javascript / expert
Snippet
Zero-Copy State Synchronization in Svelte via SharedArrayBuffer Atomic Mutexes
When sharing high-frequency state data between Web Workers and Svelte state stores, serializing payloads creates memory overhead. SharedArrayBuffer combined with Atomics enables non-blocking thread lock primitives.
snippet.js
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export function acquireLock(typedArray, index = 0) {while (Atomics.compareExchange(typedArray, index, 0, 1) !== 0) {Atomics.wait(typedArray, index, 1, 100);}}export function releaseLock(typedArray, index = 0) {Atomics.store(typedArray, index, 0);Atomics.notify(typedArray, index, 1);}
svelte
Breakdown
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export function acquireLock(typedArray, index = 0) {
Defines a thread locking mechanism using an Int32Array view over SharedArrayBuffer.
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while (Atomics.compareExchange(typedArray, index, 0, 1) !== 0) {
Atomically checks if the lock is 0 and sets it to 1, spinning until acquisition succeeds.
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Atomics.wait(typedArray, index, 1, 100);
Puts the executing agent to sleep for up to 100ms while waiting for lock release notification.
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Atomics.store(typedArray, index, 0);
Atomically updates the mutex location back to 0 to release the critical section.
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Atomics.notify(typedArray, index, 1);
Wakes up one waiting worker thread waiting on the specified array index lock.