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-rw-r--r--gnulib-tests/test-lock.c618
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diff --git a/gnulib-tests/test-lock.c b/gnulib-tests/test-lock.c
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+/* Test of locking in multithreaded situations.
+ Copyright (C) 2005, 2008-2022 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
+
+#if USE_ISOC_THREADS
+# define TEST_ISOC_THREADS 1
+#endif
+#if USE_POSIX_THREADS
+# define TEST_POSIX_THREADS 1
+#endif
+#if USE_ISOC_AND_POSIX_THREADS
+# define TEST_ISOC_AND_POSIX_THREADS 1
+#endif
+#if USE_WINDOWS_THREADS
+# define TEST_WINDOWS_THREADS 1
+#endif
+
+/* Whether to enable locking.
+ Uncomment this to get a test program without locking, to verify that
+ it crashes. */
+#define ENABLE_LOCKING 1
+
+/* Which tests to perform.
+ Uncomment some of these, to verify that all tests crash if no locking
+ is enabled. */
+#define DO_TEST_LOCK 1
+#define DO_TEST_RWLOCK 1
+#define DO_TEST_RECURSIVE_LOCK 1
+#define DO_TEST_ONCE 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.
+ This is quite high, because with a smaller count, say 5000, we often get
+ an "OK" result even without ENABLE_LOCKING (on Linux/x86). */
+#define REPEAT_COUNT 50000
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if !ENABLE_LOCKING
+# undef USE_ISOC_THREADS
+# undef USE_POSIX_THREADS
+# undef USE_ISOC_AND_POSIX_THREADS
+# undef USE_WINDOWS_THREADS
+#endif
+#include "glthread/lock.h"
+
+#if !ENABLE_LOCKING
+# if TEST_ISOC_THREADS
+# define USE_ISOC_THREADS 1
+# endif
+# if TEST_POSIX_THREADS
+# define USE_POSIX_THREADS 1
+# endif
+# if TEST_ISOC_AND_POSIX_THREADS
+# define USE_ISOC_AND_POSIX_THREADS 1
+# endif
+# if TEST_WINDOWS_THREADS
+# define USE_WINDOWS_THREADS 1
+# endif
+#endif
+
+#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
+
+#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 normal (non-recursive) 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. */
+
+gl_lock_define_initialized(static, my_lock)
+
+static void *
+lock_mutator_thread (void *arg)
+{
+ int repeat;
+
+ for (repeat = REPEAT_COUNT; repeat > 0; repeat--)
+ {
+ int i1, i2, value;
+
+ dbgprintf ("Mutator %p before lock\n", gl_thread_self_pointer ());
+ gl_lock_lock (my_lock);
+ 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 ());
+ gl_lock_unlock (my_lock);
+ dbgprintf ("Mutator %p after unlock\n", gl_thread_self_pointer ());
+
+ dbgprintf ("Mutator %p before check lock\n", gl_thread_self_pointer ());
+ gl_lock_lock (my_lock);
+ check_accounts ();
+ gl_lock_unlock (my_lock);
+ 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)
+ {
+ dbgprintf ("Checker %p before check lock\n", gl_thread_self_pointer ());
+ gl_lock_lock (my_lock);
+ check_accounts ();
+ gl_lock_unlock (my_lock);
+ 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_lock (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 ();
+}
+
+
+/* ----------------- Test read-write (non-recursive) locks ----------------- */
+
+/* Test read-write locks by having several bank accounts and several threads
+ which shuffle around money between the accounts and several other threads
+ that check that all the money is still there. */
+
+gl_rwlock_define_initialized(static, my_rwlock)
+
+static void *
+rwlock_mutator_thread (void *arg)
+{
+ int repeat;
+
+ for (repeat = REPEAT_COUNT; repeat > 0; repeat--)
+ {
+ int i1, i2, value;
+
+ dbgprintf ("Mutator %p before wrlock\n", gl_thread_self_pointer ());
+ gl_rwlock_wrlock (my_rwlock);
+ dbgprintf ("Mutator %p after wrlock\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 ());
+ gl_rwlock_unlock (my_rwlock);
+ dbgprintf ("Mutator %p after unlock\n", gl_thread_self_pointer ());
+
+ yield ();
+ }
+
+ dbgprintf ("Mutator %p dying.\n", gl_thread_self_pointer ());
+ return NULL;
+}
+
+static struct atomic_int rwlock_checker_done;
+
