1. Internationalized System Calls and Libraries Extended V4

Product Information

Environment Specification

Temporary Waivers

1.1 General Attributes

1.1.1 XSI Option Groups

Question 1: Which of the following XSI Option Groups are supported by the implementation?

Response

Encryption	Yes
Realtime	Yes
Advanced Realtime	Yes
Realtime Threads	No
Advanced Realtime Threads	No
Tracing	No
XSI STREAMS	Yes

Support for an XSI Option Group can only be claimed if all interfaces in that group behave according to the relevant descriptions in System Interfaces, Issue 7.

If an implementation does not support an Option Group then the system need not support the functions or functional behavior.

Rationale

Base Definitions, Issue 7 states that the system may provide one or more of the XSI Option Groups listed.

Reference

Technical Standard, Base Definitions, Issue 7, Section 2.1.4, XSI Conformance and Section 2.1.5.2, XSI Option Groups.

Internationalized System Calls and Libraries Extended V4 Product Standard.

1.1.2 Options

Question 2: Which of the following options are supported by the implementation?

Response

IEC 60559 Floating-Point option	No
IPV6	Yes
Raw Sockets	Yes

Support for these options enables additional semantics for interfaces as described in the relevant descriptions in System Interfaces, Issue 7.

Rationale

The system may provide support for additional options beyond those required for XSI conformance or covered by the XSI Option Groups.

Reference

Technical Standard, Base Definitions, Issue 7, Section 2.1.4, XSI Conformance and Section 2.1.6, Options.

Internationalized System Calls and Libraries Extended V4 Product Standard.

1.1.3 POSIX.1 Supported Features

Question 3: For each of the symbolic constants, specified in the <unistd.h> header file, are the associated features always available on the system?

Response

Macro Name	Meaning	Provided
_POSIX_CHOWN_RESTRICTED	The use of chown() is restricted to a process with appropriate privileges, and to changing the group ID of a file only to the effective group ID of the process or one of its supplementary group IDs.	Yes
_POSIX_NO_TRUNC	Pathname components longer than {NAME_MAX} generate an error.	Yes
_POSIX2_SYMLINKS	Symbolic links can be created.	Yes

Rationale

For a conformant implementation, these POSIX features must be provided. In some cases the feature need not be provided for all files or devices supported by the implementation.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <unistd.h>.

1.1.4 Float, Stdio, and Limit Values

Question 4: What are the values associated with the following constants specified in the <float.h> header file?

