/// <summary>
/// Discover external module dependencies and enqueue them if necessary
/// </summary>
/// <remarks>
/// The parsed file gets updated with the external module references as they are discovered.
/// </remarks>
private async Task <Possible <bool> > EnqueueSpecDependenciesIfAny(ModuleUnderConstruction owningModule, ISourceFile parsedFile)
{
var allSpecifiers = m_moduleReferenceResolver.GetExternalModuleReferences(parsedFile);
foreach (var moduleName in allSpecifiers)
{
// Get the module definition from the resolver and enqueue it. Since we don't deal with versions yet at the
// import level, there should be exactly one module definition with that name
var maybeModuleDefinition = await m_workspaceProvider.FindUniqueModuleDefinitionWithName(moduleName);
if (!maybeModuleDefinition.Succeeded)
{
return(maybeModuleDefinition.Failure);
}
var moduleDefinition = maybeModuleDefinition.Result;
// Since the referenced module has been found, we update the parsed file with the reference. This
// information is later used by the checker.
if (!m_moduleReferenceResolver.TryUpdateExternalModuleReference(parsedFile, moduleDefinition, out var failure))
{
return(failure);
}
// Update the owning module advertising that the found module was referenced
owningModule.AddReferencedModule(moduleDefinition.Descriptor, moduleName.ReferencedFrom);
EnqueueModuleForParsing(moduleDefinition);
}
return(true);
}
private void CheckForCompletionAndSignalQueueIfDone(ModuleUnderConstruction owningModule)
{
// Now that all dependencies of the owning module have been scheduled,
// we check if the module for which we just added a spec is complete
if (owningModule.IsModuleFirstTimeComplete())
{
var moduleId = owningModule.Definition.Descriptor;
// We create a parsed module out of a module under construction.
// Observe many threads can try to create the same completed module. But that's ok, the method is thread safe
// and always return the same instance.
// It is important to notice that we should add this module to m_modulesAlreadyParsed before removing it from
// m_modulesToBeParsed. This is so no producer will think the module is not there at any point in time (which
// would cause the producer to try to schedule that module again)
var success = owningModule.TryCreateCompletedModule(m_moduleReferenceResolver, m_workspaceConfiguration, m_queueOptions.CancelOnFirstFailure, out ParsedModule module, out Failure[] failures);
if (success)
{
m_modulesAlreadyParsed[moduleId] = module;
// Now the module is completed and we can bind the changed file as well.
var modifiedSourceFile = owningModule.GetSourceFileForInjectingQualifiers();
if (modifiedSourceFile != null)
{
ScheduleSourceFileBinding(new ParsedSpecWithOwningModule(parsedFile: modifiedSourceFile, owningModule: owningModule.Definition));
}
}
else
{
// This is a bogus module we put here when failures occurr. This guarantees that modules
// are not scheduled more than once (detailed reasons above). When there are failures
// we want to report them only once, so leave that to whoever successfully removes
// the module from m_modulesToBeParsed to report them.
// Observe that this (empty) module will be left in case of failures, but that's not
// likely to be a problem
m_modulesAlreadyParsed[moduleId] = new ParsedModule(owningModule.Definition, hasFailures: true);
}
// If removing fails, that means that somebody else successfully removed the module, so we do nothing
// If removing succeeds, we are responsible for signaling if the queue is done
if (m_modulesToBeParsed.TryRemove(moduleId, out ModuleUnderConstruction dummy))
{
if (!success)
{
ReportFailureAndCancelParsingIfNeeded(failures);
}
// Now we decide if we are done with parsing the transitive closure.
// This happens when the set of modules to be parsed is empty
// and EnqueuingCompleted has been called.
