ACE_Message_Queue_Vx(3)

NAME

ACE_Message_Queue_Vx - Wrapper for VxWorks message queues.

SYNOPSIS

#include <ace/Message_Queue.h>
class ACE_Message_Queue_Vx : public ACE_Message_Queue<ACE_NULL_SYNCH>
{
  public:
    ACE_Message_Queue_Vx (
        size_t max_messages,
        size_t max_message_length,
        ACE_Notification_Strategy * = 0
        );
    virtual int open (
        size_t max_messages,
        size_t max_message_length,
        ACE_Notification_Strategy * = 0
        );
    virtual int close (void);
    virtual ~ACE_Message_Queue_Vx (void);
    virtual size_t message_bytes (void);
    virtual size_t message_length (void);
    virtual size_t message_count (void);
    virtual void message_bytes (size_t new_size);
    virtual void message_length (size_t new_length);
    virtual size_t high_water_mark (void);
    virtual void high_water_mark (size_t hwm);
    virtual size_t low_water_mark (void);
    virtual void low_water_mark (size_t lwm);
    void dump (void) const;
    ACE_ALLOC_HOOK_DECLARE;
  protected:
    virtual int enqueue_i (ACE_Message_Block *new_item);
    virtual int enqueue_tail_i (ACE_Message_Block *new_item);
    virtual int enqueue_head_i (ACE_Message_Block *new_item);
    virtual int dequeue_head_i (ACE_Message_Block *&first_item);
    virtual int is_full_i (void);
    virtual int is_empty_i (void);
    virtual int deactivate_i (void);
    virtual int activate_i (void);
    virtual int wait_not_full_cond (
        ACE_Guard<ACE_Null_Mutex> &mon,
        ACE_Time_Value *tv
        );
    virtual int wait_not_empty_cond (
        ACE_Guard<ACE_Null_Mutex> &mon,
        ACE_Time_Value *tv
        );
    virtual int signal_enqueue_waiters (void);
    virtual int signal_dequeue_waiters (void);
    MSG_Q_ID msgq (void);
  private:
    int max_messages_;
    int max_message_length_;
    int options_;
    inline ACE_UNIMPLEMENTED_FUNC (
        void operator= (const ACE_Message_Queue_Vx &)
        );
    inline ACE_UNIMPLEMENTED_FUNC (
        virtual int peek_dequeue_head(ACE_Message_Block *&first_item,
        ACE_Time_Value *tv = 0)
        );
};

DESCRIPTION

Specialization of ACE_Message_Queue to simply wrap VxWorks MsgQ. It does not use any synchronization, because it relies on the native MsgQ implementation to take care of that. The only system calls that it uses are VxWorks msgQLib calls, so it is suitable for use in interrupt service routines.

NOTE: *Many* ACE_Message_Queue features are not supported with this specialization, including: * The two size arguments to the constructor and open are
interpreted differently. The first is interpreted as the
maximum number of bytes in a message. The second is
interpreted as the maximum number of messages that can be
queued. * dequeue_head *requires* that the ACE_Message_Block
pointer argument point to an ACE_Message_Block that was
allocated by the caller. It must be big enough to support
the received message, without using continutation. The
pointer argument is not modified. * Message priority. MSG_Q_FIFO is hard-coded. * enqueue method timeouts. * peek_dequeue_head. * ACE_Message_Queue_Iterators. * The ability to change low and high water marks after creation. * Message_Block chains. The continuation field of ACE_Message_Block * is ignored; only the first block of a fragment chain is * recognized.

Initialization and termination methods.

ACE_Message_Queue_Vx (
    size_t max_messages,
    size_t max_message_length,
    ACE_Notification_Strategy * = 0
    );

Create a message queue with all the defaults.

virtual int open (
    size_t max_messages,
    size_t max_message_length,
    ACE_Notification_Strategy * = 0
    );

virtual int close (void);

virtual ~ACE_Message_Queue_Vx (void);

Queue statistic methods.

virtual size_t message_bytes (void);

virtual size_t message_length (void);

virtual size_t message_count (void);

Manual changes to these stats (used when queued message blocks

change size or lengths).

virtual void message_bytes (size_t new_size);

virtual void message_length (size_t new_length);

Flow control routines

virtual size_t high_water_mark (void);

virtual void high_water_mark (size_t hwm);

virtual size_t low_water_mark (void);

virtual void low_water_mark (size_t lwm);

Activation control methods.

void dump (void) const;

ACE_ALLOC_HOOK_DECLARE;

Check the boundary conditions (assumes locks are held).

virtual int is_full_i (void);

virtual int is_empty_i (void);

= Implementation of public activate/deactivate methods above. These methods assume locks are held.

virtual int deactivate_i (void);

virtual int activate_i (void);

Helper methods to factor out common #ifdef code.

virtual int wait_not_full_cond (
    ACE_Guard<ACE_Null_Mutex> &mon,
    ACE_Time_Value *tv
    );

virtual int wait_not_empty_cond (
    ACE_Guard<ACE_Null_Mutex> &mon,
    ACE_Time_Value *tv
    );

virtual int signal_enqueue_waiters (void);

virtual int signal_dequeue_waiters (void);

MSG_Q_ID msgq (void);

Disallow these operations.

inline ACE_UNIMPLEMENTED_FUNC (
    void operator= (const ACE_Message_Queue_Vx &)
    );

inline ACE_UNIMPLEMENTED_FUNC (
    virtual int peek_dequeue_head(ACE_Message_Block *&first_item,
    ACE_Time_Value *tv = 0)
    );

AUTHOR

Doug Schmidt

LIBRARY

ace