HP 3000 Manuals HP 3000 Manuals
Special Considerations and Restrictions
There are certain considerations to bear in mind when you use Switch.
General
General considerations apply no matter what the direction of the
mixed-mode call:
* Mixed-mode procedure calls require an increased level of programming
complexity.
* The overhead of Switch can be significant.
* Since Switch does no parameter type or alignment checking, the target
procedure must make the necessary checks.
The following considerations apply to a particular direction of
mixed-mode call.
CM--> NM
When making mixed-mode procedure calls in the direction CM--> NM, be
mindful of the following:
* Any NM procedure called from CM code must reside in an Executable
Library. The CM program and its user must have access to the NL, and
the NL must be properly described to HPLOADNMPROC or HPSWTONMNAME.
All library searches default to NL.PUB.SYS.
* An NM procedure that is declared Option Extensible_Gateway must have
a 32-bit zero placed in the first and second elements of the argument
list. The descriptor list should hold a 3 (type 3, 32 bits) at the
first element. The actual arguments of the procedure follow.