On 09/09/2018 01:34, Martin Buchholz wrote:
:
See discussion in src/java.base/unix/native/libjava/ProcessImpl_md.c
Later Oracle introduced something very similar with the jspawnhelper.
But I see that jspawnhelper is not used at all for the vfork() case,
just for posix_spawn(), yes?
Implemented by other folks. I was mostly happy with vfork. I forget
the motivation to introduce jspawnhelper, but I'm sure it's in the
fossil record somewhere!
jpsawnhelper is to deal with chdir and threading issues that arise when
using posix_spawn. The move to posix_spawn was motivated by eager
allocation of swap when using fork. It was originally done for Solaris,
then macOS, and I see the AIX implementation is declared to use
posix_spawn too. Linux is using vfork and seems to be stable. Martin
will probably remember a brief foray into clone(CLONE_VM) at one point
but that didn't work out.
-Alan
