-//
+//
// async.cs: Asynchronous functions
//
// Author:
// Dual licensed under the terms of the MIT X11 or GNU GPL
//
// Copyright 2011 Novell, Inc.
+// Copyright 2011 Xamarin Inc.
//
using System;
namespace Mono.CSharp
{
- class Await : ExpressionStatement
+ public class Await : ExpressionStatement
{
Expression expr;
AwaitStatement stmt;
this.loc = loc;
}
+ public Expression Expr {
+ get {
+ return expr;
+ }
+ }
+
protected override void CloneTo (CloneContext clonectx, Expression target)
{
var t = (Await) target;
}
if (rc.IsUnsafe) {
- // TODO: New error code
- rc.Report.Error (-1900, loc,
+ rc.Report.Error (4004, loc,
"The `await' operator cannot be used in an unsafe context");
}
var bc = (BlockContext) rc;
- if (!bc.CurrentBlock.ParametersBlock.IsAsync) {
- // TODO: Should check for existence of await type but
- // what to do with it
- }
-
stmt = new AwaitStatement (expr, loc);
if (!stmt.Resolve (bc))
return null;
{
stmt.EmitStatement (ec);
}
+
+ public override object Accept (StructuralVisitor visitor)
+ {
+ return visitor.Visit (this);
+ }
}
class AwaitStatement : YieldStatement<AsyncInitializer>
protected override void Error_TypeDoesNotContainDefinition (ResolveContext rc, TypeSpec type, string name)
{
- Error_WrongGetAwaiter (rc, loc, type);
+ Error_OperatorCannotBeApplied (rc, type);
}
protected override void Error_OperatorCannotBeApplied (ResolveContext rc, TypeSpec type)
{
- rc.Report.Error (1991, loc, "Cannot await `{0}' expression", type.GetSignatureForError ());
+ rc.Report.Error (4001, loc, "Cannot await `{0}' expression", type.GetSignatureForError ());
}
}
}
Field awaiter;
- PropertyExpr is_completed;
+ PropertySpec is_completed;
MethodSpec on_completed;
MethodSpec get_result;
TypeSpec type;
+ TypeSpec result_type;
public AwaitStatement (Expression expr, Location loc)
: base (expr, loc)
#region Properties
+ bool IsDynamic {
+ get {
+ return is_completed == null;
+ }
+ }
+
public TypeSpec Type {
get {
return type;
public TypeSpec ResultType {
get {
- return get_result.ReturnType;
+ return result_type;
}
}
GetResultExpression (ec).Emit (ec);
}
- public Invocation GetResultExpression (EmitContext ec)
+ public Expression GetResultExpression (EmitContext ec)
{
var fe_awaiter = new FieldExpr (awaiter, loc);
fe_awaiter.InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, loc);
//
// result = awaiter.GetResult ();
//
- var mg_result = MethodGroupExpr.CreatePredefined (get_result, fe_awaiter.Type, loc);
- mg_result.InstanceExpression = fe_awaiter;
+ if (IsDynamic) {
+ var rc = new ResolveContext (ec.MemberContext);
+ return new Invocation (new MemberAccess (fe_awaiter, "GetResult"), new Arguments (0)).Resolve (rc);
+ } else {
+ var mg_result = MethodGroupExpr.CreatePredefined (get_result, fe_awaiter.Type, loc);
+ mg_result.InstanceExpression = fe_awaiter;
- return new GetResultInvocation (mg_result, new Arguments (0));
+ return new GetResultInvocation (mg_result, new Arguments (0));
+ }
}
public void EmitPrologue (EmitContext ec)
Label skip_continuation = ec.DefineLabel ();
- is_completed.InstanceExpression = fe_awaiter;
- is_completed.EmitBranchable (ec, skip_continuation, true);
+ Expression completed_expr;
+ if (IsDynamic) {
+ var rc = new ResolveContext (ec.MemberContext);
- base.DoEmit (ec);
+ Arguments dargs = new Arguments (1);
+ dargs.Add (new Argument (fe_awaiter));
+ completed_expr = new DynamicMemberBinder ("IsCompleted", dargs, loc).Resolve (rc);
+ } else {
+ var pe = PropertyExpr.CreatePredefined (is_completed, loc);
