Hi Claes,
611: Can't the loop break after finding the first \n?
916: I'd probably call writeln(String.valueOf(x)) and skip the extra
method call.
Is there any benefit of doing the String conversions before the
synchronized block?
As is in the old code for println(Object x).
There isn't much contention I expect so it's probably a benefit,
(compared to easy to read code).
Thanks, Roger
On 12/14/2018 12:12 PM, Claes Redestad wrote:
Hi,
the various PrintStream.println methods are inefficient: nested
synchronization, multiple flushes and a scan of the input string for
newlines that in the end is pointless in this context since newLine will
always flush anyway (if autoflush is enabled).
While performance of printing to console/file is likely to be
dominated by the I/O overheads, there are plenty of simple text
processing applications using stdout to pipe output to another process
for which performance of println could definitely matter.
Webrev: http://cr.openjdk.java.net/~redestad/8215412/jdk.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8215412
Using a simple test program like this:
public class Test {
public static void main (String ... args) {
for (int i = 0; i < Integer.parseInt(args[0]); i++)
System.out.println(args[1]);
}
}
... and stating the cost of running:
$ java Test 100000 tttttttttttttttttttttttttttttttttttttttttttttt | wc -l
... I get a 15-30% reduction in cycles and wall clock time (larger
reduction the more output is produced).
Thanks!
/Claes
