• Eric W. Biederman's avatar
    pid: Implement PIDTYPE_TGID · 6883f81a
    Eric W. Biederman authored
    Everywhere except in the pid array we distinguish between a tasks pid and
    a tasks tgid (thread group id).  Even in the enumeration we want that
    distinction sometimes so we have added __PIDTYPE_TGID.  With leader_pid
    we almost have an implementation of PIDTYPE_TGID in struct signal_struct.
    
    Add PIDTYPE_TGID as a first class member of the pid_type enumeration and
    into the pids array.  Then remove the __PIDTYPE_TGID special case and the
    leader_pid in signal_struct.
    
    The net size increase is just an extra pointer added to struct pid and
    an extra pair of pointers of an hlist_node added to task_struct.
    
    The effect on code maintenance is the removal of a number of special
    cases today and the potential to remove many more special cases as
    PIDTYPE_TGID gets used to it's fullest.  The long term potential
    is allowing zombie thread group leaders to exit, which will remove
    a lot more special cases in the code.
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    6883f81a
pid.h 5.67 KB