The mi_class_numvp() function
The mi_class_numvp() function obtains the number of active virtual processors (VPs) in a VP class.
Syntax
mi_integer mi_class_numvp(VPclass_id)
mi_integer VPclass_id;
- VPclass_id
- A VP-class identifier for the VP class whose number of active
VPs the function is to return. This argument can be either of the
following values:
- A valid VP-class identifier
- Obtains the number of active VPs in the specified VP class.
- MI_CURRENT_CLASS VP-class constant
- Obtains the number of active VPs in the VP class of the current VP.
Valid in client LIBMI application? | Valid in user-defined routine? |
---|---|
No | Yes |
Important: This advanced function can adversely
affect your UDR if you use the function incorrectly. Use it only when
no regular DataBlade®
API function
can perform the task you need done.
Usage
The mi_class_numvp() function
returns the number of active VPs in the VP class that the VPclass_id argument
specifies. An active VP is a VP that is currently executing a task.
The number of active VPs is initially the value assigned with the num option
in the VPCLASS configuration parameter. For example, suppose you have
the following VPCLASS configuration parameter:
VPCLASS=newvp, num=3, max=6
The mi_class_numvp() function
returns the value of 3
when it receives the VP-class
identifier for the newvp VP class. However, if the DBA dynamically
adds or removes VPs, the value that mi_class_numvp() returns
might not coincide with the num option. You can obtain a VP-class
identifier with the mi_vpinfo_classid() or mi_class_id() function.
This
function is useful to determine if the current VP is part of a single-instance
VP class. For such a VP class, the mi_class_numvp() function
returns a value of
1
. Tip: To obtain
the maximum number of VPs defined for the VP class (by the max option
of the VPCLASS configuration parameter), use the mi_class_maxvps() function.
For information about how to obtain information about VPs and VP classes, see the Informix® DataBlade® API Programmer's Guide.
Return values
- >=0
- The number of active VPs in the VP class associated with the specified VP-class identifier.
- MI_ERROR
- The function was not successful or that the specified VP class does not exist.