Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 127 insertions, 0 deletions

diff --git a/REORG.TODO/nptl/tst-rwlock19.c b/REORG.TODO/nptl/tst-rwlock19.c
new file mode 100644
index 0000000000..746d84d92f
--- /dev/null
+++ b/REORG.TODO/nptl/tst-rwlock19.c
@@ -0,0 +1,127 @@
+/* Test rdlock overflow.
+   Copyright (C) 2000-2017 Free Software Foundation, Inc.
+
+   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; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <error.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <pthreadP.h>
+
+
+#define NREADERS 15
+#define READTRIES 5000
+
+#define DELAY   1000000
+
+static pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
+static int eagain_returned = 0;
+static int success_returned = 0;
+
+static void *
+reader_thread (void *nr)
+{
+  struct timespec delay;
+  int n;
+
+  delay.tv_sec = 0;
+  delay.tv_nsec = DELAY;
+
+  for (n = 0; n < READTRIES; ++n)
+    {
+      int err = pthread_rwlock_rdlock (&lock);
+      if (err == EAGAIN)
+	{
+	  atomic_store_relaxed (&eagain_returned, 1);
+	  continue;
+	}
+      else if (err == 0)
+	atomic_store_relaxed (&success_returned, 1);
+      else
+	{
+	  puts ("rdlock failed");
+	  exit (1);
+	}
+
+      nanosleep (&delay, NULL);
+
+      if (pthread_rwlock_unlock (&lock) != 0)
+	{
+	  puts ("unlock for reader failed");
+	  exit (1);
+	}
+    }
+
+  return NULL;
+}
+
+
+static int
+do_test (void)
+{
+  pthread_t thrd[NREADERS];
+  int n;
+  void *res;
+
+  /* Set the rwlock so that it's close to a reader overflow.
+     PTHREAD_RWLOCK_WRPHASE and PTHREAD_RWLOCK_WRLOCK are zero initially.  */
+  unsigned int readers = PTHREAD_RWLOCK_READER_OVERFLOW
+      - ((NREADERS / 3) << PTHREAD_RWLOCK_READER_SHIFT);
+  lock.__data.__readers = readers;
+
+  for (n = 0; n < NREADERS; ++n)
+    if (pthread_create (&thrd[n], NULL, reader_thread,
+			(void *) (long int) n) != 0)
+      {
+	puts ("reader create failed");
+	exit (1);
+      }
+
+  /* Wait for all the threads.  */
+  for (n = 0; n < NREADERS; ++n)
+    if (pthread_join (thrd[n], &res) != 0)
+      {
+	puts ("reader join failed");
+	exit (1);
+      }
+
+  if (atomic_load_relaxed (&eagain_returned) == 0)
+    {
+      puts ("EAGAIN has never been returned");
+      exit (1);
+    }
+
+  if (atomic_load_relaxed (&success_returned) == 0)
+    {
+      puts ("rdlock was never successfully acquired");
+      exit (1);
+    }
+
+  if (lock.__data.__readers != readers)
+    {
+      puts ("__readers in rwlock differs from initial value");
+      exit (1);
+    }
+
+  return 0;
+}
+
+#define TIMEOUT 30
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"