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)