Remove QGLShareRegister and transfer its functionality to QGLContextGroup

Task-number: QT-2600
Reviewed-by: Samuel

9 files changed, 39 insertions, 41 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index a41d439..7655971 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -124,17 +124,20 @@ public:
 public Q_SLOTS:
     void contextDestroyed(const QGLContext *context) {
         if (context == ctx) {
-            QList<const QGLContext *> shares = qgl_share_reg()->shares(ctx);
-            if (shares.isEmpty()) {
-                glDeleteFramebuffers(1, &m_fbo);
-                if (m_width || m_height)
-                    glDeleteTextures(1, &m_texture);
+            const QGLContext *nextCtx = qt_gl_transfer_context(ctx);
+            if (!nextCtx) {
+                // the context may not be current, so we cannot directly
+                // destroy the fbo and texture here, but since the context
+                // is about to be destroyed, the GL server will do the
+                // clean up for us anyway
+                m_fbo = 0;
+                m_texture = 0;
                 ctx = 0;
             } else {
                 // since the context holding the texture is shared, and
                 // about to be destroyed, we have to transfer ownership
                 // of the texture to one of the share contexts
-                ctx = const_cast<QGLContext *>((ctx == shares.at(0)) ? shares.at(1) : shares.at(0));
+                ctx = const_cast<QGLContext *>(nextCtx);
             }
         }
     }
diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index f5e46de..c3e4a2e 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -1436,6 +1436,18 @@ void QGLContextGroup::removeGuard(QGLSharedResourceGuard *guard)
         m_guards = guard->m_next;
 }
 
+const QGLContext *qt_gl_transfer_context(const QGLContext *ctx)
+{
+    if (!ctx)
+        return 0;
+    QList<const QGLContext *> shares
+        (QGLContextPrivate::contextGroup(ctx)->shares());
+    if (shares.size() >= 2)
+        return (ctx == shares.at(0)) ? shares.at(1) : shares.at(0);
+    else
+        return 0;
+}
+
 QGLContextPrivate::~QGLContextPrivate()
 {
     if (!group->m_refs.deref()) {
@@ -1731,12 +1743,6 @@ struct DDSFormat {
 #define GL_GENERATE_MIPMAP_HINT_SGIS  0x8192
 #endif
 
-Q_GLOBAL_STATIC(QGLShareRegister, _qgl_share_reg)
-Q_OPENGL_EXPORT QGLShareRegister* qgl_share_reg()
-{
-    return _qgl_share_reg();
-}
-
 /*!
     \class QGLContext
     \brief The QGLContext class encapsulates an OpenGL rendering context.
@@ -2985,7 +2991,7 @@ bool QGLContext::create(const QGLContext* shareContext)
         wd->usesDoubleBufferedGLContext = d->glFormat.doubleBuffer();
     }
     if (d->sharing)  // ok, we managed to share
-        qgl_share_reg()->addShare(this, shareContext);
+        QGLContextGroup::addShare(this, shareContext);
     return d->valid;
 }
 
@@ -4971,7 +4977,7 @@ Q_OPENGL_EXPORT const QString qt_gl_library_name()
 }
 #endif
 
-void QGLShareRegister::addShare(const QGLContext *context, const QGLContext *share) {
+void QGLContextGroup::addShare(const QGLContext *context, const QGLContext *share) {
     Q_ASSERT(context && share);
     if (context->d_ptr->group == share->d_ptr->group)
         return;
@@ -4992,11 +4998,7 @@ void QGLShareRegister::addShare(const QGLContext *context, const QGLContext *sha
     group->m_shares.append(context);
 }
 
-QList<const QGLContext *> QGLShareRegister::shares(const QGLContext *context) {
-    return context->d_ptr->group->m_shares;
-}
-
-void QGLShareRegister::removeShare(const QGLContext *context) {
+void QGLContextGroup::removeShare(const QGLContext *context) {
     // Remove the context from the group.
     QGLContextGroup *group = context->d_ptr->group;
     if (group->m_shares.isEmpty())
diff --git a/src/opengl/qgl.h b/src/opengl/qgl.h
index b6cd128..932ea7e 100644
--- a/src/opengl/qgl.h
+++ b/src/opengl/qgl.h
@@ -398,7 +398,7 @@ private:
     friend class QGLPixmapData;
     friend class QGLPixmapFilterBase;
     friend class QGLTextureGlyphCache;
-    friend class QGLShareRegister;
+    friend class QGLContextGroup;
     friend class QGLSharedResourceGuard;
     friend class QGLPixmapBlurFilter;
     friend QGLFormat::OpenGLVersionFlags QGLFormat::openGLVersionFlags();
diff --git a/src/opengl/qgl_egl.cpp b/src/opengl/qgl_egl.cpp
index 839e8eb..084db32 100644
--- a/src/opengl/qgl_egl.cpp
+++ b/src/opengl/qgl_egl.cpp
@@ -152,7 +152,7 @@ void QGLContext::reset()
     d->valid = false;
     d->transpColor = QColor();
     d->initDone = false;
-    qgl_share_reg()->removeShare(this);
+    QGLContextGroup::removeShare(this);
 }
 
