From 6e24628d78e4785385876125cba62315ca3b04b9 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 13 Feb 2020 23:51:29 -0800 Subject: lib: Introduce generic min-heap Supports push, pop and converting an array into a heap. If the sense of the compare function is inverted then it can provide a max-heap. Based-on-work-by: Peter Zijlstra (Intel) Signed-off-by: Ian Rogers Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20200214075133.181299-3-irogers@google.com --- lib/test_min_heap.c | 194 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 194 insertions(+) create mode 100644 lib/test_min_heap.c (limited to 'lib/test_min_heap.c') diff --git a/lib/test_min_heap.c b/lib/test_min_heap.c new file mode 100644 index 000000000000..d19c8080fd4d --- /dev/null +++ b/lib/test_min_heap.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define pr_fmt(fmt) "min_heap_test: " fmt + +/* + * Test cases for the min max heap. + */ + +#include +#include +#include +#include +#include + +static __init bool less_than(const void *lhs, const void *rhs) +{ + return *(int *)lhs < *(int *)rhs; +} + +static __init bool greater_than(const void *lhs, const void *rhs) +{ + return *(int *)lhs > *(int *)rhs; +} + +static __init void swap_ints(void *lhs, void *rhs) +{ + int temp = *(int *)lhs; + + *(int *)lhs = *(int *)rhs; + *(int *)rhs = temp; +} + +static __init int pop_verify_heap(bool min_heap, + struct min_heap *heap, + const struct min_heap_callbacks *funcs) +{ + int *values = heap->data; + int err = 0; + int last; + + last = values[0]; + min_heap_pop(heap, funcs); + while (heap->nr > 0) { + if (min_heap) { + if (last > values[0]) { + pr_err("error: expected %d <= %d\n", last, + values[0]); + err++; + } + } else { + if (last < values[0]) { + pr_err("error: expected %d >= %d\n", last, + values[0]); + err++; + } + } + last = values[0]; + min_heap_pop(heap, funcs); + } + return err; +} + +static __init int test_heapify_all(bool min_heap) +{ + int values[] = { 3, 1, 2, 4, 0x8000000, 0x7FFFFFF, 0, + -3, -1, -2, -4, 0x8000000, 0x7FFFFFF }; + struct min_heap heap = { + .data = values, + .nr = ARRAY_SIZE(values), + .size = ARRAY_SIZE(values), + }; + struct min_heap_callbacks funcs = { + .elem_size = sizeof(int), + .less = min_heap ? less_than : greater_than, + .swp = swap_ints, + }; + int i, err; + + /* Test with known set of values. */ + min_heapify_all(&heap, &funcs); + err = pop_verify_heap(min_heap, &heap, &funcs); + + + /* Test with randomly generated values. */ + heap.nr = ARRAY_SIZE(values); + for (i = 0; i < heap.nr; i++) + values[i] = get_random_int(); + + min_heapify_all(&heap, &funcs); + err += pop_verify_heap(min_heap, &heap, &funcs); + + return err; +} + +static __init int test_heap_push(bool min_heap) +{ + const int data[] = { 3, 1, 2, 4, 0x80000000, 0x7FFFFFFF, 0, + -3, -1, -2, -4, 0x80000000, 0x7FFFFFFF }; + int values[ARRAY_SIZE(data)]; + struct min_heap heap = { + .data = values, + .nr = 0, + .size = ARRAY_SIZE(values), + }; + struct min_heap_callbacks funcs = { + .elem_size = sizeof(int), + .less = min_heap ? less_than : greater_than, + .swp = swap_ints, + }; + int i, temp, err; + + /* Test with known set of values copied from data. */ + for (i = 0; i < ARRAY_SIZE(data); i++) + min_heap_push(&heap, &data[i], &funcs); + + err = pop_verify_heap(min_heap, &heap, &funcs); + + /* Test with randomly generated values. */ + while (heap.nr < heap.size) { + temp = get_random_int(); + min_heap_push(&heap, &temp, &funcs); + } + err += pop_verify_heap(min_heap, &heap, &funcs); + + return err; +} + +static __init int test_heap_pop_push(bool min_heap) +{ + const int data[] = { 3, 1, 2, 4, 0x80000000, 0x7FFFFFFF, 0, + -3, -1, -2, -4, 0x80000000, 0x7FFFFFFF }; + int values[ARRAY_SIZE(data)]; + struct min_heap heap = { + .data = values, + .nr = 0, + .size = ARRAY_SIZE(values), + }; + struct min_heap_callbacks funcs = { + .elem_size = sizeof(int), + .less = min_heap ? less_than : greater_than, + .swp = swap_ints, + }; + int i, temp, err; + + /* Fill values with data to pop and replace. */ + temp = min_heap ? 0x80000000 : 0x7FFFFFFF; + for (i = 0; i < ARRAY_SIZE(data); i++) + min_heap_push(&heap, &temp, &funcs); + + /* Test with known set of values copied from data. */ + for (i = 0; i < ARRAY_SIZE(data); i++) + min_heap_pop_push(&heap, &data[i], &funcs); + + err = pop_verify_heap(min_heap, &heap, &funcs); + + heap.nr = 0; + for (i = 0; i < ARRAY_SIZE(data); i++) + min_heap_push(&heap, &temp, &funcs); + + /* Test with randomly generated values. */ + for (i = 0; i < ARRAY_SIZE(data); i++) { + temp = get_random_int(); + min_heap_pop_push(&heap, &temp, &funcs); + } + err += pop_verify_heap(min_heap, &heap, &funcs); + + return err; +} + +static int __init test_min_heap_init(void) +{ + int err = 0; + + err += test_heapify_all(true); + err += test_heapify_all(false); + err += test_heap_push(true); + err += test_heap_push(false); + err += test_heap_pop_push(true); + err += test_heap_pop_push(false); + if (err) { + pr_err("test failed with %d errors\n", err); + return -EINVAL; + } + pr_info("test passed\n"); + return 0; +} +module_init(test_min_heap_init); + +static void __exit test_min_heap_exit(void) +{ + /* do nothing */ +} +module_exit(test_min_heap_exit); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3