// Observe that it is important that we first add all dependencies to be parsed
// before removing a completed module. This ensures
// that if anybody sees an empty collection, we are done for sure
if (m_modulesToBeParsed.IsEmpty && m_enqueingComplete)
{
cancellationTokenChain.Dispose();
m_parseQueue.Complete();
}
}
}
}
/// <summary>
/// Creates a workspace from all known modules in an incremental way
/// </summary>
/// <remarks>
/// It reuses already parsed modules so they don't get recomputed again
/// </remarks>
public async Task <Workspace> CreateIncrementalWorkspaceForAllKnownModulesAsync(
IEnumerable <ParsedModule> parsedModules,
ModuleUnderConstruction moduleUnderConstruction,
IEnumerable <Failure> failures,
[CanBeNull] ParsedModule preludeModule)
{
var maybeModuleDefinitions = await GetModuleDefinitionsForAllResolversAsync();
if (!maybeModuleDefinitions.Succeeded)
{
return(Failure(maybeModuleDefinitions.Failure));
}
var moduleDefinitions = maybeModuleDefinitions.Result;
ModuleDefinition preludeDefinition;
if (preludeModule != null)
{
// Need to add prelude to a list of parsed modules if awailable
var parsedModuleList = parsedModules.ToList();
parsedModuleList.Add(preludeModule);
parsedModules = parsedModuleList;
preludeDefinition = preludeModule.Definition;
}
else
{
var possiblePreludeDefinition = await TryGetPreludeModuleDefinitionAsync();
if (!possiblePreludeDefinition.Succeeded)
{
return(Failure(possiblePreludeDefinition.Failure));
}
preludeDefinition = possiblePreludeDefinition.Result;
moduleDefinitions.Add(preludeDefinition);
}
if (!WorkspaceValidator.ValidateModuleDefinitions(moduleDefinitions, PathTable, out var validationFailures))
{
return(Failure(validationFailures));
}
var queue = ModuleParsingQueue.CreateIncrementalQueue(
this,
Configuration,
m_moduleReferenceResolver,
preludeDefinition,
GetConfigurationModule(),
parsedModules,
failures);
return(await queue.ProcessIncrementalAsync(moduleUnderConstruction));
}
/// <inheritdoc />
public async Task <Workspace> CreateIncrementalWorkspaceForAllKnownModulesAsync(
IEnumerable <ParsedModule> parsedModules,
ModuleUnderConstruction moduleUnderConstruction,
IEnumerable <Failure> failures,
ParsedModule preludeModule)
{
using (m_statistics.EndToEndParsing.Start())
{
return(await m_decoratee.CreateIncrementalWorkspaceForAllKnownModulesAsync(parsedModules, moduleUnderConstruction, failures, preludeModule));
}
}
/// <summary>
/// Process a partially constructed module
/// </summary>
public Task <Workspace> ProcessIncrementalAsync(ModuleUnderConstruction moduleUnderConstruction)
{
Contract.Requires(moduleUnderConstruction != null);
Contract.Requires(!moduleUnderConstruction.IsModuleComplete());
// Add the module to be parsed as is
var definition = moduleUnderConstruction.Definition;
Contract.Assert(!m_modulesToBeParsed.ContainsKey(definition.Descriptor));
m_modulesToBeParsed[definition.Descriptor] = moduleUnderConstruction;
// Now schedule all the pending specs
// It is extremely important to get specs in order to preserve determinism.
var pendingSpecs = moduleUnderConstruction.GetPendingSpecPathsOrderedByPath(m_workspaceProvider.PathTable);
foreach (var spec in pendingSpecs)
{
m_parseQueue.Post(new SpecWithOwningModule(spec.path, definition));
}
return(EnqueuingFinishedAndWaitForCompletion());
}
/// <summary>
/// Enqueues all the specs of <param name="moduleDefinition"/> for parsing. Actual enqueuing only happens if the module has not been
/// completed yet, nor already scheduled.
/// </summary>
/// <remarks>
/// This method can only be called before calling <see cref="EnqueuingCompleted"/>
/// </remarks>
private void EnqueueModuleForParsing(ModuleDefinition moduleDefinition)
{
if (m_modulesAlreadyParsed.ContainsKey(moduleDefinition.Descriptor) ||
m_modulesToBeParsed.ContainsKey(moduleDefinition.Descriptor))
{
return;
}
// If the module has no specs, it is already parsed
if (moduleDefinition.Specs.Count == 0)
{
m_modulesAlreadyParsed[moduleDefinition.Descriptor] = new ParsedModule(moduleDefinition);
return;
}
// Create a module with no specs and add it to the modules-to-be-parsed collection
var module = new ModuleUnderConstruction(moduleDefinition);
if (!m_modulesToBeParsed.TryAdd(moduleDefinition.Descriptor, module))
{
// If the module has already been added by someone else, we just declare the enqueue successful
return;
}
// Now schedule all the specs
foreach (var spec in moduleDefinition.Specs)
{
// Constructor of this class ensures that queue is unbounded.
// In cases of bounded queue, posting to a queue can lead to a deadlock
// because ActionBlock infrastructure removes item from the queue
// only when call back that processes that element finishes its execution.
// But in this case, callback can add item to the queue which will lead to a deadlock
// when queue is full.
m_parseQueue.Post(new SpecWithOwningModule(spec, moduleDefinition));
}
}
