Test the registry lookup, register MRU, document case-insensitive names

README.md

@@ -339,7 +339,7 @@ See [libCacheSim-node](/libCacheSim-node/) for the full API and the bundled `cac
 The name in `code` is what you pass to `cachesim` (names are case-insensitive).
 
 ### Eviction algorithms
-* [FIFO](/libCacheSim/cache/eviction/FIFO.c) `fifo`, [LRU](/libCacheSim/cache/eviction/LRU.c) `lru`, [Clock](/libCacheSim/cache/eviction/Clock.c) `clock`, [SLRU](/libCacheSim/cache/eviction/SLRU.c) `slru`, [Random](/libCacheSim/cache/eviction/Random.c) `random`, [RandomTwo](/libCacheSim/cache/eviction/RandomTwo.c) `randomtwo`
+* [FIFO](/libCacheSim/cache/eviction/FIFO.c) `fifo`, [LRU](/libCacheSim/cache/eviction/LRU.c) `lru`, [MRU](/libCacheSim/cache/eviction/MRU.c) `mru`, [Clock](/libCacheSim/cache/eviction/Clock.c) `clock`, [SLRU](/libCacheSim/cache/eviction/SLRU.c) `slru`, [Random](/libCacheSim/cache/eviction/Random.c) `random`, [RandomTwo](/libCacheSim/cache/eviction/RandomTwo.c) `randomtwo`
 * [LFU](/libCacheSim/cache/eviction/LFU.c) `lfu`, [LFU with dynamic aging](/libCacheSim/cache/eviction/LFUDA.c) `lfuda`
 * [ARC](/libCacheSim/cache/eviction/ARC.c) `arc`, [TwoQ](/libCacheSim/cache/eviction/TwoQ.c) `2q`, [MQ](/libCacheSim/cache/eviction/MQ.c) `mq`, [CLOCK-PRO](/libCacheSim/cache/eviction/ClockPro.c) `clockpro`, [CAR](/libCacheSim/cache/eviction/CAR.c) `car`, [LIRS](/libCacheSim/cache/eviction/LIRS.c) `lirs`, [Clock2QPlus](/libCacheSim/cache/eviction/Clock2QPlus.c) `clock2qplus`
 * [LRU-K](/libCacheSim/cache/eviction/cpp/LRU_K.cpp) `lru-k`, [LRU-Prob](/libCacheSim/cache/eviction/LRUProb.c) `lru-prob`, [Size](/libCacheSim/cache/eviction/Size.c) `size`

doc/advanced_lib_extend.md

@@ -53,7 +53,7 @@ Then wire it in. Using `myCache` as the example name:
 2. **Add per-object metadata, if you need it.** Add a struct for it to the union in [include/libCacheSim/cacheObj.h](/libCacheSim/include/libCacheSim/cacheObj.h).
 3. **Declare the constructor.** Add `myCache_init()` to [include/libCacheSim/evictionAlgo.h](/libCacheSim/include/libCacheSim/evictionAlgo.h).
 4. **Compile it.** Add `eviction/myCache.c` to [cache/CMakeLists.txt](/libCacheSim/cache/CMakeLists.txt).
-5. **Give it a name.** Add `{"mycache", myCache_init}` to the table in [cache/cacheAlgoRegistry.c](/libCacheSim/cache/cacheAlgoRegistry.c). The table is alphabetical. This one entry makes the algorithm available to `cachesim`, to the MINISIM mode of `mrcProfiler`, and to `create_cache_by_name()`.
+5. **Give it a name.** Add `{"mycache", myCache_init}` to the table in [cache/cacheAlgoRegistry.c](/libCacheSim/cache/cacheAlgoRegistry.c). The table is alphabetical. This one entry makes the algorithm available to `cachesim`, to the MINISIM mode of `mrcProfiler`, and to `create_cache_by_name()`. Names are matched case-insensitively, so users can type `mycache` or `myCache`. Only an algorithm that needs more than a lookup, such as a smaller hash table or a check that the trace carries future access times, also needs a branch in [bin/cachesim/cache_init.h](/libCacheSim/bin/cachesim/cache_init.h).
 6. **Test and document it.** Add a test to [test/test_evictionAlgo.c](/test/test_evictionAlgo.c), and list the algorithm in the [README](/README.md#supported-algorithms) with the name users type. If it takes `-e` parameters, add a case to the `testCLI` target too, as described in [CONTRIBUTING.md](/CONTRIBUTING.md#testing).
 