+static void *
+rwlock_checker_thread (void *arg)
+{
+ while (get_atomic_int_value (&rwlock_checker_done) == 0)
+ {
+ dbgprintf ("Checker %p before check rdlock\n", gl_thread_self_pointer ());
+ gl_rwlock_rdlock (my_rwlock);
+ check_accounts ();
+ gl_rwlock_unlock (my_rwlock);
+ 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_rwlock (void)
+{
+ int i;
+ gl_thread_t checkerthreads[THREAD_COUNT];
+ gl_thread_t threads[THREAD_COUNT];
+
+ /* Initialization. */
+ for (i = 0; i < ACCOUNT_COUNT; i++)
+ account[i] = 1000;
+ init_atomic_int (&rwlock_checker_done);
+ set_atomic_int_value (&rwlock_checker_done, 0);
+
+ /* Spawn the threads. */
+ for (i = 0; i < THREAD_COUNT; i++)
+ checkerthreads[i] = gl_thread_create (rwlock_checker_thread, NULL);
+ for (i = 0; i < THREAD_COUNT; i++)
+ threads[i] = gl_thread_create (rwlock_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 (&rwlock_checker_done, 1);
+ for (i = 0; i < THREAD_COUNT; i++)
+ gl_thread_join (checkerthreads[i], NULL);
+ check_accounts ();
+}
+
+
+/* -------------------------- Test recursive locks -------------------------- */
+
+/* Test recursive locks by having several bank accounts and several threads
+ which shuffle around money between the accounts (recursively) and another
+ thread checking that all the money is still there. */
+
+gl_recursive_lock_define_initialized(static, my_reclock)
+
+static void
+recshuffle (void)
+{
+ int i1, i2, value;
+
+ dbgprintf ("Mutator %p before lock\n", gl_thread_self_pointer ());
+ gl_recursive_lock_lock (my_reclock);
+ 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;
+
+ /* Recursive with probability 0.5. */
+ if (((unsigned int) rand () >> 3) % 2)
+ recshuffle ();
+
+ dbgprintf ("Mutator %p before unlock\n", gl_thread_self_pointer ());
+ gl_recursive_lock_unlock (my_reclock);
+ dbgprintf ("Mutator %p after unlock\n", gl_thread_self_pointer ());
+}
+
+static void *
+reclock_mutator_thread (void *arg)
+{
+ int repeat;
+
+ for (repeat = REPEAT_COUNT; repeat > 0; repeat--)
+ {
+ recshuffle ();
+
+ dbgprintf ("Mutator %p before check lock\n", gl_thread_self_pointer ());
+ gl_recursive_lock_lock (my_reclock);
+ check_accounts ();
+ gl_recursive_lock_unlock (my_reclock);
+ 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 reclock_checker_done;
+
+static void *
+reclock_checker_thread (void *arg)
+{
+ while (get_atomic_int_value (&reclock_checker_done) == 0)
+ {
+ dbgprintf ("Checker %p before check lock\n", gl_thread_self_pointer ());
+ gl_recursive_lock_lock (my_reclock);
+ check_accounts ();
+ gl_recursive_lock_unlock (my_reclock);
+ 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_recursive_lock (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 (&reclock_checker_done);
+ set_atomic_int_value (&reclock_checker_done, 0);
+
+ /* Spawn the threads. */
+ checkerthread = gl_thread_create (reclock_checker_thread, NULL);
+ for (i = 0; i < THREAD_COUNT; i++)
+ threads[i] = gl_thread_create (reclock_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 (&reclock_checker_done, 1);
+ gl_thread_join (checkerthread, NULL);
+ check_accounts ();
+}
+
+
+/* ------------------------ Test once-only execution ------------------------ */
+
+/* Test once-only execution by having several threads attempt to grab a
+ once-only task simultaneously (triggered by releasing a read-write lock). */
+
+gl_once_define(static, fresh_once)
+static int ready[THREAD_COUNT];
+static gl_lock_t ready_lock[THREAD_COUNT];
+#if ENABLE_LOCKING
+static gl_rwlock_t fire_signal[REPEAT_COUNT];
+#else
+static volatile int fire_signal_state;
+#endif
+static gl_once_t once_control;
+static int performed;
+gl_lock_define_initialized(static, performed_lock)
+
+static void
+once_execute (void)
+{
+ gl_lock_lock (performed_lock);
+ performed++;
+ gl_lock_unlock (performed_lock);
+}
+
+static void *
+once_contender_thread (void *arg)
+{
+ int id = (int) (intptr_t) arg;
