intel_rdt: update unit-tests for process monitoring
authorStarzyk, MateuszX <mateuszx.starzyk@intel.com>
Wed, 21 Mar 2018 08:14:53 +0000 (08:14 +0000)
committerAleksinski, MichalX <michalx.aleksinski@intel.com>
Wed, 6 Mar 2019 06:43:33 +0000 (06:43 +0000)
Refactor certain functions to be testable.

Change-Id: I5adb6ed1b076f0cebc70641f04dd101d4e89b9cc
Signed-off-by: Starzyk, MateuszX <mateuszx.starzyk@intel.com>
src/intel_rdt.c
src/intel_rdt_test.c

index f7d9a34..e509b87 100644 (file)
@@ -144,6 +144,14 @@ static int strlisttoarray(char *str_list, char ***names, size_t *names_num) {
   if (str_list == NULL || names == NULL)
     return -EINVAL;
 
+  if (strstr(str_list, ",,")) {
+    /* strtok ignores empty words between separators.
+     * This condition handles that by rejecting strings
+     * with consecutive seprators */
+    ERROR(RDT_PLUGIN ": Empty process name");
+    return -EINVAL;
+  }
+
   for (;;) {
     char *token = strtok_r(str_list, ",", &saveptr);
     if (token == NULL)
@@ -157,11 +165,16 @@ static int strlisttoarray(char *str_list, char ***names, size_t *names_num) {
     if (*token == '\0')
       continue;
 
-    if (!(isdupstr((const char **)*names, *names_num, token)))
+    if ((isdupstr((const char **)*names, *names_num, token))) {
+      ERROR(RDT_PLUGIN ": Duplicated process name \'%s\' in group \'%s\'",
+            token, str_list);
+      return -EINVAL;
+    } else {
       if (0 != strarray_add(names, names_num, token)) {
         ERROR(RDT_PLUGIN ": Error allocating process name string");
         return -ENOMEM;
       }
+    }
   }
 
   return 0;
@@ -242,8 +255,10 @@ static int oconfig_to_ngroups(const oconfig_item_t *item,
     char value[DATA_MAX_NAME_LEN];
 
     if ((item->values[j].value.string == NULL) ||
-        (strlen(item->values[j].value.string) == 0))
-      continue;
+        (strlen(item->values[j].value.string) == 0)) {
+      ERROR(RDT_PLUGIN ": Error - empty group");
+      return -EINVAL;
+    }
 
     sstrncpy(value, item->values[j].value.string, sizeof(value));
 
@@ -440,26 +455,27 @@ static int pids_list_free(pids_list_t *list) {
   return 0;
 }
 
-static void rdt_free_ngroups(void) {
+static void rdt_free_ngroups(rdt_ctx_t *rdt) {
   for (int i = 0; i < RDT_MAX_NAMES_GROUPS; i++) {
-    if (g_rdt->ngroups[i].desc)
+    if (rdt->ngroups[i].desc)
       DEBUG(RDT_PLUGIN ": Freeing pids \'%s\' group\'s data...",
-            g_rdt->ngroups[i].desc);
-    sfree(g_rdt->ngroups[i].desc);
-    strarray_free(g_rdt->ngroups[i].names, g_rdt->ngroups[i].num_names);
+            rdt->ngroups[i].desc);
+    sfree(rdt->ngroups[i].desc);
 
-    if (g_rdt->ngroups[i].proc_pids_array) {
-      for (size_t j = 0; j < g_rdt->ngroups[i].num_names; ++j) {
-        if (NULL == g_rdt->ngroups[i].proc_pids_array[j].pids)
+    strarray_free(rdt->ngroups[i].names, rdt->ngroups[i].num_names);
+
+    if (rdt->ngroups[i].proc_pids_array) {
+      for (size_t j = 0; j < rdt->ngroups[i].num_names; ++j) {
+        if (NULL == rdt->ngroups[i].proc_pids_array[j].pids)
           continue;
-        pids_list_free(g_rdt->ngroups[i].proc_pids_array[j].pids);
+        pids_list_free(rdt->ngroups[i].proc_pids_array[j].pids);
       }
 
-      sfree(g_rdt->ngroups[i].proc_pids_array);
+      sfree(rdt->ngroups[i].proc_pids_array);
     }
 
