int tid = pvm_parent( void ) call pvmfparent( tid )
The routine pvm_parent() returns the TID of the process that spawned this task or the value of PvmNoParent if not created by pvm_spawn().
int dtid = pvm_tidtohost( int tid ) call pvmftidtohost( tid, dtid )
The routine pvm_tidtohost() returns the TID dtid of the daemon running on the same host as TID. This routine is useful for determining on which host a given task is running. More general information about the entire virtual machine, including the textual name of the configured hosts, can be obtained by using the following functions:
int info = pvm_config( int *nhost, int *narch,
struct pvmhostinfo **hostp )
call pvmfconfig( nhost, narch, dtid, name, arch, speed, info)
The routine pvm_config() returns information about the virtual machine including the number of hosts, nhost, and the number of different data formats, narch. hostp is a pointer to a user declaried array of pvmhostinfo structures. The array should be of size at least nhost. On return, each pvmhostinfo structure contains the pvmd TID, host name, name of the architecture, and relative CPU speed for that host in the configuration.
The Fortran function returns information about one host per call and cycles through all the hosts. Thus, if pvmfconfig is called nhost times, the entire virtual machine will be represented. The Fortran interface works by saving a copy of the hostp array and returning one entry per call. All the hosts must be cycled through before a new hostp array is obtained. Thus, if the virtual machine is changing during these calls, then the change will appear in the nhost and narch parameters, but not in the host information. Presently, there is no way to reset pvmfconfig() and force it to restart the cycle when it is in the middle.
int info = pvm_tasks( int which, int *ntask,
struct pvmtaskinfo **taskp )
call pvmftasks( which, ntask, tid, ptid, dtid,
flag, aout, info )
The routine pvm_tasks() returns information about the PVM tasks running on the virtual machine. The integer which specifies which tasks to return information about. The present options are (0), which means all tasks, a pvmd TID (dtid), which means tasks running on that host, or a TID, which means just the given task.
The number of tasks is returned in ntask. taskp is a pointer to an array of pvmtaskinfo structures. The array is of size ntask. Each pvmtaskinfo structure contains the TID, pvmd TID, parent TID, a status flag, and the spawned file name. (PVM doesn't know the file name of manually started tasks and so leaves these blank.) 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. The Fortran implementation assumes that the task pool is not changing while it cycles through the tasks. If the pool changes, these changes will not appear until the next cycle of ntask calls begins.
Examples of the use of pvm_config and pvm_tasks can be found in the source to the PVM console, which is just a PVM task itself. Examples of the use of the Fortran versions of these routines can be found in the source pvm3/examples/testall.f.