#include <linux/module.h> #include <linux/rbtree_augmented.h> #include <linux/random.h> #include <asm/timex.h> #define NODES 100 #define PERF_LOOPS 100000 #define CHECK_LOOPS 100 struct test_node { struct rb_node rb; u32 key; /* following fields used for testing augmented rbtree functionality */ u32 val; u32 augmented; }; static struct rb_root root = RB_ROOT; static struct test_node nodes[NODES]; static struct rnd_state rnd; static void insert(struct test_node *node, struct rb_root *root) { struct rb_node **new = &root->rb_node, *parent = NULL; u32 key = node->key; while (*new) { parent = *new; if (key < rb_entry(parent, struct test_node, rb)->key) new = &parent->rb_left; else new = &parent->rb_right; } rb_link_node(&node->rb, parent, new); rb_insert_color(&node->rb, root); } static inline void erase(struct test_node *node, struct rb_root *root) { rb_erase(&node->rb, root); } static inline u32 augment_recompute(struct test_node *node) { u32 max = node->val, child_augmented; if (node->rb.rb_left) { child_augmented = rb_entry(node->rb.rb_left, struct test_node, rb)->augmented; if (max < child_augmented) max = child_augmented; } if (node->rb.rb_right) { child_augmented = rb_entry(node->rb.rb_right, struct test_node, rb)->augmented; if (max < child_augmented) max = child_augmented; } return max; } RB_DECLARE_CALLBACKS(static, augment_callbacks, struct test_node, rb, u32, augmented, augment_recompute) static void insert_augmented(struct test_node *node, struct rb_root *root) { struct rb_node **new = &root->rb_node, *rb_parent = NULL; u32 key = node->key; u32 val = node->val; struct test_node *parent; while (*new) { rb_parent = *new; parent = rb_entry(rb_parent, struct test_node, rb); if (parent->augmented < val) parent->augmented = val; if (key < parent->key) new = &parent->rb.rb_left; else new = &parent->rb.rb_right; } node->augmented = val; rb_link_node(&node->rb, rb_parent, new); rb_insert_augmented(&node->rb, root, &augment_callbacks); } static void erase_augmented(struct test_node *node, struct rb_root *root) { rb_erase_augmented(&node->rb, root, &augment_callbacks); } static void init(void) { int i; for (i = 0; i < NODES; i++) { nodes[i].key = prandom32(&rnd); nodes[i].val = prandom32(&rnd); } } static bool is_red(struct rb_node *rb) { return !(rb->__rb_parent_color & 1); } static int black_path_count(struct rb_node *rb) { int count; for (count = 0; rb; rb = rb_parent(rb)) count += !is_red(rb); return count; } static void check(int nr_nodes) { struct rb_node *rb; int count = 0; int blacks; u32 prev_key = 0; for (rb = rb_first(&root); rb; rb = rb_next(rb)) { struct test_node *node = rb_entry(rb, struct test_node, rb); WARN_ON_ONCE(node->key < prev_key); WARN_ON_ONCE(is_red(rb) && (!rb_parent(rb) || is_red(rb_parent(rb)))); if (!count) blacks = black_path_count(rb); else WARN_ON_ONCE((!rb->rb_left || !rb->rb_right) && blacks != black_path_count(rb)); prev_key = node->key; count++; } WARN_ON_ONCE(count != nr_nodes); } static void check_augmented(int nr_nodes) { struct rb_node *rb; check(nr_nodes); for (rb = rb_first(&root); rb; rb = rb_next(rb)) { struct test_node *node = rb_entry(rb, struct test_node, rb); WARN_ON_ONCE(node->augmented != augment_recompute(node)); } } static int rbtree_test_init(void) { int i, j; cycles_t time1, time2, time; printk(KERN_ALERT "rbtree testing"); prandom32_seed(&rnd, 3141592653589793238ULL); init(); time1 = get_cycles(); for (i = 0; i < PERF_LOOPS; i++) { for (j = 0; j < NODES; j++) insert(nodes + j, &root); for (j = 0; j < NODES; j++) erase(nodes + j, &root); } time2 = get_cycles(); time = time2 - time1; time = div_u64(time, PERF_LOOPS); printk(" -> %llu cycles\n", (unsigned long long)time); for (i = 0; i < CHECK_LOOPS; i++) { init(); for (j = 0; j < NODES; j++) { check(j); insert(nodes + j, &root); } for (j = 0; j < NODES; j++) { check(NODES - j); erase(nodes + j, &root); } check(0); } printk(KERN_ALERT "augmented rbtree testing"); init(); time1 = get_cycles(); for (i = 0; i < PERF_LOOPS; i++) { for (j = 0; j < NODES; j++) insert_augmented(nodes + j, &root); for (j = 0; j < NODES; j++) erase_augmented(nodes + j, &root); } time2 = get_cycles(); time = time2 - time1; time = div_u64(time, PERF_LOOPS); printk(" -> %llu cycles\n", (unsigned long long)time); for (i = 0; i < CHECK_LOOPS; i++) { init(); for (j = 0; j < NODES; j++) { check_augmented(j); insert_augmented(nodes + j, &root); } for (j = 0; j < NODES; j++) { check_augmented(NODES - j); erase_augmented(nodes + j, &root); } check_augmented(0); } return -EAGAIN; /* Fail will directly unload the module */ } static void rbtree_test_exit(void) { printk(KERN_ALERT "test exit\n"); } module_init(rbtree_test_init) module_exit(rbtree_test_exit) MODULE_LICENSE("GPL"); MODULE_AUTHOR("Michel Lespinasse"); MODULE_DESCRIPTION("Red Black Tree test");