Mercurial > pub > ImplabNet

comparison Implab/Promise`1.cs @ 248:5cb4826c2c2a v3

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added awaiters to promises Added static methods to Promise Resolve, Reject, All. Updated promise helpers
author cin
date Tue, 30 Jan 2018 01:37:17 +0300
parents
children
comparison
equal deleted inserted replaced
247:fb70574741a1 248:5cb4826c2c2a
1 using System;
2 using System.Diagnostics;
3 using System.Reflection;
4 using Implab.Parallels;
5
6 namespace Implab {
7 public class Promise<T> : AbstractEvent<IResolvable<T>>, IPromise<T> {
8
9 class ResolvableSignal : IResolvable<T> {
10 public Signal Signal { get; private set; }
11 public ResolvableSignal() {
12 Signal = new Signal();
13 }
14
15
16 public void Reject(Exception error) {
17 Signal.Set();
18 }
19
20 public void Resolve(T result) {
21 Signal.Set();
22 }
23 }
24
25 class ResolvableWrapper : IResolvable<T> {
26 readonly IResolvable m_resolvable;
27 public ResolvableWrapper(IResolvable resolvable) {
28 m_resolvable = resolvable;
29 }
30
31 public void Reject(Exception reason) {
32 m_resolvable.Reject(reason);
33 }
34
35 public void Resolve(T value) {
36 m_resolvable.Resolve();
37 }
38 }
39
40 PromiseState m_state;
41
42 T m_result;
43
44 Exception m_error;
45
46 public bool IsRejected {
47 get {
48 return m_state == PromiseState.Rejected;
49 }
50 }
51
52 public bool IsFulfilled {
53 get {
54 return m_state == PromiseState.Fulfilled;
55 }
56 }
57
58 public Exception RejectReason {
59 get {
60 return m_error;
61 }
62 }
63
64
65 internal void ResolvePromise(T result) {
66 if (BeginTransit()) {
67 m_result = result;
68 m_state = PromiseState.Fulfilled;
69 CompleteTransit();
70 }
71 }
72
73 internal void RejectPromise(Exception reason) {
74 if (BeginTransit()) {
75 m_error = reason;
76 m_state = PromiseState.Rejected;
77 CompleteTransit();
78 }
79 }
80
81
82 #region implemented abstract members of AbstractPromise
83
84 protected override void SignalHandler(IResolvable<T> handler) {
85 switch (m_state) {
86 case PromiseState.Fulfilled:
87 handler.Resolve(m_result);
88 break;
89 case PromiseState.Rejected:
90 handler.Reject(RejectReason);
91 break;
92 default:
93 throw new InvalidOperationException(String.Format("Invalid promise signal: {0}", m_state));
94 }
95 }
96
97 protected void WaitResult(int timeout) {
98 if (!(IsResolved || GetFulfillSignal().Wait(timeout)))
99 throw new TimeoutException();
100 }
101
102 protected Signal GetFulfillSignal() {
103 var next = new ResolvableSignal();
104 Then(next);
105 return next.Signal;
106 }
107
108 #endregion
109
110 public Type ResultType {
111 get {
112 return typeof(void);
113 }
114 }
115
116
117 protected void Rethrow() {
118 if (m_error is OperationCanceledException)
119 throw new OperationCanceledException("Operation cancelled", m_error);
120 else
121 throw new TargetInvocationException(m_error);
122 }
123
124 public void Then(IResolvable<T> next) {
125 AddHandler(next);
126 }
127
128 public void Then(IResolvable next) {
129 AddHandler(new ResolvableWrapper(next));
130 }
131
132 public IPromise<T2> Cast<T2>() {
133 return (IPromise<T2>)this;
134 }
135
136 void IPromise.Join() {
137 Join();
138 }
139
140 void IPromise.Join(int timeout) {
141 Join(timeout);
142 }
143
144 public T Join() {
145 WaitResult(-1);
146 if (IsRejected)
147 Rethrow();
148 return m_result;
149 }
150
151 public T Join(int timeout) {
152 WaitResult(timeout);
153 if (IsRejected)
154 Rethrow();
155 return m_result;
156 }
157 }
158 }
159