-    g_rdt->ngroups[i].num_names = 0;
-    sfree(g_rdt->pngroups[i]);
+    rdt->ngroups[i].num_names = 0;
+    sfree(rdt->pngroups[i]);
   }
 }
 #endif /* LIBPQOS2 */
@@ -601,7 +617,7 @@ static int rdt_config_cgroups(oconfig_item_t *item) {
 }
 
 #ifdef LIBPQOS2
-static int rdt_config_ngroups(const oconfig_item_t *item) {
+static int rdt_config_ngroups(rdt_ctx_t *rdt, const oconfig_item_t *item) {
   int n = 0;
   enum pqos_mon_event events = 0;
 
@@ -621,22 +637,26 @@ static int rdt_config_ngroups(const oconfig_item_t *item) {
     DEBUG(RDT_PLUGIN ":  [%d]: %s", j, item->values[j].value.string);
   }
 
-  n = oconfig_to_ngroups(item, g_rdt->ngroups, RDT_MAX_NAMES_GROUPS);
+  n = oconfig_to_ngroups(item, rdt->ngroups, RDT_MAX_NAMES_GROUPS);
   if (n < 0) {
-    rdt_free_ngroups();
+    rdt_free_ngroups(rdt);
     ERROR(RDT_PLUGIN ": Error parsing process name groups configuration.");
     return -EINVAL;
   }
 
   /* validate configured process name values */
   for (int group_idx = 0; group_idx < n; group_idx++) {
-    for (size_t name_idx = 0; name_idx < g_rdt->ngroups[group_idx].num_names;
+    DEBUG(RDT_PLUGIN ":  checking group [%d]: %s", group_idx,
+          rdt->ngroups[group_idx].desc);
+    for (size_t name_idx = 0; name_idx < rdt->ngroups[group_idx].num_names;
          name_idx++) {
-      if (!rdt_is_proc_name_valid(g_rdt->ngroups[group_idx].names[name_idx])) {
+      DEBUG(RDT_PLUGIN ":    checking process name [%zu]: %s", name_idx,
+            rdt->ngroups[group_idx].names[name_idx]);
+      if (!rdt_is_proc_name_valid(rdt->ngroups[group_idx].names[name_idx])) {
         ERROR(RDT_PLUGIN ": Process name group '%s' contains invalid name '%s'",
-              g_rdt->ngroups[group_idx].desc,
-              g_rdt->ngroups[group_idx].names[name_idx]);
-        rdt_free_ngroups();
+              rdt->ngroups[group_idx].desc,
+              rdt->ngroups[group_idx].names[name_idx]);
+        rdt_free_ngroups(rdt);
         return -EINVAL;
       }
     }
@@ -648,29 +668,29 @@ static int rdt_config_ngroups(const oconfig_item_t *item) {
   }
 
   /* Get all available events on this platform */
-  for (unsigned i = 0; i < g_rdt->cap_mon->u.mon->num_events; i++)
-    events |= g_rdt->cap_mon->u.mon->events[i].type;
+  for (unsigned i = 0; i < rdt->cap_mon->u.mon->num_events; i++)
+    events |= rdt->cap_mon->u.mon->events[i].type;
 
   events &= ~(PQOS_PERF_EVENT_LLC_MISS);
 
   DEBUG(RDT_PLUGIN ": Available events to monitor: %#x", events);
 
-  g_rdt->num_ngroups = n;
+  rdt->num_ngroups = n;
   for (int i = 0; i < n; i++) {
     for (int j = 0; j < i; j++) {
-      int found = ngroup_cmp(&g_rdt->ngroups[j], &g_rdt->ngroups[i]);
+      int found = ngroup_cmp(&rdt->ngroups[j], &rdt->ngroups[i]);
       if (found != 0) {
-        rdt_free_ngroups();
+        rdt_free_ngroups(rdt);
         ERROR(RDT_PLUGIN
               ": Cannot monitor same process name in different groups.");
         return -EINVAL;
       }
     }
 
-    g_rdt->ngroups[i].events = events;
-    g_rdt->pngroups[i] = calloc(1, sizeof(*g_rdt->pngroups[i]));
-    if (g_rdt->pngroups[i] == NULL) {
-      rdt_free_ngroups();
+    rdt->ngroups[i].events = events;
+    rdt->pngroups[i] = calloc(1, sizeof(*rdt->pngroups[i]));
+    if (rdt->pngroups[i] == NULL) {
+      rdt_free_ngroups(rdt);
       ERROR(RDT_PLUGIN
             ": Failed to allocate memory for process name monitoring data.");
       return -ENOMEM;
@@ -1136,7 +1156,7 @@ static int rdt_config(oconfig_item_t *ci) {
         return 0;
       }
 
