<AWT Dev> [9] Review request for 8130136: Swing window sometimes fails to repaint partially when it becomes exposed

Alexey Ivanov alexey.ivanov at oracle.com
Mon Oct 12 09:11:11 UTC 2015


Please review the fix for jdk9:
     bug: https://bugs.openjdk.java.net/browse/JDK-8130136
     webrev: http://cr.openjdk.java.net/~aivanov/8130136/jdk9/webrev.00/

Problem description:
Sometimes a window fails to repaint when it becomes exposed.

When repaint failure occurs, SetDIBitsToDevice() in 
GDIBlitLoops_nativeBlit() returns 0 with error 87 ("Parameter Error"). 
It happens because invalid, already released, hDC is passed to 

Root cause:
When a window is disposed, the DCs associated with it are released. The 
handles can be reused for another window.

A thread disposes the window and releases hDC. At this time, DC handle 
is reused for another window. When Disposer thread cleans up for a died 
thread, it tries to release the cached hDC. But that handle is already 
associated with another window. Thus a valid pair hWnd/hDC becomes 
invalid: painting to released DC fails.

The fix:
Save both hDC and hWnd in the thread local storage, and pair hDC with 
hWnd when removing it to avoid accidentally releasing hDC which is 
already reused for another window.


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