/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * This D script is used as an example in the Solaris Dynamic Tracing Guide
 * wiki in the "Variables" Chapter.
 *
 * The full text of the this chapter may be found here:
 *
 *   http://docs.oracle.com/cd/E36784_01/html/E36846/gkzhs.html#scrolltoc
 *
 * On machines that have DTrace installed, this script is available as
 * rtime.d in /usr/demo/dtrace, a directory that contains all D scripts
 * used in the Solaris Dynamic Tracing Guide.  A table of the scripts and their
 * corresponding chapters may be found here:
 *
 *   file:///usr/demo/dtrace/index.html
 */

syscall::read:entry
{
	self->t = timestamp;
}

syscall::read:return
/self->t != 0/
{
	printf("%d/%d spent %d nsecs in read(2)\n",
	    pid, tid, timestamp - self->t);
	
	/*
	 * We're done with this thread-local variable; assign zero to it to
	 * allow the DTrace runtime to reclaim the underlying storage.
	 */
	self->t = 0;
}