3 * Copyright 2006 Free Software Foundation, Inc.
5 * This file is part of GNU Radio.
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
23 #ifndef _CIRCULAR_BUFFER_H_
24 #define _CIRCULAR_BUFFER_H_
26 #include "mld_threads.h"
31 template <class T> class circular_buffer
37 // the following are in Items (type T)
38 UInt32 d_bufLen_I, d_readNdx_I, d_writeNdx_I;
39 UInt32 d_n_avail_write_I, d_n_avail_read_I;
41 // stuff to control access to class internals
42 mld_mutex_ptr d_internal;
43 mld_condition_ptr d_readBlock, d_writeBlock;
45 // booleans to decide how to control reading, writing, and aborting
46 bool d_doWriteBlock, d_doFullRead, d_doAbort;
48 void delete_mutex_cond () {
64 circular_buffer (UInt32 bufLen_I,
65 bool doWriteBlock = true, bool doFullRead = false) {
67 throw std::runtime_error ("circular_buffer(): "
68 "Number of items to buffer must be > 0.\n");
69 d_bufLen_I = bufLen_I;
70 d_buffer = (T*) new T[d_bufLen_I];
71 d_doWriteBlock = doWriteBlock;
72 d_doFullRead = doFullRead;
74 d_readBlock = d_writeBlock = NULL;
77 fprintf (stderr, "c_b(): buf len (items) = %ld, "
78 "doWriteBlock = %s, doFullRead = %s\n", d_bufLen_I,
79 (d_doWriteBlock ? "true" : "false"),
80 (d_doFullRead ? "true" : "false"));
89 inline UInt32 n_avail_write_items () {
91 UInt32 retVal = d_n_avail_write_I;
92 d_internal->unlock ();
96 inline UInt32 n_avail_read_items () {
98 UInt32 retVal = d_n_avail_read_I;
99 d_internal->unlock ();
103 inline UInt32 buffer_length_items () {return (d_bufLen_I);};
104 inline bool do_write_block () {return (d_doWriteBlock);};
105 inline bool do_full_read () {return (d_doFullRead);};
109 bzero (d_buffer, d_bufLen_I * sizeof (T));
110 d_readNdx_I = d_writeNdx_I = d_n_avail_read_I = 0;
111 d_n_avail_write_I = d_bufLen_I;
112 delete_mutex_cond ();
113 d_internal = new mld_mutex ();
114 d_readBlock = new mld_condition ();
115 d_writeBlock = new mld_condition ();
119 * enqueue: add the given buffer of item-length to the queue,
120 * first-in-first-out (FIFO).
123 * buf: a pointer to the buffer holding the data
125 * bufLen_I: the buffer length in items (of the instantiated type)
128 * -1: on overflow (write is not blocking, and data is being
129 * written faster than it is being read)
130 * 0: if nothing to do (0 length buffer)
132 * 2: in the process of aborting, do doing nothing
134 * will throw runtime errors if inputs are improper:
135 * buffer pointer is NULL
136 * buffer length is larger than the instantiated buffer length
139 int enqueue (T* buf, UInt32 bufLen_I) {
141 fprintf (stderr, "enqueue: buf = %X, bufLen = %ld.\n",
142 (unsigned int)buf, bufLen_I);
144 if (bufLen_I > d_bufLen_I) {
145 fprintf (stderr, "cannot add buffer longer (%ld"
146 ") than instantiated length (%ld"
147 ").\n", bufLen_I, d_bufLen_I);
148 throw std::runtime_error ("circular_buffer::enqueue()");
154 throw std::runtime_error ("circular_buffer::enqueue(): "
155 "input buffer is NULL.\n");
158 d_internal->unlock ();
161 if (bufLen_I > d_n_avail_write_I) {
162 if (d_doWriteBlock) {
163 while (bufLen_I > d_n_avail_write_I) {
165 fprintf (stderr, "enqueue: #len > #a, waiting.\n");
167 d_internal->unlock ();
168 d_writeBlock->wait ();
171 d_internal->unlock ();
173 fprintf (stderr, "enqueue: #len > #a, aborting.\n");
178 fprintf (stderr, "enqueue: #len > #a, done waiting.\n");
182 d_n_avail_read_I = d_bufLen_I - bufLen_I;
183 d_n_avail_write_I = bufLen_I;
185 fprintf (stderr, "circular_buffer::enqueue: overflow\n");
190 UInt32 n_now_I = d_bufLen_I - d_writeNdx_I, n_start_I = 0;
191 if (n_now_I > bufLen_I)
193 else if (n_now_I < bufLen_I)
194 n_start_I = bufLen_I - n_now_I;
195 bcopy (buf, &(d_buffer[d_writeNdx_I]), n_now_I * sizeof (T));
197 bcopy (&(buf[n_now_I]), d_buffer, n_start_I * sizeof (T));
198 d_writeNdx_I = n_start_I;
200 d_writeNdx_I += n_now_I;
201 d_n_avail_read_I += bufLen_I;
202 d_n_avail_write_I -= bufLen_I;
203 d_readBlock->signal ();
204 d_internal->unlock ();
209 * dequeue: removes from the queue the number of items requested, or
210 * available, into the given buffer on a FIFO basis.
