source: branches/vtkvis_threaded/ResponseQueue.h @ 2488

#include <pthread.h>
#include <semaphore.h>
#include <list>
#include <stdlib.h>
#include <cstdlib>

#ifndef _RESPONSE_QUEUE_H
#define _RESPONSE_QUEUE_H


class Response {
public:
    typedef enum AllocTypes {
        STATIC, DYNAMIC, VOLATILE
    } AllocationType;
    typedef enum ResponseTypes {
        IMAGE,                          /* Image to be displayed. */
        LEGEND,                         /* Legend to be displayed. */
        DATA                            /* Any other type of message. */
    } ResponseType;
    Response(ResponseType type) {
        _length = 0;
        _type = type;
        _mesg = NULL;
    }
    ResponseType Type(void) {
        return _type;
    }
    unsigned char *Message(void) {
        return _mesg;
    }
    size_t Length(void) {
        return _length;
    }
    ~Response(void) {
        if (_length > 0) {
            if (_allocType == DYNAMIC) {
                free(_mesg);
            }
        }
    }
    void SetMessage(unsigned char *mesg, size_t length, AllocationType type) {
        if (type == VOLATILE) {
            _length = length;
            _mesg = (unsigned char *)malloc(length);
            memcpy(_mesg, mesg, length);
            _allocType = DYNAMIC;
        } else {
            _length = length;
            _mesg = mesg;
            _allocType = type;
        }
    }
private:
    unsigned char *_mesg;               /* (Malloc-ed by caller, freed by
                                         * destructor) Contains the
                                         * message/bytes to be sent to the
                                         * client. */
    size_t _length;                     /* # of bytes in the above message. */
    ResponseType _type;
    AllocationType _allocType;
};

class ResponseQueue {
    pthread_mutex_t _idle;
    sem_t _ready;                       /* Semaphore indicating that a 
                                         * response has been queued. */
    std::list<Response *> _list;
    void *_clientData;

public:
    ResponseQueue(void *clientData);
    ~ResponseQueue(void);
    void *ClientData(void) {
        return _clientData;
    }
    void Enqueue(Response *responsePtr);
    Response *Dequeue();
};

#endif