[TUHS] "Fork considered harmful"

Derek Fawcus dfawcus+lists-tuhs at employees.org
Fri Apr 12 10:12:10 AEST 2019

On Thu, Apr 11, 2019 at 04:37:52PM -0700, Chris Hanson wrote:
> On Apr 10, 2019, at 4:06 PM, Richard Salz <rich.salz at gmail.com> wrote:
> > Any view on this? https://www.microsoft.com/en-us/research/publication/a-fork-in-the-road/
> Quite correct in my experience.
> The posix_spawn() API isn’t a panacea but (especially with a few *_np extensions) it’s much saner for large real-world applications that run a ton of subprocesses. I work on a large IDE which invokes compilers and such, and it makes a huge difference.

What I ended up doing for children of GUI apps (on OSX) is to fork very early on
before the GUI starts, or the process becomes multi-thread.  Then that child does
all of the real spawning, using fd passing and messages over a pipe (actually a
unix domain socket) to drive it, so usually no need for _np stuff.
There for cases where posix_spawn() is viable, as I recall it was faster than fork+exec.


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