Files: 535100729b49473f07a4c560fa6b81aa2b369544 / kernel.js
3388 bytesRaw
1 | const PriorityQueue = require('fastpriorityqueue') |
2 | const EventEmitter = require('events') |
3 | const BN = require('bn.js') |
4 | const PortManager = require('./portManager.js') |
5 | |
6 | module.exports = class Kernel extends EventEmitter { |
7 | constructor (opts) { |
8 | super() |
9 | this._opts = opts |
10 | this.state = opts.parentPort.link['/'] |
11 | this.vmState = 'idle' |
12 | this.ticks = 0 |
13 | this.ports = new PortManager(this) |
14 | this.vm = new opts.VM(this) |
15 | this._waitingQueue = new PriorityQueue((a, b) => { |
16 | return a.threshold > b.threshold |
17 | }) |
18 | this.on('result', this._runNextMessage) |
19 | this.on('idle', () => { |
20 | console.log('idle') |
21 | while (!this._waitingQueue.isEmpty()) { |
22 | console.log('clering ') |
23 | this._waitingQueue.poll().resolve() |
24 | } |
25 | }) |
26 | } |
27 | |
28 | start () { |
29 | return this.ports.start() |
30 | } |
31 | |
32 | _updateVmState (vmState, message) { |
33 | this.vmState = vmState |
34 | this.emit(vmState, message) |
35 | } |
36 | |
37 | queue (message) { |
38 | this.ports.queue(message) |
39 | if (this.vmState === 'idle') { |
40 | this._runNextMessage() |
41 | } |
42 | } |
43 | |
44 | _runNextMessage () { |
45 | this._updateVmState('running') |
46 | this.ports.getNextMessage(this.ticks).then(message => { |
47 | if (message) { |
48 | this.run(message) |
49 | } else { |
50 | this._updateVmState('idle', message) |
51 | } |
52 | }) |
53 | } |
54 | |
55 | /** |
56 | * run the kernels code with a given enviroment |
57 | * The Kernel Stores all of its state in the Environment. The Interface is used |
58 | * to by the VM to retrive infromation from the Environment. |
59 | */ |
60 | async run (message) { |
61 | // shallow copy |
62 | const oldState = Object.assign({}, this._opts.state) |
63 | let result |
64 | try { |
65 | result = await this.vm.run(message) || {} |
66 | } catch (e) { |
67 | console.log(e) |
68 | result = { |
69 | exception: true, |
70 | exceptionError: e |
71 | } |
72 | clearObject(this._opts.state) |
73 | Object.assign(this._opts.state, oldState) |
74 | } |
75 | |
76 | this.emit('result', result) |
77 | return result |
78 | } |
79 | |
80 | // returns a promise that resolves once the kernel hits the threshould tick |
81 | // count |
82 | async wait (threshold) { |
83 | return new Promise((resolve, reject) => { |
84 | if (this.vmState === 'idle' || threshold <= this.ticks) { |
85 | resolve(this.ticks) |
86 | } else { |
87 | this._waitingQueue.add({ |
88 | threshold: threshold, |
89 | resolve: resolve |
90 | }) |
91 | } |
92 | }) |
93 | } |
94 | |
95 | incrementTicks (count) { |
96 | this.ticks += count |
97 | while (!this._waitingQueue.isEmpty()) { |
98 | const waiter = this._waitingQueue.peek() |
99 | if (waiter.threshold > this.ticks) { |
100 | break |
101 | } else { |
102 | this._waitingQueue.poll().resolve(this.ticks) |
103 | } |
104 | } |
105 | } |
106 | |
107 | async createPort (manager, type, name, payload) { |
108 | // incerment the nonce |
109 | const nonce = new BN(this._opts.state.nonce) |
110 | nonce.iaddn(1) |
111 | this.state.nonce = nonce.toArrayLike(Buffer) |
112 | |
113 | const parentID = await this._opts.hypervisor.generateID({ |
114 | id: this._opts.id |
115 | }) |
116 | |
117 | let port = this._opts.hypervisor.createPort(type, payload, { |
118 | nonce: this.nonce, |
119 | parent: parentID |
120 | }) |
121 | await manager.set(name, port) |
122 | return port |
123 | } |
124 | |
125 | async send (port, message) { |
126 | message._ticks = this.ticks |
127 | const portObject = await this.ports.get(port) |
128 | portObject.hasSent = true |
129 | return this._opts.hypervisor.send(port, message) |
130 | } |
131 | } |
132 | |
133 | function clearObject (myObject) { |
134 | for (var member in myObject) { |
135 | delete myObject[member] |
136 | } |
137 | } |
138 |
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