On Tuesday, January 22, 2013 4:17:43 pm Mikolaj Golub wrote: > On Tue, Jan 22, 2013 at 12:01:06PM -0500, John Baldwin wrote: > > > How is this different from kvm_getargv()? It seems to be a direct copy. > > libprocstat(3) is a frontend for sysctl(3) and kvm(3) interfaces, so > it is good to extend it to cover "getarg/env" functionality. > > Yes the functions look similar to kvm_getargv() but I couldn't > implement them just as wrappers around kvm_getargv(): I would like to > have libprocstat functions thread safe, while kvm_getargv() uses > static variables for its internal buffers. > > It looks like I could fix kvm_getargv() to use fields of kvm structure > instead of static variables to store pointers to the buffers, and then > use it in libprocstat(3). Do you think it is worth doing? > > BTW, struct __kvm already contains some pointers, which looks like are > unused currently: > > char **argv; /* (dynamic) storage for argv pointers */ > int argc; /* length of above (not actual # present) */ > char *argbuf; /* (dynamic) temporary storage */ > > But if I even had kvm_getargv() to behave as I wanted, there is still > an issue with using it in libprocstat(): to get kvm structure you need > to initialize procstat using procstat_open_kvm(). It is supposed to > call procstat_open_kvm() when you want to read from kernel memory, > while kvm_getargv() uses sysctl. So from a user point of you it would > be a litle confusing if she had to call procstat_open_kvm() to get > runtime args and env. If she wanted e.g. to get both runtime args and > file info (via sysctl) she would have to do procstat_open_kvm() for > args and procstat_open_sysctl() for files.
Well, you could make procstat open a kvm handle in both cases (open a "live" handle in the procstat_open_sysctl() case). It just seems rather silly to be duplicating code in the two interfaces. More a question for Robert: does libprocstat intentionally duplicate the code in libkvm for other things as well in the live case? (Like fetching the list of processes?) -- John Baldwin _______________________________________________ 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"
