Re: repeating a task for a length of time

From:
Daniel Pitts <googlegroupie@coloraura.com>
Newsgroups:
comp.lang.java.programmer
Date:
2 May 2007 18:49:38 -0700
Message-ID:
<1178156978.478190.54340@e65g2000hsc.googlegroups.com>
On May 2, 9:24 am, "Red Orchid" <windfollowcl...@yahoo.com> wrote:

Daniel Pitts <googlegrou...@coloraura.com> wrote or quoted in
Message-ID <1178116602.911032.319...@y5g2000hsa.googlegroups.com>:

long endTime = System.currentTimeMillis() + 60 * 1000;
while (endTime > System.currentTimeMillis()) {
    makeRequest();
}


I think that the following code is only proper for simple testing.

<code>
long startTime = System.currentTimeMillis();

... // code block #1

long endTime = System.currentTimeMillis();
long interval = endTime - startTime;
</code>

"interval" is unreliable value because "System.currentTimeMillis()"
returns current time of *system*. In other words, if system time
is set to 01/01/1970 during "#1", the value of "interval" is negative.

Modern clock programs have the function of automatic synchronization
with internet time server (e.g. clock on WinXP tray).


How about System.nanoTime() then? That has a guaranty on the
difference between two calls, does it not?

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