sapling/eden/fs/notifications
Wez Furlong 154d7309c9 eden: introduce SpawnedProcess
Summary:
This commit introduces a new process spawning class derived
from the ChildProcess class in the watchman codebase.

`SpawnedProcess` is similar to folly::Subprocess but is designed around the
idea that we will use a system provided spawning API to start a process, rather
than assuming the use of `fork`.

`fork` is to be avoided because it can be expensive for processes with large
address spaces and also because it interacts poorly with threads on macOS.  In
particular, we see the objC runtime terminating our process in some scenarios
where fork and threads are mixed.

There are some important differences from `folly::Subprocess` and that means
that some assumptions and uses need to be altered slightly from their prior
workings.  For example, detaching a SpawnedProcess moves the responsibility of
waiting on the child to a periodic task as there is no way to detach via
posix_spawn without also using fork.

On the plus side, this commit allows unifying spawning between posix and
windows systems, which simplifies the code!

Reviewed By: xavierd

Differential Revision: D23287763

fbshipit-source-id: b662af1d7eaaa9ed445c42f6c5765ae9af975eea
2020-09-01 13:31:32 -07:00
..
CMakeLists.txt eden: show desktop notification for blob/tree fetch errors 2020-02-10 08:28:49 -08:00
Notifications.cpp eden: introduce SpawnedProcess 2020-09-01 13:31:32 -07:00
Notifications.h eden: show desktop notification for blob/tree fetch errors 2020-02-10 08:28:49 -08:00