NET-Web-API-w-Angular/my-app/node_modules/piscina/test/atomics-optimization.ts

81 lines
2.5 KiB
TypeScript
Executable file

import Piscina from '..';
import { test } from 'tap';
import { resolve } from 'path';
test('coverage test for Atomics optimization', async ({ equal }) => {
const pool = new Piscina({
filename: resolve(__dirname, 'fixtures/notify-then-sleep-or.ts'),
minThreads: 2,
maxThreads: 2,
concurrentTasksPerWorker: 2
});
const tasks = [];
let v : number;
// Post 4 tasks, and wait for all of them to be ready.
const i32array = new Int32Array(new SharedArrayBuffer(4));
for (let index = 0; index < 4; index++) {
tasks.push(pool.runTask({ i32array, index }));
}
// Wait for 2 tasks to enter 'wait' state.
do {
v = Atomics.load(i32array, 0);
if (popcount8(v) >= 2) break;
Atomics.wait(i32array, 0, v);
} while (true);
// The check above could also be !== 2 but it's hard to get things right
// sometimes and this gives us a nice assertion. Basically, at this point
// exactly 2 tasks should be in Atomics.wait() state.
equal(popcount8(v), 2);
// Wake both tasks up as simultaneously as possible. The other 2 tasks should
// then start executing.
Atomics.store(i32array, 0, 0);
Atomics.notify(i32array, 0, Infinity);
// Wait for the other 2 tasks to enter 'wait' state.
do {
v = Atomics.load(i32array, 0);
if (popcount8(v) >= 2) break;
Atomics.wait(i32array, 0, v);
} while (true);
// At this point, the first two tasks are definitely finished and have
// definitely posted results back to the main thread, and the main thread
// has definitely not received them yet, meaning that the Atomics check will
// be used. Making sure that that works is the point of this test.
// Wake up the remaining 2 tasks in order to make sure that the test finishes.
// Do the same consistency check beforehand as above.
equal(popcount8(v), 2);
Atomics.store(i32array, 0, 0);
Atomics.notify(i32array, 0, Infinity);
await Promise.all(tasks);
});
// Inefficient but straightforward 8-bit popcount
function popcount8 (v : number) : number {
v &= 0xff;
if (v & 0b11110000) return popcount8(v >>> 4) + popcount8(v & 0xb00001111);
if (v & 0b00001100) return popcount8(v >>> 2) + popcount8(v & 0xb00000011);
if (v & 0b00000010) return popcount8(v >>> 1) + popcount8(v & 0xb00000001);
return v;
}
test('avoids unbounded recursion', async () => {
const pool = new Piscina({
filename: resolve(__dirname, 'fixtures/simple-isworkerthread.ts'),
minThreads: 2,
maxThreads: 2
});
const tasks = [];
for (let i = 1; i <= 10000; i++) {
tasks.push(pool.runTask(null));
}
await Promise.all(tasks);
});