-      if (rdt_config_ngroups(child) != 0) {
+      if (rdt_config_ngroups(g_rdt, child) != 0) {
         g_state = CONFIGURATION_ERROR;
         /* if we return -1 at this point collectd
            reports a failure in configuration and
@@ -1658,7 +1678,7 @@ static int rdt_shutdown(void) {
 
   rdt_free_cgroups();
 #ifdef LIBPQOS2
-  rdt_free_ngroups();
+  rdt_free_ngroups(g_rdt);
 #endif /* LIBPQOS2 */
   sfree(g_rdt);
 
index 786fa9f..42d03c7 100644 (file)
@@ -81,8 +81,6 @@ int pqos_cap_get_type(const struct pqos_cap *cap, const enum pqos_cap_type type,
 int pqos_cap_get(const struct pqos_cap **cap, const struct pqos_cpuinfo **cpu) {
   return 0;
 }
-#endif /* LIBPQOS2 */
-
 /***************************************************************************
  * helper functions
  */
@@ -113,75 +111,6 @@ pids_list_t *pids_list_get_element(pids_list_t *list, const size_t index) {
   return list;
 }
 
-/*
- * NAME
- *   pids_list_find_element
- *
- * DESCRIPTION
- *   Gets index of element in the list matching
- *   given pid. Assumes PIDs are unique, stops searching
- *   on the first match.
- *
- * PARAMETERS
- *   `list'     Pids list
- *   `pid'      PID number to find
- *
- * RETURN VALUE
- *   Index of list element holding given PID.
- */
-int pids_list_find_element(pids_list_t *list, const pid_t pid) {
-  assert(list);
-  int result = -1;
-  size_t current = 0;
-  while (list != NULL) {
-    if (list->pid == pid) {
-      result = current;
-      break;
-    }
-    list = list->next;
-  }
-  return result;
-}
-
-/*
- * NAME
- *   pids_list_has_element
- *
- * DESCRIPTION
- *  Checks if the list contains given pid.
- *  Wrapper for pids_list_find_element function.
- *  Used to make tests easier to read.
- *
- * PARAMETERS
- *   `list'     Pids list
- *   `pid'      PID number to find
- *
- * RETURN VALUE
- *   1 if list contains given PID
- *   0 if list does not contain given PID
- */
-int pids_list_has_element(pids_list_t *list, const pid_t pid) {
-  return pids_list_find_element(list, pid) >= 0 ? 1 : 0;
-}
-
-/*
- * NAME
- *   pids_list_free_all
- *
- * DESCRIPTION
- *   Frees memory allocated in the given list
- *
- * PARAMETERS
- *   `list'     Pids list
- */
-void pids_list_free_all(pids_list_t *list) {
-  while (list) {
-    pids_list_t *previous = list;
-    list = list->next;
-    free(previous);
-  }
-}
-
 typedef struct stub_proc_pid {
   proc_comm_t comm;
   pid_t pid;
@@ -209,9 +138,8 @@ static const char *proc_fs = "/tmp/procfs_stub";
  */
 int stub_procfs_setup(const stub_proc_pid_t *proc_pids_array,
                       const size_t proc_pids_array_length) {
-  if (mkdir(proc_fs, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) != 0) {
+  if (mkdir(proc_fs, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) != 0)
     return -1;
-  }
   char path[256];
 
   for (size_t i = 0; i < proc_pids_array_length; ++i) {
@@ -222,9 +150,8 @@ int stub_procfs_setup(const stub_proc_pid_t *proc_pids_array,
     strncat(path, "/comm", STATIC_ARRAY_SIZE(path) - strlen(path) - 1);
 
     FILE *fp = fopen(path, "w");
-    if (!fp) {
+    if (!fp)
       return -2;
-    }
     fwrite(proc_pids_array[i].comm, sizeof(char),
            strlen(proc_pids_array[i].comm), fp);
     fclose(fp);
@@ -258,10 +185,52 @@ int stub_procfs_teardown() {
 #define MAX_PID 4194304
 #define MAX_PID_STR "4194304"
 
