    NAME
         drmaa_init, drmaa_exit - Start/finish Grid Engine DRMAA ses-
         sion

    SYNOPSIS
         #include "drmaa.h"

         int drmaa_init(
              const char *contact,
              char *error_diagnosis,
              size_t error_diag_len
         );

         int drmaa_exit(
              char *error_diagnosis,
              size_t error_diag_len
         );

    DESCRIPTION
      drmaa_init()
         The drmaa_init() function initializes the Grid Engine  DRMAA
         API library for all threads of the process and creates a new
         DRMAA session. This routine must be called once  before  any
         other    DRMAA    call,    except    for   drmaa_version(3),
         drmaa_get_DRM_system(3),                                 and
         drmaa_get_DRMAA_implementation(3).   Except  for  the  above
         listed functions, no DRMAA functions may  be  called  before
         the  drmaa_init()  function  completes.   Any DRMAA function
         which is called before the drmaa_init()  function  completes
         will  return a DRMAA_ERRNO_NO_ACTIVE_SESSION error.  Contact
         is an implementation dependent string which may be  used  to
         specify  which  Grid Engine cell to use. If contact is NULL,
         the default Grid Engine cell will be used. In the 1.0 imple-
         mentation    contact   may   have   the   following   value:
         session=<session_id>.   To  determine  the  session_id,  the
         drmaa_get_contact(3)  function  should  be  called after the
         session  has  already  been  initialized.   By  passing  the
         session=<session_id>  string  to  the drmaa_init() function,
         instead of creating a new session,  DRMAA  will  attempt  to
         reconnect  to  the session indicated by the session_id.  The
         result of reconnecting to a previous  session  is  that  all
         jobs  previously  submitted  in  that session that are still
         running will be available in the DRMAA session.  Note,  how-
         ever,  that jobs which ended before the call to drmaa_init()
         may not be available or may have no associated exit informa-
         tion or resource usage data.

         In the 0.95 implementation, setting contact has no effect.

      drmaa_exit()
         The drmaa_exit() function closes the DRMAA session  for  all
         threads  and must be called before process termination.  The
         drmaa_exit() function may be called only once  by  a  single
         thread  in  the  process  and  may  only be called after the
         drmaa_init() function has completed.   Any  DRMAA  function,
         other   than   drmaa_init(3),  which  is  called  after  the
         drmaa_exit()    function    completes    will    return    a
         DRMAA_ERRNO_NO_ACTIVE_SESSION error.

         The drmaa_exit() function does necessary  clean  up  of  the
         DRMAA  session state, including unregistering from the qmas-
         ter(8).  If the drmaa_exit() function  is  not  called,  the
         qmaster  will  store  events  for the DRMAA client until the
         connection times out, causing extra work for the qmaster and
         consuming system resources.

         Submitted jobs are not affected by  the  drmaa_exit()  func-
         tion.

    ENVIRONMENTAL VARIABLES
         SGE_ROOT       Specifies the location  of  the  Grid  Engine
                        standard configuration files.

         SGE_CELL       If set, specifies  the  default  Grid  Engine
                        cell  to  be  used.  To address a Grid Engine
                        cell Grid Engine uses (in the order  of  pre-
                        cedence):

                             The name of the cell  specified  in  the
                             environment  variable SGE_CELL, if it is
                             set.

                             The  name  of  the  default  cell,  i.e.
                             default.

         SGE_DEBUG_LEVEL
                        If  set,  specifies  that  debug  information
                        should  be written to stderr. In addition the
                        level of detail in which debug information is
                        generated is defined.

         SGE_QMASTER_PORT
                        If set, specifies the tcp port on  which  the
                        sge_qmaster is expected to listen for commun-
                        ication requests.   Most  installations  will
                        use  a  services  map entry instead to define
                        that port.

    RETURN VALUES
         Upon successful completion,  drmaa_init()  and  drmaa_exit()
         return DRMAA_ERRNO_SUCCESS.  Other values indicate an error.
         Up to error_diag_len characters of error  related  diagnosis
         information is then provided in the buffer error_diagnosis.

    ERRORS
         The drmaa_init() and drmaa_exit() functions will fail if:

      DRMAA_ERRNO_INTERNAL_ERROR
         Unexpected  or  internal  DRMAA  error,  like  system   call
         failure, etc.

      DRMAA_ERRNO_DRM_COMMUNICATION_FAILURE
         Could not contact DRM system for this request.

      DRMAA_ERRNO_AUTH_FAILURE
         The specified request is not processed successfully  due  to
         authorization failure.

      DRMAA_ERRNO_INVALID_ARGUMENT
         The input value for an argument is invalid.

         The drmaa_init() will fail if:

      DRMAA_ERRNO_INVALID_CONTACT_STRING
         Initialization failed due to invalid contact string.

      DRMAA_ERRNO_DEFAULT_CONTACT_STRING_ERROR
         Could not use the default contact string to connect  to  DRM
         system.

      DRMAA_ERRNO_DRMS_INIT_FAILED
         Initialization failed due to failure to init DRM system.

      DRMAA_ERRNO_ALREADY_ACTIVE_SESSION
         Initialization failed due to existing DRMAA session.

      DRMAA_ERRNO_NO_MEMORY
         Failed allocating memory.

         The drmaa_exit() will fail if:

      DRMAA_ERRNO_NO_ACTIVE_SESSION
         Failed because there is no active session.

      DRMAA_ERRNO_DRMS_EXIT_ERROR
         DRM system disengagement failed.

    SEE ALSO
         drmaa_submit(3).