FULL PRODUCT VERSION :
java version "1.8.0_31"
Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
NAME=Fedora
VERSION="20 (Heisenbug)"
ID=fedora
VERSION_ID=20
PRETTY_NAME="Fedora 20 (Heisenbug)"
ANSI_COLOR="0;34"
CPE_NAME="cpe:/o:fedoraproject:fedora:20"
HOME_URL="https://fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"


A DESCRIPTION OF THE PROBLEM :
When the fixedContentLength is set with HttpURLConnection.setFixedLengthStreamingMode(),
sun.net.www.protocol.http.HttpURLConnection.getOutputStream() is about 6 times slower than the jdk7u25 with fixedLengthStreamingMode is enabled. I checked several jdk7 version , this is introduced since jdk7u40.

This performance regression can be reproduced with code : https://github.com/jimma/jdk7u40-httpurlconnection-issue.git

ADDITIONAL REGRESSION INFORMATION:
This works in jdk7u25.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
git clone https://github.com/jimma/jdk7u40-httpurlconnection-issue.git
mvn clean install
compare the output result with setFixedLengthStreamingMode() and without setFixedLengthStreamingMode()


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
https://github.com/jimma/jdk7u40-httpurlconnection-issue.git
---------- END SOURCE ----------