+ int repeat;
+
+ for (repeat = 0; repeat <= REPEAT_COUNT; repeat++)
+ {
+ /* Tell the main thread that we're ready. */
+ gl_lock_lock (ready_lock[id]);
+ ready[id] = 1;
+ gl_lock_unlock (ready_lock[id]);
+
+ if (repeat == REPEAT_COUNT)
+ break;
+
+ dbgprintf ("Contender %p waiting for signal for round %d\n",
+ gl_thread_self_pointer (), repeat);
+#if ENABLE_LOCKING
+ /* Wait for the signal to go. */
+ gl_rwlock_rdlock (fire_signal[repeat]);
+ /* And don't hinder the others (if the scheduler is unfair). */
+ gl_rwlock_unlock (fire_signal[repeat]);
+#else
+ /* Wait for the signal to go. */
+ while (fire_signal_state <= repeat)
+ yield ();
+#endif
+ dbgprintf ("Contender %p got the signal for round %d\n",
+ gl_thread_self_pointer (), repeat);
+
+ /* Contend for execution. */
+ gl_once (once_control, once_execute);
+ }
+
+ return NULL;
+}
+
+static void
+test_once (void)
+{
+ int i, repeat;
+ gl_thread_t threads[THREAD_COUNT];
+
+ /* Initialize all variables. */
+ for (i = 0; i < THREAD_COUNT; i++)
+ {
+ ready[i] = 0;
+ gl_lock_init (ready_lock[i]);
+ }
+#if ENABLE_LOCKING
+ for (i = 0; i < REPEAT_COUNT; i++)
+ gl_rwlock_init (fire_signal[i]);
+#else
+ fire_signal_state = 0;
+#endif
+
+#if ENABLE_LOCKING
+ /* Block all fire_signals. */
+ for (i = REPEAT_COUNT-1; i >= 0; i--)
+ gl_rwlock_wrlock (fire_signal[i]);
+#endif
+
+ /* Spawn the threads. */
+ for (i = 0; i < THREAD_COUNT; i++)
+ threads[i] =
+ gl_thread_create (once_contender_thread, (void *) (intptr_t) i);
+
+ for (repeat = 0; repeat <= REPEAT_COUNT; repeat++)
+ {
+ /* Wait until every thread is ready. */
+ dbgprintf ("Main thread before synchronizing for round %d\n", repeat);
+ for (;;)
+ {
+ int ready_count = 0;
+ for (i = 0; i < THREAD_COUNT; i++)
+ {
+ gl_lock_lock (ready_lock[i]);
+ ready_count += ready[i];
+ gl_lock_unlock (ready_lock[i]);
+ }
+ if (ready_count == THREAD_COUNT)
+ break;
+ yield ();
+ }
+ dbgprintf ("Main thread after synchronizing for round %d\n", repeat);
+
+ if (repeat > 0)
+ {
+ /* Check that exactly one thread executed the once_execute()
+ function. */
+ if (performed != 1)
+ abort ();
+ }
+
+ if (repeat == REPEAT_COUNT)
+ break;
+
+ /* Preparation for the next round: Initialize once_control. */
+ memcpy (&once_control, &fresh_once, sizeof (gl_once_t));
+
+ /* Preparation for the next round: Reset the performed counter. */
+ performed = 0;
+
+ /* Preparation for the next round: Reset the ready flags. */
+ for (i = 0; i < THREAD_COUNT; i++)
+ {
+ gl_lock_lock (ready_lock[i]);
+ ready[i] = 0;
+ gl_lock_unlock (ready_lock[i]);
+ }
+
+ /* Signal all threads simultaneously. */
+ dbgprintf ("Main thread giving signal for round %d\n", repeat);
+#if ENABLE_LOCKING
+ gl_rwlock_unlock (fire_signal[repeat]);
+#else
+ fire_signal_state = repeat + 1;
+#endif
+ }
+
+ /* Wait for the threads to terminate. */
+ for (i = 0; i < THREAD_COUNT; i++)
+ gl_thread_join (threads[i], NULL);
+}
+
+
+/* -------------------------------------------------------------------------- */
+
+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
+
+#if DO_TEST_LOCK
+ printf ("Starting test_lock ..."); fflush (stdout);
+ test_lock ();
+ printf (" OK\n"); fflush (stdout);
+#endif
+#if DO_TEST_RWLOCK
+ printf ("Starting test_rwlock ..."); fflush (stdout);
+ test_rwlock ();
+ printf (" OK\n"); fflush (stdout);
+#endif
+#if DO_TEST_RECURSIVE_LOCK
+ printf ("Starting test_recursive_lock ..."); fflush (stdout);
+ test_recursive_lock ();
+ printf (" OK\n"); fflush (stdout);
+#endif
+#if DO_TEST_ONCE
+ printf ("Starting test_once ..."); fflush (stdout);
+ test_once ();
+ printf (" OK\n"); fflush (stdout);
+#endif
+
+ return 0;
+}
+
+#else
+
+/* No multithreading available. */
+
+#include <stdio.h>
+
+int
+main ()
+{
+ fputs ("Skipping test: multithreading not enabled\n", stderr);
+ return 77;
+}
+
+#endif
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