一、文档
在线参考：IEEE 1003.13-2003
免费下载Draft 版本（pdf）：IEEE Std. 1003.13
二、概念
1、POSIX标准
可移植操作系统接口（英语：Portable Operating System Interface，缩写为POSIX）是IEEE为要在各种UNIX操作系统上运行软件，而定义API的一系列互相关联的标准的总称。
目前广泛使用的 POSIX 标准是 1003.1 标准，全称为IEEE Std 1003.1（缩写写法为 POSIX.1）。
2、IEEE 1003.13
IEEE 1003.13是POSIX 针对嵌入式领域制定的标准【实时规范 (reatime profiles)】，该标准是由 IEEE Std 1003.1 筛选而来，因此是其子集。
POSIX 为了提供不同层级的RTOS能力，IEEE Std. 1003.13 定义了四个子集：
- Minimal：最小嵌入式子集规范 ------ PSE51
- Controller：工业控制器子集规范 ------ PSE52
- Dedicated：较大规模的嵌入式系统子集规范 ------ PSE53
- Multi-Purpose：具有实时性要求的大规模通用系统子集规范 ------ PSE54
3、规范划分
主要根据Module 和_POSIX_开头宏来进行细化
三、Module划分
1、Module划分表
|--------|------------------------|-----------|-----------|-----------|-----------|
| SN | Module | PSE51 | PSE52 | PSE53 | PSE54 |
| 1 | POSIX_C_LANG_JUMP | X | X | X | X |
| 2 | POSIX_C_LANG_MATH | - | X | X | X |
| 3 | POSIX_C_LANG_SUPPORT | X | X | X | X |
| 4 | POSIX_C_LANG_WIDE_CHAR | - | - | - | X |
| 5 | POSIX_DEVICE_IO | X | X | X | X |
| 6 | POSIX_DEVICE_SPECIFIC | - | - | - | X |
| 7 | POSIX_EVENT_MGMT | - | - | X | X |
| 8 | POSIX_FD_MGMT | - | X | X | X |
| 9 | POSIX_FIFO | - | - | - | X |
| 10 | POSIX_FILE_ATTRIBUTES | - | - | - | X |
| 11 | POSIX_FILE_LOCKING | X | X | X | X |
| 12 | POSIX_FILE_SYSTEM | - | X | X | X |
| 13 | POSIX_FILE_SYSTEM_EXT | - | - | - | X |
| 14 | POSIX_JOB_CONTROL | - | - | - | X |
| 15 | POSIX_MULTI_PROCESS | - | - | X | X |
| 16 | POSIX_NETWORKING | - | - | X | X |
| 17 | POSIX_PIPE | - | - | X | X |
| 18 | POSIX_PRIORITY_RANGES | X | X | X | X |
| 19 | POSIX_REGEXP | - | - | - | X |
| 20 | POSIX_SHELL_FUNC | - | - | - | X |
| 21 | POSIX_SIGNALS | X | X | X | X |
| 22 | POSIX_SIGNAL_JUMP | - | - | X | X |
| 23 | POSIX_SINGLE_PROCESS | X | X | X | X |
| 24 | POSIX_STRING_MATCHING | - | - | - | X |
| 25 | POSIX_SYMBOLIC_LINKS | - | - | - | X |
| 26 | POSIX_SYSTEM_DATABASE | - | - | - | X |
| 27 | POSIX_THREADS_BASE | X | X | X | X |
| 28 | POSIX_USER_GROUPS | - | - | - | X |
| 29 | POSIX_WIDE_CHAR_IO | - | - | - | X |
| 30 | XSI_DYNAMIC_LINKING | - | - | - | X |
| 31 | XSI_SYSTEM_LOGGING | - | - | - | X |
| 32 | XSI_THREAD_MUTEX_EXT | X | X | X | X |
| 33 | XSI_THREADS_EXT | X | X | X | X |
2、Module对应的Function表
|--------|-----------------------------|-------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| SN | Module | Profile | Function |
| 1 | POSIX_C_LANG_JUMP | PSE51 | longjmp(), setjmp() |
