android13/external/ltp/testcases/kernel/syscalls/futex/futex_wake02.c

144 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015 Cyril Hrubis <chrubis@suse.cz>
*
* Block several threads on a private mutex, then wake them up.
*/
#include <sys/types.h>
#include "futextest.h"
#include "futex_utils.h"
#include "tst_safe_pthread.h"
static futex_t futex = FUTEX_INITIALIZER;
static volatile int threads_flags[55];
static struct futex_test_variants variants[] = {
#if (__NR_futex != __LTP__NR_INVALID_SYSCALL)
{ .fntype = FUTEX_FN_FUTEX, .desc = "syscall with old kernel spec"},
#endif
#if (__NR_futex_time64 != __LTP__NR_INVALID_SYSCALL)
{ .fntype = FUTEX_FN_FUTEX64, .desc = "syscall time64 with kernel spec"},
#endif
};
static int threads_awake(void)
{
int ret = 0;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(threads_flags); i++) {
if (threads_flags[i])
ret++;
}
return ret;
}
static void clear_threads_awake(void)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(threads_flags); i++)
threads_flags[i] = 0;
}
static void *threaded(void *arg)
{
struct futex_test_variants *tv = &variants[tst_variant];
long i = (long)arg;
futex_wait(tv->fntype, &futex, futex, NULL, FUTEX_PRIVATE_FLAG);
threads_flags[i] = 1;
return NULL;
}
static void do_child(void)
{
struct futex_test_variants *tv = &variants[tst_variant];
int i, j, awake;
pthread_t t[55];
for (i = 0; i < (int)ARRAY_SIZE(t); i++)
SAFE_PTHREAD_CREATE(&t[i], NULL, threaded, (void*)((long)i));
while (wait_for_threads(ARRAY_SIZE(t)))
usleep(100);
for (i = 1; i <= 10; i++) {
clear_threads_awake();
TEST(futex_wake(tv->fntype, &futex, i, FUTEX_PRIVATE_FLAG));
if (i != TST_RET) {
tst_res(TFAIL | TTERRNO,
"futex_wake() woken up %li threads, expected %i",
TST_RET, i);
}
for (j = 0; j < 100000; j++) {
awake = threads_awake();
if (awake == i)
break;
usleep(100);
}
if (awake == i) {
tst_res(TPASS, "futex_wake() woken up %i threads", i);
} else {
tst_res(TFAIL, "Woken up %i threads, expected %i",
awake, i);
}
}
TEST(futex_wake(tv->fntype, &futex, 1, FUTEX_PRIVATE_FLAG));
if (TST_RET) {
tst_res(TFAIL | TTERRNO, "futex_wake() woken up %li, none were waiting",
TST_RET);
} else {
tst_res(TPASS, "futex_wake() woken up 0 threads");
}
for (i = 0; i < (int)ARRAY_SIZE(t); i++)
SAFE_PTHREAD_JOIN(t[i], NULL);
exit(0);
}
/*
* We do the real test in a child because with the test -i parameter the loop
* that checks that all threads are sleeping may fail with ENOENT. That is
* because some of the threads from previous run may still be there.
*
* Which is because the userspace part of pthread_join() sleeps in a futex on a
* pthread tid which is woken up at the end of the exit_mm(tsk) which is before
* the process is removed from the parent thread_group list. So there is a
* small race window where the readdir() returns the process tid as a directory
* under /proc/$PID/tasks/, but the subsequent open() fails with ENOENT because
* the thread was removed meanwhile.
*/
static void run(void)
{
if (!SAFE_FORK())
do_child();
}
static void setup(void)
{
struct futex_test_variants *tv = &variants[tst_variant];
tst_res(TINFO, "Testing variant: %s", tv->desc);
futex_supported_by_kernel(tv->fntype);
}
static struct tst_test test = {
.setup = setup,
.test_all = run,
.test_variants = ARRAY_SIZE(variants),
.forks_child = 1,
};