tests: Convert CircleBuf unit test to a GTest

Change-Id: I028c6b8d8e0ec06cac3d636689ae647f717096cd
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13735
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

2 files changed, 121 insertions, 0 deletions

diff --git a/src/base/SConscript b/src/base/SConscript
index 3065749ba..3570d1574 100644
--- a/src/base/SConscript
+++ b/src/base/SConscript
@@ -84,6 +84,7 @@ Source('stats/text.cc')
 
 GTest('addr_range_test', 'addr_range_test.cc')
 GTest('bituniontest', 'bituniontest.cc')
+GTest('CircleBufTest', 'circlebuftest.cc')
 
 DebugFlag('Annotate', "State machine annotation debugging")
 DebugFlag('AnnotateQ', "State machine annotation queue debugging")
diff --git a/src/base/circlebuftest.cc b/src/base/circlebuftest.cc
new file mode 100644
index 000000000..9f5679d84
--- /dev/null
+++ b/src/base/circlebuftest.cc
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2015, 2018 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
+ * 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: Andreas Sandberg
+ */
+
+#include <gtest/gtest.h>
+
+#include "base/circlebuf.hh"
+
+const char data[] = {
+    0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
+    0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf,
+};
+
+// Basic non-overflow functionality
+TEST(CircleBufTest, BasicReadWriteNoOverflow)
+{
+    CircleBuf<char> buf(8);
+    char foo[16];
+
+    // Write empty buffer, no overflow
+    buf.write(data, 8);
+    EXPECT_EQ(buf.size(), 8);
+    buf.peek(foo, 8);
+    EXPECT_EQ(memcmp(foo, data, 8), 0);
+
+    // Read 2
+    buf.read(foo, 2);
+    EXPECT_EQ(memcmp(foo, data, 2), 0);
+    EXPECT_EQ(buf.size(), 6);
+    buf.read(foo, 6);
+    EXPECT_EQ(memcmp(foo, data + 2, 6), 0);
+    EXPECT_EQ(buf.size(), 0);
+}
+
+// Basic single write overflow functionality
+TEST(CircleBufTest, SingleWriteOverflow)
+{
+    CircleBuf<char> buf(8);
+    char foo[16];
+
+    buf.write(data, 16);
+    EXPECT_EQ(buf.size(), 8);
+    buf.peek(foo, 8);
+    EXPECT_EQ(memcmp(data + 8, foo, 8), 0);
+}
+
+
+// Multi-write overflow functionality
+TEST(CircleBufTest, MultiWriteOverflow)
+{
+    CircleBuf<char> buf(8);
+    char foo[16];
+
+    // Write, no overflow, write overflow
+    buf.write(data, 6);
+    buf.write(data + 8, 6);
+    EXPECT_EQ(buf.size(), 8);
+    buf.peek(foo, 8);
+    EXPECT_EQ(memcmp(data + 4, foo, 2), 0);
+    EXPECT_EQ(memcmp(data + 8, foo + 2, 6), 0);
+}
+
+// Pointer wrap around
+TEST(CircleBufTest, PointerWrapAround)
+{
+    CircleBuf<char> buf(8);
+    char foo[16];
+
+    // _start == 0, _stop = 8
+    buf.write(data, 8);
+    // _start == 4, _stop = 8
+    buf.read(foo, 4);
+    // _start == 4, _stop = 12
+    buf.write(data + 8, 4);
+    EXPECT_EQ(buf.size(), 8);
+    // _start == 10, _stop = 12
+    // Normalized: _start == 2, _stop = 4
+    buf.read(foo + 4, 6);
+    EXPECT_EQ(buf.size(), 2);
+    EXPECT_EQ(memcmp(data, foo, 10), 0);
+    // Normalized: _start == 4, _stop = 4
+    buf.read(foo + 10, 2);
+    EXPECT_EQ(buf.size(), 0);
+    EXPECT_EQ(memcmp(data, foo, 12), 0);
+}