Response

Macro Name	Meaning	Value
FLT_RADIX	Radix of the exponent representation.	2
FLT_MANT_DIG	Number of base-FLT_RADIX digits in the float significand.	24
DBL_MANT_DIG	Number of base-FLT_RADIX digits in the double significand.	53
LDBL_MANT_DIG	Number of base-FLT_RADIX digits in the long double significand.	106
FLT_DIG	Number of decimal digits, q, such that any floating-point number with q digits can be rounded into a float representation and back again without change to the q digits.	6"
DBL_DIG	Number of decimal digits, q, such that any floating-point number with q digits can be rounded into a double representation and back again without change to the q digits.	15
LDBL_DIG	Number of decimal digits, q, such that any floating-point number with q digits can be rounded into a long double representation and back again without change to the q digits.	31
FLT_MIN_EXP	Minimum negative integer such that FLT_RADIX raised to that power minus 1 is a normalised float.	-125
DBL_MIN_EXP	Minimum negative integer such that FLT_RADIX raised to that power minus 1 is a normalised double.	-1021
LDBL_MIN_EXP	Minimum negative integer such that FLT_RADIX raised to that power minus 1 is a normalised long double.	-1021
FLT_MIN_10_EXP	Minimum negative integer such that 10 raised to that power is in the range of normalised floats.	-37
DBL_MIN_10_EXP	Minimum negative integer such that 10 raised to that power is in the range of normalised doubles.	-307
LDBL_MIN_10_EXP	Minimum negative integer such that 10 raised to that power is in the range of normalised long doubles.	-307
FLT_MAX_EXP	Maximum integer such that FLT_RADIX raised to that power minus 1 is a representable finite float.	128
DBL_MAX_EXP	Maximum integer such that FLT_RADIX raised to that power minus 1 is a representable finite double.	1024
LDBL_MAX_EXP	Maximum integer such that FLT_RADIX raised to that power minus 1 is a representable finite long double.	1024
FLT_MAX_10_EXP	Maximum integer such that 10 raised to that power is in the range of representable finite floats.	38
DBL_MAX_10_EXP	Maximum integer such that 10 raised to that power is in the range of representable finite doubles.	308
LDBL_MAX_10_EXP	Maximum integer such that 10 raised to that power is in the range of representable finite long doubles.	308
FLT_MAX	Maximum representable finite float.	3.4028234663852866e+38F
DBL_MAX	Maximum representable finite double.	1.7976931348623158e+308
LDBL_MAX	Maximum representable finite long double.	1.7976931348623158e+308
FLT_EPSILON	Difference between 1.0 and the least value greater than 1.0 that is representable as a float.	1.1920928955078125e-7F
DBL_EPSILON	Difference between 1.0 and the least value greater than 1.0 that is representable as a double.	2.2204460492503131e-16
LDBL_EPSILON	Difference between 1.0 and the least value greater than 1.0 that is representable as a long double.	2.4651903288156618919116517665087070E-32L
FLT_MIN	Minimum normalised positive float.	1.1754943508222875e-38F
DBL_MIN	Minimum normalised positive double.	2.2250738585072014e-308
LDBL_MIN	Minimum normalised positive long double.	2.2250738585072014e-308

Rationale

This set of constants provides useful information regarding the underlying architecture of the implementation.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <float.h>.

Question 5: What are the values associated with the following constants (optionally specified in the <limits.h> header file)?

Response

Macro Name	Meaning	Minimum	Maximum
AIO_LISTIO_MAX	Maximum number of I/O operations in a single list I/O call.	2	4096
AIO_MAX	Maximum number of outstanding asynchronous I/O operations.	1	4096
ARG_MAX	Maximum length of argument to the exec functions including the environment data.	4096	1048576
ATEXIT_MAX	Maximum number of functions that may be registered with atexit().	32	2048
CHILD_MAX	Maximum number of processes per user ID.	25	128
DELAYTIMER_MAX	Maximum number of timer expiration overruns.	32	32
FILESIZEBITS	Minimum number of bits needed to represent as a signed integer value the maximum size of a regular file.	32	45
HOST_NAME_MAX	Maximum length of a host name as returned from gethostname().	255	256
IOV_MAX	Maximum number of iovec structures that one process has available for use with readv() or writev().	16	16
LINK_MAX	Maximum number of links to a single file.	8	32767
LOGIN_NAME_MAX	Maximum length of a login name.	9	9
MAX_CANON	Maximum number of bytes in a terminal canonical input line.	255	256
MAX_INPUT	Maximum number of bytes for which space will be available in a terminal input queue.	255	512
NAME_MAX	Maximum number of bytes in a filename (not including terminating null).	14	255
OPEN_MAX	Maximum number of open files that one process can have open at any one time.	20	65534
PAGESIZE	Size of a page in bytes.	1	4096
PAGE_SIZE	Same as PAGESIZE. If either PAGESIZE or PAGE_SIZE is defined, the other will be defined with the same value.	1	4096
PATH_MAX	Maximum number of bytes in a pathname (including the terminating null).	16	1024
PIPE_BUF	Maximum number of bytes that is guaranteed to be atomic when writing to a pipe.	512	32768
PTHREAD_DESTRUCTOR_ITERATIONS	Maximum number of attempts made to destroy a thread's thread-specific data values on thread exit.	4	4
PTHREAD_KEYS_MAX	Maximum number of data keys that can be created by a process.	128	450
PTHREAD_STACK_MIN	Minimum size in bytes of thread stack storage.	0	8192
PTHREAD_THREADS_MAX	Maximum number of threads that can be created by a process.	64	512
RE_DUP_MAX	Maximum number of repeated occurrences of a BRE or ERE interval expression.	255	255
RTSIG_MAX	Maximum number of realtime signals reserved for application use.	8	8
SEM_NSEMS_MAX	Maximum number of semaphores that a process may have.	256	32768
SEM_VALUE_MAX	The maximum value a semaphore may have.	32767	32767
SIGQUEUE_MAX	Maximum number of pending queued signals.	32	32
STREAM_MAX	Number of streams that one process can have open at one time.	8	32767
SYMLINK_MAX	Number of bytes in a symbolic link.	255	255
SYMLOOP_MAX	Number of symbolic links that can be reliably traversed in the resolution of a pathname in the absence of a loop.	8	20
TIMER_MAX	Maximum number of timers per process.	32	32
TTY_NAME_MAX	Maximum length of terminal device name.	9	1024
TZNAME_MAX	Maximum number of bytes supported for the name of a time zone.	6	255

