Added a condvar implementation that works with rwlock_t

2012-09-21 18:16:27 +02:00
parent 4134108c77
commit 60dc44648f
3 changed files with 220 additions and 4 deletions
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup rwlock_condvar rwlock_condvar
+ * @{ @ingroup threading
+ */
+
+#ifndef RWLOCK_CONDVAR_H_
+#define RWLOCK_CONDVAR_H_
+
+typedef struct rwlock_condvar_t rwlock_condvar_t;
+
+#include "rwlock.h"
+
+/**
+ * A special condvar implementation that can be used in conjunction
+ * with rwlock_t (the write lock to be precise).
+ *
+ * @note The implementation does not verify that the current thread actually
+ * holds the write lock and not the read lock, so watch out.
+ */
+struct rwlock_condvar_t {
+
+	/**
+	 * Wait on a condvar until it gets signalized.
+	 *
+	 * @param lock			lock to release while waiting (write lock)
+	 */
+	void (*wait)(rwlock_condvar_t *this, rwlock_t *lock);
+
+	/**
+	 * Wait on a condvar until it gets signalized, or times out.
+	 *
+	 * @param lock			lock to release while waiting (write lock)
+	 * @param timeout		timeout im ms
+	 * @return				TRUE if timed out, FALSE otherwise
+	 */
+	bool (*timed_wait)(rwlock_condvar_t *this, rwlock_t *lock, u_int timeout);
+
+	/**
+	 * Wait on a condvar until it gets signalized, or times out.
+	 *
+	 * The passed timeval should be calculated based on the time_monotonic()
+	 * function.
+	 *
+	 * @param lock			lock to release while waiting (write lock)
+	 * @param tv			absolute time until timeout
+	 * @return				TRUE if timed out, FALSE otherwise
+	 */
+	bool (*timed_wait_abs)(rwlock_condvar_t *this, rwlock_t *lock,
+						   timeval_t tv);
+
+	/**
+	 * Wake up a single thread in a condvar.
+	 */
+	void (*signal)(rwlock_condvar_t *this);
+
+	/**
+	 * Wake up all threads in a condvar.
+	 */
+	void (*broadcast)(rwlock_condvar_t *this);
+
+	/**
+	 * Destroy a condvar and free its resources.
+	 */
+	void (*destroy)(rwlock_condvar_t *this);
+};
+
+/**
+ * Create a condvar instance.
+ *
+ * @return			condvar instance
+ */
+rwlock_condvar_t *rwlock_condvar_create();
+
+#endif /** RWLOCK_CONDVAR_H_ @} */
+