+rdt_ctx_t *stub_rdt_setup() {
+
+  rdt_ctx_t *rdt = calloc(1, sizeof(*rdt));
+  struct pqos_cpuinfo *pqos_cpu = calloc(1, sizeof(*pqos_cpu));
+  struct pqos_cap *pqos_cap = calloc(1, sizeof(*pqos_cap));
+  struct pqos_cap_mon *mon = calloc(1, sizeof(*mon));
+  struct pqos_capability *cap_mon = calloc(1, sizeof(*cap_mon));
+
+  cap_mon->u.mon = mon;
+  rdt->pqos_cap = pqos_cap;
+  rdt->pqos_cpu = pqos_cpu;
+  rdt->cap_mon = cap_mon;
+
+  return rdt;
+}
+
+void stub_rdt_teardown(rdt_ctx_t *rdt) {
+  free(rdt->cap_mon->u.mon);
+  free((void *)rdt->cap_mon);
+  free((void *)rdt->pqos_cpu);
+  free((void *)rdt->pqos_cap);
+  free(rdt);
+}
+
 /***************************************************************************
  * tests
  */
-DEF_TEST(add_proc_pid_empty_list) {
+DEF_TEST(initialize_proc_pids__on_nullptr) {
+  /* setup */
+  const char *procs_names_array[] = {"proc1", "proc2", "proc3"};
+  const size_t procs_names_array_size = STATIC_ARRAY_SIZE(procs_names_array);
+  proc_pids_t *proc_pids_array = NULL;
+
+  /* check */
+  int result = initialize_proc_pids(procs_names_array, procs_names_array_size,
+                                    &proc_pids_array);
+  EXPECT_EQ_INT(0, result);
+  for (size_t i = 0; i < procs_names_array_size; ++i)
+    EXPECT_EQ_STR(procs_names_array[i], proc_pids_array[i].proccess_name);
+
+  /* cleanup */
+  free(proc_pids_array);
+  return 0;
+}
+
+DEF_TEST(add_proc_pid__empty_list) {
   /* setup */
   proc_pids_t proc_pids_instance;
   proc_pids_instance.pids = NULL;
@@ -273,20 +242,19 @@ DEF_TEST(add_proc_pid_empty_list) {
   EXPECT_EQ_INT(pid, added->pid);
 
   /* cleanup */
-  pids_list_free_all(proc_pids_instance.pids);
+  pids_list_free(proc_pids_instance.pids);
   return 0;
 }
 
-DEF_TEST(add_proc_pid_non_empty_list) {
+DEF_TEST(add_proc_pid__non_empty_list) {
   /* setup */
   proc_pids_t proc_pids_instance;
   proc_pids_instance.pids = NULL;
   pid_t pids[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
 
   /* check */
-  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids); ++i) {
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids); ++i)
     pids_list_add_pid(&proc_pids_instance.pids, pids[i]);
-  }
 
   for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids); ++i) {
     pids_list_t *added = pids_list_get_element(proc_pids_instance.pids, i);
@@ -294,11 +262,80 @@ DEF_TEST(add_proc_pid_non_empty_list) {
   }
 
   /* cleanup */
-  pids_list_free_all(proc_pids_instance.pids);
+  pids_list_free(proc_pids_instance.pids);
+  return 0;
+}
+
+DEF_TEST(pids_list_to_array__non_empty_list) {
+  /* setup */
+  pid_t pids[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
+  pids_list_t *pids_list = NULL;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids); ++i)
+    pids_list_add_pid(&pids_list, pids[i]);
+
+  /* check */
+  pid_t target_array[STATIC_ARRAY_SIZE(pids)];
+  pids_list_to_array(target_array, pids_list, STATIC_ARRAY_SIZE(target_array));
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids); ++i)
+    EXPECT_EQ_INT(pids[i], target_array[i]);
+
+  /* cleanup */
+  pids_list_free(pids_list);
   return 0;
 }
 
