Threading abstraction layer added
diff --git a/library/threading.c b/library/threading.c
new file mode 100644
index 0000000..e79348a
--- /dev/null
+++ b/library/threading.c
@@ -0,0 +1,134 @@
+/*
+ *  Threading abstraction layer
+ *
+ *  Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ *  This file is part of PolarSSL (http://www.polarssl.org)
+ *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ *  All rights reserved.
+ *
+ *  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 2 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, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_THREADING_C)
+
+#include "polarssl/threading.h"
+
+#if defined(POLARSSL_THREADING_DUMMY)
+static int threading_mutex_init_dummy( threading_mutex_t *mutex )
+{
+    ((void) mutex );
+    return( 0 );
+}
+
+static int threading_mutex_free_dummy( threading_mutex_t *mutex )
+{
+    ((void) mutex );
+    return( 0 );
+}
+
+static int threading_mutex_lock_dummy( threading_mutex_t *mutex )
+{
+    ((void) mutex );
+    return( 0 );
+}
+
+static int threading_mutex_unlock_dummy( threading_mutex_t *mutex )
+{
+    ((void) mutex );
+    return( 0 );
+}
+
+int (*polarssl_mutex_init)( threading_mutex_t * ) = threading_mutex_init_dummy;
+int (*polarssl_mutex_free)( threading_mutex_t * ) = threading_mutex_free_dummy;
+int (*polarssl_mutex_lock)( threading_mutex_t * ) = threading_mutex_lock_dummy;
+int (*polarssl_mutex_unlock)( threading_mutex_t * ) = threading_mutex_unlock_dummy;
+#endif /* POLARSSL_THREADING_DUMMY */
+
+#if defined(POLARSSL_THREADING_PTHREAD)
+static int threading_mutex_init_pthread( threading_mutex_t *mutex )
+{
+    if( mutex == NULL )
+        return( POLARSSL_ERR_THREADING_BAD_INPUT_DATA );
+
+    if( pthread_mutex_init( mutex, NULL ) != 0 )
+        return( POLARSSL_ERR_THREADING_MUTEX_ERROR );
+
+    return( 0 );
+}
+
+static int threading_mutex_free_pthread( threading_mutex_t *mutex )
+{
+    if( mutex == NULL )
+        return( POLARSSL_ERR_THREADING_BAD_INPUT_DATA );
+
+    if( pthread_mutex_destroy( mutex ) != 0 )
+        return( POLARSSL_ERR_THREADING_MUTEX_ERROR );
+
+    return( 0 );
+}
+
+static int threading_mutex_lock_pthread( threading_mutex_t *mutex )
+{
+    if( mutex == NULL )
+        return( POLARSSL_ERR_THREADING_BAD_INPUT_DATA );
+
+    if( pthread_mutex_lock( mutex ) != 0 )
+        return( POLARSSL_ERR_THREADING_MUTEX_ERROR );
+
+    return( 0 );
+}
+
+static int threading_mutex_unlock_pthread( threading_mutex_t *mutex )
+{
+    if( mutex == NULL )
+        return( POLARSSL_ERR_THREADING_BAD_INPUT_DATA );
+
+    if( pthread_mutex_unlock( mutex ) != 0 )
+        return( POLARSSL_ERR_THREADING_MUTEX_ERROR );
+
+    return( 0 );
+}
+
+int (*polarssl_mutex_init)( threading_mutex_t * ) = threading_mutex_init_pthread;
+int (*polarssl_mutex_free)( threading_mutex_t * ) = threading_mutex_free_pthread;
+int (*polarssl_mutex_lock)( threading_mutex_t * ) = threading_mutex_lock_pthread;
+int (*polarssl_mutex_unlock)( threading_mutex_t * ) = threading_mutex_unlock_pthread;
+#endif /* POLARSSL_THREADING_PTHREAD */
+
+#if defined(POLARSSL_THREADING_ALT)
+int (*polarssl_mutex_init)( threading_mutex_t * ) = NULL;
+int (*polarssl_mutex_free)( threading_mutex_t * ) = NULL;
+int (*polarssl_mutex_lock)( threading_mutex_t * ) = NULL;
+int (*polarssl_mutex_unlock)( threading_mutex_t * ) = NULL;
+
+int threading_set_own( int (*mutex_init)( threading_mutex_t * ),
+                       int (*mutex_free)( threading_mutex_t * ),
+                       int (*mutex_lock)( threading_mutex_t * ),
+                       int (*mutex_unlock)( threading_mutex_t * ) )
+{
+    polarssl_mutex_init = mutex_init;
+    polarssl_mutex_free = mutex_free;
+    polarssl_mutex_lock = mutex_lock;
+    polarssl_mutex_unlock = mutex_unlock;
+
+    return( 0 );
+}
+#endif /* POLARSSL_THREADING_ALT_C */
+
+#endif /* POLARSSL_THREADING_C */