New upstream version 1.3upstream/1.3upstream

1 files changed, 229 insertions, 0 deletions

diff --git a/tests/test-pthread-rwlock.c b/tests/test-pthread-rwlock.c
new file mode 100644
index 00000000..7ab8d5ee
--- /dev/null
+++ b/tests/test-pthread-rwlock.c
@@ -0,0 +1,229 @@
+/* Test of read-write locks in multithreaded situations.
+   Copyright (C) 2005, 2008-2024 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 sched_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 <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if EXPLICIT_YIELD
+# include <sched.h>
+#endif
+
+#if HAVE_DECL_ALARM
+# include <signal.h>
+# include <unistd.h>
+#endif
+
+#include "macros.h"
+#include "atomic-int-posix.h"
+
+#if ENABLE_DEBUGGING
+# define dbgprintf printf
+#else
+# define dbgprintf if (0) printf
+#endif
+
+#if EXPLICIT_YIELD
+# define yield() sched_yield ()
+#else
+# define yield()
+#endif
+
+/* Returns a reference to the current thread as a pointer, for debugging.  */
+#if defined __MVS__
+  /* On IBM z/OS, pthread_t is a struct with an 8-byte '__' field.
+     The first three bytes of this field appear to uniquely identify a
+     pthread_t, though not necessarily representing a pointer.  */
+# define pthread_self_pointer() (*((void **) pthread_self ().__))
+#else
+# define pthread_self_pointer() ((void *) (uintptr_t) pthread_self ())
+#endif
+
+#define ACCOUNT_COUNT 4
+
+static int account[ACCOUNT_COUNT];
+
+static int
+random_account (void)
+{
+  return ((unsigned long) random () >> 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 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.  */
+
+static pthread_rwlock_t my_rwlock = PTHREAD_RWLOCK_INITIALIZER;
+
+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", pthread_self_pointer ());
+      ASSERT (pthread_rwlock_wrlock (&my_rwlock) == 0);
+      dbgprintf ("Mutator %p after  wrlock\n", pthread_self_pointer ());
+
+      i1 = random_account ();
+      i2 = random_account ();
+      value = ((unsigned long) random () >> 3) % 10;
+      account[i1] += value;
+      account[i2] -= value;
+
+      dbgprintf ("Mutator %p before unlock\n", pthread_self_pointer ());
+      ASSERT (pthread_rwlock_unlock (&my_rwlock) == 0);
+      dbgprintf ("Mutator %p after  unlock\n", pthread_self_pointer ());
+
+      yield ();
+    }
+
+  dbgprintf ("Mutator %p dying.\n", pthread_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", pthread_self_pointer ());
+      ASSERT (pthread_rwlock_rdlock (&my_rwlock) == 0);
+      check_accounts ();
+      ASSERT (pthread_rwlock_unlock (&my_rwlock) == 0);
+      dbgprintf ("Checker %p after  check unlock\n", pthread_self_pointer ());
+
+      yield ();
+    }
+
+  dbgprintf ("Checker %p dying.\n", pthread_self_pointer ());
+  return NULL;
+}
+
+static void
+test_rwlock (void)
+{
+  int i;
+  pthread_t checkerthreads[THREAD_COUNT];
+  pthread_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++)
+    ASSERT (pthread_create (&checkerthreads[i], NULL,
+                            rwlock_checker_thread, NULL)
+            == 0);
+  for (i = 0; i < THREAD_COUNT; i++)
+    ASSERT (pthread_create (&threads[i], NULL, rwlock_mutator_thread, NULL)
+            == 0);
+
+  /* Wait for the threads to terminate.  */
+  for (i = 0; i < THREAD_COUNT; i++)
+    ASSERT (pthread_join (threads[i], NULL) == 0);
+  set_atomic_int_value (&rwlock_checker_done, 1);
+  for (i = 0; i < THREAD_COUNT; i++)
+    ASSERT (pthread_join (checkerthreads[i], NULL) == 0);
+  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
+
+  printf ("Starting test_rwlock ..."); fflush (stdout);
+  test_rwlock ();
+  printf (" OK\n"); fflush (stdout);
+
+  return test_exit_status;
+}
+
+#else
+
+/* No multithreading available.  */
+
+#include <stdio.h>
+
+int
+main ()
+{
+  fputs ("Skipping test: multithreading not enabled\n", stderr);
+  return 77;
+}
+
+#endif