 Then rebuild and try it:

doc/quickstart_mrcProfiler.md

@@ -49,7 +49,7 @@ Each row is one cache size. When you give sizes as fractions, the first column i
 
 | Option | Meaning |
 | --- | --- |
-| `--algo` | Eviction algorithm. SHARDS only supports `LRU`. MINISIM accepts any name `cachesim` accepts. |
+| `--algo` | Eviction algorithm, case-insensitive (`fifo` and `FIFO` are the same). SHARDS only supports `LRU`. MINISIM accepts any name `cachesim` accepts. |
 | `--profiler` | `SHARDS` or `MINISIM` |
 | `--profiler-params` | See [Profiler parameters](#profiler-parameters) |
 | `--size` | See [Choose the cache sizes](#choose-the-cache-sizes) |

libCacheSim/bin/mrcProfiler/cli_parser.cpp

@@ -1,6 +1,7 @@
 #include <argp.h>
 #include <stdbool.h>
 #include <string.h>
+#include <strings.h>
 
 #include <string>
 #include <vector>
@@ -370,10 +371,10 @@ void mrc_profiler_params_parse(const char *cache_algorithm_str,
                                mrcProfiler::mrc_profiler_e &profiler_type,
                                mrcProfiler::mrc_profiler_params_t &params) {
   // initial the params of mrc profiler
-  if (strcmp(profiler_str, "SHARDS") == 0 ||
-      strcmp(profiler_str, "shards") == 0) {
+  // names are case-insensitive, the same as cachesim and the MINISIM registry
+  if (strcasecmp(profiler_str, "SHARDS") == 0) {
     profiler_type = mrcProfiler::SHARDS_PROFILER;
-    if (strcmp(cache_algorithm_str, "LRU")) {
+    if (strcasecmp(cache_algorithm_str, "LRU") != 0) {
       ERROR("cache algorithm must be LRU for SHARDS\n")
       exit(1);
     }
@@ -382,8 +383,7 @@ void mrc_profiler_params_parse(const char *cache_algorithm_str,
 
     // init shards params
     params.shards_params.parse_params(params_str);
-  } else if (strcmp(profiler_str, "MINISIM") == 0 ||
-             strcmp(profiler_str, "minisim") == 0) {
+  } else if (strcasecmp(profiler_str, "MINISIM") == 0) {
     profiler_type = mrcProfiler::MINISIM_PROFILER;
 
     params.cache_algorithm_str = (char *)cache_algorithm_str;

libCacheSim/cache/cacheAlgoRegistry.c

@@ -53,8 +53,13 @@ static const cache_algo_entry_t g_cache_algos[] = {
     {"lru", LRU_init},
     {"lru-k", LRU_K_init},
     {"lru-prob", LRU_Prob_init},
+    /* lruv0 is deliberately absent. LRUv0 is the older GLib-based LRU and keeps
+     * its own hash table, so it bypasses the shared find, insert and evict
+     * paths that implement TTL expiry, admission and the prefetcher callbacks.
+     * Naming it here would let the CLI silently ignore those options. */
     {"merlin", merlin_init},
     {"mq", MQ_init},
+    {"mru", MRU_init},
     {"multiqueue", MQ_init},
     {"nop", nop_init},
     /* plugin cache that allows user to implement custom cache */

libCacheSim/cache/eviction/MRU.c

@@ -177,8 +177,14 @@ static cache_obj_t *MRU_to_evict(cache_t *cache, const request_t *req) {
 static void MRU_evict(cache_t *cache, const request_t *req) {
   MRU_params_t *params = (MRU_params_t *)cache->eviction_params;
   cache_obj_t *obj_to_evict = MRU_to_evict(cache, req);
-  params->q_head = params->q_head->queue.next;
-  params->q_head->queue.prev = NULL;
+  DEBUG_ASSERT(obj_to_evict != NULL);
+  params->q_head = obj_to_evict->queue.next;
+  if (likely(params->q_head != NULL)) {
+    params->q_head->queue.prev = NULL;
+  } else {
+    /* that was the only object, so the queue is now empty */
+    params->q_tail = NULL;
+  }
   cache_evict_base(cache, obj_to_evict, true);
 }
 

