--- /dev/null
+
+/*******************************************************************************
+
+ Copyright (c) 2009, Charles McGarvey
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*******************************************************************************/
+
+#ifndef _TIMER_HH_
+#define _TIMER_HH_
+
+/**
+ * @file timer.hh
+ * Functions for measuring time in a friendly unit.
+ */
+
+#include "math.hh"
+
+
+namespace dc {
+
+
+/**
+ * Get the number of seconds since a fixed, arbitrary point in the past.
+ * @return Seconds.
+ */
+
+scalar ticks();
+
+
+/**
+ * Put the thread to sleep for a certain period of time. If absolute is true,
+ * then it will sleep until seconds after the fixed time in the past. If
+ * absolute is false, it will sleep for seconds starting now. Unlike system
+ * sleep functions, this one automatically resumes sleep if sleep was
+ * interrupted by a signal. Therefore, calling this function is guaranteed to
+ * sleep for the requested amount of time.
+ */
+
+void sleep(scalar seconds, bool absolute = false);
+
+
+} // namespace dc
+
+
+#endif // _TIMER_HH_
+