| 2 | POSIX_C_LANG_MATH （249） | PSE52 | acos(), acosf(), acosh(), acoshf(), acoshl(), acosl(), asin(), asinf(), asinh(), asinhf(), asinhl(), asinl(), atan(), atan2(), atan2f(), atan2l(), atanf(), atanh(), atanhf(), atanhl(), atanl(), cabs(), cabsf(), cabsl(), cacos(), cacosf(), cacosh(), cacoshf(), cacoshl(), cacosl(), carg(), cargf(), cargl(), casin(), casinf(), casinh(), casinhf(), casinhl(), casinl(), catan(), catanf(), catanh(), catanhf(), catanhl(), catanl(), cbrt(), cbrtf(), cbrtl(), ccos(), ccosf(), ccosh(), ccoshf(), ccoshl(), ccosl(), ceil(), ceilf(), ceill(), cexp(), cexpf(), cexpl(), cimag(), cimagf(), cimagl(), clog(), clogf(), clogl(), conj(), conjf(), conjl(), copysign(), copysignf(), copysignl(), cos(), cosf(), cosh(), coshf(), coshl(), cosl(), cpow(), cpowf(), cpowl(), cproj(), cprojf(), cprojl(), creal(), crealf(), creall(), csin(), csinf(), csinh(), csinhf(), csinhl(), csinl(), csqrt(), csqrtf(), csqrtl(), ctan(), ctanf(), ctanh(), ctanhf(), ctanhl(), ctanl(), erf(), erfc(), erfcf(), erfcl(), erff(), erfl(), exp(), exp2(), exp2f(), exp2l(), expf(), expl(), expm1(), expm1f(), expm1l(), fabs(), fabsf(), fabsl(), fdim(), fdimf(), fdiml(), floor(), floorf(), floorl(), fma(), fmaf(), fmal(), fmax(), fmaxf(), fmaxl(), fmin(), fminf(), fminl(), fmod(), fmodf(), fmodl(), fpclassify(), frexp(), frexpf(), frexpl(), hypot(), hypotf(), hypotl(), ilogb(), ilogbf(), ilogbl(), isfinite(), isgreater(), isgreaterequal(), isinf(), isless(), islessequal(), islessgreater(), isnan(), isnormal(), isunordered(), ldexp(), ldexpf(), ldexpl(), lgamma(), lgammaf(), lgammal(), llrint(), llrintf(), llrintl(), llround(), llroundf(), llroundl(), log(), log10(), log10f(), log10l(), log1p(), log1pf(), log1pl(), log2(), log2f(), log2l(), logb(), logbf(), logbl(), logf(), logl(), lrint(), lrintf(), lrintl(), lround(), lroundf(), lroundl(), modf(), modff(), modfl(), nan(), nanf(), nanl(), nearbyint(), nearbyintf(), nearbyintl(), nextafter(), nextafterf(), nextafterl(), nexttoward(), nexttowardf(), nexttowardl(), pow(), powf(), powl(), remainder(), remainderf(), remainderl(), remquo(), remquof(), remquol(), rint(), rintf(), rintl(), round(), roundf(), roundl(), scalbln(), scalblnf(), scalblnl(), scalbn(), scalbnf(), scalbnl(), signbit(), sin(), sinf(), sinh(), sinhf(), sinhl(), sinl(), sqrt(), sqrtf(), sqrtl(), tan(), tanf(), tanh(), tanhf(), tanhl(),tanl(), tgamma(), tgammaf(),tgammal(), trunc(), truncf(), truncl() |
| 3 | POSIX_C_LANG_SUPPORT （105） | PSE51 | abs(), asctime(), asctime_r(), atof(), atoi(), atol(), atoll(), bsearch(), calloc(), ctime(), ctime_r(), difftime(), div(), feclearexcept(), fegetenv(), fegetexceptflag(), fegetround(), feholdexcept(), feraiseexcept(), fesetenv(), fesetexceptflag(), fesetround(), fetestexcept(), feupdateenv(), free(), gmtime(), gmtime_r(), imaxabs(), imaxdiv(), isalnum(), isalpha(), isblank(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(), isxdigit(), labs(), ldiv(), llabs(), lldiv(), localeconv(), localtime(), localtime