Merge QGLContextReference into QGLContextGroup

Reviewed-by: trustme

2 files changed, 62 insertions, 73 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 72dd184..7dbe642 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -1393,11 +1393,39 @@ bool operator!=(const QGLFormat& a, const QGLFormat& b)
 /*****************************************************************************
   QGLContext implementation
  *****************************************************************************/
-QGLContextPrivate::~QGLContextPrivate()
+
+QGLContextGroup::~QGLContextGroup()
+{
+    // Clear any remaining QGLSharedResourceGuard objects on the group.
+    QGLSharedResourceGuard *guard = m_guards;
+    while (guard != 0) {
+        guard->m_group = 0;
+        guard->m_id = 0;
+        guard = guard->m_next;
+    }
+}
+
+void QGLContextGroup::addGuard(QGLSharedResourceGuard *guard)
+{
+    if (m_guards)
+        m_guards->m_prev = guard;
+    guard->m_next = m_guards;
+    guard->m_prev = 0;
+    m_guards = guard;
+}
+
+void QGLContextGroup::removeGuard(QGLSharedResourceGuard *guard)
 {
-    if (!reference->deref())
-        delete reference;
+    if (guard->m_next)
+        guard->m_next->m_prev = guard->m_prev;
+    if (guard->m_prev)
+        guard->m_prev->m_next = guard->m_next;
+    else
+        m_guards = guard->m_next;
+}
 
+QGLContextPrivate::~QGLContextPrivate()
+{
     if (!group->m_refs.deref()) {
         Q_ASSERT(group->context() == q_ptr);
         delete group;
@@ -4959,30 +4987,22 @@ void QGLContextGroup::cleanupResources(const QGLContext *ctx)
         it.key()->cleanup(ctx, it.value());
 }
 
-QGLContextReference::QGLContextReference(const QGLContext *ctx)
-    : m_ref(1), m_ctx(ctx)
+QGLSharedResourceGuard::~QGLSharedResourceGuard()
 {
-    connect(QGLSignalProxy::instance(),
-            SIGNAL(aboutToDestroyContext(const QGLContext *)),
-            this, SLOT(aboutToDestroyContext(const QGLContext *)));
+    if (m_group)
+        m_group->removeGuard(this);
 }
 
-void QGLContextReference::aboutToDestroyContext(const QGLContext *ctx)
+void QGLSharedResourceGuard::setContext(const QGLContext *context)
 {
-    // Bail out if our context is not being destroyed.
-    if (ctx != m_ctx || !m_ctx)
-        return;
-
-    // Find some other context that this one is shared with to take over.
-    QList<const QGLContext *> shares = qgl_share_reg()->shares(m_ctx);
-    shares.removeAll(m_ctx);
-    if (!shares.isEmpty()) {
-        m_ctx = shares[0];
-        return;
+    if (m_group)
+        m_group->removeGuard(this);
+    if (context) {
+        m_group = QGLContextPrivate::contextGroup(context);
+        m_group->addGuard(this);
+    } else {
+        m_group = 0;
     }
-
-    // No more contexts sharing with this one, so the reference is now invalid.
-    m_ctx = 0;
 }
 
 QT_END_NAMESPACE
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index fd7f544..38a1845 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -220,6 +220,7 @@ public:
 };
 
 class QGLContextResource;
+class QGLSharedResourceGuard;
 
 // QGLContextPrivate has the responsibility of creating context groups.
 // QGLContextPrivate and QGLShareRegister will both maintain the reference counter and destroy
@@ -228,15 +229,21 @@ class QGLContextResource;
 class QGLContextGroup
 {
 public:
+    ~QGLContextGroup();
+
     QGLExtensionFuncs &extensionFuncs() {return m_extensionFuncs;}
     const QGLContext *context() const {return m_context;}
+
+    void addGuard(QGLSharedResourceGuard *guard);
+    void removeGuard(QGLSharedResourceGuard *guard);
 private:
-    QGLContextGroup(const QGLContext *context) : m_context(context), m_refs(1) { }
+    QGLContextGroup(const QGLContext *context) : m_context(context), m_guards(0), m_refs(1) { }
 
