Fixed Issue 54: No GL listener callbacks when setting render thread before window is visible

The issue (or a related one) is still present in the current JOGL
build, although the symptom was different: a deadlock upon startup of
the application. When the OpenGL context is created in the
WindowsOnscreenGLContext implementation, it causes
Component.getGraphicsConfiguration() to be called, which causes the
AWT tree lock to be grabbed. Under some circumstances, another thread
can already hold the AWT tree lock and call GLContext.invokeGL(),
which leads to a classic deadlock. Resolved this by eagerly grabbing
the tree lock under some circumstances (not all the time) before
entering the synchronized invokeGL in (only) the Windows onscreen
context implementation.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@193 232f8b59-042b-4e1e-8c03-345bb8c30851

1 files changed, 19 insertions, 0 deletions

diff --git a/src/net/java/games/jogl/impl/windows/WindowsOnscreenGLContext.java b/src/net/java/games/jogl/impl/windows/WindowsOnscreenGLContext.java
index 3bfdee5d1..1838f62aa 100644
--- a/src/net/java/games/jogl/impl/windows/WindowsOnscreenGLContext.java
+++ b/src/net/java/games/jogl/impl/windows/WindowsOnscreenGLContext.java
@@ -61,6 +61,25 @@ public class WindowsOnscreenGLContext extends WindowsGLContext {
     super(component, capabilities, chooser, shareWith);
   }
   
+  public void invokeGL(Runnable runnable, boolean isReshape, Runnable initAction) throws GLException {
+    // Unfortunately, invokeGL can be called with the AWT tree lock
+    // held, and the Windows onscreen implementation of
+    // choosePixelFormatAndCreateContext calls
+    // Component.getGraphicsConfiguration(), which grabs the tree
+    // lock. To avoid deadlock we have to lock the tree lock before
+    // grabbing the GLContext's lock if we're going to create an
+    // OpenGL context during this call. This code might not be
+    // completely correct, and we might need to uniformly grab the AWT
+    // tree lock, which might become a performance issue...
+    if (hglrc == 0) {
+      synchronized(component.getTreeLock()) {
+        super.invokeGL(runnable, isReshape, initAction);
+      }
+    } else {
+      super.invokeGL(runnable, isReshape, initAction);
+    }
+  }
+
   protected GL createGL()
   {
     return new WindowsGLImpl(this);