Rationale

Each of these limits can vary within bounds set by the Base Definitions, Issue 7. The minimum permitted value is specified in Chapter 13, <limits.h>.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <limits.h>.

Question 6: What are the values associated with the following constants specified in the <limits.h> header file?

Response

For each line in the table below, add the minimum and maximum values for your implementation. These values may be stated to be "Unlimited" if your implementation does not impose a limit. The minimum should be the smallest value that is returned from sysconf(), pathconf(), or fpathconf(), or as defined in <limits.h>. The maximum value should be the largest value that is returned from sysconf(), pathconf(), or fpathconf().

Macro Name	Meaning	Minimum	Maximum
BC_BASE_MAX	Maximum ibase and obase values allowed by the bc utility.	99	99
BC_DIM_MAX	Maximum number of elements permitted in an array by the bc utility.	2048	2048
BC_SCALE_MAX	Maximum scale value allowed by the bc utility.	99	99
BC_STRING_MAX	Maximum length of a string constant accepted by the bc utility.	1000	2048
CHARCLASS_NAME_MAX	Maximum number of bytes in a character class name.	14	14
COLL_WEIGHTS_MAX	Maximum number of weights that can be assigned to an entry of the LC_COLLATE order keyword in the locale definition file.	2	4
EXPR_NEST_MAX	Maximum number of expressions that can be nested within parentheses by the expr utility.	32	32
LINE_MAX	Maximum length in bytes including the trailing newline of a utility's input line when the utility is described as processing text files.	2048	2048
NGROUPS_MAX	Maximum number of simultaneous supplementary group IDs per process.	8	128
RE_DUP_MAX	Maximum number of repeated occurrences of a regular expression permitted when using interval notation.	255	255

Rationale

Each of these limits can vary within bounds set by the Base Definitions, Issue 7. The minimum value that a limit can take on any conforming system is given in the corresponding _POSIX_ or _POSIX2_ value. A specific conforming implementation may provide a higher minimum value than this and the maximum value that it provides can differ from the minimum. Some conforming implementations may provide a potentially infinite value as the maximum, in which case the value is considered to be indeterminate. The minimum value must always be definitive since the _POSIX_ or _POSIX2_ value provides a known lower bound for the range of possible values.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <limits.h>.

Question 7: What are the values associated with the following numerical constants specified in the <limits.h> header file?

Response

Macro Name	Meaning	Value
CHAR_MAX	Maximum value of a char.	255
INT_MAX	Maximum value of an int.	2147483647
LONG_BIT	Number of bits in a long int.	32
LONG_MAX	Maximum value of a long int.	2147483647
LLONG_MAX	Maximum value of a long long.	9223372036854775807
MB_LEN_MAX	Maximum number of bytes in a character, for any supported locale.	4
SHRT_MAX	Maximum value of a short.	32767
SSIZE_MAX	Maximum value of an object of type ssize_t.	2147483647
UINT_MAX	Maximum value of an unsigned int.	4294967295
ULONG_MAX	Maximum value of an unsigned long int.	4294967295
ULLONG_MAX	Maximum value of a unsigned long long.	18446744073709551615
USHRT_MAX	Maximum value of an unsigned short int.	65535
WORD_BIT	Number of bits in a word or int.	32

Rationale

This set of constants provides useful information regarding the underlying architecture of the implementation.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <limits.h>.

