public Task RequestOpen(LazyResourceManager requester, CancellationToken cancellationToken)
{
lock (LockObj)
{
ReferenceCount++;
switch (state)
{
case ResourceState.Reset:
state = ResourceState.Opening;
return(OpenTask = OpenResource(requester, cancellationToken));
case ResourceState.Opening:
return(OpenTask);
case ResourceState.Open:
return(Task.CompletedTask);
case ResourceState.Closing:
return(CloseTask.ContinueWith(t => RequestOpen(requester, cancellationToken).Wait()));
}
return(Task.CompletedTask);
}
}
public Task RequestClose(LazyResourceManager requester)
{
lock (LockObj)
{
ReferenceCount--;
if (ReferenceCount == 0)
{
switch (state)
{
case ResourceState.Reset:
case ResourceState.Closing:
throw new Exception("Should never happen");
case ResourceState.Opening:
case ResourceState.Open:
{
state = ResourceState.Closing;
return(CloseTask = Task.Factory.StartNew(() =>
{
try
{
// wait for the resource to open before close.
requester.resources[ResourceNode.Resource].OpenTask?.Wait();
}
catch
{
}
Task.WaitAll(ResourceNode.WeakDependencies.Select(requester.RequestResourceClose).ToArray());
var reslog = ResourceTaskManager.GetLogSource(ResourceNode.Resource);
Stopwatch timer = Stopwatch.StartNew();
try
{
ResourceNode.Resource.Close();
}
catch (Exception e)
{
reslog.Error("Error while closing \"{0}\": {1}", ResourceNode.Resource.Name, e.Message);
reslog.Debug(e);
}
reslog.Info(timer, "Resource \"{0}\" closed.", ResourceNode.Resource);
Task.WaitAll(ResourceNode.StrongDependencies.Select(requester.RequestResourceClose).ToArray());
state = ResourceState.Reset;
}));
}
}
}
return(Task.CompletedTask);
}
}
async Task OpenResource(LazyResourceManager requester, CancellationToken cancellationToken)
{
var node = ResourceNode;
foreach (var dep in node.StrongDependencies)
{
if (dep == null)
{
continue;
}
await requester.RequestResourceOpen(dep, cancellationToken);
}
Stopwatch swatch = Stopwatch.StartNew();
try
{
// start a new thread to do synchronous work
await Task.Factory.StartNew(node.Resource.Open);
var reslog = ResourceTaskManager.GetLogSource(node.Resource);
reslog.Info(swatch, "Resource \"{0}\" opened.", node.Resource);
}
finally
{
lock (LockObj)
if (state == ResourceState.Opening)
{
state = ResourceState.Open;
}
}
foreach (var dep in node.WeakDependencies)
{
if (dep == null)
{
continue;
}
await requester.RequestResourceOpen(dep, cancellationToken);
}
requester.ResourceOpenedCallback(node.Resource);
}