Re: kern/49017: vfork does not suspend all threads

[Joerg Sonnenberger <joerg%bec.de@localhost>]

The following reply was made to PR kern/49017; it has been noted by GNATS.

From: Joerg Sonnenberger <joerg%bec.de@localhost>
To: Christos Zoulas <christos%zoulas.com@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost,
	gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/49017: vfork does not suspend all threads
Date: Wed, 5 Apr 2017 23:03:19 +0200

 On Wed, Apr 05, 2017 at 04:38:32PM -0400, Christos Zoulas wrote:
 >     Can the other threads harm the child or the parent while it is vfork()ing?
 > 
 > I can't think of a way.
 
 Race conditions in mutex code. Keep in mind that the park/unpark events
 are per-process.
 
 I fully support the proposal to block all threads in the parent. If you
 want to create child processes from multi-threaded programs and care at
 all about performance, use posix_spawn. How it is implemented is an
 implementation detail and independent of vfork.
 
 Joerg