tests: Added GTests for base/atomicio.cc

Change-Id: I586a06c70f4e7331b4a31208ef7831e8473509c5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21699
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/base/SConscript

@@ -35,6 +35,7 @@ if env['CP_ANNOTATE']:
     Source('cp_annotate.cc')
 SimObject('Graphics.py')
 Source('atomicio.cc')
+GTest('atomicio.test', 'atomicio.test.cc', 'atomicio.cc')
 Source('bitfield.cc')
 Source('imgwriter.cc')
 Source('bmpwriter.cc')

src/base/atomicio.test.cc

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2019 The Regents of the University of California
+ * 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: Bobby R. Bruce
+ */
+
+#include <gtest/gtest.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "base/atomicio.hh"
+
+/*
+ * This will test reading from a file with a buffer capable of storing the
+ * entirity of the file.
+ */
+TEST(AtomicioTest, AtomicReadBigBuffer)
+{
+    FILE* file;
+    file = tmpfile();
+
+    std::string file_contents = "This is just some test data to ensure that we"
+                                " can read correctly from a file.";
+
+    fputs(file_contents.c_str(), file);
+    fflush(file);
+    rewind(file);
+
+    char s[1000];
+
+    ssize_t size = atomic_read(fileno(file), s, 1000);
+    fclose(file);
+
+    EXPECT_EQ(file_contents.size(), size);
+    for (unsigned int i = 0; i < size; i++) {
+        EXPECT_EQ(file_contents[i], s[i]);
+    }
+}
+
+/*
+ * This will test reading from a file using a buffer smaller than the file
+ * contents. The buffer should be filled and the remainder left unread.
+ */
+TEST(AtomicioTest, AtomicReadSmallBuffer)
+{
+    FILE* file;
+    file = tmpfile();
+
+    std::string file_contents = "This is just some test data to ensure that we"
+                                " can read correctly from a file.";
+
+    fputs(file_contents.c_str(), file);
+    fflush(file);
+    rewind(file);
+
+    char s[10];
+
+    ssize_t size = atomic_read(fileno(file), s, 10);
+    fclose(file);
+
+    EXPECT_EQ(10, size);
+    for (unsigned int i = 0; i < size; i++) {
+        EXPECT_EQ(file_contents[i], s[i]);
+    }
+}
+
+/*
+ * This tests writing a string to a file via the atomic_write function.
+ */
+TEST(AtomicioTest, AtomicWrite)
+{
+    FILE* file;
+    file = tmpfile();
+
+    std::string file_contents = "This is just some test data to ensure that we"
+                                " can write correctly to a file.";
+
+    ssize_t size = atomic_write(fileno(file),
+                                file_contents.c_str(),
+                                file_contents.size());
+    fflush(file);
+    rewind(file);
+
+    EXPECT_EQ(file_contents.size(), size);
+
+    char c;
+    for (unsigned int i = 0; (c = fgetc(file)) != EOF; i++) {
+        EXPECT_EQ(file_contents[i], c);
+    }
+
+    fclose(file);
+}