR *client_id);
        ACE_TOKEN_CONST::MUTEX lock_;
        typedef ACE_Token_Name TOKEN_NAME;
            typedef ACE_Map_Manager<TOKEN_NAME, ACE_Tokens *, ACE_Null_Mutex> COLLECTION;

            typedef ACE_Map_Iterator<TOKEN_NAME, ACE_Tokens *, ACE_Null_Mutex> COLLECTION_ITERATOR;

        typedef ACE_Map_Entry<TOKEN_NAME, ACE_Tokens *> COLLECTION_ENTRY;
        COLLECTION collection_;
    };

## DESCRIPTION

Factory: Proxies use the token manager to obtain token references. This allows multiple proxies to reference the same logical token. Deadlock detection: Tokens use the manager to check for deadlock situations during acquires.

## PUBLIC MEMBERS

    ACE_Token_Manager (void);

    virtual ~ACE_Token_Manager (void);

    static ACE_Token_Manager *instance (void);

    void instance (ACE_Token_Manager *);

    void get_token (ACE_Token_Proxy *, const ASYS_TCHAR *token_name);

The Token manager uses ACE_Token_Proxy::token_id_ to look for an existing token. If none is found, the Token Manager calls ACE_Token_Proxy::create_token to create a new one. When finished, sets ACE_Token_Proxy::token_. `token_name` uniquely id's the token name.

    int check_deadlock (ACE_Token_Proxy *proxy);

    int check_deadlock (ACE_Tokens *token, ACE_Token_Proxy *proxy);

returns 1 if the acquire will _not_ cause deadlock. returns 0 if the acquire _will_ cause deadlock. this method ignores recursive acquisition. That is, it will not report deadlock if the client holding the token requests the token again. Thus, it assumes recursive mutexes.

    void release_token (ACE_Tokens *&token);

notify the token manager that a token has been released. If as a result, there is no owner of the token, the token is deleted.

    ACE_TOKEN_CONST::MUTEX &mutex (void);

This is to allow Tokens to perform atomic transactions. The typical usage is to acquire this mutex, check for a safe_acquire, perform some queueing (if need be) and then release the lock. This is necessary since safe_acquire is implemented in terms of the Token queues.

    void dump (void) const;

Dump the state of the class.

    void debug (int d);

Turn debug mode on/off.

## PRIVATE MEMBERS

    int debug_;

Whether to print debug messages or not.

    static ACE_Token_Manager *token_manager_;

pointer to singleton token manager.

    ACE_Tokens *token_waiting_for (const ASYS_TCHAR *client_id);

return the token that the given client_id is waiting for, if any

    ACE_TOKEN_CONST::MUTEX lock_;

ACE_Mutex_Token used to lock internal data structures.

    typedef ACE_Token_Name TOKEN_NAME;

This may be changed to a template type.

        typedef ACE_Map_Manager<TOKEN_NAME, ACE_Tokens *, ACE_Null_Mutex> COLLECTION;

COLLECTION maintains a mapping from token names to ACE_Tokens*

        typedef ACE_Map_Iterator<TOKEN_NAME, ACE_Tokens *, ACE_Null_Mutex> COLLECTION_ITERATOR;

Allows iterations through collection_

    typedef ACE_Map_Entry<TOKEN_NAME, ACE_Tokens *> COLLECTION_ENTRY;

Allows iterations through collection_

    COLLECTION collection_;

COLLECTION maintains a mapping from token names to ACE_Tokens*.

## AUTHOR

Tim Harrison (harrison@cs.wustl.edu)

## LIBRARY

ace