Question 8: What are the values associated with the following numerical constants specified in the <stdio.h> header file?

Response

Macro Name	Meaning	Value
FILENAME_MAX	Maximum size in bytes of the longest filename string that the implementation guarantees can be opened.	255
FOPEN_MAX	Number of streams which the implementation guarantees can be open simultaneously.	32767
L_ctermid	Maximum size of character array to hold ctermid() output.	9
L_tmpnam	Maximum size of character array to hold tmpnam() output.	20
TMP_MAX	Minimum number of unique filenames generated by tmpnam(), which is the maximum number of times an application can call tmpnam() reliably.	16384

Rationale

This set of constants provides useful information about the implementation.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <stdio.h>.

1.1.5 File Timestamp Resolution

Question 9: What is the resolution of file timestamps in a file system?

Response

Nanoseconds.

Rationale

The resolution of timestamps of files in a file system is implementation-defined, but is no coarser than one-second resolution.

Reference

Technical Standard, Base Definitions, Issue 7, Section 4.9, File Times Update.

1.1.6 Mathematical Interfaces

Question 10: What format of floating-point numbers is supported by this implementation?

Response

IEEE floating-point format.

Rationale

Most implementations support IEEE floating-point format either in hardware or software. Some implementations support other formats with different exponent and mantissa accuracy. These differences need to be defined.

Reference

Technical Standard, System Interfaces, Issue 7, Section 1.1, Relationship to Other Formal Standards.

Question 11: Which floating-point exceptions are supported by this implementation for the fegetexecptflag(), feraiseexcept(), fesetexecptflag(), and fetestexecptflag() functions?

Response

FE_DIVBYZERO, FE_INEXACT, FE_INVALID, FE_OVERFLOW, FE_UNDERFLOW

Rationale

The behavior of a conforming implementation in this area is not mandated in the specification and needs to be defined.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <fenv.h>.

Question 12: Which floating-point rounding directions are supported by this implementation for the fegetround(), and fesetround() functions?

Response

FE_DOWNWARD, FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD

Rationale

The behavior of a conforming implementation in this area is not mandated in the specification and needs to be defined.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <fenv.h>.

Question 13: Is a non-stop floating-point exception mode supported by this implementation?

Response

Yes

Rationale

The behavior of a conforming implementation in this area is not mandated in the specification and needs to be defined.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, feholdexcept().

1.1.7 Data Encryption

Question 14: Are the optional data encryption interfaces provided?

Response

Function	Provided
crypt()	Yes
encrypt()	Yes
setkey()	Yes

Export Restrictions:

None.

Rationale

Normally, an implementation will either provide all three of these routines or will provide none of them at all. If the routines are not provided, then the implementation must provide a dummy interface which always raises an ENOSYS error condition.

It is also possible that the implementation of the encrypt() function may be affected by export restrictions, in which case, the restrictions should be documented here.

For example, historical implementations have supplied all three of these routines outside the U.S.A., but due to export restrictions on the decoding algorithm, a dummy version of encrypt() is provided that does encoding but no decoding.

Reference

Technical Standard, Base Definitions, Issue 7, Section 2.1.5.2, XSI Option Groups.

1.2 Process Handling

1.2.1 Process Generation

Question 15: Which file types (regular, directory, FIFO, special and so on) are considered to be executable?

Response

Only regular files may be executed.

Rationale

The EACCES error associated with exec functions occurs in circumstances when the implementation does not support execution of files of the type specified. A list of these file types needs to be provided.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, exec.

1.3 File Handling

1.3.1 Access Control

Question 16: What file access control mechanisms does the implementation provide?

