New upstream version 1.3upstream/1.3upstream

1 files changed, 179 insertions, 0 deletions

diff --git a/tests/atomic-int-posix.h b/tests/atomic-int-posix.h
new file mode 100644
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+/* Atomic integers.  Useful for testing multithreaded locking primitives.
+   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/>.  */
+
+
+/* Whether to use 'volatile' on some variables that communicate information
+   between threads.  If set to 0, a semaphore or a lock is used to protect
+   these variables.  If set to 1, 'volatile' is used; this is theoretically
+   equivalent but can lead to much slower execution (e.g. 30x slower total
+   run time on a 40-core machine), because 'volatile' does not imply any
+   synchronization/communication between different CPUs.  */
+#define USE_VOLATILE 0
+
+#if USE_POSIX_THREADS && HAVE_SEMAPHORE_H
+/* Whether to use a semaphore to communicate information between threads.
+   If set to 0, a lock is used. If set to 1, a semaphore is used.
+   Uncomment this to reduce the dependencies of this test.  */
+# define USE_SEMAPHORE 1
+/* Mac OS X provides only named semaphores (sem_open); its facility for
+   unnamed semaphores (sem_init) does not work.  */
+# if defined __APPLE__ && defined __MACH__
+#  define USE_NAMED_SEMAPHORE 1
+# else
+#  define USE_UNNAMED_SEMAPHORE 1
+# endif
+#endif
+
+
+#if USE_SEMAPHORE
+# include <errno.h>
+# include <fcntl.h>
+# include <semaphore.h>
+# include <unistd.h>
+#endif
+
+
+#if USE_VOLATILE
+struct atomic_int {
+  volatile int value;
+};
+static void
+init_atomic_int (struct atomic_int *ai)
+{
+}
+static int
+get_atomic_int_value (struct atomic_int *ai)
+{
+  return ai->value;
+}
+static void
+set_atomic_int_value (struct atomic_int *ai, int new_value)
+{
+  ai->value = new_value;
+}
+#elif USE_SEMAPHORE
+/* This atomic_int implementation can only support the values 0 and 1.
+   It is initially 0 and can be set to 1 only once.  */
+# if USE_UNNAMED_SEMAPHORE
+struct atomic_int {
+  sem_t semaphore;
+};
+#define atomic_int_semaphore(ai) (&(ai)->semaphore)
+static void
+init_atomic_int (struct atomic_int *ai)
+{
+  sem_init (&ai->semaphore, 0, 0);
+}
+# endif
+# if USE_NAMED_SEMAPHORE
+struct atomic_int {
+  sem_t *semaphore;
+};
+#define atomic_int_semaphore(ai) ((ai)->semaphore)
+static void
+init_atomic_int (struct atomic_int *ai)
+{
+  sem_t *s;
+  unsigned int count;
+  for (count = 0; ; count++)
+    {
+      char name[80];
+      /* Use getpid() in the name, so that different processes running at the
+         same time will not interfere.  Use ai in the name, so that different
+         atomic_int in the same process will not interfere.  Use a count in
+         the name, so that even in the (unlikely) case that a semaphore with
+         the specified name already exists, we can try a different name.  */
+      sprintf (name, "test-lock-%lu-%p-%u",
+               (unsigned long) getpid (), ai, count);
+      s = sem_open (name, O_CREAT | O_EXCL, 0600, 0);
+      if (s == SEM_FAILED)
+        {
+          if (errno == EEXIST)
+            /* Retry with a different name.  */
+            continue;
+          else
+            {
+              perror ("sem_open failed");
+              fflush (stderr);
+              abort ();
+            }
+        }
+      else
+        {
+          /* Try not to leave a semaphore hanging around on the file system
+             eternally, if we can avoid it.  */
+          sem_unlink (name);
+          break;
+        }
+    }
+  ai->semaphore = s;
+}
+# endif
+static int
+get_atomic_int_value (struct atomic_int *ai)
+{
+  if (sem_trywait (atomic_int_semaphore (ai)) == 0)
+    {
+      if (sem_post (atomic_int_semaphore (ai)))
+        abort ();
+      return 1;
+    }
+  else if (errno == EAGAIN)
+    return 0;
+  else
+    abort ();
+}
+static void
+set_atomic_int_value (struct atomic_int *ai, int new_value)
+{
+  if (new_value == 0)
+    /* It's already initialized with 0.  */
+    return;
+  /* To set the value 1: */
+  if (sem_post (atomic_int_semaphore (ai)))
+    abort ();
+}
+#else
+struct atomic_int {
+  pthread_mutex_t lock;
+  int value;
+};
+static void
+init_atomic_int (struct atomic_int *ai)
+{
+  pthread_mutexattr_t attr;
+
+  ASSERT (pthread_mutexattr_init (&attr) == 0);
+  ASSERT (pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_NORMAL) == 0);
+  ASSERT (pthread_mutex_init (&ai->lock, &attr) == 0);
+  ASSERT (pthread_mutexattr_destroy (&attr) == 0);
+}
+static int
+get_atomic_int_value (struct atomic_int *ai)
+{
+  ASSERT (pthread_mutex_lock (&ai->lock) == 0);
+  int ret = ai->value;
+  ASSERT (pthread_mutex_unlock (&ai->lock) == 0);
+  return ret;
+}
+static void
+set_atomic_int_value (struct atomic_int *ai, int new_value)
+{
+  ASSERT (pthread_mutex_lock (&ai->lock) == 0);
+  ai->value = new_value;
+  ASSERT (pthread_mutex_unlock (&ai->lock) == 0);
+}
+#endif