private void ParseDocumentAsync(Document document)
{
var cancellationTokenSource = new CancellationTokenSource();
using (_stateLock.DisposableWrite())
{
_workMap = _workMap.Add(document.Id, cancellationTokenSource);
}
var cancellationToken = cancellationTokenSource.Token;
var task = _taskScheduler.ScheduleTask(
() => document.GetSyntaxTreeAsync(cancellationToken),
"BackgroundParser.ParseDocumentAsync",
cancellationToken);
// Always ensure that we mark this work as done from the workmap.
task.SafeContinueWith(
_ =>
{
using (_stateLock.DisposableWrite())
{
// Check that we are still the active parse in the workmap before we remove it.
// Concievably if this continuation got delayed and another parse was put in, we might
// end up removing the tracking for another in-flight task.
if (_workMap.TryGetValue(document.Id, out var sourceInMap) && sourceInMap == cancellationTokenSource)
{
_workMap = _workMap.Remove(document.Id);
}
}
}, CancellationToken.None, TaskContinuationOptions.None, TaskScheduler.Default);
}
private void ParseDocumentAsync(Document document)
{
var cancellationTokenSource = new CancellationTokenSource();
using (_stateLock.DisposableWrite())
{
_workMap = _workMap.Add(document.Id, cancellationTokenSource);
}
var cancellationToken = cancellationTokenSource.Token;
var task = _taskScheduler.ScheduleTask(
() => document.GetSyntaxTreeAsync(cancellationToken),
"BackgroundParser.ParseDocumentAsync",
cancellationToken);
// Always ensure that we mark this work as done from the workmap.
task.SafeContinueWith(
_ =>
{
using (_stateLock.DisposableWrite())
{
_workMap = _workMap.Remove(document.Id);
}
}, CancellationToken.None, TaskContinuationOptions.None, TaskScheduler.Default);
}
private void BuildCompilationsAsync(
Solution solution,
ProjectId initialProject,
ISet <ProjectId> allProjects)
{
var cancellationToken = _cancellationSource.Token;
_compilationScheduler.ScheduleTask(
() => BuildCompilationsAsync(solution, initialProject, allProjects, cancellationToken),
"BackgroundCompiler.BuildCompilationsAsync",
cancellationToken);
}
private void OnGlobalOptionServiceOptionChanged(object sender, OptionChangedEventArgs e)
{
_taskQueue?.ScheduleTask(() =>
{
// Ensure we grab the event handlers inside the scheduled task to prevent a race of people unsubscribing
// but getting the event later on the UI thread
var eventHandlers = GetEventHandlers();
foreach (var handler in eventHandlers)
{
handler(this, e);
}
}, "OptionsService.SetOptions");
}
private void OnGlobalOptionServiceOptionChanged(object sender, OptionChangedEventArgs e)
{
var eventHandlers = GetEventHandlers();
if (eventHandlers.Length > 0)
{
_taskQueue?.ScheduleTask(() =>
{
foreach (var handler in eventHandlers)
{
handler(this, e);
}
}, "OptionsService.SetOptions");
}
}
private void ParseDocumentAsync(Document document)
{
var cancellationTokenSource = new CancellationTokenSource();
using (_stateLock.DisposableWrite())
{
_workMap = _workMap.Add(document.Id, cancellationTokenSource);
}
var cancellationToken = cancellationTokenSource.Token;
// We end up creating a chain of parsing tasks that each attempt to produce
// the appropriate syntax tree for any given document. Once we start work to create
// the syntax tree for a given document, we don't want to stop.
// Otherwise we can end up in the unfortunate scenario where we keep cancelling work,
// and then having the next task re-do the work we were just in the middle of.
// By not cancelling, we can reuse the useful results of previous tasks when performing later steps in the chain.
//
// we still cancel whole task if the task didn't start yet. we just don't cancel if task is started but not finished yet.
var task = _taskScheduler.ScheduleTask(
() => document.GetSyntaxTreeAsync(CancellationToken.None),
"BackgroundParser.ParseDocumentAsync",
cancellationToken);
// Always ensure that we mark this work as done from the workmap.
task.SafeContinueWith(
_ =>
{
using (_stateLock.DisposableWrite())
{
// Check that we are still the active parse in the workmap before we remove it.
// Concievably if this continuation got delayed and another parse was put in, we might
// end up removing the tracking for another in-flight task.
if (_workMap.TryGetValue(document.Id, out var sourceInMap) && sourceInMap == cancellationTokenSource)
{
_workMap = _workMap.Remove(document.Id);
}
}
}, CancellationToken.None, TaskContinuationOptions.None, TaskScheduler.Default);
}
/// <summary>
/// Executes an action as a background task, as part of a sequential queue of tasks.
/// </summary>
protected internal Task ScheduleTask(Action action, string taskName = "Workspace.Task")
{
return(_taskQueue.ScheduleTask(action, taskName));
}