Response

Access control lists are provided to augment the POSIX access modes. The base access list consists of the standard owner, group and other permissions. Access control lists can be created for regular files, directories, named pipes, message queues, shared memory segments, semaphores and special files.(When chmod() is called and alternate access control methods are disabled, additional file access control methods are disabled as well.) Access control lists are an alternate file access control method.

Rationale

System Interfaces, Issue 7 notes that implementations may provide additional or alternate file access control mechanisms, or both.

Reference

Technical Standard, Base Definitions, Issue 7, Section 4.5, File Access Permissions.

Question 17: Are any additional or alternate file access control mechanisms implemented that could cause fstat(), fstatat(), lstat() or stat() to fail?

Response

Yes

Rationale

System Interfaces, Issue 7 notes that there could be an interaction between additional and alternate access controls and the success of fstat(), fstatat(), lstat(), and stat(). This would suggest that an implementation can allow access to a file but not allow the process to gain information about the status of the file.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, fstat() and fstatat().

1.3.2 Directory Protection

Question 18: When mode bit S_ISVTX is set on a directory, can writable files be removed and renamed within the directory?

Response

Yes.

Rationale

Whether or not files that are writable by the process can be removed or renamed within a directory that has mode bit S_ISVTX set is implementation-defined.

Reference

Technical Standard, Base Definitions, Issue 7, Section 4.3, Directory Protection.

1.3.3 Symbolic Links

Question 19: How does link() handle symbolic links?

Response

It follows the symbolic link

Rationale

If path1 names a symbolic link, it is implementation-defined whether link() follows the symbolic link, or creates a new link to the symbolic link itself.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, link().

1.4 Coded Character Sets

Question 20: What coded character sets are supported by the implementation?

Response

ISO 8859-1, 8859-2, 8859-3, 8859-4, 8859-5, 8859-6, 8859-7, 8859-8, 8859-9 IBM-eucJP(Japanese EUC) IBM-eucKR(Korean EUC) IBM-eucTW(Traditional Chinese EUC) UTF-8(FSS-UTF) IBM-850, IBM-856, IBM-932, IBM-1046, IBM-eucCN TIS-620

Rationale

Base Definitions, Issue 7 states that conforming implementations support one or more coded character sets, and that each of these includes the portable character set.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 6, Character Set.

Question 21: What is the implementation's underlying internal codeset?

Response

AIX supports the IBM-850 codeset as an option

Rationale

It is useful to be aware of the underlying codeset of the implementation.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 6, Character Set.

1.5 Pseudo-Terminals

1.5.1 Master close

Question 22: Does closing the master side of a pseudo-terminal flush all queued input and output?

Response

Yes

Rationale

The behaviour of a conforming implementation in this area is not mandated in the specification and needs to be defined.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, close().

1.5.2 Slave close

Question 23: Does closing the slave side of a STREAMS-based pseudo-terminal cause a zero-length message to be sent to the master?

Response

Yes

Rationale

The behaviour of a conforming implementation in this area is not mandated in the specification and needs to be defined.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, close().

1.5.3 Naming Conventions

Question 24: What naming conventions are associated with the master side of pseudo-terminal devices?

Response

For BSD ptys: /dev/ptyXN, where X is in the following set; [p-z][A-Z] and N is in the following set; [0-9][a-f]. For AT&T ptys: the clone device is /dev/ptc.

Rationale

This information is not specified in System Interfaces, Issue 7, and needs to be defined.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, open().

1.6 Polling

Question 25: What types of file can be polled?

Response

Regular files, Terminals, Pseudo-Terminals, STREAMS, Sockets, FIFOs, Pipes

Rationale

Conformance requires that the poll() function supports regular files, terminals, pseudo-terminals, FIFOs, pipes, sockets, and (if the XSI STREAMS option is supported) STREAMS. The behaviour of poll() with regards to other file types needs to be defined.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, poll().

1.7 Signal Codes

Question 26: Which of the following si_code values may be generated?