_r(), malloc(), memchr(), memcmp(), memcpy(), memmove(), memset(), mktime(), qsort(), rand(), rand_r(), realloc(), setlocale(), snprintf(), sprintf(), srand(), sscanf(), strcat(), strchr(), strcmp(), strcoll(), strcpy(), strcspn(), strerror(), strerror_r(), strftime(), strlen(), strncat(), strncmp(), strncpy(), strpbrk(), strrchr(), strspn(), strstr(), strtod(), strtof(), strtoimax(), strtok(), strtok_r(), strtol(), strtold(), strtoll(), strtoul(), strtoull(), strtoumax(), strxfrm(), time(), tolower(), toupper(), tzname, tzset(), va_arg(), va_copy(), va_end(), va_start(), vsnprintf(), vsprintf(), vsscanf() |
| 4 | POSIX_C_LANG_WIDE_CHAR （66） | PSE54 | btowc(), iswalnum(), iswalpha(), iswblank(), iswcntrl(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), mblen(), mbrlen(), mbrtowc(), mbsinit(), mbsrtowcs(), mbstowcs(), mbtowc(), swprintf(), swscanf(), towctrans(), towlower(), towupper(), vswprintf(), vswscanf(), wcrtomb(), wcscat(), wcschr(), wcscmp(), wcscoll(), wcscpy(), wcscspn(), wcsftime(), wcslen(), wcsncat(), wcsncmp(), wcsncpy(), wcspbrk(), wcsrchr(), wcsrtombs(), wcsspn(), wcsstr(), wcstod(), wcstof(), wcstoimax(), wcstok(), wcstol(), wcstold(), wcstoll(), wcstombs(), wcstoul(), wcstoull(), wcstoumax(), wcsxfrm(), wctob(), wctomb(), wctrans(), wctype(), wmemchr(), wmemcmp(), wmemcpy(), wmemmove(), wmemset() |
| 5 | POSIX_DEVICE_IO （40） | PSE51 | clearerr(), close(), fclose(), fdopen(), feof (), ferror(), fflush (), fgetc(), fgets(), fileno(), fopen(), fprintf(), fputc(), fputs(), fread(), freopen(), fscanf(), fwrite(), getc(), getchar(), gets(), open(), perror(), printf(), putc(), putchar(), puts(), read(), scanf(), setbuf(), setvbuf(), stderr(), stdin(), stdout(), ungetc(), vfprintf (), vfscanf(), vprintf(), vscanf(), write() |
| 6 | POSIX_DEVICE_SPECIFIC （14） | PSE54 | cfgetispeed(), cfgetospeed(), cfsetispeed(), cfsetospeed(), ctermid(), isatty(), tcdrain(), tcflow(), tcflush(), tcgetattr(), tcsendbreak(), tcsetattr(), ttyname(), ttyname_r() |
| 7 | POSIX_EVENT_MGMT | PSE53 | FD_CLR(), FD_ISSET(), FD_SET(), FD_ZERO(), pselect(), select() |
| 8 | POSIX_FD_MGMT | PSE52 | dup(), dup2(), fcntl(), fgetpos(), fseek(), fseeko(), fsetpos(), ftell(), ftello(), ftruncate(), lseek(), rewind() |
| 9 | POSIX_FIFO | PSE54 | mkfifo() |
| 10 | POSIX_FILE_ATTRIBUTES | PSE54 | chmod(), chown(), fchmod(), fchown(), umask() |
| 11 | POSIX_FILE_LOCKING | PSE51 | flockfile(), ftrylockfile(), funlockfile(), getc_unlocked(), getchar_unlocked(), putc_unlocked(), putchar_unlocked() |
| 12 | POSIX_FILE_SYSTEM | PSE52 | access(), chdir(), closedir(), creat(), fpathconf(), fstat(), getcwd(), link(), mkdir(), opendir(), pathconf(), readdir(), readdir_r(), remove(), rename(), rewinddir(), rmdir(), stat(), tmpfile(), tmpnam(), unlink(), utime() |
