What "internal_fields" variable stand for?

[Dan Nahari]

Hi all,

libuv docs explain how timeout is calculated.

In the code, the timeout is calculated by uv_backend_timeout function and then we are  passing this value to uv__io_poll function.

for example "If there are any idle handles active, the timeout is 0."

but there is one case I didn't understand and maybe you can assist me,

inside uv__io_poll function (at epoll.c file) there is one condition that will override timeout we receive:

"if (uv__get_internal_fields(loop)->flags & UV_METRICS_IDLE_TIME) {

  ...

  timeout = 0; "

what internal_fields variable stand for? what are the cases it will be set?

Thank you,

Dan