Response

Signal	Code	Generated?
SIGILL	ILL_ILLOPC	No
	ILL_ILLOPN	No
	ILLL_ILLADR	No
	ILL_ILLTRP	No
	ILL_PRVOPC	No
	ILL_PRVREG	No
	ILL_COPROC	No
	ILL_BADSTK	No
SIGFPE	FPE_INTDIV	No
	FPE_INTOVF	No
	FPE_FLTDIV	No
	FPE_FLTOVF	No
	FPE_FLTUND	No
	FPE_FLTRES	No
	FPE_FLTINV	No
	FPE_FLTSUB	No
SIGSEGV	SEGV_MAPERR	No
	SEGV_ACCERR	No
SIGBUS	BUS_ADRALN	No
	BUS_ADRERR	No
	BUS_OBJERR	No
SIGTRAP	TRAP_BRKPT	No
	TRAP_TRACE	No
SIGCHLD	CLD_EXITED	Yes
	CLD_KILLED	Yes
	CLD_DUMPED	Yes
	CLD_TRAPPED	No
	CLD_STOPPED	Yes
	CLD_CONTINUED	Yes
SIGPOLL	POLL_IN	No
	POLL_OUT	No
	POLL_MSG	No
	POLL_ERR	No
	POLL_PRI	No
	POLL_HUP	No
Any	SI_USER	No
	SI_QUEUE	No
	SI_TIMER	No
	SI_ASYNCIO	No
	SI_MESGQ	No

Rationale

An Internationalized System Calls and Libraries Extended V4 conformant system may contain limitations that prevent some of the above values from being generated.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 13, Headers, <signal.h>.

1.8 Set Process Group ID

Question 27: Does the setpgrp() function create a new session?

Response

Yes

Rationale

It is unspecified whether or not a successful call to the setpgrp() function will cause a new session to be created.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, setpgrp().

1.9 Signals Generating a Core File

Question 28: Does the implementation generate a core file when the following signals are delivered to a process and the default action is taken?

Response

Signal	Core File Generated
SIGABRT	No
SIGFPE	Yes
SIGILL	Yes
SIGQUIT	Yes
SIGSEGV	Yes
SIGBUS	Yes
SIGSYS	Yes
SIGTRAP	Yes
SIGXCPU	No
SIGXFSZ	No

Rationale

Implementation-defined actions, such as creation of a core file, may occur when the default action for the signal is to terminate the process abnormally with additional actions.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.4.3, SIG_DFL.

1.10 Sockets

1.10.1 Listen Queues

Question 29: What is the limit the implementation places on the length of a socket's listen queue?

Response

5

Rationale

The specification states that an implementation may limit the length of a socket's listen queue, and that this limit may be imposed if the setting of the backlog argument exceeds an implementation-defined maximum value.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, listen().

1.10.2 Address Families, Socket Types, and Protocols

Question 30: What combinations of address family, socket types, and protocols does the implementation support?

Response

Address Family	Protocol	Socket Type	Supported?
AF_UNIX	N/A	STREAM	Yes
AF_UNIX	N/A	SEQPACKET	No
AF_UNIX	N/A	DGRAM	No
AF_INET	TCP	STREAM	Yes
AF_INET	UDP	DGRAM	Yes
AF_INET6	TCP	STREAM	Yes
AF_INET6	UDP	DGRAM	Yes

Rationale

The specification states that the domains, socket types and protocols supported by a conforming system are implementation-defined. The Internationalized System Calls and Libraries Extended V4 Product Standard states that conforming products shall be available in configurations that support at least following socket domains:

• AF_INET, with at least SOCK_STREAM and SOCK_DGRAM socket types
• AF_UNIX, with at least the SOCK_STREAM socket type.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.10, Sockets.

Product Standard, Internationalized System Calls and Libraries Extended V4.

1.10.3 Socket Types

Question 31: What socket types does the implementation support?

