DP_CNTL(2-N)               SYSTEM CALLS              DP_CNTL(2-N)


NAME
     dp_cntl -- control a process in an MPPG


SYNOPSIS
     #include <sys/mppg.h>

     int dp_cntl(int cmd, long long arg1, long long arg2,

             long long arg3, long long arg4, long long arg5);


DESCRIPTION
     When  cmd  is  equal to DPCNTL_CHKIN, the signal mode of the
     calling process is changed.

     dp_kill(2) and dp_resume(2)  become  possible  only  in  the
     group  of  processes  that  have  changed their signal mode.
     When a process in this group aborts  due  to  an  exception,
     e.g.,  invalid  memory  access,  SIGXABT  is sent to all the
     other processes in the group.

     For the usual parallel programs, a deadlock is detected  and
     a  SIGDEAD signal is sent to the process when all threads in
     a process have suspended.  However, MPPG  processes  may  be
     resumed  from  another  process, so the deadlock must not be
     detected even when all threads  of  the  process  have  sus-
     pended.

     When  a  thread  that  belongs  to  an MPPG and has executed
     dp_cntl(DPCNTL_CHKIN) is suspended by the thread library,  a
     deadlock is checked through all processes that belong to the
     MPPG and that have  executed  dp_cntl(DPCNTL_CHKIN).   If  a
     deadlock  is detected, SIGDEAD is sent to the last suspended
     process and as a result SIGXABT is sent  to  all  the  other
     processes.

     dp_cntl fails if one or more of the following are true:

     [EINVAL]   The calling process doesn't belong to an MPPG.

     [EINVAL]   cmd is not a valid value.

SEE ALSO
     dp_create(2),    dp_join(2),    dp_exit(2),   dp_xmalloc(2),
     dp_xmfree(2), dp_xmshare(2), dp_xmatt(2),
     dp_kill(2), dp_resume(2)
     Global Memory in the SUPER-UX Programmer's Guide

DIAGNOSTICS
     Upon  successful completion, a value of 0 is returned.  Oth-
     erwise, a value of -1 is returned and errno is set to  indi-
     cate the error.




SUPER-UX            Last change: Oct 13, 1999                   1