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BUN ADDS SHARED-MEMORY THREADS TO JAVASCRIPTCORE

DEV DESK1 MIN READ
SAT, JUN 20, 2026

■ AI-SUMMARIZED FROM 1 SOURCE ▸ TIMELINE

Bun, the JavaScript runtime, has opened a pull request to add shared-memory threading capabilities to JavaScriptCore. The implementation would enable true concurrent execution in JavaScript applications.

The PR, submitted to Bun's WebKit fork, introduces support for shared-memory threads—a feature that allows multiple JavaScript threads to access and modify the same memory space. This differs from Web Workers, which operate in isolated contexts. Shared-memory threading enables more efficient parallelism for compute-intensive tasks and better resource utilization in multi-core systems. The feature relies on JavaScript's SharedArrayBuffer and atomic operations for safe concurrent access. The pull request has garnered significant developer interest, with 177 comments and 102 points on Hacker News, indicating community enthusiasm for performance improvements in the Bun runtime. If merged, this addition would position Bun as a more capable server-side JavaScript runtime, potentially attracting developers working on performance-critical applications. The implementation's timeline and any architectural implications remain to be determined through the review process.

■ SOURCES

Hacker News

■ SUMMARY WRITTEN BY AI FROM THE LINKS ABOVE

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