Response

SOCK_RAW, SOCK_STREAM, SOCK_SEQPACKET, SOCK_DGRAM

Rationale

The specification states that there are four socket types defined - SOCK_RAW, SOCK_STREAM, SOCK_SEQPACKET and SOCK_DGRAM - but does not state which are required. Implementations may also support additional socket types.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.10.6, Socket Types.

1.11 Threads

1.11.1 Cancellation Points

Question 32: Which functions have cancellation points that occur when a thread is executing?

Response

Function	Cancellation Point?
access()	No
asctime_r()	No
catclose()	No
catopen()	No
chmod()	No
chown()	No
closedir()	No
closelog()	No
ctermid()	No
ctime_r()	No
dlclose()	No
dlopen()	No
dprintf()	No
endhostent()	No
endnetent()	No
endprotoent()	No
endservent()	No
faccessat()	No
fchmod()	No
fchmodat()	No
fchown()	No
fchownat()	No
fclose()	No
fcntl()	No
fflush()	No
fgetc()	No
fgetpos()	No
fgets()	No
fgetwc()	No
fgetws()	No
fmtmsg()	No
fopen()	No
fpathconf()	No
fprintf()	No
fputc()	No
fputs()	No
fputwc()	No
fputws()	No
fread()	No
freopen()	No
fscanf()	No
fseek()	No
fseeko()	No
fsetpos()	No
fstat()	No
fstatat()	No
ftell()	No
ftello()	No
futimens()	No
fwprintf()	No
fwrite()	No
fwscanf()	No
getaddrinfo()	No
getc()	No
getc_unlocked()	No
getchar()	No
getchar_unlocked()	No
getcwd()	No
getdelim()	No
getgrgid_r()	No
getgrnam_r()	No
gethostid()	No
gethostname()	No
getline()	No
getlogin_r()	No
getnameinfo()	No
getpwnam_r()	No
getpwuid_r()	No
gets()	No
getwc()	No
getwchar()	No
glob()	No
iconv_close()	No
iconv_open()	No
ioctl()	No
link()	No
linkat()	No
lio_listio()	No
localtime_r()	No
lockf()	No
lseek()	No
lstat()	No
mkdir()	No
mkdirat()	No
mkdtemp()	No
mkfifo()	No
mkfifoat()	No
mknod()	No
mknodat()	No
mkstemp()	No
mktime()	No
opendir()	No
openlog()	No
pathconf()	No
perror()	No
popen()	No
posix_fadvise()	No
posix_fallocate()	No
posix_madvise()	No
posix_openpt()	No
posix_spawn()	No
posix_spawnp()	No
posix_typed_mem_open()	No
printf()	No
psiginfo()	No
psignal()	No
pthread_rwlock_rdlock()	No
pthread_rwlock_timedrdlock()	No
pthread_rwlock_timedwrlock()	No
pthread_rwlock_wrlock()	No
putc()	No
putc_unlocked()	No
putchar()	No
putchar_unlocked()	No
puts()	No
putwc()	No
putwchar()	No
readdir_r()	No
readlink()	No
readlinkat()	No
remove()	No
rename()	No
renameat()	No
rewind()	No
rewinddir()	No
scandir()	No
scanf()	No
seekdir()	No
semop()	No
sethostent()	No
setnetent()	No
setprotoent()	No
setservent()	No
sigpause()	No
stat()	No
strerror_l()	No
strerror_r()	No
strftime()	No
strftime_l()	No
syslog()	No
tmpfile()	No
tmpnam()	No
ttyname_r()	No
tzset()	No
ungetc()	No
ungetwc()	No
unlink()	No
unlinkat()	No
utime()	No
utimensat()	No
utimes()	No
vdprintf()	No
vfprintf()	No
vfwprintf()	No
vprintf()	No
vwprintf()	No
wcsftime()	No
wordexp()	No
wprintf()	No
wscanf()	No

Rationale

System Interfaces, Issue 7 states that a cancellation point may occur for these functions.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.9.5.2, Cancellation Points.

1.12 C-language Compilation Environment

Question 33: What C-language compilation environments are provided?

