src/vendor/shared_child/README.md

   1 # shared_child.rs [![Travis build](https://travis-ci.org/oconnor663/shared_child.rs.svg?branch=master)](https://travis-ci.org/oconnor663/shared_child.rs) [![Build status](https://ci.appveyor.com/api/projects/status/900ckow3c5awq3t5/branch/master?svg=true)](https://ci.appveyor.com/project/oconnor663/shared-child-rs/branch/master) [![crates.io](https://img.shields.io/crates/v/shared_child.svg)](https://crates.io/crates/shared_child) [![docs.rs](https://docs.rs/shared_child/badge.svg)](https://docs.rs/shared_child)
   2
   3 A library for awaiting and killing child processes from multiple threads.
   4
   5 The
   6 [`std::process::Child`](https://doc.rust-lang.org/std/process/struct.Child.html)
   7 type in the standard library provides
   8 [`wait`](https://doc.rust-lang.org/std/process/struct.Child.html#method.wait)
   9 and
  10 [`kill`](https://doc.rust-lang.org/std/process/struct.Child.html#method.kill)
  11 methods that take `&mut self`, making it impossible to kill a child process
  12 while another thread is waiting on it. That design works around a race
  13 condition in Unix's `waitpid` function, where a PID might get reused as soon
  14 as the wait returns, so a signal sent around the same time could
  15 accidentally get delivered to the wrong process.
  16
  17 However with the newer POSIX `waitid` function, we can wait on a child
  18 without freeing its PID for reuse. That makes it safe to send signals
  19 concurrently. Windows has actually always supported this, by preventing PID
  20 reuse while there are still open handles to a child process. This library
  21 wraps `std::process::Child` for concurrent use, backed by these APIs.
  22
  23 - [Docs](https://docs.rs/shared_child)
  24 - [Crate](https://crates.io/crates/shared_child)
  25 - [Repo](https://github.com/oconnor663/shared_child.rs)