Bug 1055 - Access and query shared master GLContext in a deterministic fashion ; Don't use arbitrary shared context as 'master'.

GLContext* passes the shared-master to GLContextShareSet,
which only creates a sets of shared contexts
without differentiating the master context.

GLContext*'s shared-slave attempts to lock
the realized shared-master's surface at creation.

Currently only an arbitrary shared context is selected
due to the missing 'master' identity.
The arbitrary shared context's surface is locked
and its shared context handle used to create the slave context.

Lacking of using the user given shared-master
can lead to deadlock situations - and locking a 'wrong' surface.

+++

The patch:

  - Allows query the user given shared-master!

  - Use the user given shared-master for locking and it's
    context handle for the slave's creation.

  - The shared-context mapping maps each shared-master
    to a shared-slave within one shared-context-set,
    allowing deterministic and individual shared-master queries.

1 files changed, 23 insertions, 16 deletions

diff --git a/src/jogl/classes/jogamp/opengl/GLContextImpl.java b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
index e278afc92..9280d9830 100644
--- a/src/jogl/classes/jogamp/opengl/GLContextImpl.java
+++ b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
@@ -151,7 +151,9 @@ public abstract class GLContextImpl extends GLContext {
     if ( null != shareWith ) {
       GLContextShareSet.registerSharing(this, shareWith);
       bufferObjectTracker = ((GLContextImpl)shareWith).getBufferObjectTracker();
-      assert (bufferObjectTracker != null) : "shared context hash null GLBufferObjectTracker: "+shareWith;
+      if( null == bufferObjectTracker ) {
+          throw new InternalError("shared-master context hash null GLBufferObjectTracker: "+toHexString(shareWith.hashCode()));
+      }
     } else {
       bufferObjectTracker = new GLBufferObjectTracker();
     }
@@ -661,6 +663,10 @@ public abstract class GLContextImpl extends GLContext {
     return res;
   }
 
+  private final GLContextImpl getOtherSharedMaster() {
+      final GLContextImpl sharedMaster = (GLContextImpl) GLContextShareSet.getSharedMaster(this);
+      return this != sharedMaster ? sharedMaster : null;
+  }
   private final int makeCurrentWithinLock(final int surfaceLockRes) throws GLException {
       if (!isCreated()) {
         if( 0 >= drawable.getSurfaceWidth() || 0 >= drawable.getSurfaceHeight() ) {
@@ -675,22 +681,23 @@ public abstract class GLContextImpl extends GLContext {
             additionalCtxCreationFlags |= GLContext.CTX_OPTION_DEBUG ;
         }
 
-        final GLContextImpl shareWith = (GLContextImpl) GLContextShareSet.getCreatedShare(this);
-        final long shareWithHandle;
-        if (null != shareWith) {
-            if ( NativeSurface.LOCK_SURFACE_NOT_READY >= shareWith.drawable.lockSurface() ) {
-                throw new GLException("GLContextShareSet could not lock surface: "+shareWith.drawable);
-            }
-            shareWithHandle = shareWith.getHandle();
-            if (0 == shareWithHandle) {
-                throw new GLException("GLContextShareSet returned an invalid OpenGL context: "+this);
+        final boolean created;
+        final GLContextImpl sharedMaster = getOtherSharedMaster();
+        if ( null != sharedMaster ) {
+            if ( NativeSurface.LOCK_SURFACE_NOT_READY >= sharedMaster.drawable.lockSurface() ) {
+                throw new GLException("GLContextShareSet could not lock sharedMaster surface: "+sharedMaster.drawable);
             }
-        } else {
-            shareWithHandle = 0;
         }
-        final boolean created;
         try {
-            created = createImpl(shareWithHandle); // may throws exception if fails
+            if ( null != sharedMaster ) {
+                final long sharedMasterHandle = sharedMaster.getHandle();
+                if ( 0 == sharedMasterHandle ) {
+                    throw new GLException("GLContextShareSet returned an invalid sharedMaster context: "+sharedMaster);
+                }
+                created = createImpl(sharedMasterHandle); // may throws exception if fails
+            } else {
+                created = createImpl(0); // may throws exception if fails
+            }
             if( created && hasNoDefaultVAO() ) {
                 final int[] tmp = new int[1];
                 final GL rootGL = gl.getRootGL();
@@ -702,8 +709,8 @@ public abstract class GLContextImpl extends GLContext {
                 }
             }
         } finally {
-            if (null != shareWith) {
-                shareWith.drawable.unlockSurface();
+            if ( null != sharedMaster ) {
+                sharedMaster.drawable.unlockSurface();
             }
         }
         if ( DEBUG_TRACE_SWITCH ) {