Response

Programming Environment	Provided
The implementation provides a C-language compilation environment with 32-bit int, long, pointer and off_t types.	Yes
The implementation provides a C-language compilation environment with 32-bit int, long and pointer types and an off_t type using at least 64 bits.	Yes
The implementation provides a C-language compilation environment with 32-bit int, and 64-bit long, pointer and off_t types.	Yes
The implementation provides a C-language compilation environment with int using at least 32-bits, and long, pointer and off_t types using at least 64 bits.	Yes

Rationale

Base Definitions, Issue 7 defines these scenarios as possible C-language compilation environment offerings.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <unistd.h>.

Question 34: What execution environments are provided on the system under test?

Response

Execution Environment	Provided
The implementation provides an execution environment with 32-bit int, long, pointer and off_t types.	Yes
The implementation provides an execution environment with 32-bit int, long and pointer types and an off_t type using at least 64 bits.	Yes
The implementation provides an execution environment with 32-bit int, and 64-bit long, pointer and off_t types.	No
The implementation provides an execution environment with int using at least 32-bits, and long, pointer and off_t types using at least 64 bits.	No

Rationale

Base Definitions, Issue 7 defines four scenarios as possible C-language compilation environment offerings but does not define which corresponding execution environments are supported.

Reference

Technical Standard, Base Definitions, Issue 7, Chapter 13, Headers, <unistd.h>.

1.13 Realtime

1.13.1 Prioritized I/O

Question 35: If the Realtime Option Group is supported, does the implementation support _POSIX_PRIORITIZED_IO?

Response

The system supports _POSIX_PRIORITIZED_IO for the following file types:

Regular files

Rationale

Support for _POSIX_PRIORITIZED_IO is optional.

Reference

Technical Standard, Base Definitions, Issue 7, Section 2.1.5.2, Realtime

1.13.2 Cancelable Asynchronous I/O Operations

Question 36: What asynchronous I/O operations are cancelable with aio_cancel()?

Response

I/O requests initiated by the following commands are cancel-able if the request has not been started: aio_read() aio_write() lio_listio() with the LIO_WAIT or LIO_NOWAIT mode (other modes are not cancel-able)

Rationale

The operations which are cancelable are implementation-defined.

Reference

Technical Standard, System Interfaces, Issue 7, Chapter 3, System Interfaces, aio_cancel().

1.14 Realtime Threads

1.14.1 Scheduling Policies

Question 37: If the Realtime Threads Option Group is supported, what scheduling policy is associated with SCHED_OTHER?

Response

Not Applicable.

Rationale

Base Definitions, Issue 7 states that conforming implementations must support a scheduling policy identified as SCHED_OTHER but define its effects as implementation-defined.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.8.4, Scheduling Policies.

1.14.2 Scheduling Contention Scope

Question 38: If the Realtime Threads Option Group is supported, what scheduling contention scopes are supported: PTHREAD_SCOPE_PROCESS, PTHREAD_SCOPE_SYSTEM, or both?

Response

Not applicable - the Realtime Threads Option Group is not supported.

Rationale

System Interfaces, Issue 7 states that conforming implementations will support PTHREAD_SCOPE_PROCESS, PTHREAD_SCOPE_SYSTEM, or both.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.9.4, Thread Scheduling Contention Scope.

1.14.3 Default Scheduling Contention Scope

Question 39: If the Realtime Threads Option Group is supported, what is the default scheduling contention scope when a process is created?

Response

Not applicable - the Realtime Threads Option Group is not supported.

Rationale

The specification defines the default scheduling contention scope as implementation-defined.

Reference

Technical Standard, System Interfaces, Issue 7, Section 2.9.4, Thread Scheduling Contention Scope.

2. Appendix

This appendix contains additional, explanatory material that was provided by the vendor.

Full response to Question 28: The AIX default socket listen queue length is 1024, the maximum is 32767, the value must be modified by using the "no -o somaxconn=5" command to set UNIX03 conforming length of 5.

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3. Change History

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