public async Task <TryImportModuleResult> TryImportModuleAsync(
string name,
TryImportModuleContext context,
CancellationToken cancellationToken
)
{
IPythonModule module = null;
if (string.IsNullOrEmpty(name))
{
return(TryImportModuleResult.ModuleNotFound);
}
Debug.Assert(!name.EndsWithOrdinal("."), $"{name} should not end with '.'");
// Handle builtins explicitly
if (name == BuiltinModuleName)
{
Debug.Fail($"Interpreters must handle import {name} explicitly");
return(TryImportModuleResult.NotSupported);
}
var modules = context?.ModuleCache;
SentinelModule sentinalValue = null;
if (modules != null)
{
// Return any existing module
if (modules.TryGetValue(name, out module) && module != null)
{
if (module is SentinelModule smod)
{
// If we are importing this module on another thread, allow
// time for it to complete. This does not block if we are
// importing on the current thread or the module is not
// really being imported.
try {
module = await smod.WaitForImportAsync(cancellationToken);
} catch (OperationCanceledException) {
_log?.Log(TraceLevel.Warning, "ImportTimeout", name);
return(TryImportModuleResult.Timeout);
}
if (module is SentinelModule)
{
_log?.Log(TraceLevel.Warning, "RecursiveImport", name);
}
}
return(new TryImportModuleResult(module));
}
// Set up a sentinel so we can detect recursive imports
sentinalValue = new SentinelModule(name, true);
if (!modules.TryAdd(name, sentinalValue))
{
// Try to get the new module, in case we raced with a .Clear()
if (modules.TryGetValue(name, out module) && !(module is SentinelModule))
{
return(new TryImportModuleResult(module));
}
// If we reach here, the race is too complicated to recover
// from. Signal the caller to try importing again.
_log?.Log(TraceLevel.Warning, "RetryImport", name);
return(TryImportModuleResult.NeedRetry);
}
}
// Do normal searches
if (!string.IsNullOrEmpty(Configuration?.InterpreterPath))
{
try {
module = await ImportFromSearchPathsAsync(name, context, cancellationToken);
} catch (OperationCanceledException) {
_log?.Log(TraceLevel.Error, "ImportTimeout", name, "ImportFromSearchPaths");
return(TryImportModuleResult.Timeout);
}
if (module == null)
{
module = ImportFromBuiltins(name, context.BuiltinModule as AstBuiltinsPythonModule);
}
}
if (module == null)
{
module = ImportFromCache(name, context);
}
if (modules != null)
{
if (sentinalValue == null)
{
_log?.Log(TraceLevel.Error, "RetryImport", name, "sentinalValue==null");
Debug.Fail("Sentinal module was never created");
return(TryImportModuleResult.NeedRetry);
}
// Replace our sentinel, or if we raced, get the current
// value and abandon the one we just created.
if (!modules.TryUpdate(name, module, sentinalValue))
{
// Try to get the new module, in case we raced
if (modules.TryGetValue(name, out module) && !(module is SentinelModule))
{
return(new TryImportModuleResult(module));
}
// If we reach here, the race is too complicated to recover
// from. Signal the caller to try importing again.
_log?.Log(TraceLevel.Warning, "RetryImport", name);
return(TryImportModuleResult.NeedRetry);
}
sentinalValue.Complete(module);
}
// Also search for type stub packages if enabled and we are not a blacklisted module
if (module != null && context?.TypeStubPaths != null && module.Name != "typing")
{
var tsModule = await ImportFromTypeStubsAsync(module.Name, context, cancellationToken);
if (tsModule != null)
{
if (context.MergeTypeStubPackages)
{
module = AstPythonMultipleModules.Combine(module, tsModule);
}
else
{
module = tsModule;
}
}
}
return(new TryImportModuleResult(module));
}
public TryImportModuleResult TryImportModule(
string name,
out IPythonModule module,
TryImportModuleContext context
)
{
module = null;
if (string.IsNullOrEmpty(name))
{
return(TryImportModuleResult.ModuleNotFound);
}
Debug.Assert(!name.EndsWithOrdinal("."), $"{name} should not end with '.'");
// Handle builtins explicitly
if (name == BuiltinModuleName)
{
Debug.Fail($"Interpreters must handle import {name} explicitly");
return(TryImportModuleResult.NotSupported);
}
var modules = context?.ModuleCache;
int importTimeout = context?.Timeout ?? 5000;
SentinelModule sentinalValue = null;
if (modules != null)
{
// Return any existing module
if (modules.TryGetValue(name, out module) && module != null)
{
if (module is SentinelModule smod)
{
// If we are importing this module on another thread, allow
// time for it to complete. This does not block if we are
// importing on the current thread or the module is not
// really being imported.
