Bug reported by customer, HervM-	 Guillemet,  xxxxx :

"The TIFF decoder seems to be thread
unsafe. When getTiles are called simultaneously on several image coming
from a single multipage tiff file, I can get, for some of the images :

With packbits TIFF :

java.lang.RuntimeException: Unable to decode Packbits compressed data -
not enough data.
        at com.sun.media.jai.codecimpl.TIFFImage.decodePackbits(TIFFImage.java:1925)
        at com.sun.media.jai.codecimpl.TIFFImage.getTile(TIFFImage.java:1566)
        at javax.media.jai.RenderedImageAdapter.getTile(RenderedImageAdapter.java:146)
        at javax.media.jai.NullOpImage.computeTile(NullOpImage.java:170)
        at com.sun.media.jai.util.SunTileScheduler.scheduleTile(SunTileScheduler.java:848)
        at javax.media.jai.OpImage.getTile(OpImage.java:851)

With Zip TIFF :
java.lang.RuntimeException: Error inflating data: unknown compression
method
        at com.sun.media.jai.codecimpl.TIFFImage.inflate(TIFFImage.java:185)
        at com.sun.media.jai.codecimpl.TIFFImage.getTile(TIFFImage.java:1573)
        at javax.media.jai.RenderedImageAdapter.getTile(RenderedImageAdapter.java:146)
        at javax.media.jai.NullOpImage.computeTile(NullOpImage.java:170)
        at com.sun.media.jai.util.SunTileScheduler.scheduleTile(SunTileScheduler.java:848)
        at javax.media.jai.OpImage.getTile(OpImage.java:851)


With no compression, I don't get any exception but some images are just
missing or are wrong.


Testcase :

---
import java.awt.image.*;
import javax.media.jai.*;
import com.sun.media.jai.codec.*;
import java.io.*;

class T {
  public static void main(String[] a) {
    try {
      ImageDecoder id = ImageCodec.createImageDecoder("tiff",
                                                      new File(a[0]),
                                                      null);
      final RenderedImage[] ri = new RenderedImage[id.getNumPages()];
      for (int i=0; i<ri.length; i++)
        ri[i] = id.decodeAsRenderedImage(i);
      for (int i=0; i<ri.length; i++) {
        final RenderedImage r = ri[i];
        new Thread() {  public void run() { r.getData(); } }.start();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

---

== HervM-	 Guillemet
    xxxxx 
"
Posted Date : 2005-11-17 01:20:57.0

N/A

A separate instance of TIFFImage is created for each page in the multi-page TIFF and all of them refers to the same stream. All references to the stream are contained in a single method, getTile(), or methods that it in turn calls and getTile() is synchronized. This does not force synchronization of this method across all TIFFImage instances however.
Posted Date : 2005-11-17 01:20:57.0