7.2 psb_info — Return information about PSBLAS parallel environment

call psb_info(ctxt, iam, np)

This subroutine returns information about the PSBLAS parallel environment, defining a virtual parallel machine.

Type:

Asynchronous.

On Entry

ctxt

the communication context identifying the virtual parallel machine.
Scope: global.
Type: required.
Intent: in.
Specified as: an integer variable.

On Return

iam

Identifier of current process in the PSBLAS virtual parallel machine.
Scope: local.
Type: required.
Intent: out.
Specified as: an integer value. -1 ≤ iam ≤ np - 1 

np

Number of processes in the PSBLAS virtual parallel machine.
Scope: global.
Type: required.
Intent: out.
Specified as: an integer variable.  

Notes

1. For processes in the virtual parallel machine the identifier will satisfy 0 ≤ iam ≤ np - 1;
2. If the user has requested on psb_init a number of processes less than the total available in the parallel execution environment, the remaining processes will have on return iam = -1; the only call involving ctxt that any such process may execute is to psb_exit.