i#4842 drcachesim unit tests: Add cache_lru unit test

This change adds unit tests for clients/drcachesim/simulators/cache_lru.cpp.
These unit tests catch issues reported in i#4881 which was tested by
reverting the fix for that issue (#4883).

Issue: #4842

clients/drcachesim/CMakeLists.txt

@@ -499,6 +499,17 @@ endif ()
 # Be sure to give the targets qualified test names ("tool.drcache*...").
 
 if (BUILD_TESTS)
+  add_executable(tool.drcachesim.cache_lru_unit_tests tests/cache_lru_unit_tests.cpp)
+  if (ZLIB_FOUND)
+    target_link_libraries(tool.drcachesim.cache_lru_unit_tests drmemtrace_simulator
+      drmemtrace_static drmemtrace_analyzer ${ZLIB_LIBRARIES})
+  else ()
+    target_link_libraries(tool.drcachesim.cache_lru_unit_tests drmemtrace_simulator
+      drmemtrace_static drmemtrace_analyzer)
+  endif ()
+  add_win32_flags(tool.drcachesim.cache_lru_unit_tests)
+  add_test(NAME tool.drcachesim.cache_lru_unit_tests
+           COMMAND tool.drcachesim.cache_lru_unit_tests)
   add_executable(tool.drcachesim.unit_tests tests/drcachesim_unit_tests.cpp)
   if (ZLIB_FOUND)
     target_link_libraries(tool.drcachesim.unit_tests drmemtrace_simulator

clients/drcachesim/tests/cache_lru_unit_tests.cpp

@@ -0,0 +1,106 @@
+/* **********************************************************
+ * Copyright (c) 2016-2021 Google, Inc.  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 Google, Inc. 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 GOOGLE, INC. 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.
+ */
+
+// Unit tests for cache_lru
+#include <iostream>
+#include <assert.h>
+#include "simulator/cache_lru.h"
+
+struct cache_config_t {
+    int associativity = 4;
+    int line_size = 32;
+    int total_size = 256;
+    caching_device_t *parent = nullptr;
+    caching_device_stats_t *stats = new cache_stats_t(line_size, "", true);
+    prefetcher_t *prefetcher = nullptr;
+    bool inclusive = true;
+    bool coherent_cache = true;
+    int id = -1;
+    snoop_filter_t *snoop_filter = nullptr;
+};
+
+static cache_config_t
+make_test_configs(int associativity, int line_size, int total_size)
+{
+    cache_config_t config;
+    config.associativity = associativity;
+    config.line_size = line_size;
+    config.total_size = total_size;
+    return config;
+}
+
+class cache_lru_test_t : public cache_lru_t {
+public:
+    void
+    unit_test_access_update()
+    {
+        // Create and initialize an 8-way set associative cache with line size of 32 and
+        // total size of 1024 bytes.
+        cache_config_t config_two = make_test_configs(8, 32, 1024);
+        if (!init(config_two.associativity, config_two.line_size, config_two.total_size,
+                  config_two.parent, config_two.stats, config_two.prefetcher,
+                  config_two.inclusive, config_two.coherent_cache, config_two.id,
+                  config_two.snoop_filter)) {
+            std::cerr << "LRU cache failed to initialize"
+                      << "\n";
+            exit(1);
+        }
+
+        // Access the cacheclines in set 1 in the following sequence and ensure the
+        // counters are updated properly.
+        access_update(1, 6);
+        access_update(1, 1);
+        access_update(1, 2);
+        access_update(1, 3);
+        access_update(1, 4);
+        access_update(1, 5);
+        access_update(1, 0);
+        access_update(1, 7);
+
+        assert(get_caching_device_block(1, 0).counter_ == 1);
+        assert(get_caching_device_block(1, 1).counter_ == 6);
+        assert(get_caching_device_block(1, 2).counter_ == 5);
+        assert(get_caching_device_block(1, 3).counter_ == 4);
+        assert(get_caching_device_block(1, 4).counter_ == 3);
+        assert(get_caching_device_block(1, 5).counter_ == 2);
+        assert(get_caching_device_block(1, 6).counter_ == 7);
+        assert(get_caching_device_block(1, 7).counter_ == 0);
+    }
+};
+
+int
+main(int argc, const char *argv[])
+{
+    cache_lru_test_t cache_lru;
+    cache_lru.unit_test_access_update();
+    return 0;
+}