-DEF_TEST(get_pid_number_valid_dir) {
+DEF_TEST(pids_list_add_pids_list__non_empty_lists) {
+  /* setup */
+  pid_t pids_array_1[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
+  pid_t pids_array_2[] = {2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007};
+  pids_list_t *pids_list_1 = NULL;
+  pids_list_t *pids_list_2 = NULL;
+  size_t increase = 0;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_1); ++i) {
+    pids_list_add_pid(&pids_list_1, pids_array_1[i]);
+    pids_list_add_pid(&pids_list_2, pids_array_2[i]);
+  }
+
+  /* check */
+  int result = pids_list_add_pids_list(&pids_list_1, pids_list_2, &increase);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(STATIC_ARRAY_SIZE(pids_array_2), increase);
+
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_1); ++i) {
+    EXPECT_EQ_INT(1, pids_list_contains_pid(pids_list_1, pids_array_1[i]));
+    EXPECT_EQ_INT(1, pids_list_contains_pid(pids_list_1, pids_array_2[i]));
+  }
+
+  /* setup */
+  pids_list_free(pids_list_1);
+  pids_list_free(pids_list_2);
+  return 0;
+}
+
+DEF_TEST(pids_list_add_pids_list__add_to_empty) {
+  /* setup */
+  pid_t pids_array[] = {2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007};
+  pids_list_t *pids_list_1 = NULL;
+  pids_list_t *pids_list_2 = NULL;
+  size_t increase = 0;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array); ++i)
+    pids_list_add_pid(&pids_list_2, pids_array[i]);
+
+  /* check */
+  int result = pids_list_add_pids_list(&pids_list_1, pids_list_2, &increase);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(STATIC_ARRAY_SIZE(pids_array), increase);
+
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array); ++i)
+    EXPECT_EQ_INT(1, pids_list_contains_pid(pids_list_1, pids_array[i]));
+
+  /* setup */
+  pids_list_free(pids_list_1);
+  pids_list_free(pids_list_2);
+  return 0;
+}
+
+DEF_TEST(get_pid_number__valid_dir) {
   /* setup */
   struct dirent d;
   sstrncpy(d.d_name, MAX_PID_STR, STATIC_ARRAY_SIZE(d.d_name));
@@ -315,7 +352,7 @@ DEF_TEST(get_pid_number_valid_dir) {
   return 0;
 }
 
-DEF_TEST(get_pid_number_invalid_dir_name) {
+DEF_TEST(get_pid_number__invalid_dir_name) {
   /* setup */
   struct dirent d;
   sstrncpy(d.d_name, "invalid", STATIC_ARRAY_SIZE(d.d_name));
@@ -325,14 +362,14 @@ DEF_TEST(get_pid_number_invalid_dir_name) {
   /* check */
   int pid_conversion = get_pid_number(&d, &pid);
 
-  EXPECT_EQ_INT(-2, pid_conversion);
+  EXPECT_EQ_INT(-1, pid_conversion);
   EXPECT_EQ_INT(0, pid);
 
   /* cleanup */
   return 0;
 }
 
-DEF_TEST(read_proc_name_valid_name) {
+DEF_TEST(read_proc_name__valid_name) {
   /* setup */
   stub_proc_pid_t pp_stubs[] = {{"proc1", MAX_PID}};
   stub_procfs_setup(pp_stubs, STATIC_ARRAY_SIZE(pp_stubs));
@@ -352,7 +389,7 @@ DEF_TEST(read_proc_name_valid_name) {
   return 0;
 }
 
-DEF_TEST(read_proc_name_invalid_name) {
+DEF_TEST(read_proc_name__invalid_name) {
   /* setup */
   struct dirent d;
   sstrncpy(d.d_name, MAX_PID_STR, STATIC_ARRAY_SIZE(d.d_name));
@@ -368,7 +405,7 @@ DEF_TEST(read_proc_name_invalid_name) {
   return 0;
 }
 
-DEF_TEST(fetch_pids_for_procs_one_proc_many_pid) {
+DEF_TEST(fetch_pids_for_procs__one_proc_many_pid) {
   /* setup */
   const char *proc_names[] = {"proc1"};
   stub_proc_pid_t pp_stubs[] = {{"proc1", 1007},
@@ -388,25 +425,23 @@ DEF_TEST(fetch_pids_for_procs_one_proc_many_pid) {
   EXPECT_EQ_STR(proc_names[0], output[0].proccess_name);
 
   for (size_t i = 0; i < STATIC_ARRAY_SIZE(pp_stubs); ++i) {
-    if (0 == strcmp(pp_stubs[i].comm, proc_names[0])) {
+    if (0 == strcmp(pp_stubs[i].comm, proc_names[0]))
       /* check if proc struct has correct pids */
-      EXPECT_EQ_INT(pids_list_has_element(output[0].pids, pp_stubs[i].pid), 1);
-    } else {
+      EXPECT_EQ_INT(pids_list_contains_pid(output[0].pids, pp_stubs[i].pid), 1);
+    else
       /* check if proc struct has no incorrect pids */
-      EXPECT_EQ_INT(pids_list_has_element(output[0].pids, pp_stubs[i].pid), 0);
-    }
+      EXPECT_EQ_INT(pids_list_contains_pid(output[0].pids, pp_stubs[i].pid), 0);
   }
 