213 * buf: a pointer to the buffer into which to copy the data
215 * bufLen_I: pointer to the number of items to remove in items
216 * (of the instantiated type)
219 * 0: if nothing to do (0 length buffer)
221 * 2: in the process of aborting, do doing nothing
223 * will throw runtime errors if inputs are improper:
224 * buffer pointer is NULL
225 * buffer length pointer is NULL
226 * buffer length is larger than the instantiated buffer length
230 int dequeue (T* buf, UInt32* bufLen_I) {
232 fprintf (stderr, "dequeue: buf = %X, *bufLen = %ld.\n",
233 (unsigned int)buf, *bufLen_I);
236 throw std::runtime_error ("circular_buffer::dequeue(): "
237 "input bufLen pointer is NULL.\n");
239 throw std::runtime_error ("circular_buffer::dequeue(): "
240 "input buffer pointer is NULL.\n");
241 UInt32 l_bufLen_I = *bufLen_I;
244 if (l_bufLen_I > d_bufLen_I) {
245 fprintf (stderr, "cannot remove buffer longer (%ld"
246 ") than instantiated length (%ld"
247 ").\n", l_bufLen_I, d_bufLen_I);
248 throw std::runtime_error ("circular_buffer::dequeue()");
253 d_internal->unlock ();
257 while (d_n_avail_read_I < l_bufLen_I) {
259 fprintf (stderr, "dequeue: #a < #len, waiting.\n");
261 d_internal->unlock ();
262 d_readBlock->wait ();
265 d_internal->unlock ();
267 fprintf (stderr, "dequeue: #a < #len, aborting.\n");
272 fprintf (stderr, "dequeue: #a < #len, done waiting.\n");
276 while (d_n_avail_read_I == 0) {
278 fprintf (stderr, "dequeue: #a == 0, waiting.\n");
280 d_internal->unlock ();
281 d_readBlock->wait ();
284 d_internal->unlock ();
286 fprintf (stderr, "dequeue: #a == 0, aborting.\n");
291 fprintf (stderr, "dequeue: #a == 0, done waiting.\n");
295 if (l_bufLen_I > d_n_avail_read_I)
296 l_bufLen_I = d_n_avail_read_I;
297 UInt32 n_now_I = d_bufLen_I - d_readNdx_I, n_start_I = 0;
298 if (n_now_I > l_bufLen_I)
299 n_now_I = l_bufLen_I;
300 else if (n_now_I < l_bufLen_I)
301 n_start_I = l_bufLen_I - n_now_I;
302 bcopy (&(d_buffer[d_readNdx_I]), buf, n_now_I * sizeof (T));
304 bcopy (d_buffer, &(buf[n_now_I]), n_start_I * sizeof (T));
305 d_readNdx_I = n_start_I;
307 d_readNdx_I += n_now_I;
308 *bufLen_I = l_bufLen_I;
309 d_n_avail_read_I -= l_bufLen_I;
310 d_n_avail_write_I += l_bufLen_I;
311 d_writeBlock->signal ();
312 d_internal->unlock ();
319 d_writeBlock->signal ();
320 d_readBlock->signal ();
321 d_internal->unlock ();
325 #endif /* _CIRCULAR_BUFFER_H_ */