+ pe.InstanceExpression = fe_awaiter;
+ completed_expr = pe;
+ }
+
+ completed_expr.EmitBranchable (ec, skip_continuation, true);
- FieldSpec[] stack_fields = null;
- TypeSpec[] stack = null;
+ base.DoEmit (ec);
//
// The stack has to be empty before calling await continuation. We handle this
//
ec.AssertEmptyStack ();
- var mg_completed = MethodGroupExpr.CreatePredefined (on_completed, fe_awaiter.Type, loc);
- mg_completed.InstanceExpression = fe_awaiter;
+ var storey = (AsyncTaskStorey) machine_initializer.Storey;
+ var cont_field = storey.EmitContinuationInitialization (ec);
var args = new Arguments (1);
- var storey = (AsyncTaskStorey) machine_initializer.Storey;
- var fe_cont = new FieldExpr (storey.Continuation, loc);
- fe_cont.InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, loc);
+ args.Add (new Argument (cont_field));
- args.Add (new Argument (fe_cont));
+ if (IsDynamic) {
+ var rc = new ResolveContext (ec.MemberContext);
+ var mg_expr = new Invocation (new MemberAccess (fe_awaiter, "OnCompleted"), args).Resolve (rc);
- //
- // awaiter.OnCompleted (continuation);
- //
- mg_completed.EmitCall (ec, args);
+ ExpressionStatement es = (ExpressionStatement) mg_expr;
+ es.EmitStatement (ec);
+ } else {
+ var mg_completed = MethodGroupExpr.CreatePredefined (on_completed, fe_awaiter.Type, loc);
+ mg_completed.InstanceExpression = fe_awaiter;
+
+ //
+ // awaiter.OnCompleted (continuation);
+ //
+ mg_completed.EmitCall (ec, args);
+ }
// Return ok
machine_initializer.EmitLeave (ec, unwind_protect);
ec.MarkLabel (resume_point);
-
- if (stack_fields != null) {
- for (int i = 0; i < stack_fields.Length; ++i) {
- ec.EmitThis ();
-
- var field = stack_fields[i];
-
- //
- // We don't store `this' because it can be easily re-created
- //
- if (field == null)
- continue;
-
- if (stack[i] is ReferenceContainer)
- ec.Emit (OpCodes.Ldflda, field);
- else
- ec.Emit (OpCodes.Ldfld, field);
- }
- }
-
ec.MarkLabel (skip_continuation);
}
}
}
- static void Error_WrongGetAwaiter (ResolveContext rc, Location loc, TypeSpec type)
- {
- rc.Report.Error (1986, loc,
- "The `await' operand type `{0}' must have suitable GetAwaiter method",
- type.GetSignatureForError ());
- }
-
void Error_WrongAwaiterPattern (ResolveContext rc, TypeSpec awaiter)
{
- rc.Report.Error (1999, loc, "The awaiter type `{0}' must have suitable IsCompleted, OnCompleted, and GetResult members",
+ rc.Report.Error (4011, loc, "The awaiter type `{0}' must have suitable IsCompleted, OnCompleted, and GetResult members",
awaiter.GetSignatureForError ());
}
if (!base.Resolve (bc))
return false;
+ Arguments args = new Arguments (0);
+
type = expr.Type;
//
- // The task result is of dynamic type
+ // The await expression is of dynamic type
//
- if (expr.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
- throw new NotImplementedException ("dynamic await");
+ if (type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
+ result_type = type;
+
+ awaiter = ((AsyncTaskStorey) machine_initializer.Storey).AddAwaiter (type, loc);
+
+ expr = new Invocation (new MemberAccess (expr, "GetAwaiter"), args).Resolve (bc);
+ return true;
+ }
//
// Check whether the expression is awaitable
if (ama == null)
return false;
- Arguments args = new Arguments (0);
-
var errors_printer = new SessionReportPrinter ();
var old = bc.Report.SetPrinter (errors_printer);
ama = new Invocation (ama, args).Resolve (bc);
+ bc.Report.SetPrinter (old);
if (errors_printer.ErrorsCount > 0 || !MemberAccess.IsValidDotExpression (ama.Type)) {
