How to get the SPID in linux 2.6 from C++

Question

Hi!

I have a question: Is there some way to the SPID in linux 2.6 from a C++ application? When I do a "ps -amT" I can see the threads in the process:

[email protected]:~# ps -amT
  PID  SPID TTY          TIME CMD
 1120     - pts/1    00:00:20 sncmdd
    -  1120 -        00:00:00 -
    -  1125 -        00:00:00 -
    -  1126 -        00:00:00 -
    -  1128 -        00:00:00 -
    -  1129 -        00:00:09 -
    -  1130 -        00:00:00 -
    -  1131 -        00:00:09 -
 1122     - pts/1    00:00:00 snstatusdemuxd
    -  1122 -        00:00:00 -
    -  1127 -        00:00:00 -
    -  1132 -        00:00:00 -
    -  1133 -        00:00:00 -

And then in the filesystem I can see the threads:

[email protected]:~# ls /proc/1120/task/
1120  1125  1126  1128  1129  1130  1131

So is there some way I can get the SPID from my application so I can somehow identify what my SPID is in each running thread?

Thanks!

/Mike

Edit: I should add that the PID returned from getpid() is the same in each thread.

When I add this code to my threads:

// Log thread information to syslog
syslog(LOG_NOTICE, "ibnhwsuperv: gettid()= %ld,  pthread_self()=%ld", (long int)syscall(224), pthread_self());

I get this result:

Jan  1 01:24:13 10 ibnhwsupervd[1303]: ibnhwsuperv: gettid()= -1,  pthread_self()=839027488

Neither of which look like the SPID given by ps or in the proc filesystem.

Also, note that gettid does not return the SPID.

Answer 1

How about gettid()?

Edit: If your libc doesn't have the gettid() function, you should run it like this:

#include <sys/syscall.h>
syscall(SYS_gettid);

... or see example on this manual page.

Answer 2

what is an alternative to this on AIX?