Planning Considerations for
Two assembler language macros,
the reserving and releasing of a device. The data integrity of shared
devices can be maintained by application program use of the
reserve macro if the target of their update operation is to a shared
device.
In addition,
the access method services control statement has no function in
attempt is made by
use of shared
operating systems which will maintain the integrity of shared data, such
as catalogs,
the
thosE operating systems. The only other alternative is the use of the
hardware reserve or release
and release
virtual machine or processor operating systems for the purpose of
preserving data integrity. The integrity of the data is preserved by the
hardware on a device basis during the interval of time between the
reserve and release
via any other path.
map to the same real channel interface to the device, the hardware
protection is lost and a software locking structure is required to
maintain the data integrity during reserve/release seguences.
The
reserve CCws. The use of reserve/release remains the full responsibility
of the operating system running in the virtual machine. The
dynamically determine whether the two-or-four channel switch feature is
installed.
preserve data integrity in the following environments:
Reserve/Release
integrity. In this environment devices should be generated, at system
generation time in
dedicated to a virtual machine by means of the ATTACH command or
DEDICATE control statement in the directory.