[PATCH v2] libgfortran: Bugfix if not define HAVE_ATOMIC_FETCH_ADD

[Lipeng Zhu <lipeng.zhu@intel.com>]

This patch try to fix the bug when HAVE_ATOMIC_FETCH_ADD is
not defined in dec_waiting_unlocked function. As io.h does
not include async.h, the WRLOCK and RWUNLOCK macros are
undefined.

libgfortran/ChangeLog:

	* io/io.h (dec_waiting_unlocked): Use
	__gthread_rwlock_wrlock/__gthread_rwlock_unlock or
	__gthread_mutex_lock/__gthread_mutex_unlock functions
	to replace WRLOCK and RWUNLOCK macros.

Signed-off-by: Lipeng Zhu <lipeng.zhu@intel.com>
---
 libgfortran/io/io.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/libgfortran/io/io.h b/libgfortran/io/io.h
index 15daa0995b1..c7f0f7d7d9e 100644
--- a/libgfortran/io/io.h
+++ b/libgfortran/io/io.h
@@ -1020,9 +1020,15 @@ dec_waiting_unlocked (gfc_unit *u)
 #ifdef HAVE_ATOMIC_FETCH_ADD
   (void) __atomic_fetch_add (&u->waiting, -1, __ATOMIC_RELAXED);
 #else
-  WRLOCK (&unit_rwlock);
+#ifdef __GTHREAD_RWLOCK_INIT
+  __gthread_rwlock_wrlock (&unit_rwlock);
+  u->waiting--;
+  __gthread_rwlock_unlock (&unit_rwlock);
+#else
+  __gthread_mutex_lock (&unit_rwlock);
   u->waiting--;
-  RWUNLOCK (&unit_rwlock);
+  __gthread_mutex_unlock (&unit_rwlock);
+#endif
 #endif
 }
 
-- 
2.39.3