EC2_$WAIT                         Domain/OS                          EC2_$WAIT


NAME
     ec2_$wait - wait for an eventcount trigger

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/ec2.h>

     pinteger ec2_$wait(
          ec2_$ptr_t *ec_plist,
          long *ec_vlist,
          short &ec_count,
          status_$t *status)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/ec2.ins.pas';

     function ec2_$wait(
          in ec_plist: univ ec2_$ptr_list_t;
          in ec_vlist: univ ec2_$val_list_t;
          ec_count: integer;
          out status: status_$t): pinteger;

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/ec2.ins.ftn'

           integer*4 ec_plist(128), ec_vlist(128), status
           integer*2 ec_satisfied, ec_count

           ec_satisfied = ec2_$wait(ec_plist, ec_vlist, ec_count, status)

DESCRIPTION
     Ec2_$wait waits until one of the eventcounts in the ec_plist reaches its
     trigger value in the ec_vlist.  When an eventcount reaches its trigger
     value, ec2_$wait returns the position in ec_plist of the pointer to the
     eventcount that is satisfied.  If the first eventcount in ec_plist is
     satisfied, ec2_$wait returns 1; if the last eventcount is satisfied,
     ec2_$wait returns ec_count.

     Several eventcounts may have been satisfied by the time this call
     returns.  The value returned is the position of the eventcount with the
     smallest subscript that is satisfied.

     ec_plist
          An array of pointers to eventcounts.  The total number of pointers
          in ec_plist on any one node cannot exceed 128.  The pointers in
          ec_plist for system eventcounts are returned by the get_ec calls for
          the manager of the eventcounts.

     ec_vlist
          An array of positive trigger values for each of the eventcounts in
          ec_plist.  Ec2_$wait returns when any of the eventcounts from
          ec_plist reaches its trigger value in ec_vlist.

     ec_count
          Number of eventcount pointers in ec_plist.

     status
          The completion status.

NOTES
     The difference between ec2_$wait and ec2_$wait_svc or ec2_$wait_slow_io
     is in how they respond to asynchronous faults.  Ec2_$wait only returns
     when an eventcount advances; it never returns due to an asynchronous
     fault.  If the calling process has disabled asynchronous faults,
     ec2_$wait just ignores any asynchronous faults received.  If asynchronous
     faults are enabled and one is received during a call to ec2_$wait, then
     ec2_$wait responds in the following way:

          ⊕  It calls the clean-up handler, if the calling process has one.

          ⊕  If the calling process lacks a clean-up handler but has a fault
             handler, then ec2_$wait calls the fault handler.  If the fault
             handler returns, ec2_$wait resumes and continues waiting.

          ⊕  If the calling process has neither a clean-up handler nor a fault
             handler, the system aborts the calling process.

SEE ALSO
     gpr_$get_ec, ios_$get_ec, ipc_$get_ec, mbx_$get_ec, pbu_$get_ec,
     pfm_$enable, pfm_$inhibit, pgm_$get_ec, time_$get_ec.