- bc.Report.SetPrinter (old);
- Error_WrongGetAwaiter (bc, loc, expr.Type);
+ bc.Report.Error (1986, expr.Location,
+ "The `await' operand type `{0}' must have suitable GetAwaiter method",
+ expr.Type.GetSignatureForError ());
+
return false;
}
var awaiter_type = ama.Type;
awaiter = ((AsyncTaskStorey) machine_initializer.Storey).AddAwaiter (awaiter_type, loc);
+
expr = ama;
//
// Predefined: bool IsCompleted { get; }
//
- var is_completed_ma = new MemberAccess (expr, "IsCompleted").Resolve (bc);
- if (is_completed_ma != null) {
- is_completed = is_completed_ma as PropertyExpr;
- if (is_completed != null && is_completed.Type.BuiltinType == BuiltinTypeSpec.Type.Bool && is_completed.IsInstance && is_completed.Getter != null) {
- // valid
- } else {
- bc.Report.SetPrinter (old);
- Error_WrongAwaiterPattern (bc, awaiter_type);
- return false;
- }
- }
+ is_completed = MemberCache.FindMember (awaiter_type, MemberFilter.Property ("IsCompleted", bc.Module.Compiler.BuiltinTypes.Bool),
+ BindingRestriction.InstanceOnly) as PropertySpec;
- bc.Report.SetPrinter (old);
-
- if (errors_printer.ErrorsCount > 0) {
+ if (is_completed == null || !is_completed.HasGet) {
Error_WrongAwaiterPattern (bc, awaiter_type);
return false;
}
return false;
}
+ result_type = get_result.ReturnType;
+
return true;
}
}
public static void Create (IMemberContext context, ParametersBlock block, ParametersCompiled parameters, TypeContainer host, TypeSpec returnType, Location loc)
{
- if (returnType != null && returnType.Kind != MemberKind.Void &&
- returnType != host.Module.PredefinedTypes.Task.TypeSpec &&
- !returnType.IsGenericTask) {
- host.Compiler.Report.Error (1983, loc, "The return type of an async method must be void, Task, or Task<T>");
- }
-
for (int i = 0; i < parameters.Count; i++) {
Parameter p = parameters[i];
Parameter.Modifier mod = p.ModFlags;
return;
}
- // TODO:
if (p is ArglistParameter) {
- host.Compiler.Report.Error (1636, p.Location,
- "__arglist is not allowed in parameter list of iterators");
+ host.Compiler.Report.Error (4006, p.Location,
+ "__arglist is not allowed in parameter list of async methods");
return;
}
- // TODO:
if (parameters.Types[i].IsPointer) {
- host.Compiler.Report.Error (1637, p.Location,
- "Iterators cannot have unsafe parameters or yield types");
+ host.Compiler.Report.Error (4005, p.Location,
+ "Async methods cannot have unsafe parameters");
return;
}
}
- // TODO: Warning
- //if (!block.HasAwait) {
- //}
+ if (!block.HasAwait) {
+ host.Compiler.Report.Warning (1998, 1, loc,
+ "Async block lacks `await' operator and will run synchronously");
+ }
block.WrapIntoAsyncTask (context, host, returnType);
}
class AsyncTaskStorey : StateMachine
{
- sealed class ParametersLoadStatement : Statement
- {
- readonly FieldSpec[] fields;
- readonly TypeSpec[] parametersTypes;
- readonly int thisParameterIndex;
-
- public ParametersLoadStatement (FieldSpec[] fields, TypeSpec[] parametersTypes, int thisParameterIndex)
- {
- this.fields = fields;
- this.parametersTypes = parametersTypes;
- this.thisParameterIndex = thisParameterIndex;
- }
-
- protected override void CloneTo (CloneContext clonectx, Statement target)
- {
- throw new NotImplementedException ();
- }
-
- protected override void DoEmit (EmitContext ec)
- {
- for (int i = 0; i < fields.Length; ++i) {
- var field = fields[i];
- if (field == null)
- continue;
-
- ec.EmitArgumentLoad (thisParameterIndex);
- ec.EmitArgumentLoad (i);
