Arr! Me hearties! I be highly impressed to see that prime landlubber Brendan Gregg be applying the power of DTrace t’ JavaScript. For those o’ ye scurvy dogs that dunno, DTrace be this marvellous thing on Solaris that traces kernel calls. Apparently it be for more than that, though; see Brandan trace the JavaScript code
function padZero(i)
{
if (i < 10) return "0" + i
return i
}
function startTime()
{
var now = new Date
var time = padZero(now.getHours()) + ":" +
padZero(now.getMinutes()) + ":" +
padZero(now.getSeconds());
document.getElementById('clock').innerHTML = "time: " + time + ""
var timeout = setTimeout('startTime()', 1000)
}
and be gettin’ the followin’ output:
FILE FUNC CALLS
clock.html getElementById 9
clock.html getHours 9
clock.html getMinutes 9
clock.html getSeconds 9
clock.html setTimeout 9
clock.html startTime 9
clock.html padZero 27
as well as much more complex output t’ be seen below. Every day I be amazed at DTrace, and now I be even more amazed as it be useful for work that I actually do. Avast!