FULL PRODUCT VERSION :
java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b12)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
mac os x 10.8.5

A DESCRIPTION OF THE PROBLEM :
I use ImageIO.read in Multiple threads
look at my test case,I use 100 thread,ervery thread process 100 urls
after about 10 min ,the process is "dead" but not crash
I use "jstat -gcutil" look at the garbage collection stat
And found that no garbage collection occurred
  S0 S1 E O P YGC YGCT FGC FGCT GCT
 9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
  9.46 0.00 89.56 80.74 39.14 314 1.102 21 0.558 1.659
So what's the problem?How can I slove it?


REGRESSION. Last worked in version 7u21


REPRODUCIBILITY :
This bug can be reproduced occasionally.

---------- BEGIN SOURCE ----------
private List<String> urls = new ArrayList<String>();
public void setUrls(List<String> urls) {
this.urls = urls;
}
@Override
public void run() {
for (String url : urls) {
try {
 InputStream is = new URL(url).openStream();
 BufferedImage img = ImageIO.read(is);
 is.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
---------- END SOURCE ----------