| 13 | POSIX_FILE_SYSTEM_EXT | PSE54 | glob(), globfree() |
| 14 | POSIX_JOB_CONTROL | PSE54 | setpgid(), tcgetpgrp(), tcsetpgrp() |
| 15 | POSIX_MULTI_PROCESS | PSE53 | _Exit(), _exit(), assert(), atexit(), clock(), execl(), execle(), execlp(), execv(), execve(), execvp(), exit(), fork(), getpgrp(), getpid(), getppid(), setsid(), sleep(), times(), wait(), waitpid() |
| 16 | POSIX_NETWORKING | PSE53 | accept(), bind(), connect(), endhostent(), endnetent(), endprotoent(), endservent(), freeaddrinfo(), gai_strerror(), getaddrinfo(), gethostbyaddr(), gethostbyname(), gethostent(), gethostname(), getnameinfo(), getnetbyaddr(), getnetbyname(), getnetent(), getpeername(), getprotobyname(), getprotobynumber(), getprotoent(), getservbyname(), getservbyport(), getservent(), getsockname(), getsockopt(), htonl(), htons(), if_freenameindex(), if_indextoname(), if_nameindex(), if_nametoindex(), inet_addr(), inet_ntoa(), inet_ntop(), inet_pton(), listen(), ntohl(), ntohs(), recv(), recvfrom(), recvmsg(), send(), sendmsg(), sendto(), sethostent(), setnetent(), setprotoent(), setservent(), setsockopt(), shutdown(), socket(), sockatmark(), socketpair() |
| 17 | POSIX_PIPE | PSE53 | pipe() |
| 18 | POSIX_PRIORITY_RANGES | PSE51 | sched_get_priority_max(), sched_get_priority_min(), sched_rr_get_interval() |
| 19 | POSIX_REGEXP | PSE54 | regcomp(), regerror(), regexec(), regfree() |
| 20 | POSIX_SHELL_FUNC | PSE54 | pclose(), popen(), system(), wordexp(), wordfree() |
| 21 | POSIX_SIGNALS | PSE51 | abort(), alarm(), kill(), pause(), raise(), sigaction(), sigaddset(), sigdelset(), sigemptyset(), sigfillset(), sigismember(), signal(), sigpending(), sigprocmask(), sigsuspend(), sigwait() |
| 22 | POSIX_SIGNAL_JUMP | PSE53 | siglongjmp(), sigsetjmp() |
| 23 | POSIX_SINGLE_PROCESS | PSE51 | confstr(), getenv(), setenv(), sysconf(), uname(), unsetenv() |
| 24 | POSIX_STRING_MATCHING | PSE54 | fnmatch(), getopt() |
| 25 | POSIX_SYMBOLIC_LINKS | PSE54 | lstat(), readlink(), symlink() |
| 26 | POSIX_SYSTEM_DATABASE | PSE54 | getgrgid(), getgrgid_r(), getgrnam(), getgrnam_r(), getpwnam(), getpwnam_r(), getpwuid(), getpwuid_r() |
| 27 | POSIX_THREADS_BASE | PSE51 | pthread_atfork(), pthread_attr_destroy(), pthread_attr_getdetachstate(), pthread_attr_getschedparam(), pthread_attr_init(), pthread_attr_setdetachstate(), pthread_attr_setschedparam(), pthread_cancel(), pthread_cleanup_pop(), pthread_cleanup_push(), pthread_cond_broadcast(), pthread_cond_destroy(), pthread_cond_init(), pthread_cond_signal(), pthread_cond_timedwait(), pthread_cond_wait(), pthread_condattr_destroy(), pthread_condattr_