Add a regression test for GNOME#642026

Bug: https://bugzilla.gnome.org/show_bug.cgi?id=642026
Bug-NB: NB#257512

gthread/tests/642026.c

@@ -0,0 +1,91 @@
+/*
+ * Author: Simon McVittie <simon.mcvittie@collabora.co.uk>
+ * Copyright © 2011 Nokia Corporation
+ *
+ * This program 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 of the
+ * License, or (at your option) any later version.
+ *
+ * See the included COPYING file for more information.
+ */
+
+#include <glib.h>
+
+/* On smcv's laptop, 1e4 iterations didn't always exhibit the bug, but 1e5
+ * iterations exhibited it 10/10 times in practice. YMMV. */
+#define ITERATIONS 100000
+
+static GStaticPrivate sp;
+static GMutex *mutex;
+static GCond *cond;
+static guint i;
+
+static volatile gint freed = 0;
+
+static void
+notify (gpointer p)
+{
+  if (!g_atomic_int_compare_and_exchange (&freed, 0, 1))
+    {
+      g_error ("someone already freed it after %u iterations", i);
+    }
+}
+
+static gpointer thread_func (gpointer nil)
+{
+  /* wait for main thread to reach its g_cond_wait call */
+  g_mutex_lock (mutex);
+
+  g_static_private_set (&sp, &sp, notify);
+  g_cond_broadcast (cond);
+  g_mutex_unlock (mutex);
+
+  return nil;
+}
+
+void
+testcase (void)
+{
+  g_test_bug ("642026");
+
+  g_thread_init (NULL);
+
+  mutex = g_mutex_new ();
+  cond = g_cond_new ();
+
+  g_mutex_lock (mutex);
+
+  for (i = 0; i < ITERATIONS; i++)
+    {
+      GThread *t1;
+
+      g_static_private_init (&sp);
+      freed = 0;
+
+      t1 = g_thread_create (thread_func, NULL, TRUE, NULL);
+
+      /* wait for t1 to set up its thread-private data */
+      g_cond_wait (cond, mutex);
+
+      /* exercise the bug, by racing with t1 to free the private data */
+      g_static_private_free (&sp);
+      g_thread_join (t1);
+    }
+
+  g_cond_free (cond);
+  g_mutex_unlock (mutex);
+  g_mutex_free (mutex);
+}
+
+int
+main (int argc,
+    char **argv)
+{
+  g_test_init (&argc, &argv, NULL);
+  g_test_bug_base ("https://bugzilla.gnome.org/show_bug.cgi?id=");
+
+  g_test_add_func ("/glib/642026", testcase);
+
+  return g_test_run ();
+}

gthread/tests/Makefile.am

@@ -9,6 +9,9 @@ progs_ldadd     = $(top_builddir)/glib/libglib-2.0.la \
 TEST_PROGS	 += 1bit-mutex
 1bit_mutex_LDADD  = $(progs_ldadd) $(top_builddir)/gthread/libgthread-2.0.la
 
+TEST_PROGS	 += 642026
+642026_LDADD	  = $(progs_ldadd)
+
 TEST_PROGS	      += 1bit-emufutex
 1bit_emufutex_SOURCES  = 1bit-mutex.c
 1bit_emufutex_CFLAGS   = -DTEST_EMULATED_FUTEX