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, 137 insertions, 0 deletions

diff --git a/REORG.TODO/malloc/tst-malloc-thread-exit.c b/REORG.TODO/malloc/tst-malloc-thread-exit.c
new file mode 100644
index 0000000000..8a0909b2f8
--- /dev/null
+++ b/REORG.TODO/malloc/tst-malloc-thread-exit.c
@@ -0,0 +1,137 @@
+/* Test malloc with concurrent thread termination.
+   Copyright (C) 2015-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This thread spawns a number of outer threads, equal to the arena
+   limit.  The outer threads run a loop which start and join two
+   different kinds of threads: the first kind allocates (attaching an
+   arena to the thread; malloc_first_thread) and waits, the second
+   kind waits and allocates (wait_first_threads).  Both kinds of
+   threads exit immediately after waiting.  The hope is that this will
+   exhibit races in thread termination and arena management,
+   particularly related to the arena free list.  */
+
+#include <errno.h>
+#include <malloc.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <support/support.h>
+#include <support/xthread.h>
+#include <support/test-driver.h>
+
+static bool termination_requested;
+static int inner_thread_count = 4;
+static size_t malloc_size = 32;
+
+static void
+__attribute__ ((noinline, noclone))
+unoptimized_free (void *ptr)
+{
+  free (ptr);
+}
+
+static void *
+malloc_first_thread (void * closure)
+{
+  pthread_barrier_t *barrier = closure;
+  void *ptr = xmalloc (malloc_size);
+  xpthread_barrier_wait (barrier);
+  unoptimized_free (ptr);
+  return NULL;
+}
+
+static void *
+wait_first_thread (void * closure)
+{
+  pthread_barrier_t *barrier = closure;
+  xpthread_barrier_wait (barrier);
+  void *ptr = xmalloc (malloc_size);
+  unoptimized_free (ptr);
+  return NULL;
+}
+
+static void *
+outer_thread (void *closure)
+{
+  pthread_t *threads = xcalloc (sizeof (*threads), inner_thread_count);
+  while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
+    {
+      pthread_barrier_t barrier;
+      xpthread_barrier_init (&barrier, NULL, inner_thread_count + 1);
+      for (int i = 0; i < inner_thread_count; ++i)
+        {
+          void *(*func) (void *);
+          if ((i  % 2) == 0)
+            func = malloc_first_thread;
+          else
+            func = wait_first_thread;
+          threads[i] = xpthread_create (NULL, func, &barrier);
+        }
+      xpthread_barrier_wait (&barrier);
+      for (int i = 0; i < inner_thread_count; ++i)
+        xpthread_join (threads[i]);
+      xpthread_barrier_destroy (&barrier);
+    }
+
+  free (threads);
+
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  /* The number of threads should be smaller than the number of
+     arenas, so that there will be some free arenas to add to the
+     arena free list.  */
+  enum { outer_thread_count = 2 };
+  if (mallopt (M_ARENA_MAX, 8) == 0)
+    {
+      printf ("error: mallopt (M_ARENA_MAX) failed\n");
+      return 1;
+    }
+
+  /* Leave some room for shutting down all threads gracefully.  */
+  int timeout = 3;
+  if (timeout > DEFAULT_TIMEOUT)
+    timeout = DEFAULT_TIMEOUT - 1;
+
+  pthread_t *threads = xcalloc (sizeof (*threads), outer_thread_count);
+  for (long i = 0; i < outer_thread_count; ++i)
+    threads[i] = xpthread_create (NULL, outer_thread, NULL);
+
+  struct timespec ts = {timeout, 0};
+  if (nanosleep (&ts, NULL))
+    {
+      printf ("error: error: nanosleep: %m\n");
+      abort ();
+    }
+
+  __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED);
+
+  for (long i = 0; i < outer_thread_count; ++i)
+    xpthread_join (threads[i]);
+  free (threads);
+
+  return 0;
+}
+
+#include <support/test-driver.c>