init(), pthread_create(), pthread_detach(), pthread_equal(), pthread_exit(), pthread_getspecific(), pthread_join(), pthread_key_create(), pthread_key_delete(), pthread_kill(), pthread_mutex_destroy(), pthread_mutex_init(), pthread_mutex_lock(), pthread_mutex_trylock(), pthread_mutex_unlock(), pthread_mutexattr_destroy(), pthread_mutexattr_init(), pthread_once(), pthread_self(), pthread_setcalcelstate(), pthread_setcanceltype(), pthread_setspecific(), pthread_sigmask(), pthread_testcancel() |
| 28 | POSIX_USER_GROUPS | PSE54 | getegid(), geteuid(), getgid(), getgroups(), getlogin(), getlogin_r(), getuid(), setegid(), seteuid, setgid(), setuid() |
| 29 | POSIX_WIDE_CHAR_IO | PSE54 | fgetwc(), fgetws(), fputwc(), fputws(), fwide(), fwprintf(), fwscanf(), getwc(), getwchar(), putwc(), putwchar(), ungetwc(), vfwprintf(), vfwscanf(), vwprintf(), vwscanf(), wprintf(), wscanf() |
| 30 | XSI_DYNAMIC_LINKING | PSE54 | dlclose(), dlerror(), dlopen(), dlsym() |
| 31 | XSI_SYSTEM_LOGGING | PSE54 | closelog(), openlog(), setlogmask(), syslog() |
| 32 | XSI_THREAD_MUTEX_EXT | PSE51 | pthread_mutexattr_gettype(), pthread_mutexattr_settype() |
| 33 | XSI_THREADS_EXT | PSE51 | pthread_attr_getguardsize(), pthread_attr_getstack(), pthread_attr_setguardsize(), pthread_attr_setstack(), pthread_getconcurrency(), pthread_setconcurrency() |
四、_POSIX_开头宏划分
1、_POSIX_开头宏划分表
|--------|-----------------------------------|-----------|-----------|-----------|-----------|
| SN | _POSIX_宏 | PSE51 | PSE52 | PSE53 | PSE54 |
| 1 | _POSIX_ADVISORY_INFO | - | - | - | X |
| 2 | _POSIX_ASYNCHRONOUS_IO | - | - | X | X |
| 3 | _POSIX_CLOCK_SELECTION | X | X | X | X |
| 4 | _POSIX_CPUTIME | - | - | X | X |
| 5 | _POSIX_FSYNC | X | X | X | X |
| 6 | _POSIX_MAPPED_FILES | - | X | X | X |
| 7 | _POSIX_MEMLOCK | X | X | X | X |
| 8 | _POSIX_MEMLOCK_RANGE | X | X | X | X |
| 9 | _POSIX_MEMORY_PROTECTION | - | - | X | X |
| 10 | _POSIX_MESSAGE_PASSING | - | X | X | X |
| 11 | _POSIX_PRIORITY_SCHEDULING | - | - | X | X |
| 12 | _POSIX_REALTIME_SIGNALS | X | X | X | X |
| 13 | _POSIX_SEMAPHORES | X | X | X | X |
| 14 | _POSIX_SHARED_MEMORY_OBJECTS | X | X | X | X |
| 15 | _POSIX_SPAWN | - | - | X | X |
| 16 | _POSIX_SYNCHRONIZED_IO | X | X | X | X |
| 17 | _POSIX_THREAD_ATTR_STACKADDR | X | X | X | X |
| 18 | _POSIX_THREAD_ATTR_STACKSIZE | X | X | X | X |
| 19 | _POSIX_THREAD_CPUTIME | X | X | X | X |
| 20 | _POSIX_THREAD_PRIO_INHERIT | X | X | X | X |
| 21 | _POSIX_THREAD_PRIO_PROTECT | X | X | X | X |
| 22 | _POSIX_THREAD_PRIORITY_SCHEDULING | X | X | X | X |
| 23 | _POSIX_THREAD_PROCESS_SHARED | - | - | X | X |
| 24 | _POSIX_TIMEOUTS | X | X | X | X |
| 25 | _POSIX_TIMERS | X | X | X | X |
