// SPDX-License-Identifier: GPL-2.0-or-later
/******************************************************************************
 *
 *   Copyright © International Business Machines  Corp., 2009
 *
 * DESCRIPTION
 *      Block on a futex and wait for timeout.
 *
 * AUTHOR
 *      Darren Hart <dvhart@linux.intel.com>
 *
 * HISTORY
 *      2009-Nov-6: Initial version by Darren Hart <dvhart@linux.intel.com>
 *      2021-Apr-26: More test cases by André Almeida <andrealmeid@collabora.com>
 *
 *****************************************************************************/

#include <pthread.h>
#include "futextest.h"
#include "logging.h"

#define TEST_NAME "futex-wait-timeout"

static long timeout_ns = 100000;        /* 100us default timeout */
static futex_t futex_pi;

void usage(char *prog)
{
        printf("Usage: %s\n", prog);
        printf("  -c    Use color\n");
        printf("  -h    Display this help message\n");
        printf("  -t N  Timeout in nanoseconds (default: 100,000)\n");
        printf("  -v L  Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
               VQUIET, VCRITICAL, VINFO);
}

/*
 * Get a PI lock and hold it forever, so the main thread lock_pi will block
 * and we can test the timeout
 */
void *get_pi_lock(void *arg)
{
        int ret;
        volatile futex_t lock = 0;

        ret = futex_lock_pi(&futex_pi, NULL, 0, 0);
        if (ret != 0)
                error("futex_lock_pi failed\n", ret);

        /* Blocks forever */
        ret = futex_wait(&lock, 0, NULL, 0);
        error("futex_wait failed\n", ret);

        return NULL;
}

/*
 * Check if the function returned the expected error
 */
static void test_timeout(int res, int *ret, char *test_name, int err)
{
        if (!res || errno != err) {
                ksft_test_result_fail("%s returned %d\n", test_name,
                                      res < 0 ? errno : res);
                *ret = RET_FAIL;
        } else {
                ksft_test_result_pass("%s succeeds\n", test_name);
        }
}

/*
 * Calculate absolute timeout and correct overflow
 */
static int futex_get_abs_timeout(clockid_t clockid, struct timespec *to,
                                 long timeout_ns)
{
        if (clock_gettime(clockid, to)) {
                error("clock_gettime failed\n", errno);
                return errno;
        }

        to->tv_nsec += timeout_ns;

        if (to->tv_nsec >= 1000000000) {
                to->tv_sec++;
                to->tv_nsec -= 1000000000;
        }

        return 0;
}

int main(int argc, char *argv[])
{
        futex_t f1 = FUTEX_INITIALIZER;
        int res, ret = RET_PASS;
        struct timespec to;
        pthread_t thread;
        int c;

        while ((c = getopt(argc, argv, "cht:v:")) != -1) {
                switch (c) {
                case 'c':
                        log_color(1);
                        break;
                case 'h':
                        usage(basename(argv[0]));
                        exit(0);
                case 't':
                        timeout_ns = atoi(optarg);
                        break;
                case 'v':
                        log_verbosity(atoi(optarg));
                        break;
                default:
                        usage(basename(argv[0]));
                        exit(1);
                }
        }

        ksft_print_header();
        ksft_set_plan(7);
        ksft_print_msg("%s: Block on a futex and wait for timeout\n",
               basename(argv[0]));
        ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns);

        pthread_create(&thread, NULL, get_pi_lock, NULL);

        /* initialize relative timeout */
        to.tv_sec = 0;
        to.tv_nsec = timeout_ns;

        res = futex_wait(&f1, f1, &to, 0);
        test_timeout(res, &ret, "futex_wait relative", ETIMEDOUT);

        /* FUTEX_WAIT_BITSET with CLOCK_REALTIME */
        if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
                return RET_FAIL;
        res = futex_wait_bitset(&f1, f1, &to, 1, FUTEX_CLOCK_REALTIME);
        test_timeout(res, &ret, "futex_wait_bitset realtime", ETIMEDOUT);

        /* FUTEX_WAIT_BITSET with CLOCK_MONOTONIC */
        if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
                return RET_FAIL;
        res = futex_wait_bitset(&f1, f1, &to, 1, 0);
        test_timeout(res, &ret, "futex_wait_bitset monotonic", ETIMEDOUT);

        /* FUTEX_WAIT_REQUEUE_PI with CLOCK_REALTIME */
        if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
                return RET_FAIL;
        res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, FUTEX_CLOCK_REALTIME);
        test_timeout(res, &ret, "futex_wait_requeue_pi realtime", ETIMEDOUT);

        /* FUTEX_WAIT_REQUEUE_PI with CLOCK_MONOTONIC */
        if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
                return RET_FAIL;
        res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, 0);
        test_timeout(res, &ret, "futex_wait_requeue_pi monotonic", ETIMEDOUT);

        /*
         * FUTEX_LOCK_PI with CLOCK_REALTIME
         * Due to historical reasons, FUTEX_LOCK_PI supports only realtime
         * clock, but requires the caller to not set CLOCK_REALTIME flag.
         *
         * If you call FUTEX_LOCK_PI with a monotonic clock, it'll be
         * interpreted as a realtime clock, and (unless you mess your machine's
         * time or your time machine) the monotonic clock value is always
         * smaller than realtime and the syscall will timeout immediately.
         */
        if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
                return RET_FAIL;
        res = futex_lock_pi(&futex_pi, &to, 0, 0);
        test_timeout(res, &ret, "futex_lock_pi realtime", ETIMEDOUT);

        /* Test operations that don't support FUTEX_CLOCK_REALTIME */
        res = futex_lock_pi(&futex_pi, NULL, 0, FUTEX_CLOCK_REALTIME);
        test_timeout(res, &ret, "futex_lock_pi invalid timeout flag", ENOSYS);

        ksft_print_cnts();
        return ret;
}