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/* -*- c++ -*- */
/*
* Copyright 2006 Free Software Foundation, Inc.
*
* This file is part of GNU Radio.
*
* GNU Radio 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 3, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef _CIRCULAR_BUFFER_H_
#define _CIRCULAR_BUFFER_H_
#include "mld_threads.h"
#include <stdexcept>
#ifndef DO_DEBUG
#define DO_DEBUG 0
#endif
#if DO_DEBUG
#define DEBUG(X) do{X} while(0);
#else
#define DEBUG(X) do{} while(0);
#endif
template <class T> class circular_buffer
{
private:
// the buffer to use
T* d_buffer;
// the following are in Items (type T)
UInt32 d_bufLen_I, d_readNdx_I, d_writeNdx_I;
UInt32 d_n_avail_write_I, d_n_avail_read_I;
// stuff to control access to class internals
mld_mutex_ptr d_internal;
mld_condition_ptr d_readBlock, d_writeBlock;
// booleans to decide how to control reading, writing, and aborting
bool d_doWriteBlock, d_doFullRead, d_doAbort;
void delete_mutex_cond () {
if (d_internal) {
delete d_internal;
d_internal = NULL;
}
if (d_readBlock) {
delete d_readBlock;
d_readBlock = NULL;
}
if (d_writeBlock) {
delete d_writeBlock;
d_writeBlock = NULL;
}
};
public:
circular_buffer (UInt32 bufLen_I,
bool doWriteBlock = true, bool doFullRead = false) {
if (bufLen_I == 0)
throw std::runtime_error ("circular_buffer(): "
"Number of items to buffer must be > 0.\n");
d_bufLen_I = bufLen_I;
d_buffer = (T*) new T[d_bufLen_I];
d_doWriteBlock = doWriteBlock;
d_doFullRead = doFullRead;
d_internal = NULL;
d_readBlock = d_writeBlock = NULL;
reset ();
DEBUG (fprintf (stderr, "c_b(): buf len (items) = %ld, "
"doWriteBlock = %s, doFullRead = %s\n", d_bufLen_I,
(d_doWriteBlock ? "true" : "false"),
(d_doFullRead ? "true" : "false")););
};
~circular_buffer () {
delete_mutex_cond ();
delete [] d_buffer;
};
inline UInt32 n_avail_write_items () {
d_internal->lock ();
UInt32 retVal = d_n_avail_write_I;
d_internal->unlock ();
return (retVal);
};
inline UInt32 n_avail_read_items () {
d_internal->lock ();
UInt32 retVal = d_n_avail_read_I;
d_internal->unlock ();
return (retVal);
};
inline UInt32 buffer_length_items () {return (d_bufLen_I);};
inline bool do_write_block () {return (d_doWriteBlock);};
inline bool do_full_read () {return (d_doFullRead);};
void reset () {
d_doAbort = false;
bzero (d_buffer, d_bufLen_I * sizeof (T));
d_readNdx_I = d_writeNdx_I = d_n_avail_read_I = 0;
d_n_avail_write_I = d_bufLen_I;
delete_mutex_cond ();
// create a mutex to handle contention of shared resources;
// any routine needed access to shared resources uses lock()
// before doing anything, then unlock() when finished.
d_internal = new mld_mutex ();
// link the internal mutex to the read and write conditions;
// when wait() is called, the internal mutex will automatically
// be unlock()'ed. Upon return (from a signal() to the condition),
// the internal mutex will be lock()'ed.
d_readBlock = new mld_condition (d_internal);
d_writeBlock = new mld_condition (d_internal);
};
/*
* enqueue: add the given buffer of item-length to the queue,
* first-in-first-out (FIFO).
*
* inputs:
* buf: a pointer to the buffer holding the data
*
* bufLen_I: the buffer length in items (of the instantiated type)
*
* returns:
* -1: on overflow (write is not blocking, and data is being
* written faster than it is being read)
* 0: if nothing to do (0 length buffer)
* 1: if success
* 2: in the process of aborting, do doing nothing
*
* will throw runtime errors if inputs are improper:
* buffer pointer is NULL
* buffer length is larger than the instantiated buffer length
*/
int enqueue (T* buf, UInt32 bufLen_I) {
DEBUG (fprintf (stderr, "enqueue: buf = %X, bufLen = %ld, #av_wr = %ld, "
"#av_rd = %ld.\n", (unsigned int)buf, bufLen_I,
d_n_avail_write_I, d_n_avail_read_I););
if (bufLen_I > d_bufLen_I) {
fprintf (stderr, "cannot add buffer longer (%ld"
") than instantiated length (%ld"
").\n", bufLen_I, d_bufLen_I);
throw std::runtime_error ("circular_buffer::enqueue()");
}
if (bufLen_I == 0)
return (0);
if (!buf)
throw std::runtime_error ("circular_buffer::enqueue(): "
"input buffer is NULL.\n");
d_internal->lock ();
if (d_doAbort) {
d_internal->unlock ();
return (2);
}
// set the return value to 1: success; change if needed
int retval = 1;
if (bufLen_I > d_n_avail_write_I) {
if (d_doWriteBlock) {
while (bufLen_I > d_n_avail_write_I) {
DEBUG (fprintf (stderr, "enqueue: #len > #a, waiting.\n"););
// wait will automatically unlock() the internal mutex
d_writeBlock->wait ();
// and lock() it here.
