--- /dev/null
+/* -*- c++ -*- */
+/*
+ * Copyright 2006,2009,2010 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 <gruel/thread.h>
+#include <iostream>
+#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)
+ size_t d_bufLen_I, d_readNdx_I, d_writeNdx_I;
+ size_t d_n_avail_write_I, d_n_avail_read_I;
+
+// stuff to control access to class internals
+ gruel::mutex* d_internal;
+ gruel::condition_variable* d_readBlock;
+ gruel::condition_variable* 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 (size_t 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 (std::cerr << "c_b(): buf len (items) = " << d_bufLen_
+ << ", doWriteBlock = " << (d_doWriteBlock ? "true" : "false")
+ << ", doFullRead = " << (d_doFullRead ? "true" : "false")
+ << std::endl);
+ };
+
+ ~circular_buffer () {
+ delete_mutex_cond ();
+ delete [] d_buffer;
+ };
+
+ inline size_t n_avail_write_items () {
+ gruel::scoped_lock l (*d_internal);
+ size_t retVal = d_n_avail_write_I;
+ return (retVal);
+ };
+
+ inline size_t n_avail_read_items () {
+ gruel::scoped_lock l (*d_internal);
+ size_t retVal = d_n_avail_read_I;
+ return (retVal);
+ };
+
+ inline size_t 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 gruel::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 notify_one() to the condition),
+ // the internal mutex will be lock()'ed.
+ d_readBlock = new gruel::condition_variable ();
+ d_writeBlock = new gruel::condition_variable ();
+ };
+
+/*
+ * 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, size_t bufLen_I) {
+ DEBUG (std::cerr << "enqueue: buf = " << (void*) buf
+ << ", bufLen = " << bufLen_I
+ << ", #av_wr = " << d_n_avail_write_I
+ << ", #av_rd = " << d_n_avail_read_I << std::endl);
+ if (bufLen_I > d_bufLen_I) {
+ std::cerr << "ERROR: cannot add buffer longer ("
+ << bufLen_I << ") than instantiated length ("
+ << d_bufLen_I << ")." << std::endl;
+ 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");
+ gruel::scoped_lock l (*d_internal);
+ if (d_doAbort) {
+ 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 (std::cerr << "enqueue: #len > #a, waiting." << std::endl);
+ // wait; will automatically unlock() the internal mutex via
+ // the scoped lock
+ d_writeBlock->wait (l);
+ // and auto re-lock() it here.
+ if (d_doAbort) {
+ DEBUG (std::cerr << "enqueue: #len > #a, aborting." << std::endl);
+ return (2);
+ }
+ DEBUG (std::cerr << "enqueue: #len > #a, done waiting." << std::endl);
+ }
+ } else {
+ d_n_avail_read_I = d_bufLen_I - bufLen_I;
+ d_n_avail_write_I = bufLen_I;
+ DEBUG (std::cerr << "circular_buffer::enqueue: overflow" << std::endl);
+ retval = -1;
+ }
+ }
+ size_t 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->notify_one ();
+ 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, size_t* bufLen_I) {
+ DEBUG (std::cerr << "dequeue: buf = " << ((void*) buf)
+ << ", *bufLen = " << (*bufLen_I)
+ << ", #av_wr = " << d_n_avail_write_I
+ << ", #av_rd = " << d_n_avail_read_I << std::endl);
+ 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");
+ size_t l_bufLen_I = *bufLen_I;
+ if (l_bufLen_I == 0)
+ return (0);
+ if (l_bufLen_I > d_bufLen_I) {
+ std::cerr << "ERROR: cannot remove buffer longer ("
+ << l_bufLen_I << ") than instantiated length ("
+ << d_bufLen_I << ")." << std::endl;
+ throw std::runtime_error ("circular_buffer::dequeue()");
+ }
+
+ gruel::scoped_lock l (*d_internal);
+ if (d_doAbort) {
+ return (2);
+ }
+ if (d_doFullRead) {
+ while (d_n_avail_read_I < l_bufLen_I) {
+ DEBUG (std::cerr << "dequeue: #a < #len, waiting." << std::endl);
+ // wait; will automatically unlock() the internal mutex via
+ // the scoped lock
+ d_readBlock->wait (l);
+ // and re-lock() it here.
+ if (d_doAbort) {
+ DEBUG (std::cerr << "dequeue: #a < #len, aborting." << std::endl);
+ return (2);
+ }
+ DEBUG (std::cerr << "dequeue: #a < #len, done waiting." << std::endl);
+ }
+ } else {
+ while (d_n_avail_read_I == 0) {
+ DEBUG (std::cerr << "dequeue: #a == 0, waiting." << std::endl);
+ // wait; will automatically unlock() the internal mutex via
+ // the scoped lock
+ d_readBlock->wait (l);
+ // and re-lock() it here.
+ if (d_doAbort) {
+ DEBUG (std::cerr << "dequeue: #a == 0, aborting." << std::endl);
+ return (2);
+ }
+ DEBUG (std::cerr << "dequeue: #a == 0, done waiting." << std::endl);
+ }
+ }
+ if (l_bufLen_I > d_n_avail_read_I)
+ l_bufLen_I = d_n_avail_read_I;
+ size_t 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->notify_one ();
+ return (1);
+ };
+
+ void abort () {
+ gruel::scoped_lock l (*d_internal);
+ d_doAbort = true;
+ d_writeBlock->notify_one ();
+ d_readBlock->notify_one ();
+ };
+};
+
+#endif /* _CIRCULAR_BUFFER_H_ */
projects / debian / gnuradio / blobdiff