How to get the value of max_old_space_size from the code?

Question

As I understand it is possible to set a maximum memory usage limit for an application like this:

node --max_old_space_size=500 app.js

Is it possible to get a value of the max_old_space_size from the code?

UPDATE

With the help of @Grégory NEUT we found out that v8.getHeapStatistics() contains a field heap_size_limit which looks like what I am looking for.

However I'm still not sure about it since I didn't find any official documentation (or some piece of code from Node.js) which will approve this theory.

I also don't understand why heap_size_limit becomes 557842432 bytes ( 557.8 MB) when I set max_old_space_size to 500 MB

Answer 1

In the Node.js v9.4.0 Documentation you can find the function v8.getHeapStatistics() that gives you the heap size information.

UPDATE 2019 : Node.js v11.x Documentation

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LEQADA Example from the comment:

For max_old_space_size=500

heap_size_limit : 557842432

total_available_size : 548898944

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For max_old_space_size=900

heap_size_limit : 977272832

total_available_size : 968329344

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EDIT : process.memoryUsage() do not give informations about the max size of the heap

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In the Node.js v9.4.0 Documentation you can find the function process.memoryUsage() that gives you the heap size information.

UPDATE 2019 : Node.js v11.x Documentation