| 26 | _POSIX_TRACE | - | X | X | X |
| 27 | _POSIX_TRACE_EVENT_FILTER | - | X | X | X |
| 28 | _POSIX_TRACE_LOG | - | X | X | X |
2、_POSIX_开头宏应的Function表
|--------|---------------------------------------------------------------------------------------|-------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| SN | POSIX | Profile | Function | 备注 |
| 1 | _POSIX_ADVISORY_INFO | PSE54 | posix_fadvise(), posix_fallocate(), posix_memalign() | |
| 2 | POSIX ADVISORY_INFO and either _POSIX_MAPPED_FILES or POSIX_SHARED MEMORY_OBJECTS | PSE54 | posix_madvise() | _POSIX_ADVISORY_INFO（PSE54） _POSIX_MAPPED_FILES（PSE52） _POSIX_SHARED_MEMORY _OBJECTS（PSE51） |
| 3 | _POSIX _ASYNCHRONOUS_IO | PSE53 | aio_cancel(),aio_error(),aio_fsync(), aio_read(),aio_return(), aio_suspend(), aio_write(), lio_listio() | |
| 4 | POSIX CLOCK_SELECTION | PSE51 | clock_nanosleep() | |
| 5 | POSIX CLOCK_SELECTION and _POSIX_THREADS | PSE51 | pthread_condattr_getclock(), pthread_condattr_setclock() | _POSIX_THREADS同 = POSIX_THREADS_BASE（支持） + _POSIX_READER_WRITER_LOCKS （不支持) |
| 6 | _POSIX_CPUTIME | PSE53 | clock_getcpuclokid() | |
| 7 | _POSIX_FSYNC | PSE51 | fsync() | |
| 8 | _POSIX_MAPPED_FILES and POSIX SYNCHRONIZED_IO | PSE52 | msync() | _POSIX_MAPPED_FILES（PSE52） _POSIX_SYNCHRONIZED_IO（PSE51） |
| 9 | _POSIX_MEMLOCK | PSE51 | mlockall(), munlockall() | |
| 10 | POSIX MEMLOCK_RANGE | PSE51 | mlock(), munlock() | |
| 11 | _POSIX_MEMORY _PROTECTION | PSE53 | mprotect() | |
| 12 | POSIX MESSAGE_PASSING | PSE52 | mq_close(), mq_getattr(), mq_notify(), mq_open(), mq_receive(), mq_send(), mq_setattr(), mq_unlink() | |
| 13 | POSIX MESSAGE_PASSING and _POSIX_TIMEOUTS | PSE52 | mq_timedreceive(), mq_timedsend() | _POSIX_MESSAGE_PASSING（PSE52） _POSIX_TIMEOUTS（PSE51） |
| 14 | _POSIX_PRIORITY _SCHEDULING | PSE53 | sched_get_priority_max(), sched_get_priority_min(), sched_getparam(), sched_getscheduler(), sched_rr_get_interval(), sched_setparam(), sched_setscheduler(), sched_yield() | _POSIX_THREAD_PRIORITY _SCHEDULING and _POSIX_THREADS里面也包含（PSE51） 下面3个sched_get_priority_max(), sched_get_priority_min(), sched_rr_get_interval() |
| 15 | _POSIX_REALTIME _SIGNALS | PSE51 | sigqueue(), sigtimedwait(), sigwaitinfo() | |
| 16 | _POSIX_SEMAPHORES | PSE51 | sem_close(), sem_destroy(), sem_getvalue(), sem_init(), sem_open(), sem_post(), sem_trywait(), sem_wait(), sem_unlink() | |
| 17 | _POSIX_SEMAPHORES and _POSIX_TIMEOUTS | PSE51 | sem_timedwait() | _POSIX_SEMAPHORES（PSE51） _POSIX_TIMEOUTS（PSE51） |
| 18 | POSIX_SHARED MEMORY_OBJECTS | PSE51 | shm_open(), shm_unlink() | |
| 19 | POSIX_SHARED MEMORY_OBJECTS or _POSIX_MAPPED_FILES | PSE51 | mmap(), munmap() | _POSIX_SHARED_MEMORY _OBJECTS（PSE51） _POSIX_MAPPED_FILES（PSE52） |
