[commit-cp] classpath ChangeLog java/lang/System.java

[Andrew John Hughes]

CVSROOT:        /cvsroot/classpath
Module name:    classpath
Changes by:     Andrew John Hughes <gnu_andrew> 06/06/04 18:15:05

Modified files:
        .              : ChangeLog 
        java/lang      : System.java 

Log message:
        2006-03-20  Andrew John Hughes  <address@hidden>
        
                * java/lang/System.java:
                (nanoTime()): Documented.
        
        2006-03-20  Tom Tromey  <address@hidden>
        
                * java/lang/System.java:
                (nanoTime()): Implemented.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/classpath/ChangeLog?cvsroot=classpath&r1=1.7647&r2=1.7648
http://cvs.savannah.gnu.org/viewcvs/classpath/java/lang/System.java?cvsroot=classpath&r1=1.57&r2=1.58

Patches:
Index: ChangeLog
===================================================================
RCS file: /cvsroot/classpath/classpath/ChangeLog,v
retrieving revision 1.7647
retrieving revision 1.7648
diff -u -b -r1.7647 -r1.7648
--- ChangeLog   4 Jun 2006 17:59:12 -0000       1.7647
+++ ChangeLog   4 Jun 2006 18:15:04 -0000       1.7648
@@ -1,3 +1,13 @@
+2006-03-20  Andrew John Hughes  <address@hidden>
+
+       * java/lang/System.java:
+       (nanoTime()): Documented.
+
+2006-03-20  Tom Tromey  <address@hidden>
+
+       * java/lang/System.java:
+       (nanoTime()): Implemented.
+
 2006-03-01  Anthony Balkissoon  <address@hidden>
 
        * java/math/BigDecimal.java:

Index: java/lang/System.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/lang/System.java,v
retrieving revision 1.57
retrieving revision 1.58
diff -u -b -r1.57 -r1.58
--- java/lang/System.java       12 May 2006 15:54:38 -0000      1.57
+++ java/lang/System.java       4 Jun 2006 18:15:05 -0000       1.58
@@ -223,6 +223,36 @@
   }
 
   /**
+   * <p>
+   * Returns the current value of a nanosecond-precise system timer.
+   * The value of the timer is an offset relative to some arbitrary fixed
+   * time, which may be in the future (making the value negative).  This
+   * method is useful for timing events where nanosecond precision is
+   * required.  This is achieved by calling this method before and after the
+   * event, and taking the difference betweent the two times:
+   * </p>
+   * <p>
+   * <code>long startTime = System.nanoTime();</code><br />
+   * <code>... <emph>event code</emph> ...</code><br />
+   * <code>long endTime = System.nanoTime();</code><br />
+   * <code>long duration = endTime - startTime;</code><br />
+   * </p>
+   * <p>
+   * Note that the value is only nanosecond-precise, and not accurate; there
+   * is no guarantee that the difference between two values is really a
+   * nanosecond.  Also, the value is prone to overflow if the offset
+   * exceeds 2^63.
+   * </p>
+   *
+   * @return the time of a system timer in nanoseconds.
+   * @since 1.5 
+   */
+  public static long nanoTime()
+  {
+    return VMSystem.nanoTime();
+  }
+
+  /**
    * Copy one array onto another from <code>src[srcStart]</code> ...
    * <code>src[srcStart+len-1]</code> to <code>dest[destStart]</code> ...
    * <code>dest[destStart+len-1]</code>. First, the arguments are validated: