List all threads

Question

How can I list all threads within the current process in FreeBSD? Or at least, get the number of threads running.

I found the Linux system call pstat_getproc which returns a struct containing pst_nlwps, the number of threads. I am looking for something similar to this on FreeBSD.

Or perhaps there is something like /dev/fd but for threads.

Anything I can use to get some kind of idea about how many other threads are running.

I want to be able to do this programmatically in C, not using an existing application.

Perhaps this is what you're looking for? [libprocstat](https://www.freebsd.org/cgi/man.cgi?query=libprocstat&sektion=3&apropos=0&manpath=FreeBSD%2010.0-RELEASE). Specifically, `procstat_getprocs` — Christopher Schneider, Aug 26 '15 at 23:30
See also https://stackoverflow.com/questions/3475750/posix-api-call-to-list-all-the-pthreads-running-in-a-process — Raedwald, Jun 05 '18 at 16:09

score 2 · Answer 1 · answered Aug 26 '15 at 20:05

2

Use procstat(1), eg

# procstat -t $(pgrep openvpn)
  PID    TID COMM             TDNAME           CPU  PRI STATE   WCHAN    
  537 100051 openvpn          -                  0  120 sleep   select

which depends on libprocstat(3).

answered Aug 26 '15 at 20:05

xcah

143
3

Sorry, I should have clarified. I am not looking for a command line tool, I wish to do it programmatically in C. – user2868331 Aug 26 '15 at 20:43
1

@user2868331Look at /usr/src/usr.bin/procstat/procstat_threads.c. – xcah Aug 27 '15 at 13:03
... and https://github.com/freebsd/freebsd-src/blob/main/usr.bin/procstat/procstat_basic.c as called from procstat.c as that has a simple field to access with the thread count rather than counting TIDs. – gps Jan 23 '22 at 21:53

List all threads

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