if (d_doAbort) {
d_internal->unlock ();
DEBUG (fprintf (stderr, "enqueue: #len > #a, aborting.\n"););
return (2);
}
DEBUG (fprintf (stderr, "enqueue: #len > #a, done waiting.\n"););
}
} else {
d_n_avail_read_I = d_bufLen_I - bufLen_I;
d_n_avail_write_I = bufLen_I;
DEBUG (fprintf (stderr, "circular_buffer::enqueue: overflow\n"););
retval = -1;
}
}
UInt32 n_now_I = d_bufLen_I - d_writeNdx_I, n_start_I = 0;
if (n_now_I > bufLen_I)
n_now_I = bufLen_I;
else if (n_now_I < bufLen_I)
n_start_I = bufLen_I - n_now_I;
bcopy (buf, &(d_buffer[d_writeNdx_I]), n_now_I * sizeof (T));
if (n_start_I) {
bcopy (&(buf[n_now_I]), d_buffer, n_start_I * sizeof (T));
d_writeNdx_I = n_start_I;
} else
d_writeNdx_I += n_now_I;
d_n_avail_read_I += bufLen_I;
d_n_avail_write_I -= bufLen_I;
d_readBlock->signal ();
d_internal->unlock ();
return (retval);
};
/*
* dequeue: removes from the queue the number of items requested, or
* available, into the given buffer on a FIFO basis.
*
* inputs:
* buf: a pointer to the buffer into which to copy the data
*
* bufLen_I: pointer to the number of items to remove in items
* (of the instantiated type)
*
* returns:
* 0: if nothing to do (0 length buffer)
* 1: if success
* 2: in the process of aborting, do doing nothing
*
* will throw runtime errors if inputs are improper:
* buffer pointer is NULL
* buffer length pointer is NULL
* buffer length is larger than the instantiated buffer length
*/
int dequeue (T* buf, UInt32* bufLen_I) {
DEBUG (fprintf (stderr, "dequeue: buf = %X, *bufLen = %ld, #av_wr = %ld, "
"#av_rd = %ld.\n", (unsigned int)buf, *bufLen_I,
d_n_avail_write_I, d_n_avail_read_I););
if (!bufLen_I)
throw std::runtime_error ("circular_buffer::dequeue(): "
"input bufLen pointer is NULL.\n");
if (!buf)
throw std::runtime_error ("circular_buffer::dequeue(): "
"input buffer pointer is NULL.\n");
UInt32 l_bufLen_I = *bufLen_I;
if (l_bufLen_I == 0)
return (0);
if (l_bufLen_I > d_bufLen_I) {
fprintf (stderr, "cannot remove buffer longer (%ld"
") than instantiated length (%ld"
").\n", l_bufLen_I, d_bufLen_I);
throw std::runtime_error ("circular_buffer::dequeue()");
}
d_internal->lock ();
if (d_doAbort) {
d_internal->unlock ();
return (2);
}
if (d_doFullRead) {
while (d_n_avail_read_I < l_bufLen_I) {
DEBUG (fprintf (stderr, "dequeue: #a < #len, waiting.\n"););
// wait will automatically unlock() the internal mutex
d_readBlock->wait ();
// and lock() it here.
if (d_doAbort) {
d_internal->unlock ();
DEBUG (fprintf (stderr, "dequeue: #a < #len, aborting.\n"););
return (2);
}
DEBUG (fprintf (stderr, "dequeue: #a < #len, done waiting.\n"););
}
} else {
while (d_n_avail_read_I == 0) {
DEBUG (fprintf (stderr, "dequeue: #a == 0, waiting.\n"););
// wait will automatically unlock() the internal mutex
d_readBlock->wait ();
// and lock() it here.
if (d_doAbort) {
d_internal->unlock ();
DEBUG (fprintf (stderr, "dequeue: #a == 0, aborting.\n"););
return (2);
}
DEBUG (fprintf (stderr, "dequeue: #a == 0, done waiting.\n"););
}
}
if (l_bufLen_I > d_n_avail_read_I)
l_bufLen_I = d_n_avail_read_I;
UInt32 n_now_I = d_bufLen_I - d_readNdx_I, n_start_I = 0;
if (n_now_I > l_bufLen_I)
n_now_I = l_bufLen_I;
else if (n_now_I < l_bufLen_I)
n_start_I = l_bufLen_I - n_now_I;
bcopy (&(d_buffer[d_readNdx_I]), buf, n_now_I * sizeof (T));
if (n_start_I) {
bcopy (d_buffer, &(buf[n_now_I]), n_start_I * sizeof (T));
d_readNdx_I = n_start_I;
} else
d_readNdx_I += n_now_I;
*bufLen_I = l_bufLen_I;
d_n_avail_read_I -= l_bufLen_I;
d_n_avail_write_I += l_bufLen_I;
d_writeBlock->signal ();
d_internal->unlock ();
return (1);
};
void abort () {
d_internal->lock ();
d_doAbort = true;
d_writeBlock->signal ();
d_readBlock->signal ();
d_internal->unlock ();
};
};
#endif /* _CIRCULAR_BUFFER_H_ */
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