GDSX Manual

Service Routines
Extended General Device Support (GDSX) Manual–134303
8-53
PROCESS_HANDLE_IS_NULL_
•
Because the working stack images of tasks are swapped to and from an extended
data segment during I/O operations, I/O must be performed to and from global
buffers.
•
If you want USCODE to provide calls to ^AWAITIO[X] in order to wait for I/O
completion on ^DEVICEINFO2, ^FILE_GETINFOBYNAME_, and
^PROCESS_CREATE_ service routines, as would be done for typical nowaited
Guardian procedure calls, you must set the PROCNOWAIT configuration parameter
to 1.
If you want TSCODE to supply AWAITIO[X] calls to complete these nowaited I/Os
on behalf of USCODE, you must set PROCNOWAIT to 0. See “PROCNOWAIT”
on page 2-67 for more information.
•
If a USCODE task calls ^PROCESS_CREATE_ to create a new process when the
number of existing processes is equal to the number defined by the
MAXPROCESSES configuration parameter, a new process is not created. File-
system error 34 is returned from ^PROCESS_CREATE_.
•
If a USCODE task calls ^PROCESS_CREATE_, and the created process stops,
abends, or is lost due to a CPU failure, TSCODE receives a process deletion system
message (type -101). If sysmsgs^flag of the CONTROLFLAGS configuration
parameter is set to 1, TSCODE forwards the system message to the USCODE task
that created the process. See the Guardian Procedure Errors and Messages Manual
for the format of the D-series process deletion system message. Maximum length of
the passed message is 97 words.
PROCESS_HANDLE_IS_NULL_
This procedure determines whether the passed-in process handle is a null process
handle.
result returned value
INT:value
is the result of the operation. The value of result is one of the following:
processhandle input
INT .EXT:ref:10
is a pointer to the process handle to be tested.
result := PROCESS_HANDLE_IS_NULL_ ( processhandle ); !
i
-1 The process handle is null (each word of the ten-word buffer is equal to -1)
0 The process handle is not null