tasks(3)

NAME

pvm_tasks - Returns information about the tasks running on the virtual machine.

SYNOPSIS

C    int info = pvm_tasks( int where, int *ntask, struct pvmtaskinfo **taskp )
     struct pvmtaskinfo {
     int ti_tid;
     int ti_ptid;
     int ti_host;
     int ti_flag;
     char *ti_a_out;
     } taskp;
Fortran   call pvmftasks( where, ntask, tid, ptid, dtid, flag, aout, info )

PARAMETERS

where Integer specifying what tasks to return information about. The

options are:

0 for all the tasks on the virtual machine

pvmd tid for all tasks on a given host

tid for a specific task

ntask Integer returning the number of tasks being reported on.

taskp Returns pointer to an array of structures which contain infor

mation about each task including its task ID, parent tid, pvmd task ID, status flag, and the name of this task's executable file. The status flag values are: waiting for a message, waiting for the pvmd, and running.

tid Integer returning task ID of one task

ptid Integer returning parent task ID

dtid Integer returning pvmd task ID of host task is on.

flag Integer returning status of task

aout Character string returning the name of spawned task. Manually

started tasks return blank.

info Integer status code returned by the routine. Values less than

zero indicate an error.

DESCRIPTION

The routine pvm_tasks returns information about tasks presently running on the virtual machine. The information returned is the same as that available from the console command ps. The C function returns information about the entire virtual machine in one call. The Fortran function returns information about one task per call and cycles through all the tasks. Thus, if where = 0, and pvmftasks is called ntask times, all tasks will be represented.

Note that in Fortran the reported value of ntask and the set of tasks do not change until the function resets at the end of a complete cycle. The user can reset pvmftasks() at any time by calling it with ntask = -1.

If pvm_tasks is successful, info will be 0. If some error occurs then info will be < 0.

EXAMPLES

C:

struct pvmtaskinfo *taskp;
int i, ntask;

info = pvm_tasks( 0, &ntask, &taskp );
for (i = 0; i < ntask; i++)

printf("t%x\n", taskp[i].ti_tid);

Fortran:

Do i=1, NTASK

CALL PVMFTASKS( DTID, NTASK, TID(i), PTID(i), DTID(i),

& FLAG(i), AOUT(i), INFO )
EndDo

ERRORS

The following error condition can be returned by pvm_tasks

PvmBadParam

invalid value for where argument.

PvmSysErr

pvmd not responding.

PvmNoHost

specified host not in virtual machine.

SEE ALSO

pvm_config(3PVM), pvm_tidtohost(3PVM)

31 August, 1994 TASKS(3PVM)