69 lines
1.8 KiB
JavaScript
69 lines
1.8 KiB
JavaScript
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'use strict'
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// Maximum wait time for a single waitAsync call
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// Used as a fallback poll interval in case notifications are missed
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// Keep this low enough for good throughput but high enough to not busy-loop
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const WAIT_MS = 10000
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function wait (state, index, expected, timeout, done) {
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const max = timeout === Infinity ? Infinity : Date.now() + timeout
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const check = () => {
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const current = Atomics.load(state, index)
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if (current === expected) {
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done(null, 'ok')
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return
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}
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if (max !== Infinity && Date.now() > max) {
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done(null, 'timed-out')
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return
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}
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// Wait for any change from current value
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const remaining = max === Infinity ? WAIT_MS : Math.min(WAIT_MS, Math.max(1, max - Date.now()))
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const result = Atomics.waitAsync(state, index, current, remaining)
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if (result.async) {
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result.value.then(check)
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} else {
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// Value already changed (not-equal) - recheck on next tick
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setImmediate(check)
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}
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}
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check()
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}
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function waitDiff (state, index, expected, timeout, done) {
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const max = timeout === Infinity ? Infinity : Date.now() + timeout
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const check = () => {
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const current = Atomics.load(state, index)
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if (current !== expected) {
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done(null, 'ok')
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return
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}
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if (max !== Infinity && Date.now() > max) {
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done(null, 'timed-out')
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return
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}
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// Wait for value to change from expected
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const remaining = max === Infinity ? WAIT_MS : Math.min(WAIT_MS, Math.max(1, max - Date.now()))
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const result = Atomics.waitAsync(state, index, expected, remaining)
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if (result.async) {
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result.value.then(check)
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} else {
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// Value already changed (not-equal) - recheck on next tick
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setImmediate(check)
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}
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}
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check()
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}
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module.exports = { wait, waitDiff }
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