     QGLExtensionFuncs m_extensionFuncs;
     const QGLContext *m_context; // context group's representative
     QList<const QGLContext *> m_shares;
     QHash<QGLContextResource *, void *> m_resources;
+    QGLSharedResourceGuard *m_guards; // double-linked list of active guards.
     QAtomicInt m_refs;
 
     void cleanupResources(const QGLContext *ctx);
@@ -247,37 +254,13 @@ private:
     friend class QGLContextResource;
 };
 
-// Reference to a QGLContext which automatically switches to another
-// shared context when the main one is destroyed.  If there is no
-// shared context to switch to, the context pointer is set to null.
-// Note: should be merged into QGLContextGroup at some point.
-class QGLContextReference : public QObject
-{
-    Q_OBJECT
-public:
-    QGLContextReference(const QGLContext *ctx);
-    ~QGLContextReference() {}
-
-    const QGLContext *context() const { return m_ctx; }
-
-    void ref() { m_ref.ref(); }
-    bool deref() { return m_ref.deref(); }
-
-private slots:
-    void aboutToDestroyContext(const QGLContext *ctx);
-
-private:
-    QAtomicInt m_ref;
-    const QGLContext *m_ctx;
-};
-
 class QGLTexture;
 
 class QGLContextPrivate
 {
     Q_DECLARE_PUBLIC(QGLContext)
 public:
-    explicit QGLContextPrivate(QGLContext *context) : internal_context(false), q_ptr(context) {reference = new QGLContextReference(context); group = new QGLContextGroup(context);}
+    explicit QGLContextPrivate(QGLContext *context) : internal_context(false), q_ptr(context) {group = new QGLContextGroup(context);}
     ~QGLContextPrivate();
     QGLTexture *bindTexture(const QImage &image, GLenum target, GLint format,
                             QGLContext::BindOptions options);
@@ -340,7 +323,6 @@ public:
     QGLContext *q_ptr;
     QGLFormat::OpenGLVersionFlags version_flags;
 
-    QGLContextReference *reference;
     QGLContextGroup *group;
     GLint max_texture_size;
 
@@ -579,44 +561,27 @@ class Q_OPENGL_EXPORT QGLSharedResourceGuard
 {
 public:
     QGLSharedResourceGuard(const QGLContext *context)
-        : m_ctxref(0), m_id(0)
+        : m_group(0), m_id(0), m_next(0), m_prev(0)
     {
         setContext(context);
     }
     QGLSharedResourceGuard(const QGLContext *context, GLuint id)
-        : m_ctxref(0), m_id(id)
+        : m_group(0), m_id(id), m_next(0), m_prev(0)
     {
         setContext(context);
     }
-    ~QGLSharedResourceGuard()
-    {
-        if (m_ctxref && !m_ctxref->deref())
-            delete m_ctxref;
-    }
+    ~QGLSharedResourceGuard();
 
     const QGLContext *context() const
     {
-        return m_ctxref ? m_ctxref->context() : 0;
+        return m_group ? m_group->context() : 0;
     }
 
-    void setContext(const QGLContext *context)
-    {
-        if (m_ctxref && !m_ctxref->deref())
-            delete m_ctxref;
-        if (context) {
-            m_ctxref = context->d_ptr->reference;
-            m_ctxref->ref();
-        } else {
-            m_ctxref = 0;
-        }
-    }
+    void setContext(const QGLContext *context);
 
     GLuint id() const
     {
-        if (m_ctxref && m_ctxref->context())
-            return m_id;
-        else
-            return 0;
+        return m_id;
     }
 
     void setId(GLuint id)
@@ -625,8 +590,12 @@ public:
     }
 
 private:
-    QGLContextReference *m_ctxref;
+    QGLContextGroup *m_group;
     GLuint m_id;
+    QGLSharedResourceGuard *m_next;
+    QGLSharedResourceGuard *m_prev;
+
+    friend class QGLContextGroup;
 };
 
 QT_END_NAMESPACE