#include <assert.h>
#include <errno.h>
#include <stdint.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>

/* 校准探针：正常释放、失败 realloc、零大小释放和已知的 37 字节残留。 */
static void *volatile retained;
static pthread_barrier_t start;

static void exercise(void) {
    for (int index = 0; index < 1000; index++) {
        void *first = malloc(10);
        assert(first);
        first = realloc(first, 20);
        assert(first);
        void *second = calloc(2, 16);
        assert(second);
        volatile size_t impossible = SIZE_MAX;
        assert(realloc(first, impossible) == NULL);
        free(second);
        assert(realloc(first, 0) == NULL);
        void *aligned = NULL;
        assert(posix_memalign(&aligned, 64, 96) == 0);
        assert((uintptr_t)aligned % 64 == 0);
        void *original = aligned;
        errno = E2BIG;
        assert(posix_memalign(&aligned, 3, 96) == EINVAL);
        assert(aligned == original && errno == E2BIG);
        assert(posix_memalign(&aligned, 64, impossible) == ENOMEM);
        assert(aligned == original && errno == E2BIG);
        free(aligned);
    }
}

static void *worker(void *input) {
    pthread_barrier_wait(&start);
    free(input);
    exercise();
    return NULL;
}

int main(int count, char **arguments) {
    int concurrent = count > 1 && strcmp(arguments[1], "threads") == 0;
    if (concurrent) {
        pthread_t workers[4];
        assert(pthread_barrier_init(&start, NULL, 5) == 0);
        for (size_t index = 0; index < 4; index++) {
            void *input = malloc(16);
            assert(input);
            assert(pthread_create(&workers[index], NULL, worker, input) == 0);
        }
        pthread_barrier_wait(&start);
        for (size_t index = 0; index < 4; index++) {
            assert(pthread_join(workers[index], NULL) == 0);
        }
        assert(pthread_barrier_destroy(&start) == 0);
    } else {
        exercise();
    }
    if (count > (concurrent ? 2 : 1)) retained = malloc(37);
    return 0;
}