From 782e4282841fae59d60b16ddfc00bb45cf40771e Mon Sep 17 00:00:00 2001 From: wm4 Date: Fri, 18 May 2018 20:30:56 +0200 Subject: misc: add linked list helpers This provides macros for managing intrusive doubly linked lists. There are many ways how to do those in a "generic" way in C. For example Solaris style lists are pretty nice: https://github.com/illumos/illumos-gate/blob/master/usr/src/uts/common/sys/list.h https://github.com/illumos/illumos-gate/blob/master/usr/src/common/list/list.c I even have an independent implementation of this, which could be ISC licensed. But I think it's easier to vomit ~100 lines of preprocessor garbage, which has a lower footprint, and I think it wins slightly on the side of type safety, simplicity, and ease of use, even if it doesn't look as magically nice. --- test/linked_list.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 test/linked_list.c (limited to 'test/linked_list.c') diff --git a/test/linked_list.c b/test/linked_list.c new file mode 100644 index 0000000000..6ad61f36ec --- /dev/null +++ b/test/linked_list.c @@ -0,0 +1,162 @@ +#include "test_helpers.h" + +#include "common/common.h" +#include "misc/linked_list.h" + +struct list_item { + int v; + struct { + struct list_item *prev, *next; + } list_node; +}; + +struct the_list { + struct list_item *head, *tail; +}; + +static bool do_check_list(struct the_list *lst, int *c, int num_c) +{ + if (!lst->head) + assert_true(!lst->tail); + if (!lst->tail) + assert_true(!lst->head); + + for (struct list_item *cur = lst->head; cur; cur = cur->list_node.next) { + if (cur->list_node.prev) { + assert_true(cur->list_node.prev->list_node.next == cur); + assert_true(lst->head != cur); + } else { + assert_true(lst->head == cur); + } + if (cur->list_node.next) { + assert_true(cur->list_node.next->list_node.prev == cur); + assert_true(lst->tail != cur); + } else { + assert_true(lst->tail == cur); + } + + if (num_c < 1) + return false; + if (c[0] != cur->v) + return false; + + num_c--; + c++; + } + + if (num_c) + return false; + + return true; +} + +static void test_linked_list(void **state) +{ + struct the_list lst = {0}; + struct list_item e1 = {1}; + struct list_item e2 = {2}; + struct list_item e3 = {3}; + struct list_item e4 = {4}; + struct list_item e5 = {5}; + struct list_item e6 = {6}; + +#define check_list(...) \ + assert_true(do_check_list(&lst, (int[]){__VA_ARGS__}, \ + sizeof((int[]){__VA_ARGS__}) / sizeof(int))); +#define check_list_empty() \ + assert_true(do_check_list(&lst, NULL, 0)); + + check_list_empty(); + LL_APPEND(list_node, &lst, &e1); + + check_list(1); + LL_APPEND(list_node, &lst, &e2); + + check_list(1, 2); + LL_APPEND(list_node, &lst, &e4); + + check_list(1, 2, 4); + LL_CLEAR(list_node, &lst); + + check_list_empty(); + LL_PREPEND(list_node, &lst, &e4); + + check_list(4); + LL_PREPEND(list_node, &lst, &e2); + + check_list(2, 4); + LL_PREPEND(list_node, &lst, &e1); + + check_list(1, 2, 4); + LL_CLEAR(list_node, &lst); + + check_list_empty(); + LL_INSERT_BEFORE(list_node, &lst, (struct list_item *)NULL, &e6); + + check_list(6); + LL_INSERT_BEFORE(list_node, &lst, (struct list_item *)NULL, &e1); + + check_list(6, 1); + LL_INSERT_BEFORE(list_node, &lst, (struct list_item *)NULL, &e2); + + check_list(6, 1, 2); + LL_INSERT_BEFORE(list_node, &lst, &e6, &e3); + + check_list(3, 6, 1, 2); + LL_INSERT_BEFORE(list_node, &lst, &e6, &e5); + + check_list(3, 5, 6, 1, 2); + LL_INSERT_BEFORE(list_node, &lst, &e2, &e4); + + check_list(3, 5, 6, 1, 4, 2); + LL_REMOVE(list_node, &lst, &e6); + + check_list(3, 5, 1, 4, 2); + LL_REMOVE(list_node, &lst, &e3); + + check_list(5, 1, 4, 2); + LL_REMOVE(list_node, &lst, &e2); + + check_list(5, 1, 4); + LL_REMOVE(list_node, &lst, &e4); + + check_list(5, 1); + LL_REMOVE(list_node, &lst, &e5); + + check_list(1); + LL_REMOVE(list_node, &lst, &e1); + + check_list_empty(); + LL_APPEND(list_node, &lst, &e2); + + check_list(2); + LL_REMOVE(list_node, &lst, &e2); + + check_list_empty(); + LL_INSERT_AFTER(list_node, &lst, (struct list_item *)NULL, &e1); + + check_list(1); + LL_INSERT_AFTER(list_node, &lst, (struct list_item *)NULL, &e2); + + check_list(2, 1); + LL_INSERT_AFTER(list_node, &lst, (struct list_item *)NULL, &e3); + + check_list(3, 2, 1); + LL_INSERT_AFTER(list_node, &lst, &e3, &e4); + + check_list(3, 4, 2, 1); + LL_INSERT_AFTER(list_node, &lst, &e4, &e5); + + check_list(3, 4, 5, 2, 1); + LL_INSERT_AFTER(list_node, &lst, &e1, &e6); + + check_list(3, 4, 5, 2, 1, 6); +} + +int main(void) { + const struct CMUnitTest tests[] = { + cmocka_unit_test(test_linked_list), + }; + return cmocka_run_group_tests(tests, NULL, NULL); +} + -- cgit v1.2.3