var newMod = smod.WaitForImport(importTimeout);
if (newMod is SentinelModule)
{
_log?.Log(TraceLevel.Warning, "RecursiveImport", name);
module = newMod;
}
else if (newMod == null)
{
_log?.Log(TraceLevel.Warning, "ImportTimeout", name);
module = null;
return(TryImportModuleResult.Timeout);
}
else
{
module = newMod;
}
}
return(TryImportModuleResult.Success);
}
// Set up a sentinel so we can detect recursive imports
sentinalValue = new SentinelModule(name, true);
if (!modules.TryAdd(name, sentinalValue))
{
// Try to get the new module, in case we raced with a .Clear()
if (modules.TryGetValue(name, out module) && !(module is SentinelModule))
{
return(module == null ? TryImportModuleResult.ModuleNotFound : TryImportModuleResult.Success);
}
// If we reach here, the race is too complicated to recover
// from. Signal the caller to try importing again.
_log?.Log(TraceLevel.Warning, "RetryImport", name);
return(TryImportModuleResult.NeedRetry);
}
}
// Do normal searches
if (!string.IsNullOrEmpty(Configuration?.InterpreterPath))
{
var importTask = ImportFromSearchPathsAsync(name, context);
if (importTask.Wait(importTimeout))
{
module = importTask.Result;
}
else
{
_log?.Log(TraceLevel.Error, "ImportTimeout", name, "ImportFromSearchPaths");
module = null;
}
module = module ?? ImportFromBuiltins(name, context.BuiltinModule as AstBuiltinsPythonModule);
}
if (module == null)
{
module = ImportFromCache(name);
}
if (modules != null)
{
// Replace our sentinel, or if we raced, get the current
// value and abandon the one we just created.
if (!modules.TryUpdate(name, module, sentinalValue))
{
// Try to get the new module, in case we raced
if (modules.TryGetValue(name, out module) && !(module is SentinelModule))
{
return(module == null ? TryImportModuleResult.ModuleNotFound : TryImportModuleResult.Success);
}
// If we reach here, the race is too complicated to recover
// from. Signal the caller to try importing again.
_log?.Log(TraceLevel.Warning, "RetryImport", name);
return(TryImportModuleResult.NeedRetry);
}
sentinalValue.Complete(module);
sentinalValue.Dispose();
}
// Also search for type stub packages if enabled and we are not a blacklisted module
if (module != null && module.Name != "typing")
{
// Note that this currently only looks in the typeshed package, as type stub
// packages are not yet standardised so we don't know where to look.
// The details will be in PEP 561.
if (context.TypeStubPaths?.Any() == true)
{
var mtsp = FindModuleInSearchPath(context.TypeStubPaths, null, module.Name);
if (mtsp.HasValue)
{
var mp = mtsp.Value;
if (mp.IsCompiled)
{
Debug.Fail("Unsupported native module in typeshed");
}
else
{
_log?.Log(TraceLevel.Verbose, "ImportTypeShed", mp.FullName, FastRelativePath(mp.SourceFile));
var tsModule = PythonModuleLoader.FromFile(context.Interpreter, mp.SourceFile, LanguageVersion, mp.FullName);
if (tsModule != null)
{
if (context.MergeTypeStubPackages)
{
module = AstPythonMultipleModules.Combine(module, tsModule);
}
else
{
module = tsModule;
}
}
}
}
}
}
return(module == null ? TryImportModuleResult.ModuleNotFound : TryImportModuleResult.Success);
}