   /* cleanup */
-  for (size_t i = 0; i < STATIC_ARRAY_SIZE(proc_names); ++i) {
-    pids_list_free_all(output[i].pids);
-  }
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(proc_names); ++i)
+    pids_list_free(output[i].pids);
   free(output);
   stub_procfs_teardown();
   return 0;
 }
 
-DEF_TEST(fetch_pids_for_procs_many_proc_many_pid) {
+DEF_TEST(fetch_pids_for_procs__many_proc_many_pid) {
   /* setup */
   const char *proc_names[] = {"proc1", "proc2", "proc3"};
   stub_proc_pid_t pp_stubs[] = {
@@ -428,37 +463,347 @@ DEF_TEST(fetch_pids_for_procs_many_proc_many_pid) {
     EXPECT_EQ_STR(proc_names[i], output[i].proccess_name);
 
     for (size_t j = 0; j < STATIC_ARRAY_SIZE(pp_stubs); ++j) {
-      if (0 == strcmp(pp_stubs[j].comm, proc_names[i])) {
+      if (0 == strcmp(pp_stubs[j].comm, proc_names[i]))
         /* check if proc struct has correct pids */
-        EXPECT_EQ_INT(pids_list_has_element(output[i].pids, pp_stubs[j].pid),
+        EXPECT_EQ_INT(pids_list_contains_pid(output[i].pids, pp_stubs[j].pid),
                       1);
-      } else {
+      else
         /* check if proc struct has no incorrect pids */
-        EXPECT_EQ_INT(pids_list_has_element(output[i].pids, pp_stubs[j].pid),
+        EXPECT_EQ_INT(pids_list_contains_pid(output[i].pids, pp_stubs[j].pid),
                       0);
-      }
     }
   }
 
   /* cleanup */
-  for (size_t i = 0; i < STATIC_ARRAY_SIZE(proc_names); ++i) {
-    pids_list_free_all(output[i].pids);
-  }
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(proc_names); ++i)
+    pids_list_free(output[i].pids);
   free(output);
   stub_procfs_teardown();
   return 0;
 }
 
