GDSX (Extended General Device Support) Manual

Service Routines
Extended General Device Support (GDSX) Manual—529931-001
8-4
Semaphore Control
Semaphore Control
The purpose of a semaphore is to ensure the serial access of a shared resource. A
task is considered to have acquired a resource when it owns the semaphore
associated with the resource. A unique user-defined semaphore should be established
for each resource requiring exclusive access.
The following procedures are available for managing semaphores other than the
checkpoint semaphore. The checkpoint semaphore is managed with the GET^CPSEM
and GIVE^CPSEM procedures.
INIT^SEM
PSEM
VSEM
Task Maintenance
The following procedures support various features related to task processing and
shutdown:
GET^TASK^NAME TCBADDR
^SHUTDOWN ^TERMINATE
STOP^TASK WAITED^IO[X]
Pseudo Procedures
TSCODE provides you with a set of pseudo procedure calls that, with some
exceptions, have the same parameters, syntax, meaning, and resultant capabilities as
their counterparts. They comprise a layer of TSCODE between USCODE and the
Guardian file system, NonStop server classes, and the TMF that is virtually transparent
to USCODE, providing you with a consistent interface to facilities similar to NonStop
systems.
This layer of software allows TSCODE to keep track of each internal I/O operation and
to ensure that every I/O operation is handled correctly at completion time. Pseudo
procedures determine whether an operation is to be handled completely within GDSX
or is to be handled outside GDSX.
Table 8-1 contains a list of the pseudo procedure calls supported by TSCODE. Many
TSCODE-supported utility procedures do not have Guardian file-system counterparts,
and are not included here. A bracketed X at the end of or in the middle of a procedure
name indicates that both local-memory and extended-memory procedures are
available. For example, ^AWAITIO[X] indicates that the ^AWAITIO and ^AWAITIOX
procedures are available.
Caution. The pseudo procedure calls must be used instead of their counterparts.