--- /dev/null
+/* Test of spin locks for communication between threads and signal handlers.
+ Copyright (C) 2005, 2008-2020 Free Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2020. */
+
+#include <config.h>
+
+/* Specification. */
+#include "asyncsafe-spin.h"
+
+#include <signal.h>
+
+asyncsafe_spinlock_t global_spin_lock = ASYNCSAFE_SPIN_INIT;
+
+int
+main (void)
+{
+ sigset_t set;
+
+ sigemptyset (&set);
+ sigaddset (&set, SIGINT);
+
+ /* Check a spin-lock initialized through the constant initializer. */
+ {
+ sigset_t saved_set;
+ asyncsafe_spin_lock (&global_spin_lock, &set, &saved_set);
+ asyncsafe_spin_unlock (&global_spin_lock, &saved_set);
+ }
+
+ /* Check a spin-lock initialized through asyncsafe_spin_init. */
+ {
+ asyncsafe_spinlock_t local_spin_lock;
+ int i;
+
+ asyncsafe_spin_init (&local_spin_lock);
+
+ for (i = 0; i < 10; i++)
+ {
+ sigset_t saved_set;
+ asyncsafe_spin_lock (&local_spin_lock, &set, &saved_set);
+ asyncsafe_spin_unlock (&local_spin_lock, &saved_set);
+ }
+
+ asyncsafe_spin_destroy (&local_spin_lock);
+ }
+
+ return 0;
+}
--- /dev/null
+/* Test of spin locks for communication between threads and signal handlers.
+ Copyright (C) 2005, 2008-2020 Free Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2005. */
+
+#include <config.h>
+
+#if USE_ISOC_THREADS || USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS || USE_WINDOWS_THREADS
+
+/* Whether to enable locking.
+ Uncomment this to get a test program without locking, to verify that
+ it crashes. */
+#define ENABLE_LOCKING 1
+
+/* Whether to help the scheduler through explicit yield().
+ Uncomment this to see if the operating system has a fair scheduler. */
+#define EXPLICIT_YIELD 1
+
+/* Whether to print debugging messages. */
+#define ENABLE_DEBUGGING 0
+
+/* Number of simultaneous threads. */
+#define THREAD_COUNT 10
+
+/* Number of operations performed in each thread. */
+#if !(defined _WIN32 && ! defined __CYGWIN__) && HAVE_PTHREAD_H && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) && !defined __ibmxl__
+/* The GCC built-ins are known to work fine. */
+# define REPEAT_COUNT 5000
+#else
+/* This is quite high, because with a smaller count, say 50000, we often get
+ an "OK" result even with the racy implementation that we pick on Fedora 13
+ Linux/x86_64 (gcc 4.4). */
+# define REPEAT_COUNT 100000
+#endif
+
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "asyncsafe-spin.h"
+#if !ENABLE_LOCKING
+# define asyncsafe_spin_init(lock) (void)(lock)
+# define asyncsafe_spin_lock(lock, mask, saved_mask) \
+ ((void)(lock), (void)(mask), (void)(saved_mask))
+# define asyncsafe_spin_unlock(lock, saved_mask) \
+ ((void)(lock), (void)(saved_mask))
+# define asyncsafe_spin_destroy(lock) (void)(lock)
+#endif
+
+#include "glthread/lock.h"
+#include "glthread/thread.h"
+#include "glthread/yield.h"
+
+#if HAVE_DECL_ALARM
+# include <signal.h>
+# include <unistd.h>
+#endif
+
+#include "atomic-int-gnulib.h"
+
+#if ENABLE_DEBUGGING
+# define dbgprintf printf
+#else
+# define dbgprintf if (0) printf
+#endif
+
+#if EXPLICIT_YIELD
+# define yield() gl_thread_yield ()
+#else
+# define yield()
+#endif
+
+static sigset_t signals_to_block;
+
+#define ACCOUNT_COUNT 4
+
+static int account[ACCOUNT_COUNT];
+
+static int
+random_account (void)
+{
+ return ((unsigned int) rand () >> 3) % ACCOUNT_COUNT;
+}
+
+static void
+check_accounts (void)
+{
+ int i, sum;
+
+ sum = 0;
+ for (i = 0; i < ACCOUNT_COUNT; i++)
+ sum += account[i];
+ if (sum != ACCOUNT_COUNT * 1000)
