CEEOFORK creates a new POSIX process, called a child process, supporting
the POSIX 1003.1
fork() function. CEEOFORK supports
the XPG4 standard
vfork() function.
Note: The CEEOFORK
CWI does not support the use of fork handlers. Support for the registration
and execution of fork handlers only exists in the C/C++ Runtime Library.
Syntax
void
CEEOFORK (
function_code,
pid,
[
fc])
INT4 *function_code;
INT4 *pid;
FEED_BACK *fc;
- CEEOFORK
- Call this CWI interface as follows:
L R15,CEECAACELV-CEECAA(,R12) CAA address is in R12
L R15,3284(,R15)
BALR R14,R15
- function_code (input)
- A full word binary integer that specifies whether the function
is fork() or vfork(). It must contain
one of the following values:
- 0
- Language Environment has
been requested to perform fork(), if the member language
tolerate the fork(). If so, perform fork().
- 1
- Language Environment has
been requested to perform vfork(), if the member
language tolerate the vfork(). If so, perform vfork().
- pid (output)
- A full word binary integer to contain the process identifier of
the newly-created child process. When fork() or vfork() returns
to the calling (parent) process, it returns the process identifier
of the newly create child.Because the child is a duplicate, it contains
the same call to fork() or vfork() that
was in the parent. Execution of the child begins with this fork() or vfork() call
returning a value of zero, the child then proceeds with normal execution.If
the pid is returned as minus 1, then no
child process was created, for the reason specified in feedback token
CEE510.
- fc (output/optional)
- The parameter in which the CWI service feedback code is placed.
The following conditions can result from this CWI service.
| Condition |
|
|---|
| CEE000 |
Severity |
0 |
| Msg_No |
0000 |
| Message |
The service completed successfully. |
| CEE4SA |
Severity |
3 |
| Msg_No |
5002 |
| Message |
POSIX function not available. z/OS UNIX system
services were not started. |
| CEE50V |
Severity |
3 |
| Msg_No |
5151 |
| Message |
Language Environment member
identifier number [member_id] cannot tolerate
the POSIX fork() or vfork() function. |
| CEE510 |
Severity |
3 |
| Msg_No |
5152 |
| Message |
The z/OS UNIX callable
service for the fork() function was unsuccessful.
The system return code was [return_code];
the reason code was [reason_code]. Note: The
system return code and reason code are documented in the z/OS UNIX information.
|
| CEE512 |
Severity |
3 |
| Msg_No |
5154 |
| Message |
The requested fork() or vfork() service
failed because it was invoked from a multithread environment. |
Qualifying data (when CEE510): | No. |
Name |
Input/ Output |
Type |
Value |
|---|
| 1 |
parm_count |
Input |
INT4 |
3 |
| 2 |
return_code |
Input |
INT4 |
Return code from kernel, BPX1FRK
function - nn
- Codes defined by ANSI C, POSIX, and z/OS UNIX
|
| 3 |
reason_code |
Input |
INT4 |
Reason code from kernel, BPX1FRK
function - nn
- Codes defined by ANSI C, POSIX, and z/OS UNIX
|
Usage notes: - The new process (called the child process)
is a duplicate of the process that calls fork() (called
the parent process).
- Member languages are notified (event code 24 and function code
1) that a fork() has been requested and can the member
tolerate a fork().
The event handler CEEEVnnn
sets the return code in R15 to the following values:
- 0
- Member language can tolerate fork()
- -4
- Member language cannot tolerate fork()
- 16
- Event handler encountered an unrecoverable error.
- Member languages are notified (event code 24 and function code
2) to perform any required cleanup in the child process.
- The values of the return_code and reason_code (nn)
are as defined in the z/OS UNIX System Services Programming: Assembler Callable Services Reference.
- This function is accessible independent of the POSIX runtime option.