- if (parametersTypes[i] is ReferenceContainer)
- ec.EmitLoadFromPtr (field.MemberType);
-
- ec.Emit (OpCodes.Stfld, field);
- }
- }
- }
-
int awaiters;
Field builder, continuation;
readonly TypeSpec return_type;
PropertySpec task;
LocalVariable hoisted_return;
int locals_captured;
+ Dictionary<TypeSpec, List<StackField>> stack_fields;
+ TypeSpec action;
public AsyncTaskStorey (IMemberContext context, AsyncInitializer initializer, TypeSpec type)
: base (initializer.OriginalBlock, initializer.Host,context.CurrentMemberDefinition as MemberBase, context.CurrentTypeParameters, "async")
}
}
- public Field Continuation {
- get {
- return continuation;
- }
- }
-
public LocalVariable HoistedReturn {
get {
return hoisted_return;
public Field AddAwaiter (TypeSpec type, Location loc)
{
- return AddCompilerGeneratedField ("$awaiter" + awaiters++.ToString ("X"), new TypeExpression (type, loc));
+ return AddCapturedVariable ("$awaiter" + awaiters++.ToString ("X"), type);
}
- public Field AddCapturedLocalVariable (TypeSpec type)
+ public StackField AddCapturedLocalVariable (TypeSpec type)
{
if (mutator != null)
type = mutator.Mutate (type);
- var field = AddCompilerGeneratedField ("<s>$" + locals_captured++.ToString ("X"), new TypeExpression (type, Location));
+ List<StackField> existing_fields = null;
+ if (stack_fields == null) {
+ stack_fields = new Dictionary<TypeSpec, List<StackField>> ();
+ } else if (stack_fields.TryGetValue (type, out existing_fields)) {
+ foreach (var f in existing_fields) {
+ if (f.CanBeReused) {
+ f.CanBeReused = false;
+ return f;
+ }
+ }
+ }
+
+ const Modifiers mod = Modifiers.COMPILER_GENERATED | Modifiers.PRIVATE;
+ var field = new StackField (this, new TypeExpression (type, Location), mod, new MemberName ("<s>$" + locals_captured++.ToString ("X"), Location));
+ AddField (field);
+
field.Define ();
+ if (existing_fields == null) {
+ existing_fields = new List<StackField> ();
+ stack_fields.Add (type, existing_fields);
+ }
+
+ existing_fields.Add (field);
+
return field;
}
protected override bool DoDefineMembers ()
{
- var action = Module.PredefinedTypes.Action.Resolve ();
- if (action != null) {
- continuation = AddCompilerGeneratedField ("$continuation", new TypeExpression (action, Location));
- continuation.ModFlags |= Modifiers.READONLY;
- }
+ action = Module.PredefinedTypes.Action.Resolve ();
PredefinedType builder_type;
PredefinedMember<MethodSpec> bf;
bf = pred_members.AsyncTaskMethodBuilderCreate;
sr = pred_members.AsyncTaskMethodBuilderSetResult;
se = pred_members.AsyncTaskMethodBuilderSetException;
- task = pred_members.AsyncTaskMethodBuilderTask.Resolve (Location);
+ task = pred_members.AsyncTaskMethodBuilderTask.Get ();
} else {
builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilderGeneric;
bf = pred_members.AsyncTaskMethodBuilderGenericCreate;
sr = pred_members.AsyncTaskMethodBuilderGenericSetResult;
se = pred_members.AsyncTaskMethodBuilderGenericSetException;
- task = pred_members.AsyncTaskMethodBuilderGenericTask.Resolve (Location);
+ task = pred_members.AsyncTaskMethodBuilderGenericTask.Get ();
has_task_return_type = true;
}
- set_result = sr.Resolve (Location);
- set_exception = se.Resolve (Location);
- var builder_factory = bf.Resolve (Location);
- var bt = builder_type.Resolve ();
- if (bt == null || set_result == null || builder_factory == null || set_exception == null)
- return false;
+ set_result = sr.Get ();
+ set_exception = se.Get ();
+ var builder_factory = bf.Get ();
