From bc888a3976700a3607f6ec4a36dbf3030161cb3e Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 3 Oct 2023 09:22:51 -0300 Subject: [PATCH] stdlib: Add more qsort{_r} coverage This patch adds a qsort and qsort_r to trigger the worst case scenario for the quicksort (which glibc current lacks coverage). The test is done with random input, dfferent internal types (uint8_t, uint16_t, uint32_t, uint64_t, large size), and with different set of element numbers. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Noah Goldstein --- stdlib/Makefile | 1 + stdlib/tst-qsort3.c | 366 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 367 insertions(+) create mode 100644 stdlib/tst-qsort3.c diff --git a/stdlib/Makefile b/stdlib/Makefile index 095518eef4..6af606136e 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -214,6 +214,7 @@ tests := \ tst-on_exit \ tst-qsort \ tst-qsort2 \ + tst-qsort3 \ tst-quick_exit \ tst-rand48 \ tst-rand48-2 \ diff --git a/stdlib/tst-qsort3.c b/stdlib/tst-qsort3.c new file mode 100644 index 0000000000..421560d744 --- /dev/null +++ b/stdlib/tst-qsort3.c @@ -0,0 +1,366 @@ +/* qsort(_r) tests to trigger worst case for quicksort. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +typedef enum +{ + Sorted, + Random, + Repeated, + Bitonic, + Duplicated, +} arraytype_t; + +/* Ratio of total of elements which will be repeated. */ +static const double RepeatedRatio = 0.2; + +/* Ratio of duplicated element . */ +static const double DuplicatedRatio = 0.4; + +struct array_t +{ + arraytype_t type; + const char *name; +} static const arraytypes[] = +{ + { Sorted, "Sorted" }, + { Random, "Random" }, + { Repeated, "Repeated" }, + { Bitonic, "Bitonic" }, + { Duplicated, "Duplicated" }, +}; + +/* Return the index of BASE as interpreted as an array of elements + of size SIZE. */ +static inline void * +arr (void *base, size_t idx, size_t size) +{ + return (void*)((uintptr_t)base + (idx * size)); +} + +/* Functions used to check qsort. */ +static int +uint8_t_cmp (const void *a, const void *b) +{ + uint8_t ia = *(uint8_t*)a; + uint8_t ib = *(uint8_t*)b; + return (ia > ib) - (ia < ib); +} + +static int +uint16_t_cmp (const void *a, const void *b) +{ + uint16_t ia = *(uint16_t*)a; + uint16_t ib = *(uint16_t*)b; + return (ia > ib) - (ia < ib); +} + +static int +uint32_t_cmp (const void *a, const void *b) +{ + uint32_t ia = *(uint32_t*)a; + uint32_t ib = *(uint32_t*)b; + return (ia > ib) - (ia < ib); +} + +static int +uint64_t_cmp (const void *a, const void *b) +{ + uint64_t ia = *(uint64_t*)a; + uint64_t ib = *(uint64_t*)b; + return (ia > ib) - (ia < ib); +} + +#define LARGE_SIZE 47 + +static int +large_cmp (const void *a, const void *b) +{ + return memcmp (a, b, LARGE_SIZE); +} + +/* Function used to check qsort_r. */ +typedef enum +{ + UINT8_CMP_T, + UINT16_CMP_T, + UINT32_CMP_T, + UINT64_CMP_T, + LARGE_CMP_T +} type_cmp_t; + +static type_cmp_t +uint_t_cmp_type (size_t sz) +{ + switch (sz) + { + case sizeof (uint8_t): return UINT8_CMP_T; + case sizeof (uint16_t): return UINT16_CMP_T; + case sizeof (uint64_t): return UINT64_CMP_T; + case sizeof (uint32_t): return UINT32_CMP_T; + default: return LARGE_CMP_T; + } +} + +static int +uint_t_cmp (const void *a, const void *b, void *arg) +{ + type_cmp_t type = *(type_cmp_t*) arg; + switch (type) + { + case UINT8_CMP_T: return uint8_t_cmp (a, b); + case UINT32_CMP_T: return uint32_t_cmp (a, b); + case UINT16_CMP_T: return uint16_t_cmp (a, b); + case UINT64_CMP_T: return uint64_t_cmp (a, b); + default: return large_cmp (a, b); + } +} + +static void +seq (void *elem, size_t type_size, int value) +{ + if (type_size == sizeof (uint8_t)) + *(uint8_t*)elem = value; + else if (type_size == sizeof (uint16_t)) + *(uint16_t*)elem = value; + else if (type_size == sizeof (uint32_t)) + *(uint32_t*)elem = value; + else if (type_size == sizeof (uint64_t)) + *(uint64_t*)elem = value; + else + memset (elem, value, type_size); +} + +static void +fill_array (void *array, void *refarray, size_t nmemb, size_t type_size, + arraytype_t type) +{ + size_t size = nmemb * type_size; + + switch (type) + { + case Sorted: + for (size_t i = 0; i < nmemb; i++) + seq (arr (array, i, type_size), type_size, i); + break; + + case Random: + arc4random_buf (array, size); + break; + + case Repeated: + { + arc4random_buf (array, size); + + void *randelem = xmalloc (type_size); + arc4random_buf (randelem, type_size); + + /* Repeat REPEATED elements (based on RepeatRatio ratio) in the random + array. */ + size_t repeated = (size_t)(nmemb * RepeatedRatio); + for (size_t i = 0; i < repeated; i++) + { + size_t pos = arc4random_uniform (nmemb - 1); + memcpy (arr (array, pos, type_size), randelem, type_size); + } + free (randelem); + } + break; + + case Bitonic: + { + size_t i; + for (i = 0; i < nmemb / 2; i++) + seq (arr (array, i, type_size), type_size, i); + for ( ; i < nmemb; i++) + seq (arr (array, i, type_size), type_size, (nmemb - 1) - i); + } + break; + + case Duplicated: + { + int randelem1 = arc4random (); + for (size_t i = 0; i < nmemb; i++) + seq (arr (array, i, type_size), type_size, randelem1); + + size_t duplicates = (size_t)(nmemb * DuplicatedRatio); + int randelem2 = arc4random (); + for (size_t i = 0; i < duplicates; i++) + { + size_t pos = arc4random_uniform (nmemb - 1); + seq (arr (array, pos, type_size), type_size, randelem2); + } + } + break; + } + + memcpy (refarray, array, size); +} + +typedef int (*cmpfunc_t)(const void *, const void *); + +/* Simple insertion sort to use as reference sort. */ +static void +qsort_r_ref (void *p, size_t n, size_t s, __compar_d_fn_t cmp, void *arg) +{ + if (n <= 1) + return; + + int i = 1; + char tmp[s]; + while (i < n) + { + memcpy (tmp, arr (p, i, s), s); + int j = i - 1; + while (j >= 0 && cmp (arr (p, j, s), tmp, arg) > 0) + { + memcpy (arr (p, j + 1, s), arr (p, j, s), s); + j = j - 1; + } + memcpy (arr (p, j + 1, s), tmp, s); + i = i + 1; + } +} + +static void +qsort_ref (void *b, size_t n, size_t s, __compar_fn_t cmp) +{ + return qsort_r_ref (b, n, s, (__compar_d_fn_t) cmp, NULL); +} + +/* Check if ARRAY of total NMEMB element of size SIZE is sorted + based on CMPFUNC. */ +static void +check_array (void *array, void *refarray, size_t nmemb, size_t type_size, + cmpfunc_t cmpfunc) +{ + for (size_t i = 1; i < nmemb; i++) + { + int ret = cmpfunc (arr (array, i, type_size), + arr (array, i-1, type_size)); + TEST_VERIFY_EXIT (ret >= 0); + } + + size_t size = nmemb * type_size; + TEST_COMPARE_BLOB (array, size, refarray, size); +} + +static void +check_qsort (void *buf, void *refbuf, size_t nelem, size_t type_size, + arraytype_t type, cmpfunc_t cmpfunc) +{ + fill_array (buf, refbuf, nelem, type_size, type); + + qsort (buf, nelem, type_size, cmpfunc); + qsort_ref (refbuf, nelem, type_size, cmpfunc); + + check_array (buf, refbuf, nelem, type_size, cmpfunc); +} + +static void +check_qsort_r (void *buf, void *refbuf, size_t nelem, size_t type_size, + arraytype_t type, cmpfunc_t cmpfunc) +{ + fill_array (buf, refbuf, nelem, type_size, type); + + type_cmp_t typecmp = uint_t_cmp_type (type_size); + + qsort_r (buf, nelem, type_size, uint_t_cmp, &typecmp); + qsort_r_ref (refbuf, nelem, type_size, uint_t_cmp, &typecmp); + + check_array (buf, refbuf, nelem, type_size, cmpfunc); +} + +static int +do_test (void) +{ + /* Some random sizes. */ + static const size_t nelems[] = { 0, 1, 7, 20, 32, 100, 256, 1024, 4256 }; + size_t max_nelems = 0; + for (int i = 0; i < array_length (nelems); i++) + if (nelems[i] > max_nelems) + max_nelems = nelems[i]; + + static const struct test_t + { + size_t type_size; + cmpfunc_t cmpfunc; + } + tests[] = + { + { sizeof (uint8_t), uint8_t_cmp }, + { sizeof (uint16_t), uint16_t_cmp }, + { sizeof (uint32_t), uint32_t_cmp }, + { sizeof (uint64_t), uint64_t_cmp }, + /* Test swap with large elements. */ + { LARGE_SIZE, large_cmp }, + }; + size_t max_type_size = 0; + for (int i = 0; i < array_length (tests); i++) + if (tests[i].type_size > max_type_size) + max_type_size = tests[i].type_size; + + void *buf = reallocarray (NULL, max_nelems, max_type_size); + TEST_VERIFY_EXIT (buf != NULL); + void *refbuf = reallocarray (NULL, max_nelems, max_type_size); + TEST_VERIFY_EXIT (refbuf != NULL); + + for (const struct test_t *test = tests; test < array_end (tests); ++test) + { + if (test_verbose > 0) + printf ("info: testing qsort with type_size=%zu\n", test->type_size); + for (const struct array_t *arraytype = arraytypes; + arraytype < array_end (arraytypes); + ++arraytype) + { + if (test_verbose > 0) + printf (" distribution=%s\n", arraytype->name); + for (const size_t *nelem = nelems; + nelem < array_end (nelems); + ++nelem) + { + if (test_verbose > 0) + printf (" nelem=%zu, total size=%zu\n", *nelem, + *nelem * test->type_size); + + check_qsort (buf, refbuf, *nelem, test->type_size, + arraytype->type, test->cmpfunc); + check_qsort_r (buf, refbuf, *nelem, test->type_size, + arraytype->type, test->cmpfunc); + } + } + } + + free (buf); + free (refbuf); + + return 0; +} + +#include -- 2.43.5