Open System Services Programmer's Guide

for the fields in the input structure that contains Guardian attributes. Examples of these attribute
fields are pe_cpu (processor), pe_debug_options (debug options), and pe_hometerm (home
terminal).
Some Guardian attributes are more important for you to manipulate than others. The following lists
the attributes you might want to set when you create a process using the OSS HP extension functions.
For more information about setting these attributes, see the process-creation functions in the reference
pages either online or in the Open System Services System Calls Reference Manual.
• Processor. Specifying the processor on which a process executes allows you to distribute an
application across processors. tdm_fork() does not allow you to specify a value for the
processor attribute, but the tdm_exec and tdm_spawn sets of functions do. You cannot change
the processor in which a process executes after the process is created.
• Debug options. Debug options can instruct a debugging program to create a saveabend file
if the process terminates abnormally. A saveabend file contains data-area and file-status
information at the time of the failure. Debug options also can force the child process to enter
a debugging program after returning from the tdm_fork() function. You cannot change the
debug options of a process after the process is created.
• Home terminal. Making the home terminal different from the controlling terminal allows you
to avoid information collisions. For example, you can make another terminal or terminal
emulator window (other than the controlling terminal) the home terminal, and a debugging
program can display messages there. Use the PROCESS_SETSTRINGINFO_ procedure to
change the home terminal of a process after it is created.
• Priority. Changing the execution priority of a process changes the position of the process in
the ready queue. Use the PROCESS_SETINFO_ procedure to change the priority of a process
after it is created.
• DEFINEs. Specifying a set of DEFINEs to be propagated to a new process lets you pass
information to the process. For example, you can specify an SQL catalog to be used by an
SQL process. Use Guardian procedures, such as DEFINEADD and DEFINEDELETE, or OSS
utilities, such as add_define and del_define, to change the DEFINEs of a process after
it is created.
Comparing OSS and Guardian Process Attributes
Table 10 summarizes some important process attributes that OSS and Guardian processes have
in common and those they do not share. Notice that except for a program type of Guardian, OSS
processes almost always have Guardian process attributes while Guardian processes lack several
OSS-specific attributes.
Table 10 OSS and Guardian Process Attribute Comparison
Part of a Guardian Process?Part of an OSS Process?Process Attribute
Ancestors
SometimesSometimesGuardian ancestor
SometimesSometimesGuardian MOM/GMOM
NeverAlwaysOSS parent
Groups
NeverAlwaysOSS group leader
NeverAlwaysOSS session leader
Identification
AlwaysAlwaysGuardian creator access ID
AlwaysAlwaysGuardian process access ID
AlwaysAlwaysGuardian process handle
SometimesSometimesGuardian process name
114 Managing Processes