buffer.h

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// Copyright (C) 1999-2005 Open Source Telecom Corporation.
// Copyright (C) 2006-2010 David Sugar, Tycho Softworks.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// This exception applies only to the code released under the name GNU
// Common C++.  If you copy code from other releases into a copy of GNU
// Common C++, as the General Public License permits, the exception does
// not apply to the code that you add in this way.  To avoid misleading
// anyone as to the status of such modified files, you must delete
// this exception notice from them.
//
// If you write modifications of your own for GNU Common C++, it is your choice
// whether to permit this exception to apply to your modifications.
// If you do not wish that, delete this exception notice.
//

#ifndef CCXX_BUFFER_H_
#define CCXX_BUFFER_H_

#ifndef CCXX_THREAD_H_
#include <cc++/thread.h>
#endif
#ifndef CCXX_STRING_H_
#include <cc++/string.h>
#endif
#ifdef  CCXX_NAMESPACES
namespace ost {
#endif

#ifdef  WIN32
class __EXPORT Buffer : public Mutex
#else
class __EXPORT Buffer : public Conditional
#endif
{
private:
#ifdef  WIN32
    HANDLE  sem_head, sem_tail;
#endif
    size_t _size;
    size_t _used;

protected:
    virtual size_t onPeek(void *buf) = 0;

    virtual size_t onWait(void *buf) = 0;

    virtual size_t onPost(void *buf) = 0;

public:
    static const size_t timeout;

    Buffer(size_t capacity);
    virtual ~Buffer();

    inline size_t getSize(void)
        {return _size;};

    inline size_t getUsed(void)
        {return _used;};

    size_t wait(void *buf, timeout_t timeout = 0);

    size_t post(void *buf, timeout_t timeout = 0);

    size_t peek(void *buf);

    virtual bool isValid(void);
};

class __EXPORT FixedBuffer : public Buffer
{
private:
    char *buf, *head, *tail;
    size_t objsize;

protected:
    size_t onPeek(void *buf);

    size_t onWait(void *buf);

    size_t onPost(void *buf);

public:
    FixedBuffer(size_t capacity, size_t objsize);

    FixedBuffer(const FixedBuffer &fb);

    virtual ~FixedBuffer();

    FixedBuffer &operator=(const FixedBuffer &fb);

    bool isValid(void);
};

class __EXPORT ThreadQueue : public Mutex, public Thread, public Semaphore
{
private:
    void run(void);         // private run method

protected:
    typedef struct _data {
        struct _data *next;
        unsigned len;
        char data[1];
    }   data_t;

    timeout_t timeout;
    bool started;

    data_t *first, *last;       // head/tail of list

    String name;

    /*
     * Overloading of final(). It demarks Semaphore to avoid deadlock.
     */
    virtual void final();

    virtual void startQueue(void);

    virtual void stopQueue(void);

    virtual void onTimer(void);

    virtual void runQueue(void *data) = 0;

public:
    ThreadQueue(const char *id, int pri, size_t stack = 0);

    virtual ~ThreadQueue();

    void setTimer(timeout_t timeout);

    void post(const void *data, unsigned len);
};


inline size_t get(Buffer &b, void *o, timeout_t t = 0)
    {return b.wait(o, t);}

inline size_t put(Buffer &b, void *o, timeout_t t = 0)
    {return b.post(o, t);}

inline size_t peek(Buffer &b, void *o)
    {return b.peek(o);}


#ifdef  CCXX_NAMESPACES
}
#endif

#endif