1

I have a high-performance node app where every ms needlessly blocked in the main thread is detrimental. Most of the heavy processing is done in a C++ native node addon. Works great.

Sometimes, the Javascript code needs to pass a very long string to the addon C++ code. What bothers me (validated by profiling) is that there is a significant block in the main thread when (copying &) converting the (very long) string to UTF-8, before the copy finally gets offloaded to the worker thread.

Is it possible to offload the copy & conversion to the worker thread?

I'm aware that in general one may not access Javascript objects from a seperate thread, but this is not a hard rule (as some suggest). For example, it is possible (and common) to take a Persistent reference to a Buffer object and access the data directly (no copy) in a separate thread. The ideal solution would be doing the same for string data, thus avoiding any copy of the string in the main thread.

Improve this question

1 Answer 1

Reset to default
0

Usage of ArrayBuffer or TypedArray likely minimize duplication of content by avoiding memory copy, here is an example for that.

https://github.com/msatyan/MyNodeC/blob/master/src/mync1/ArrayBuff.cpp https://github.com/msatyan/MyNodeC/blob/master/test/TestArrayBuff.js

To avoid blocking of node.js main thread you may introduce Asynchronous operation by delegating the heavy task to a thread. This following StackOverflow post has an example for such scenario by using promise.

How to create async function using NAPI that return Promises

Improve this answer
Sign up to request clarification or add additional context in comments.

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.