hi all, recently, I have asked couple of questions about handling inputs and outputs, but unfortunately have got not much feedback to them (maybe because of the technical nature of these questions). Few days ago I was reviewing 10 years old code which handles named pipe inputs with some thoughts of slightly modifying it.
The users who have used named pipe inputs probably know that SEC keeps the named pipe inputs open at all times, even when the writers disappear. However, it is hard to achieve with a pipe opened in read-only mode, since after all writers have closed the pipe, every subsequent read always returns EOF, and calls to select(2) always indicate the availability of data. To fix this issue, the pipe has to be closed and reopened. In the current code, SEC uses a slightly different approach -- it opens the pipe in read-write mode, although in never writes into the pipe. However, this guarantees that there is always at least one writer on the pipe, and thus reopening is not needed. Nevertheless, recently I noticed in some man pages that POSIX does not encourage opening named pipes in read-write mode. Also, read-write mode has one small drawback -- SEC must have a write-permission for the pipe, although this permission is of course never used. This requirement must be therefore confusing to the users, although it is explained in the FAQ. I'd like to ask a question from the users -- would you favor a change in the named pipe handling and the use of the read-only mode, or do you think the current approach is good enough? I would especially welcome comments from the people with system programming experience. You can also reply to my private e-mail, if you don't want to discuss the issue in the mailing list. kind regards, risto ------------------------------------------------------------------------------ How ServiceNow helps IT people transform IT departments: 1. A cloud service to automate IT design, transition and operations 2. Dashboards that offer high-level views of enterprise services 3. A single system of record for all IT processes http://p.sf.net/sfu/servicenow-d2d-j _______________________________________________ Simple-evcorr-users mailing list Simple-evcorr-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/simple-evcorr-users