scripts/README.md

@@ -28,6 +28,7 @@ python3 plot_mrc_time.py \
 ## Profile miss ratio curves
 
 `mrcProfiler` enables fast profiling of miss ratio curves. With a proper parameter setting (such as `sampling_rate`, see [here](../doc/quickstart_mrcProfiler.md) for details) `mrcProfiler` can profile miss ratio curves in a fast way with acceptable accuracy.
+Names passed to `--algos` are case-insensitive, so `LRU,FIFO` and `lru,fifo` both work.
 
 ```bash
 # plot profiled miss ratio over sizes

test/test_evictionAlgo.c

@@ -419,6 +419,28 @@ static void test_MRU(gconstpointer user_data) {
   test_cache_algorithm(user_data, &test_data_truth[18]);
 }
 
+// Evicting the only object empties the queue. MRU_evict used to write through
+// the new, NULL, head and leave the tail pointing at the freed object, so the
+// second miss in a one-object cache segfaulted.
+static void test_MRU_evict_only_object(void) {
+  common_cache_params_t cc_params = {.cache_size = 1, .hashpower = 8};
+  cache_t *cache = MRU_init(cc_params, NULL);
+  request_t *req = new_request();
+  req->obj_size = 1;
+
+  for (obj_id_t id = 1; id <= 4; id++) {
+    req->obj_id = id;
+    g_assert_false(cache->get(cache, req));
+    g_assert_cmpint(cache->get_n_obj(cache), ==, 1);
+    g_assert_nonnull(cache->find(cache, req, false));
+    req->obj_id = id - 1;
+    g_assert_null(cache->find(cache, req, false));
+  }
+
+  free_request(req);
+  cache->cache_free(cache);
+}
+
 static void test_QDLP_FIFO(gconstpointer user_data) {
   test_cache_algorithm(user_data, &test_data_truth[19]);
 }
@@ -563,6 +585,36 @@ static void test_WTinyLFU(gconstpointer user_data) {
   // TODO: to be implemented
 }
 
+/* The MINISIM profiler only knows an algorithm by its name and reaches it
+ * through create_cache_using_plugin(). That used to go straight to dlsym(),
+ * which cannot see a built-in constructor in a statically linked build — the
+ * archive member holding it is never pulled in — so every built-in name failed
+ * with "undefined symbol: lru_init" (issue #304). The registry lookup that
+ * replaced it matches names case-insensitively, the same way cachesim does. */
+static void test_create_cache_by_name(gconstpointer user_data) {
+  common_cache_params_t cc_params = {
+      .cache_size = CACHE_SIZE, .hashpower = 20, .default_ttl = DEFAULT_TTL};
+
+  static const struct {
+    const char *requested;
+    const char *expected_name;
+  } names[] = {
+      {"lru", "LRU"},   {"LRU", "LRU"},   {"Lru", "LRU"}, {"fifo", "FIFO"},
+      {"FIFO", "FIFO"}, {"fIfO", "FIFO"}, {"mru", "MRU"}, {"MRU", "MRU"},
+  };
+
+  for (size_t i = 0; i < sizeof(names) / sizeof(names[0]); i++) {
+    cache_t *cache =
+        create_cache_using_plugin(names[i].requested, cc_params, NULL);
+    g_assert_nonnull(cache);
+    g_assert_cmpstr(cache->cache_name, ==, names[i].expected_name);
+    cache->cache_free(cache);
+  }
+
+  // left out of the registry on purpose, see cacheAlgoRegistry.c
+  g_assert_null(create_cache_by_name("lruv0", cc_params, NULL));
+}
+
 static void empty_test(gconstpointer user_data) { ; }
 
 static void test_WorkloadAware(gconstpointer user_data) {
@@ -611,6 +663,8 @@ int main(int argc, char *argv[]) {
   g_test_add_data_func("/libCacheSim/cacheAlgo_Merlin", reader, test_Merlin);
   g_test_add_data_func("/libCacheSim/cacheAlgo_MQ", reader, test_MQ);
   g_test_add_data_func("/libCacheSim/cacheAlgo_MRU", reader, test_MRU);
+  g_test_add_func("/libCacheSim/cacheAlgo_MRU_evict_only_object",
+                  test_MRU_evict_only_object);
   g_test_add_data_func("/libCacheSim/cacheAlgo_QDLP_FIFO", reader,
                        test_QDLP_FIFO);
   g_test_add_data_func("/libCacheSim/cacheAlgo_Random", reader, test_Random);
@@ -646,6 +700,9 @@ int main(int argc, char *argv[]) {
   g_test_add_data_func("/libCacheSim/cacheAlgo_BeladySize", reader,
                        test_BeladySize);
 
+  g_test_add_data_func("/libCacheSim/create_cache_by_name", reader,
+                       test_create_cache_by_name);
+
   g_test_add_data_func_full("/libCacheSim/empty", reader, empty_test,
                             test_teardown);