changeset be3b60b52b31 in /z/repo/gem5
details: http://repo.gem5.org/gem5?cmd=changeset;node=be3b60b52b31
description:
base: Rewrite the CircleBuf to fix bugs and add serialization
The CircleBuf class has at least one bug causing it to overwrite the
wrong elements when wrapping. The current code has a lot of unused
functionality and duplicated code. This changeset replaces the old
implementation with a new version that supports serialization and
arbitrary types in the buffer (not just char).
diffstat:
src/base/SConscript | 1 -
src/base/circlebuf.cc | 215 -----------------------------------
src/base/circlebuf.hh | 276 ++++++++++++++++++++++++++++++++++++++++----
src/dev/terminal.cc | 12 +-
src/dev/terminal.hh | 6 +-
src/unittest/SConscript | 2 +-
src/unittest/circlebuf.cc | 122 +++++++++++++++++++
src/unittest/circletest.cc | 76 ------------
8 files changed, 382 insertions(+), 328 deletions(-)
diffs (truncated from 801 to 300 lines):
diff -r 179bc8ca2d8c -r be3b60b52b31 src/base/SConscript
--- a/src/base/SConscript Fri Aug 07 09:59:15 2015 +0100
+++ b/src/base/SConscript Fri Aug 07 09:59:19 2015 +0100
@@ -37,7 +37,6 @@
Source('bigint.cc')
Source('bitmap.cc')
Source('callback.cc')
-Source('circlebuf.cc')
Source('cprintf.cc')
Source('debug.cc')
if env['USE_FENV']:
diff -r 179bc8ca2d8c -r be3b60b52b31 src/base/circlebuf.cc
--- a/src/base/circlebuf.cc Fri Aug 07 09:59:15 2015 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,215 +0,0 @@
-/*
- * Copyright (c) 2002-2005 The Regents of The University of Michigan
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors: Nathan Binkert
- */
-
-#include <algorithm>
-#include <cstdio>
-#include <cstring>
-#include <string>
-
-#include "base/atomicio.hh"
-#include "base/circlebuf.hh"
-#include "base/cprintf.hh"
-#include "base/intmath.hh"
-
-using namespace std;
-
-CircleBuf::CircleBuf(int l)
- : _rollover(false), _buflen(l), _size(0), _start(0), _stop(0)
-{
- _buf = new char[_buflen];
-}
-
-CircleBuf::~CircleBuf()
-{
- if (_buf)
- delete [] _buf;
-}
-
-void
-CircleBuf::dump()
-{
- cprintf("start = %10d, stop = %10d, buflen = %10d\n",
- _start, _stop, _buflen);
- fflush(stdout);
- atomic_write(STDOUT_FILENO, _buf, _buflen);
- atomic_write(STDOUT_FILENO, "<\n", 2);
-}
-
-void
-CircleBuf::flush()
-{
- _start = 0;
- _stop = 0;
- _size = 0;
- _rollover = false;
-}
-
-void
-CircleBuf::read(char *b, int len)
-{
- _size -= len;
- if (_size < 0)
- _size = 0;
-
- if (_stop > _start) {
- len = min(len, _stop - _start);
- memcpy(b, _buf + _start, len);
- _start += len;
- }
- else {
- int endlen = _buflen - _start;
- if (endlen > len) {
- memcpy(b, _buf + _start, len);
- _start += len;
- }
- else {
- memcpy(b, _buf + _start, endlen);
- _start = min(len - endlen, _stop);
- memcpy(b + endlen, _buf, _start);
- }
- }
-}
-
-void
-CircleBuf::read(int fd, int len)
-{
- _size -= len;
- if (_size < 0)
- _size = 0;
-
- if (_stop > _start) {
- len = min(len, _stop - _start);
- atomic_write(fd, _buf + _start, len);
- _start += len;
- }
- else {
- int endlen = _buflen - _start;
- if (endlen > len) {
- atomic_write(fd, _buf + _start, len);
- _start += len;
