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https://github.com/vercel-labs/scriptc.git
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Chris Tate
3d00b5b837
A message encoder started its node array at 16 nodes of 184 bytes and kept the array, with its unused capacity, until the message was received. A port that queued many messages held about 3 KB of zeroed memory per message: 200,000 queued numbers took about 590 MB, and the page faults made postMessage cost about 1.3 µs. The node array now starts at 4 nodes and is trimmed to the message's node count when encoding ends. scr_channel_post posted a wake event, and with it a pipe write and a condition broadcast, to the receiving thread's mailbox for every message. The owner's loop counts a port with queued messages as ready, so only a message that finds the queue empty needs to wake it. bench/channel-messages, added here, posts 200,000 messages (numbers and small objects) on a MessageChannel before the port delivers any.
22 lines
813 B
TypeScript
22 lines
813 B
TypeScript
// MessageChannel messages within one thread: the program posts the given
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// number of messages, half of them numbers and half small objects, before
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// the port delivers any, so all of them are queued at once. Argument: the
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// number of messages.
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import { MessageChannel } from "node:worker_threads";
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const count = Number(process.argv[2] ?? "200000");
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const { port1, port2 } = new MessageChannel();
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let received = 0;
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let sum = 0;
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port1.on("message", (value: number | { id: number; name: string }) => {
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sum += typeof value === "number" ? value : value.id + value.name.length;
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if (++received === count) {
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console.log(`${count} messages, sum ${sum}`);
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port1.close();
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}
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});
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for (let i = 0; i < count; i++) {
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if (i % 2 === 0) port2.postMessage(i);
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else port2.postMessage({ id: i, name: "item" });
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}
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