+ if (!builder_type.Define () || set_result == null || builder_factory == null || set_exception == null) {
+ Report.Error (1993, Location,
+ "Cannot find compiler required types for asynchronous functions support. Are you targeting the wrong framework version?");
+ return base.DoDefineMembers ();
+ }
+
+ var bt = builder_type.TypeSpec;
//
// Inflate generic Task types
}
builder = AddCompilerGeneratedField ("$builder", new TypeExpression (bt, Location));
- builder.ModFlags |= Modifiers.READONLY;
if (!base.DoDefineMembers ())
return false;
- MethodGroupExpr mg;
var block = instance_constructors[0].Block;
- //
- // Initialize continuation with state machine method
- //
- if (continuation != null) {
- var args = new Arguments (1);
- mg = MethodGroupExpr.CreatePredefined (StateMachineMethod.Spec, spec, Location);
- args.Add (new Argument (mg));
-
- block.AddStatement (
- new StatementExpression (new SimpleAssign (
- new FieldExpr (continuation, Location),
- new NewDelegate (action, args, Location),
- Location
- )));
- }
-
- mg = MethodGroupExpr.CreatePredefined (builder_factory, bt, Location);
+ var mg = MethodGroupExpr.CreatePredefined (builder_factory, bt, Location);
block.AddStatement (
new StatementExpression (new SimpleAssign (
- new FieldExpr (builder, Location),
- new Invocation (mg, new Arguments (0)),
+ new FieldExpr (builder, Location),
+ new Invocation (mg, new Arguments (0)),
Location)));
if (has_task_return_type) {
return true;
}
+ public Expression EmitContinuationInitialization (EmitContext ec)
+ {
+ //
+ // When more than 1 awaiter has been used in the block we
+ // introduce class scope field to cache continuation delegate
+ //
+ if (awaiters > 1) {
+ if (continuation == null) {
+ continuation = AddCompilerGeneratedField ("$continuation", new TypeExpression (action, Location), true);
+ continuation.Define ();
+ }
+
+ var fexpr = new FieldExpr (continuation, Location);
+ fexpr.InstanceExpression = new CompilerGeneratedThis (CurrentType, Location);
+
+ //
+ // if ($continuation == null)
+ // $continuation = new Action (MoveNext);
+ //
+ fexpr.Emit (ec);
+
+ var skip_cont_init = ec.DefineLabel ();
+ ec.Emit (OpCodes.Brtrue_S, skip_cont_init);
+
+ ec.EmitThis ();
+ EmitActionLoad (ec);
+ ec.Emit (OpCodes.Stfld, continuation.Spec);
+ ec.MarkLabel (skip_cont_init);
+
+ return fexpr;
+ }
+
+ //
+ // Otherwise simply use temporary local variable
+ //
+ var field = LocalVariable.CreateCompilerGenerated (action, OriginalSourceBlock, Location);
+ EmitActionLoad (ec);
+ field.EmitAssign (ec);
+ return new LocalVariableReference (field, Location);
+ }
+
+ void EmitActionLoad (EmitContext ec)
+ {
+ ec.EmitThis ();
+ ec.Emit (OpCodes.Ldftn, StateMachineMethod.Spec);
+ ec.Emit (OpCodes.Newobj, (MethodSpec) MemberCache.FindMember (action, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly));
+ }
+
public void EmitSetException (EmitContext ec, LocalVariableReference exceptionVariable)
{
//
mg.EmitCall (ec, args);
}
}
+
+ class StackField : Field
+ {
+ public StackField (DeclSpace parent, FullNamedExpression type, Modifiers mod, MemberName name)
+ : base (parent, type, mod, name, null)
+ {
+ }
+
+ public bool CanBeReused { get; set; }
+ }
+
+ class StackFieldExpr : FieldExpr
+ {
+ public StackFieldExpr (Field field)
+ : base (field, Location.Null)
+ {
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ base.Emit (ec);
+
+ var field = (StackField) spec.MemberDefinition;
+ field.CanBeReused = true;
+ }
+ }
}
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