glibc/sysdeps/unix/sysv/linux/tst-gettid-kill.c

130 lines
3.9 KiB
C

/* Verify the interaction of kill and thread groups.
Copyright (C) 2019-2020 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
<https://www.gnu.org/licenses/>. */
/* This test demonstrates that a signal which is sent to a specified
thread ID using the kill function is delivered to the entire thread
group (as if it had been sent to the process group). */
#include <errno.h>
#include <signal.h>
#include <support/check.h>
#include <support/xsignal.h>
#include <support/xthread.h>
#include <support/xunistd.h>
/* Signal set containing SIGUSR1. */
static sigset_t sigusr1_set;
/* Used to synchronize the threads. */
static pthread_barrier_t barrier;
/* TID of the thread to which the signal is sent. */
static pid_t target_tid;
/* Thread which is expected to receive the SIGUSR1 signal. */
static pthread_t signal_thread;
/* Pipe used to block and terminate the signal thread. */
static int pipe_signal[2];
static volatile sig_atomic_t handler_tid;
static void
sigusr1_handler (int signo)
{
TEST_COMPARE (signo, SIGUSR1);
TEST_VERIFY (pthread_self () == signal_thread);
TEST_COMPARE (handler_tid, 0);
handler_tid = gettid ();
TEST_VERIFY (handler_tid > 0);
/* Ensure that the read system call in thread_read exits if the
signal is delivered before the system call is invoked. */
char ch = 'X';
xwrite (pipe_signal[1], &ch, 1);
}
/* Thread which calls pause without expecting it to return. The TID
of this thread is used as the target in the kill function call. */
static void *
thread_pause_noreturn (void *closure)
{
target_tid = gettid ();
TEST_VERIFY (target_tid > 0);
xpthread_barrier_wait (&barrier);
pause ();
FAIL_EXIT1 ("The pause function returned");
return NULL;
}
/* Thread which is expected to receive the signal. */
static void *
thread_read_signal (void *closure)
{
xpthread_sigmask (SIG_UNBLOCK, &sigusr1_set, NULL);
xpthread_barrier_wait (&barrier);
TEST_VERIFY (target_tid > 0);
TEST_VERIFY (gettid () != target_tid);
char ch;
ssize_t ret = read (pipe_signal[0], &ch, 1);
if (ret == 1)
/* The signal was delivered before we entered the read system
call. */
TEST_COMPARE (ch, 'X');
else
{
/* The signal was delivered while blocked in the read system
call. */
TEST_COMPARE (ret, -1);
TEST_COMPARE (errno, EINTR);
}
TEST_COMPARE (handler_tid, gettid ());
return NULL;
}
static int
do_test (void)
{
/* Block the SIGUSR1 signal in all threads. */
sigemptyset (&sigusr1_set);
sigaddset (&sigusr1_set, SIGUSR1);
xpthread_sigmask (SIG_BLOCK, &sigusr1_set, NULL);
xsignal (SIGUSR1, sigusr1_handler);
xpipe (pipe_signal);
xpthread_barrier_init (&barrier, NULL, 3);
pthread_t target_thread
= xpthread_create (NULL, thread_pause_noreturn, NULL);
signal_thread = xpthread_create (NULL, thread_read_signal, NULL);
xpthread_barrier_wait (&barrier);
/* Send the SIGUSR1 signal to the thread which has it blocked, and
expect it to be delivered to the other thread. */
TEST_COMPARE (kill (target_tid, SIGUSR1), 0);
xpthread_join (signal_thread);
xpthread_cancel (target_thread);
xpthread_join (target_thread);
xpthread_barrier_destroy (&barrier);
return 0;
}
#include <support/test-driver.c>