+DEF_TEST(rdt_config_ngroups__one_process) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "proc1", .type = OCONFIG_TYPE_STRING},
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_STR(values[0].value.string, rdt->ngroups[0].desc);
+  EXPECT_EQ_INT(1, rdt->num_ngroups);
+
+  /* cleanup */
+  rdt_free_ngroups(rdt);
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_config_ngroups__two_groups) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "proc11,proc12,proc13", .type = OCONFIG_TYPE_STRING},
+      {.value.string = "proc21,proc22,proc23", .type = OCONFIG_TYPE_STRING},
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(2, rdt->num_ngroups);
+  EXPECT_EQ_STR("proc11,proc12,proc13", rdt->ngroups[0].desc);
+  EXPECT_EQ_STR("proc21,proc22,proc23", rdt->ngroups[1].desc);
+  EXPECT_EQ_STR("proc11", rdt->ngroups[0].names[0]);
+  EXPECT_EQ_STR("proc12", rdt->ngroups[0].names[1]);
+  EXPECT_EQ_STR("proc13", rdt->ngroups[0].names[2]);
+  EXPECT_EQ_STR("proc21", rdt->ngroups[1].names[0]);
+  EXPECT_EQ_STR("proc22", rdt->ngroups[1].names[1]);
+  EXPECT_EQ_STR("proc23", rdt->ngroups[1].names[2]);
+
+  /* cleanup */
+  rdt_free_ngroups(rdt);
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_config_ngroups__too_long_proc_name) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "_seventeen_chars_", .type = OCONFIG_TYPE_STRING},
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(-EINVAL, result);
+
+  /* cleanup */
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_config_ngroups__duplicate_proc_name_between_groups) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "proc11,proc12,proc", .type = OCONFIG_TYPE_STRING},
+      {.value.string = "proc21,proc,proc23", .type = OCONFIG_TYPE_STRING},
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(-EINVAL, result);
+
+  /* cleanup */
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_config_ngroups__duplicate_proc_name_in_group) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "proc11,proc,proc,proc14", .type = OCONFIG_TYPE_STRING},
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(-EINVAL, result);
+
+  /* cleanup */
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_config_ngroups__empty_group) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "proc11,proc12,proc13", .type = OCONFIG_TYPE_STRING},
+      {.value.string = "", .type = OCONFIG_TYPE_STRING},
+
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(-EINVAL, result);
+
+  /* cleanup */
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_config_ngroups__empty_proc_name) {
+  /* setup */
+  rdt_ctx_t *rdt = stub_rdt_setup();
+
+  oconfig_value_t values[] = {
+      {.value.string = "proc11,,proc13", .type = OCONFIG_TYPE_STRING},
+  };
+  oconfig_item_t config_item = {
+      .values = values, .values_num = STATIC_ARRAY_SIZE(values),
+  };
+
+  /* check */
+  int result = rdt_config_ngroups(rdt, &config_item);
+  EXPECT_EQ_INT(-EINVAL, result);
+
+  /* cleanup */
+  stub_rdt_teardown(rdt);
+
+  return 0;
+}
+
+DEF_TEST(rdt_pid_list_diff__all_changed) {
+  /* setup */
+  pid_t pids_array_before[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
+  pid_t pids_array_after[] = {2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007};
+  pids_list_t *pids_list_before = NULL;
+  pids_list_t *pids_list_after = NULL;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_after); ++i) {
+    pids_list_add_pid(&pids_list_before, pids_array_before[i]);
+    pids_list_add_pid(&pids_list_after, pids_array_after[i]);
+  }
+
+  pids_list_t *new_pids = NULL;
+  size_t new_pids_count = 0;
+  pids_list_t *lost_pids = NULL;
+  size_t lost_pids_count = 0;
+
+  /* check */
+  int result = rdt_pid_list_diff(pids_list_before, pids_list_after, &new_pids,
+                                 &new_pids_count, &lost_pids, &lost_pids_count);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(STATIC_ARRAY_SIZE(pids_array_before), lost_pids_count);
+  EXPECT_EQ_INT(STATIC_ARRAY_SIZE(pids_array_after), new_pids_count);
+
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_before); ++i) {
+    EXPECT_EQ_INT(1, pids_list_contains_pid(new_pids, pids_array_after[i]));
+    EXPECT_EQ_INT(1, pids_list_contains_pid(lost_pids, pids_array_before[i]));
+  }
+
+  /* cleanup */
+  pids_list_free(pids_list_before);
+  pids_list_free(pids_list_after);
+  pids_list_free(new_pids);
+  pids_list_free(lost_pids);
+
+  return 0;
+}
+
+DEF_TEST(rdt_pid_list_diff__nothing_changed) {
+  /* setup */
+  pid_t pids_array_before[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
+  pids_list_t *pids_list_before = NULL;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_before); ++i) {