 void QGLContext::makeCurrent()
diff --git a/src/opengl/qgl_mac.mm b/src/opengl/qgl_mac.mm
index 4dd822d..8ecc48b 100644
--- a/src/opengl/qgl_mac.mm
+++ b/src/opengl/qgl_mac.mm
@@ -476,7 +476,7 @@ void QGLContext::reset()
     d->valid = false;
     d->transpColor = QColor();
     d->initDone = false;
-    qgl_share_reg()->removeShare(this);
+    QGLContextGroup::removeShare(this);
 }
 
 void QGLContext::makeCurrent()
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index 834ff96..fcfe791 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -222,9 +222,8 @@ class QGLSharedResourceGuard;
 typedef QHash<QString, GLuint> QGLDDSCache;
 
 // QGLContextPrivate has the responsibility of creating context groups.
-// QGLContextPrivate and QGLShareRegister will both maintain the reference counter and destroy
+// QGLContextPrivate maintains the reference counter and destroys
 // context groups when needed.
-// QGLShareRegister has the responsibility of keeping the context pointer up to date.
 class QGLContextGroup
 {
 public:
@@ -233,9 +232,13 @@ public:
     QGLExtensionFuncs &extensionFuncs() {return m_extensionFuncs;}
     const QGLContext *context() const {return m_context;}
     bool isSharing() const { return m_shares.size() >= 2; }
+    QList<const QGLContext *> shares() const { return m_shares; }
 
     void addGuard(QGLSharedResourceGuard *guard);
     void removeGuard(QGLSharedResourceGuard *guard);
+
+    static void addShare(const QGLContext *context, const QGLContext *share);
+    static void removeShare(const QGLContext *context);
 private:
     QGLContextGroup(const QGLContext *context) : m_context(context), m_guards(0), m_refs(1) { }
 
@@ -249,12 +252,15 @@ private:
 
     void cleanupResources(const QGLContext *ctx);
 
-    friend class QGLShareRegister;
     friend class QGLContext;
     friend class QGLContextPrivate;
     friend class QGLContextResource;
 };
 
+// Get the context that resources for "ctx" will transfer to once
+// "ctx" is destroyed.  Returns null if nothing is sharing with ctx.
+Q_OPENGL_EXPORT const QGLContext *qt_gl_transfer_context(const QGLContext *);
+
 class QGLTexture;
 
 // This probably needs to grow to GL_MAX_VERTEX_ATTRIBS, but 3 is ok for now as that's
@@ -404,19 +410,6 @@ public:
 Q_DECLARE_OPERATORS_FOR_FLAGS(QGLExtensions::Extensions)
 
 
-class Q_OPENGL_EXPORT QGLShareRegister
-{
-public:
-    QGLShareRegister() {}
-    ~QGLShareRegister() {}
-
-    void addShare(const QGLContext *context, const QGLContext *share);
-    QList<const QGLContext *> shares(const QGLContext *context);
-    void removeShare(const QGLContext *context);
-};
-
-extern Q_OPENGL_EXPORT QGLShareRegister* qgl_share_reg();
-
 // Temporarily make a context current if not already current or
 // shared with the current contex.  The previous context is made
 // current when the object goes out of scope.
diff --git a/src/opengl/qgl_win.cpp b/src/opengl/qgl_win.cpp
index 5b5820a..f80025d 100644
--- a/src/opengl/qgl_win.cpp
+++ b/src/opengl/qgl_win.cpp
@@ -1145,7 +1145,7 @@ void QGLContext::reset()
     delete d->cmap;
     d->cmap = 0;
     d->initDone = false;
-    qgl_share_reg()->removeShare(this);
+    QGLContextGroup::removeShare(this);
 }
 
 //
diff --git a/src/opengl/qgl_x11.cpp b/src/opengl/qgl_x11.cpp
index 9c3fc79..8173bec 100644
--- a/src/opengl/qgl_x11.cpp
+++ b/src/opengl/qgl_x11.cpp
@@ -825,7 +825,7 @@ void QGLContext::reset()
     d->valid = false;
     d->transpColor = QColor();
     d->initDone = false;
-    qgl_share_reg()->removeShare(this);
+    QGLContextGroup::removeShare(this);
 }
 
 
diff --git a/src/opengl/qglpixelbuffer.cpp b/src/opengl/qglpixelbuffer.cpp
index 7c97ebb..fab6efc 100644
--- a/src/opengl/qglpixelbuffer.cpp
+++ b/src/opengl/qglpixelbuffer.cpp
@@ -127,7 +127,7 @@ void QGLPixelBufferPrivate::common_init(const QSize &size, const QGLFormat &form
         qctx = new QGLContext(format);
         qctx->d_func()->sharing = (shareWidget != 0);
         if (shareWidget != 0 && shareWidget->d_func()->glcx) {
-            qgl_share_reg()->addShare(qctx, shareWidget->d_func()->glcx);
+            QGLContextGroup::addShare(qctx, shareWidget->d_func()->glcx);
             shareWidget->d_func()->glcx->d_func()->sharing = true;
         }