--- /dev/null
+/*
+ * Simple semaphore implementation, P() and V().
+ *
+ * Copyright (C) 2011 Simon Ruderich
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef SEM_H
+#define SEM_H
+
+typedef struct SEM SEM;
+
+SEM *sem_init(int init_value);
+int sem_del(SEM *sem);
+
+void P(SEM *sem);
+void V(SEM *sem);
+
+#endif