+    pids_list_add_pid(&pids_list_before, pids_array_before[i]);
+  }
+
+  pids_list_t *new_pids = NULL;
+  size_t new_pids_count = 0;
+  pids_list_t *lost_pids = NULL;
+  size_t lost_pids_count = 0;
+
+  /* check */
+  int result = rdt_pid_list_diff(pids_list_before, pids_list_before, &new_pids,
+                                 &new_pids_count, &lost_pids, &lost_pids_count);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(0, lost_pids_count);
+  EXPECT_EQ_INT(0, new_pids_count);
+  OK(NULL == new_pids);
+  OK(NULL == lost_pids);
+
+  /* cleanup */
+  pids_list_free(pids_list_before);
+
+  return 0;
+}
+
+DEF_TEST(rdt_pid_list_diff__one_added) {
+  /* setup */
+  pid_t pids_array_before[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
+  pid_t pids_array_after[] = {1000, 1001, 1002, 1003, 1004,
+                              1005, 1006, 1007, 1008};
+  pids_list_t *pids_list_before = NULL;
+  pids_list_t *pids_list_after = NULL;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_before); ++i)
+    pids_list_add_pid(&pids_list_before, pids_array_before[i]);
+
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_after); ++i)
+    pids_list_add_pid(&pids_list_after, pids_array_after[i]);
+
+  pids_list_t *new_pids = NULL;
+  size_t new_pids_count = 0;
+  pids_list_t *lost_pids = NULL;
+  size_t lost_pids_count = 0;
+
+  /* check */
+  int result = rdt_pid_list_diff(pids_list_before, pids_list_after, &new_pids,
+                                 &new_pids_count, &lost_pids, &lost_pids_count);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(0, lost_pids_count);
+  EXPECT_EQ_INT(1, new_pids_count);
+  EXPECT_EQ_INT(1008, new_pids->pid);
+
+  /* cleanup */
+  pids_list_free(pids_list_before);
+  pids_list_free(pids_list_after);
+  pids_list_free(new_pids);
+
+  return 0;
+}
+
+DEF_TEST(rdt_pid_list_diff__one_removed) {
+  /* setup */
+  pid_t pids_array_before[] = {1000, 1001, 1002, 1003, 1004,
+                               1005, 1006, 1007, 1008};
+  pid_t pids_array_after[] = {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007};
+  pids_list_t *pids_list_before = NULL;
+  pids_list_t *pids_list_after = NULL;
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_before); ++i)
+    pids_list_add_pid(&pids_list_before, pids_array_before[i]);
+
+  for (size_t i = 0; i < STATIC_ARRAY_SIZE(pids_array_after); ++i)
+    pids_list_add_pid(&pids_list_after, pids_array_after[i]);
+
+  pids_list_t *new_pids = NULL;
+  size_t new_pids_count = 0;
+  pids_list_t *lost_pids = NULL;
+  size_t lost_pids_count = 0;
+
+  /* check */
+  int result = rdt_pid_list_diff(pids_list_before, pids_list_after, &new_pids,
+                                 &new_pids_count, &lost_pids, &lost_pids_count);
+  EXPECT_EQ_INT(0, result);
+  EXPECT_EQ_INT(1, lost_pids_count);
+  EXPECT_EQ_INT(0, new_pids_count);
+  EXPECT_EQ_INT(1008, lost_pids->pid);
+
+  /* cleanup */
+  pids_list_free(pids_list_before);
+  pids_list_free(pids_list_after);
+  pids_list_free(lost_pids);
+
+  return 0;
+}
+
 int main(void) {
   stub_procfs_teardown();
-  RUN_TEST(add_proc_pid_empty_list);
-  RUN_TEST(add_proc_pid_non_empty_list);
-  RUN_TEST(get_pid_number_valid_dir);
-  RUN_TEST(get_pid_number_invalid_dir_name);
-  RUN_TEST(read_proc_name_valid_name);
-  RUN_TEST(read_proc_name_invalid_name);
-  RUN_TEST(fetch_pids_for_procs_one_proc_many_pid);
-  RUN_TEST(fetch_pids_for_procs_many_proc_many_pid);
+  RUN_TEST(initialize_proc_pids__on_nullptr);
+  RUN_TEST(add_proc_pid__empty_list);
+  RUN_TEST(add_proc_pid__non_empty_list);
+  RUN_TEST(pids_list_to_array__non_empty_list);
+  RUN_TEST(pids_list_add_pids_list__non_empty_lists);
+  RUN_TEST(pids_list_add_pids_list__add_to_empty);
+  RUN_TEST(get_pid_number__valid_dir);
+  RUN_TEST(get_pid_number__invalid_dir_name);
+  RUN_TEST(read_proc_name__valid_name);
+  RUN_TEST(read_proc_name__invalid_name);
+  RUN_TEST(fetch_pids_for_procs__one_proc_many_pid);
+  RUN_TEST(fetch_pids_for_procs__many_proc_many_pid);
+  RUN_TEST(rdt_config_ngroups__one_process);
+  RUN_TEST(rdt_config_ngroups__two_groups);
+  RUN_TEST(rdt_config_ngroups__too_long_proc_name);
+  RUN_TEST(rdt_config_ngroups__duplicate_proc_name_between_groups);
+  RUN_TEST(rdt_config_ngroups__duplicate_proc_name_in_group);
+  RUN_TEST(rdt_config_ngroups__empty_group);
+  RUN_TEST(rdt_config_ngroups__empty_proc_name);
+  RUN_TEST(rdt_pid_list_diff__all_changed);
+  RUN_TEST(rdt_pid_list_diff__nothing_changed);
+  RUN_TEST(rdt_pid_list_diff__one_added);
+  RUN_TEST(rdt_pid_list_diff__one_removed);
   stub_procfs_teardown();
   END_TEST;
 }