// 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 <[email protected]>
*
* HISTORY
* 2009-Nov-6: Initial version by Darren Hart <[email protected]>
* 2021-Apr-26: More test cases by André Almeida <[email protected]>
*
*****************************************************************************/
#include <pthread.h>
#include "futextest.h"
#include "futex2test.h"
#include "logging.h"
#define TEST_NAME "futex-wait-timeout"
static long timeout_ns = 100000; /* 100us default timeout */
static futex_t futex_pi;
static pthread_barrier_t barrier;
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);
pthread_barrier_wait(&barrier);
/* 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;
struct futex_waitv waitv = {
.uaddr = (uintptr_t)&f1,
.val = f1,
.flags = FUTEX_32,
.__reserved = 0
};
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(9);
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_barrier_init(&barrier, NULL, 2);
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);
/* Wait until the other thread calls futex_lock_pi() */
pthread_barrier_wait(&barrier);
pthread_barrier_destroy(&barrier);
/*
* 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);
/* futex_waitv with CLOCK_MONOTONIC */
if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
return RET_FAIL;
res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC);
test_timeout(res, &ret, "futex_waitv monotonic", ETIMEDOUT);
/* futex_waitv with CLOCK_REALTIME */
if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
return RET_FAIL;
res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME);
test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT);
ksft_print_cnts();
return ret;
}
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