- }
- else {
- atomic_write(fd, _buf + _start, endlen);
- _start = min(len - endlen, _stop);
- atomic_write(fd, _buf, _start);
- }
- }
-}
-
-void
-CircleBuf::read(int fd)
-{
- _size = 0;
-
- if (_stop > _start) {
- atomic_write(fd, _buf + _start, _stop - _start);
- }
- else {
- atomic_write(fd, _buf + _start, _buflen - _start);
- atomic_write(fd, _buf, _stop);
- }
-
- _start = _stop;
-}
-
-void
-CircleBuf::read(ostream &out)
-{
- _size = 0;
-
- if (_stop > _start) {
- out.write(_buf + _start, _stop - _start);
- }
- else {
- out.write(_buf + _start, _buflen - _start);
- out.write(_buf, _stop);
- }
-
- _start = _stop;
-}
-
-void
-CircleBuf::readall(int fd)
-{
- if (_rollover)
- atomic_write(fd, _buf + _stop, _buflen - _stop);
-
- atomic_write(fd, _buf, _stop);
- _start = _stop;
-}
-
-void
-CircleBuf::write(char b)
-{
- write(&b, 1);
-}
-
-void
-CircleBuf::write(const char *b)
-{
- write(b, strlen(b));
-}
-
-void
-CircleBuf::write(const char *b, int len)
-{
- if (len <= 0)
- return;
-
- _size += len;
- if (_size > _buflen)
- _size = _buflen;
-
- int old_start = _start;
- int old_stop = _stop;
-
- if (len >= _buflen) {
- _start = 0;
- _stop = _buflen;
- _rollover = true;
- memcpy(_buf, b + (len - _buflen), _buflen);
- return;
- }
-
- if (_stop + len <= _buflen) {
- memcpy(_buf + _stop, b, len);
- _stop += len;
- } else {
- int end_len = _buflen - old_stop;
- _stop = len - end_len;
- memcpy(_buf + old_stop, b, end_len);
- memcpy(_buf, b + end_len, _stop);
- _rollover = true;
- }
-
- if ((old_start > old_stop && old_start < _stop) ||
- (old_start < old_stop && _stop < old_stop))
- _start = _stop + 1;
-}
diff -r 179bc8ca2d8c -r be3b60b52b31 src/base/circlebuf.hh
--- a/src/base/circlebuf.hh Fri Aug 07 09:59:15 2015 +0100
+++ b/src/base/circlebuf.hh Fri Aug 07 09:59:19 2015 +0100
@@ -1,6 +1,15 @@
/*
- * Copyright (c) 2002-2005 The Regents of The University of Michigan
- * All rights reserved.
+ * Copyright (c) 2015 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
@@ -25,40 +34,251 @@
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
- * Authors: Nathan Binkert
+ * Authors: Andreas Sandberg
*/
-#ifndef __CIRCLEBUF_HH__
-#define __CIRCLEBUF_HH__
+#ifndef __BASE_CIRCLEBUF_HH__
+#define __BASE_CIRCLEBUF_HH__
-#include <iosfwd>
+#include <algorithm>
+#include <cassert>
+#include <vector>
+#include "base/misc.hh"
+#include "sim/serialize.hh"
+
+/**
+ * Circular buffer backed by a vector
+ *
+ * The data in the cricular buffer is stored in a standard
+ * vector. _start designates the first element in the buffer and _stop
+ * points to the last element + 1 (i.e., the position of the next
+ * insertion). The _stop index may be outside the range of the backing
+ * store, which means that the actual index must be calculated as
+ * _stop % capacity.
+ *
+ * Invariants:
+ * <ul>
+ * <li>_start <= _stop
+ * <li>_start < capacity
+ * <li>_stop < 2 * capacity
+ * </ul>
+ */
+template<typename T>
class CircleBuf
{
- protected:
- char *_buf;
- bool _rollover;
- int _buflen;
- int _size;
- int _start;
- int _stop;
+ public:
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