worker_threads is used by many people,but we can only use SharedArrayBuffer(for shared memory) ,but Buffer is node's first citizen（socket eg）,can you share Buffer to SharedArrayBuffer ? #4288

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1. aduh95

   transferred this issue fromnodejs/nodeon Nov 7, 2023
2. aduh95 commented on Nov 7, 2023

   

   aduh95

   on Nov 7, 2023

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   You mean node:worker_threads, right? If all buffers could be shared, the language would not have bothered to come up with a SharedArrayBuffer implementation. What you can do is the following:

   function sabToBuffer(sab) {
     return new Uint8Array(sab);
   }

   Uint8Array is not exactly a Buffer, but I don't think you'll find any Node.js API that accept Buffer and not Uint8Array (if you do, that'd be a bug, please report it).

   On the other hand, if you have a Buffer/Uint8Array and want to transfer its content to an other thread, you have two options:

   // Option 1: copy the content to a SharedArrayBuffer:
   function copyBufferToSAB(buffer, sab) {
     if (buffer.byteLength > sab.byteLength) throw new Error('Buffer overflow');
     new Uint8Array(sab).set(buffer);
   }
   
   // Option 2: transfer the underlying array buffer:
   function transferBuffer(buffer) {
     otherThread.postMessage(buffer, [buffer.buffer]);
   }

   Option 2 is way faster, but note that only one thread interact with a non-sharable buffer, meaning that once it is transfered, the original thread can no longer have access to that buffer data.
3. introspection3 commented on Nov 7, 2023

   

   introspection3

   on Nov 7, 2023 · Hidden as abuse

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4. introspection3 commented on Nov 7, 2023

   

   introspection3

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5. aduh95 commented on Nov 7, 2023

   

   aduh95

   on Nov 7, 2023

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   no,you are wrong. copy ArrayBuffer is so expensive

   I don't know why you say I'm wrong, I don't think I have said anything about copy not being expensive. Like I said, transfering is the faster option, that's the one that let you reuse the same data on another thread without copying data.
6. avivkeller commented on Jun 15, 2024

   

   avivkeller

   on Jun 15, 2024

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   @introspection3 @aduh95 is this issue resolved? If so, feel free to close the issue!

   Thanks!
7. aduh95

   closed this as not plannedon Jun 15, 2024
8. avivkeller

   removed this from Node.js feature requestson Jun 26, 2024