I added it in commit 57231d5286 ("src: notify V8 profiler when we're
idle") from October 2013 as a stop-gap measure to measure CPU time
rather than wall clock time, otherwise processes that spend a lot
of time sleeping in system calls give a false impression of being
very busy.
That fix is not without drawbacks because the idle flag is set before
libuv makes I/O callbacks and cleared again after. I/O callbacks can
result into calls into JS code and executing JS code is as non-idle
as you can get.
In commit 96ffcb9a21 ("src: reduce cpu profiler overhead") from January
2015, I made Node.js block off the SIGPROF signal that V8's CPU profiler
uses before Node.js goes to sleep. The goal of that commit is to reduce
the overhead from EINTR system call wakeups but it also has the pleasant
side effect of fixing what the idle notifier tried to fix.
This commit removes the idle notifier and turns the JS process object
methods into no-ops.
Fixes: https://github.com/nodejs/node/issues/19009
Refs: https://github.com/nodejs/node/pull/33138
PR-URL: https://github.com/nodejs/node/pull/34010
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Whether these APIs should be available for Node.js instances
semantically depends on whether the current Node.js instance
was assigned ownership of process-wide state, and not whether
it refers to the main thread or not.
PR-URL: https://github.com/nodejs/node/pull/31172
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
This patch splits the handling of `isMainThread` and
`ownsProcessState` from conditionals in
`lib/internal/bootstrap/node.js` into different scripts under
`lib/internal/bootstrap/switches/`, and call them accordingly
from C++ after `node.js` is run.
This:
- Creates a common denominator of the main thread and the worker
thread bootstrap that can be snapshotted and shared by
both.
- Makes it possible to override the configurations on-the-fly.
PR-URL: https://github.com/nodejs/node/pull/30862
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
