oracular (5) proc_pid_task.5.gz

NAME

       /proc/pid/task/, /proc/tid/, /proc/thread-self/ - thread information

DESCRIPTION

       /proc/pid/task/ (since Linux 2.6.0)
              This  is  a  directory that contains one subdirectory for each thread in the process.  The name of
              each subdirectory is the numerical thread ID (tid) of the thread (see gettid(2)).

              Within each of these subdirectories, there is a set of files with the same names and  contents  as
              under  the /proc/pid directories.  For attributes that are shared by all threads, the contents for
              each of the files under the task/tid subdirectories will be the same as in the corresponding  file
              in the parent /proc/pid directory (e.g., in a multithreaded process, all of the task/tid/cwd files
              will have the same value as the /proc/pid/cwd file in the  parent  directory,  since  all  of  the
              threads  in  a  process  share  a  working  directory).  For attributes that are distinct for each
              thread, the corresponding files under task/tid may have different values (e.g., various fields  in
              each  of  the  task/tid/status files may be different for each thread), or they might not exist in
              /proc/pid at all.

              In a multithreaded process, the contents of the /proc/pid/task directory are not available if  the
              main thread has already terminated (typically by calling pthread_exit(3)).

       /proc/tid/
              There   is  a  numerical  subdirectory  for  each running thread that is not a thread group leader
              (i.e., a thread whose thread ID is not the same as its process ID); the subdirectory is  named  by
              the  thread  ID.   Each  one  of  these  subdirectories contains files and subdirectories exposing
              information about the thread with the thread ID tid.  The contents of these  directories  are  the
              same as the corresponding /proc/pid/task/tid directories.

              The  /proc/tid  subdirectories  are not visible when iterating through /proc with getdents(2) (and
              thus are not visible when one uses ls(1) to view the contents of /proc).  However,  the  pathnames
              of  these  directories  are visible to (i.e., usable as arguments in) system calls that operate on
              pathnames.

       /proc/thread-self/ (since Linux 3.17)
              This directory refers to the thread accessing the  /proc  filesystem,  and  is  identical  to  the
              /proc/self/task/tid directory named by the process thread ID (tid) of the same thread.

SEE ALSO

       proc(5)