/// <summary>
/// Removes the registered instance from the dictionary.
/// </summary>
internal static void DeregisterHandle(IntPtr handle, SKObject instance)
{
if (handle == IntPtr.Zero)
{
return;
}
if (instance is ISKSkipObjectRegistration)
{
return;
}
instancesLock.EnterWriteLock();
try {
var existed = instances.TryGetValue(handle, out var weak);
if (existed && (!weak.IsAlive || weak.Target == instance))
{
instances.Remove(handle);
}
else
{
#if THROW_OBJECT_EXCEPTIONS
InvalidOperationException ex = null;
if (!existed)
{
// the object may have been replaced
if (!instance.IsDisposed)
{
// recoverable error
// there was no object there, but we are still alive
ex = new InvalidOperationException(
$"A managed object did not exist for the specified native object. " +
$"H: {handle.ToString ("x")} Type: {instance.GetType ()}");
}
}
else if (weak.Target is SKObject o && o != instance)
{
// there was an object in the dictionary, but it was NOT this object
if (!instance.IsDisposed)
{
// recoverable error
// there was a new living object there, but we are still alive
ex = new InvalidOperationException(
$"Trying to remove a different object with the same native handle. " +
$"H: {handle.ToString ("x")} Type: ({o.GetType ()}, {instance.GetType ()})");
}
}
if (ex != null)
{
if (instance.fromFinalizer)
{
exceptions.Add(ex);
}
else
{
throw ex;
}
}
#endif
}
} finally {
instancesLock.ExitWriteLock();
}
}
/// <summary>
/// Registers the specified instance with the dictionary.
/// </summary>
internal static void RegisterHandle(IntPtr handle, SKObject instance)
{
if (handle == IntPtr.Zero || instance == null)
{
return;
}
if (instance is ISKSkipObjectRegistration)
{
return;
}
SKObject objectToDispose = null;
instancesLock.EnterWriteLock();
try {
if (instances.TryGetValue(handle, out var oldValue) && oldValue.Target is SKObject obj && !obj.IsDisposed)
{
#if THROW_OBJECT_EXCEPTIONS
if (obj.OwnsHandle)
{
// a mostly recoverable error
// if there is a managed object, then maybe something happened and the native object is dead
throw new InvalidOperationException(
$"A managed object already exists for the specified native object. " +
$"H: {handle.ToString ("x")} Type: ({obj.GetType ()}, {instance.GetType ()})");
}
#endif
// this means the ownership was handed off to a native object, so clean up the managed side
objectToDispose = obj;
}
instances[handle] = new WeakReference(instance);
} finally {
instancesLock.ExitWriteLock();
}
// dispose the object we just replaced
objectToDispose?.DisposeInternal();
}
