Regarding MakeCallback()

[deostroll]

Which MakeCallback() implememtation is called here 👉

node/src/node_file.cc

Line 581 in 52e4fb5

MakeCallback(env()->oncomplete_string(),

Is it this?

What about the case about the same call from here?

Will it execute js code immediately? If so, how can I convince my self that it won't run concurrently when say two IO tasks simultaneously finished and wants to make a js callback?

Ps: I was tracing how fs.readFile() works under the hood.

[jasnell]

IO tasks do not run simultaneously. All of the IO callbacks for an isolate are executed one at a time.

[deostroll]

So what guarantees that callbacks in an isolate execute one at a time? Is it libuv?