Serialize context construction to avoid threading issues with shared contexts.

This commit is contained in:
the_fiddler 2009-11-03 23:39:03 +00:00
parent 7e1ebfea6b
commit 544cf9d405
2 changed files with 123 additions and 114 deletions

View file

@ -32,7 +32,7 @@ namespace OpenTK.Graphics
static bool share_contexts = true;
static bool direct_rendering = true;
readonly static object context_lock = new object();
readonly static object SyncRoot = new object();
// Maps OS-specific context handles to GraphicsContext weak references.
readonly static Dictionary<ContextHandle, WeakReference> available_contexts = new Dictionary<ContextHandle, WeakReference>();
@ -50,7 +50,7 @@ namespace OpenTK.Graphics
{
implementation = new OpenTK.Platform.Dummy.DummyGLContext(handle);
lock (context_lock)
lock (SyncRoot)
{
available_contexts.Add((implementation as IGraphicsContextInternal).Context, new WeakReference(this));
}
@ -77,6 +77,8 @@ namespace OpenTK.Graphics
/// Different hardware supports different flags, major and minor versions. Invalid parameters will be silently ignored.
/// </remarks>
public GraphicsContext(GraphicsMode mode, IWindowInfo window, int major, int minor, GraphicsContextFlags flags)
{
lock (SyncRoot)
{
bool designMode = false;
if (mode == null && window == null)
@ -101,8 +103,6 @@ namespace OpenTK.Graphics
IGraphicsContext shareContext = null;
if (GraphicsContext.ShareContexts)
{
lock (context_lock)
{
// A small hack to create a shared context with the first available context.
foreach (WeakReference r in GraphicsContext.available_contexts.Values)
@ -111,7 +111,6 @@ namespace OpenTK.Graphics
break;
}
}
}
// Todo: Add a DummyFactory implementing IPlatformFactory.
if (designMode)
@ -123,16 +122,14 @@ namespace OpenTK.Graphics
case true: implementation = Factory.Embedded.CreateGLContext(mode, window, shareContext, direct_rendering, major, minor, flags); break;
}
lock (context_lock)
{
available_contexts.Add((this as IGraphicsContextInternal).Context, new WeakReference(this));
}
}
finally
{
Debug.Unindent();
}
}
}
#endregion
@ -201,7 +198,7 @@ namespace OpenTK.Graphics
{
get
{
lock (context_lock)
lock (SyncRoot)
{
if (available_contexts.Count > 0)
{
@ -282,7 +279,7 @@ namespace OpenTK.Graphics
/// </remarks>
void CreateContext(bool direct, IGraphicsContext source)
{
lock (context_lock)
lock (SyncRoot)
{
available_contexts.Add((this as IGraphicsContextInternal).Context, new WeakReference(this));
}
@ -418,7 +415,7 @@ namespace OpenTK.Graphics
if (!IsDisposed)
{
Debug.Print("Disposing context {0}.", (this as IGraphicsContextInternal).Context.ToString());
lock (context_lock)
lock (SyncRoot)
{
available_contexts.Remove((this as IGraphicsContextInternal).Context);
}

View file

@ -26,6 +26,8 @@ namespace OpenTK.Platform.Windows
/// </summary>
internal sealed class WinGLContext : DesktopGraphicsContext
{
static object SyncRoot = new object();
static IntPtr opengl32Handle;
static bool wgl_loaded;
const string opengl32Name = "OPENGL32.DLL";
@ -35,6 +37,8 @@ namespace OpenTK.Platform.Windows
#region --- Contructors ---
static WinGLContext()
{
lock (SyncRoot)
{
// Dynamically load the OpenGL32.dll in order to use the extension loading capabilities of Wgl.
if (opengl32Handle == IntPtr.Zero)
@ -46,9 +50,15 @@ namespace OpenTK.Platform.Windows
Debug.WriteLine(String.Format("Loaded opengl32.dll: {0}", opengl32Handle));
}
}
}
public WinGLContext(GraphicsMode format, WinWindowInfo window, IGraphicsContext sharedContext,
int major, int minor, GraphicsContextFlags flags)
{
// There are many ways this code can break when accessed by multiple threads. The biggest offender is
// the sharedContext stuff, which will only become valid *after* this constructor returns.
// The easiest solution is to serialize all context construction - hence the big lock, below.
lock (SyncRoot)
{
if (window == null)
throw new ArgumentNullException("window", "Must point to a valid window.");
@ -89,6 +99,7 @@ namespace OpenTK.Platform.Windows
if (flags != 0)
{
attributes.Add((int)ArbCreateContext.Flags);
#warning "This is not entirely correct: Embedded is not a valid flag! We need to add a GetARBContextFlags(GraphicsContextFlags) method."
attributes.Add((int)flags);
}
attributes.Add(0);
@ -128,6 +139,7 @@ namespace OpenTK.Platform.Windows
Wgl.Imports.ShareLists((sharedContext as IGraphicsContextInternal).Context.Handle, Handle.Handle);
}
}
}
#endregion