+ abort ();
+}
+
+
+/* ------------------- Test use like normal locks ------------------- */
+
+/* Test normal locks by having several bank accounts and several threads
+ which shuffle around money between the accounts and another thread
+ checking that all the money is still there. */
+
+static asyncsafe_spinlock_t my_lock;
+
+static void *
+lock_mutator_thread (void *arg)
+{
+ int repeat;
+
+ for (repeat = REPEAT_COUNT; repeat > 0; repeat--)
+ {
+ sigset_t saved_signals;
+ int i1, i2, value;
+
+ dbgprintf ("Mutator %p before lock\n", gl_thread_self_pointer ());
+ asyncsafe_spin_lock (&my_lock, &signals_to_block, &saved_signals);
+ dbgprintf ("Mutator %p after lock\n", gl_thread_self_pointer ());
+
+ i1 = random_account ();
+ i2 = random_account ();
+ value = ((unsigned int) rand () >> 3) % 10;
+ account[i1] += value;
+ account[i2] -= value;
+
+ dbgprintf ("Mutator %p before unlock\n", gl_thread_self_pointer ());
+ asyncsafe_spin_unlock (&my_lock, &saved_signals);
+ dbgprintf ("Mutator %p after unlock\n", gl_thread_self_pointer ());
+
+ dbgprintf ("Mutator %p before check lock\n", gl_thread_self_pointer ());
+ asyncsafe_spin_lock (&my_lock, &signals_to_block, &saved_signals);
+ check_accounts ();
+ asyncsafe_spin_unlock (&my_lock, &saved_signals);
+ dbgprintf ("Mutator %p after check unlock\n", gl_thread_self_pointer ());
+
+ yield ();
+ }
+
+ dbgprintf ("Mutator %p dying.\n", gl_thread_self_pointer ());
+ return NULL;
+}
+
+static struct atomic_int lock_checker_done;
+
+static void *
+lock_checker_thread (void *arg)
+{
+ while (get_atomic_int_value (&lock_checker_done) == 0)
+ {
+ sigset_t saved_signals;
+
+ dbgprintf ("Checker %p before check lock\n", gl_thread_self_pointer ());
+ asyncsafe_spin_lock (&my_lock, &signals_to_block, &saved_signals);
+ check_accounts ();
+ asyncsafe_spin_unlock (&my_lock, &saved_signals);
+ dbgprintf ("Checker %p after check unlock\n", gl_thread_self_pointer ());
+
+ yield ();
+ }
+
+ dbgprintf ("Checker %p dying.\n", gl_thread_self_pointer ());
+ return NULL;
+}
+
+static void
+test_asyncsafe_spin (void)
+{
+ int i;
+ gl_thread_t checkerthread;
+ gl_thread_t threads[THREAD_COUNT];
+
+ /* Initialization. */
+ for (i = 0; i < ACCOUNT_COUNT; i++)
+ account[i] = 1000;
+ init_atomic_int (&lock_checker_done);
+ set_atomic_int_value (&lock_checker_done, 0);
+
+ /* Spawn the threads. */
+ checkerthread = gl_thread_create (lock_checker_thread, NULL);
+ for (i = 0; i < THREAD_COUNT; i++)
+ threads[i] = gl_thread_create (lock_mutator_thread, NULL);
+
+ /* Wait for the threads to terminate. */
+ for (i = 0; i < THREAD_COUNT; i++)
+ gl_thread_join (threads[i], NULL);
+ set_atomic_int_value (&lock_checker_done, 1);
+ gl_thread_join (checkerthread, NULL);
+ check_accounts ();
+}
+
+
+/* -------------------------------------------------------------------------- */
+
+int
+main ()
+{
+#if HAVE_DECL_ALARM
+ /* Declare failure if test takes too long, by using default abort
+ caused by SIGALRM. */
+ int alarm_value = 600;
+ signal (SIGALRM, SIG_DFL);
+ alarm (alarm_value);
+#endif
+
+ sigemptyset (&signals_to_block);
+ sigaddset (&signals_to_block, SIGINT);
+
+ asyncsafe_spin_init (&my_lock);
+
+ printf ("Starting test_asyncsafe_spin ..."); fflush (stdout);
+ test_asyncsafe_spin ();
+ printf (" OK\n"); fflush (stdout);
+
+ return 0;
+}
+
+#else
+
+/* No multithreading available. */
+
+#include <stdio.h>
+
+int
+main ()
+{
+ fputs ("Skipping test: multithreading not enabled\n", stderr);
+ return 77;
+}
+
+#endif