| 20 | _POSIX_SPAWN | PSE53 | posix_spawn(), posix_spawn_file _actions_addclose(), posix_spawn_file _actions_adddup2(), posix_spawn_file _actions_addopen(), posix_spawn_file _actions_destroy(), posix_spawn_file_actions_init(), posix_spawnattr_destroy(), posix_spawnattr_getflags(), posix_spawnattr_getpgroup(), posix_spawnattr_getsigdefault(), posix_spawnattr_getsigmask(), posix_spawnattr_init(), posix_spawnattr_setflags(), posix_spawnattr_setpgroup(), posix_spawnattr_setsigdefault(), posix_spawnattr_setsigmask(), posix_spawnp() | |
| 21 | _POSIX_SPAWN and _POSIX_PRIORITY _SCHEDULING | PSE53 | posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam(), posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy() | _POSIX_PRIORITY_SCHEDULING （PSE53） _POSIX_SPAWN（PSE53） |
| 22 | POSIX SYNCHRONIZED_IO | PSE51 | fdatasync() | |
| 23 | POSIX_THREAD ATTR_STACKADDR and _POSIX_THREADS | PSE51 | pthread_attr_getstackaddr(), pthread_attr_setstackaddr() | POSIX_THREAD_ATTR STACKADDR（PSE51） |
| 24 | POSIX_THREAD ATTR_STACKADDR, _POSIX_THREADS and POSIX_THREAD ATTR_STACKSIZE | PSE51 | pthread_attr_getstack(), pthread_attr_setstack() | _POSIX_THREAD_ATTR _STACKADDR（PSE51）_POSIX_THREAD_ATTR _STACKSIZE（PSE51） 【XSI_THREADS_EXT中也有pthread_attr_getstack(), pthread_attr_setstack()】 |
| 25 | POSIX_THREAD ATTR_STACKSIZE and _POSIX_THREADS | PSE51 | pthread_attr_getstacksize(), pthread_attr_setstacksize() | _POSIX_THREAD_ATTR_STACKSIZE（PSE51） |
| 26 | POSIX THREAD_CPUTIME and _POSIX_THREADS | PSE51 | pthread_getcpuclockid() | _POSIX_THREAD_CPUTIME（PSE51） |
| 27 | _POSIX_THREAD _PRIO_INHERIT and _POSIX_THREADS | PSE51 | pthread_mutexattr_getprotocol(), pthread_mutexattr_setprotocol() | _POSIX_THREAD_PRIO_INHERIT（PSE51） 【这两个函数同_POSIX_THREAD_PRIO_PROTECT and _POSIX_THREADS】 |
| 28 | POSIX_THREAD PRIO_PROTECT and _POSIX_THREADS | PSE51 | pthread_mutex_getprioceiling(), pthread_mutex_setprioceiling(), pthread_mutexattr_getprioceiling(), pthread_mutexattr_getprotocol(), pthread_mutexattr_setprioceiling(), pthread_mutexattr_setprotocol() | _POSIX_THREAD_PRIO_PROTECT（PSE51） 【_POSIX_THREAD_PRIO_INHERIT and _POSIX_THREADS里面也有pthread_mutexattr_getprotocol(), pthread_mutexattr_setprotocol()】 |
| 29 | _POSIX_THREAD _PRIORITY_SCHEDULING and _POSIX_THREADS | PSE51 | pthread_attr_getinheritsched(), pthread_attr_getschedpolicy(), pthread_attr_getscope(), pthread_attr_setinheritsched(), pthread_attr_setschedpolicy(), pthread_attr_setscope(), pthread_getschedparam(), pthread_setschedparam(), pthread_setschedprio(), sched_get_priority_max(), sched_get_priority_min(), sched_rr_get_interval() | _POSIX_THREAD_PRIORITY _SCHEDULING（PSE51） 【POSIX_PRIORITY SCHEDULING里面也包含（PSE53） 下面3个sched_get_priority_max(), sched_get_priority_min(), sched_rr_get_interval()】 |
