Jeremy Maitin-Shepard
On 09/14/2010 04:04 AM, Stewart, Robert wrote:
Indeed, calling waitpid() for each child, in turn, is not a good idea from a scalability perspective. Putting all of Boost.Process' children into a unique process group and using waitpid(), with WNOHANG, to wait for children in that process group could work though.
The process group approach does have some nice properties, but I'm not sure it is reasonable for the library to impose such a restriction. (Maybe it is, I am simply not sufficiently familiar with process groups and their intended purpose/practical use to know.) One thing of note is that a process can change its own process group id.
From Wikipedia: "Process groups are used to control the distribution of signals."
The idea is that you can send a signal to all members of a process group, but using that to monitor a signal from any member of the group via waitpid() seems quit within scope, particularly since that is part of the waitpid() interface. I'm also not familiar with the behaviors and uses of process groups so I don't know if this would just shift the problem in some way, albeit to presumably less common application types. _____ Rob Stewart robert.stewart@sig.com Software Engineer, Core Software using std::disclaimer; Susquehanna International Group, LLP http://www.sig.com IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.