Hi, Some time ago Stanislav Sedov suggested to me extending libprocstat(3) with functions to retrieve process command line arguments and environment variables.
In the first approach I tried, the newly added functions procstat_getargv/getenvv allocated a buffer of necessary size, stored the values and returned to the caller: http://people.freebsd.org/~trociny/libprocstat.1.patch The problem with this approach was that when I updated procstat(1) to use this interface, I observed noticeable performance degradation (about 30% on systems with MALLOC_PRODUCTION off), due to memory allocation overhead: the original procstat(1) reuses the buffer for all its retrievals. So my second approach was to add internal buffers to struct procstat, which are used by procstat_getargv/getenvv to store values and reused on the subsequent call: http://people.freebsd.org/~trociny/libprocstat.2.patch The drawback of this approach is that a user has to take care and remember that a subsequent call rewrites argument vector obtained from the previous call. On the other hand this is ok for typical use cases while does not add allocation overhead, so I like this approach more. I would like to commit this second patch, if there are no objections or suggestions how to improve the things. -- Mikolaj Golub _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