| 30 | _POSIX_THREAD _PROCESS_SHARED and _POSIX_THREADS | PSE53 | pthread_condattr_getpshared(), pthread_condattr_setpshared(), pthread_mutexattr_getpshared(), pthread_mutexattr_setpshared(), pthread_rwlockattr_getpshared(), pthread_rwlockattr_setpshared() | POSIX_THREAD PROCESS_SHARED（PSE51） _POSIX_THREADS = POSIX_THREADS_BASE（支持）+ _POSIX_READER_WRITER_LOCKS（不支持) 【pthread_rwlock*不支持】 |
| 31 | _POSIX_TIMEOUTS and _POSIX_THREADS | PSE51 | pthread_mutex_timedlock(), pthread_rwlock_timedrdlock(), pthread_rwlock_timedwrlock() | _POSIX_TIMEOUTS（PSE51） _POSIX_THREADS = POSIX_THREADS_BASE（支持）+ _POSIX_READER_WRITER_LOCKS（不支持) 【pthread_rwlock*不支持】 |
| 32 | _POSIX_TIMEOUTS and _POSIX_TRACE | PSE52 | posix_trace_timedgetnext_event() | _POSIX_TIMEOUTS（PSE51） _POSIX_TRACE（PSE52） |
| 33 | _POSIX_TIMERS | PSE51 | clock_getres(), clock_gettime(), clock_settime(), nanosleep(), timer_create(), timer_detele(), timer_getoverrun(), timer_gettime(), timer_settime() | |
| 34 | _POSIX_TRACE | PSE52 | posix_trace_attr_destroy(), posix_trace_attr_getclockres(), posix_trace_attr_getcreatetime(), posix_trace_attr_getgenversion(), posix_trace_attr_getname(), posix_trace_attr _getstreamfullpolicy(), posix_trace_attr_getmaxdatasize(), posix_trace_attr _getmaxsystemeventsize(), posix_trace_attr _getmaxusereventsize(), posix_trace_attr_getstreamsize(), posix_trace_attr_init(), posix_trace_attr_setname(), posix_trace_attr _setstreamfullpolicy(), posix_trace_attr_setmaxdatasize(), posix_trace_attr_setstreamsize(), posix_trace_clear(), posix_trace_create(), posix_trace_event(), posix_trace_eventid_open(), posix_trace_eventid_equal(), posix_trace_eventid_get_name(), posix_trace_eventtypelist _getnext_id(), posix_trace_eventtypelist_rewind(), posix_trace_get_attr(), posix_trace_get_status(), posix_trace_getnext_event(), posix_trace_shutdown(), posix_trace_start(), posix_trace_stop(), posix_trace_trygetnext_event() | |
| 35 | _POSIX_TRACE and _POSIX_TRACE_LOG | PSE52 | posix_trace_attr_getlogfullpolicy(), posix_trace_attr_getlogsize(), posix_trace_attr_setlogfullpolicy(), posix_trace_attr_setlogsize(), posix_trace_close(), posix_trace_open(), posix_trace_rewind(), posix_trace_create_withlog(), posix_trace_flush() | _POSIX_TRACE（PSE52） _POSIX_TRACE_LOG（PSE52） |
| 36 | _POSIX_TRACE and _POSIX_TRACE _EVENT_FILTER | PSE52 | posix_trace_eventset_add(), posix_trace_eventset_del(), posix_trace_eventset_empty(), posix_trace_eventset_fill(), posix_trace_eventset_ismember(), posix_trace_get_filter(), posix_trace_set_filter(), posix_trace_trid_eventid_open() | _POSIX_TRAC（PSE52） _POSIX_TRACE_EVENT_FILTER（PSE52） |