Open System Services System Calls Reference Manual (G06.25+, H06.03+)

System Functions (t) tdm_fork(2)
• Login, remote login, and saveabend flags
• File creation mask
• System debugger selection (based on Inspect mode and OSS read access rights on the
program file)
If the pe_parms parameter contains a null pointer, then the default Guardian attributes of the
child process differ from those of the parent process in the following ways:
• Segments created or shared using Guardian procedures such as
SEGMENT_ALLOCATE_ are not inherited.
• The child process does not inherit the parent process extended swap file (if any). For a
G-series TNS process or an accelerated process, the extended data segment is managed
by the Kernel Managed Storage Facility (KMSF) unless an extended swap file is
specified in the pe_extswap_file_name field of the process_extension structure
described elsewhere in this reference page.
• The child’s process name is system-generated if the RUNNAMED option is set in the
program file. Otherwise, the process is unnamed.
• The DEFINEs inheritance for the child is based on the parent’s DEFINE mode.
• The process identification number (PIN) of the child process is unrelated to that of the
parent process. Usually, the PIN of the child process is unrestricted. However, the PIN
can be restricted to the range 0 through 254 under the following conditions:
— The HIGHPIN flag is not set in, or is absent from, the program file or any library
file.
— _TPC_HIGHPIN_OFF is specified in the pe_create_options field of the
process_extension structure, described elsewhere in this reference page.
— The restriction is inherited. See _TPC_IGNORE_FORCEPIN_ATTR in the
pe_create_options field of the process_extension structure, described else-
where in this reference page, for more information about controlling inheritance.
• The MOM field for the child process is set to 0 (zero).
• Code breakpoints and memory breakpoints are not inherited.
For detailed information about Guardian process attributes, see the PROCESS_LAUNCH_ pro-
cedure in the Guardian Procedure Calls Reference Manual.
Setting Guardian Attributes
The input structure pointed to by the pe_parms parameter permits the setting of Guardian attri-
butes for the child process.
First, the input structure must be initialized to the default values (see Default Guardian Attri-
butes, earlier in this reference page) using the #define DEFAULT_PROCESS_EXTENSION.
After the data structure is initialized, the values can be set using literals that are defined in the
tdmext.h header file.
If any optional parameter specified in the structure pointed to by pe_parms is not passed, the
child process assumes the corresponding default value.
The input structure is defined in the tdmext.h header file. This structure can contain fields that
vary from release to release, including reserved and filler fields.
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