nptl(7) Miscellaneous Information Manual nptl(7) nptl - POSIX NPTL (Native POSIX Threads Library -- POSIX) GNU C, POSIX, Linux. NPTL NPTL makes internal use of the first two real-time signals (signal numbers 32 and 33). One of these signals is used to support thread cancelation and POSIX timers (see timer_create(2)); the other is used as part of a mechanism that ensures all threads in a process always have the same UIDs and GIDs, as required by POSIX. These signals cannot be used in applications. , NPTL, glibc : o SIGRTMIN 34 ( 32). o sigwaitinfo(2), sigtimedwait(2) sigwait(3) , . o sigprocmask(2) pthread_sigmask(3) . o sigaction(2), pthread_kill(3) pthread_sigqueue(3) EINVAL ( ), . o sigfillset(3) . NPTL Linux ( ID) . POSIX , POSIX . NPTL , , , , . , ( tgkill(2)) , . , , , . . , : setgid(2), setuid(2), setegid(2), seteuid(2), setregid(2), setreuid(2), setresgid(2), setresuid(2) setgroups(2). NPTL POSIX pthreads(7). POSIX , , (PTHREAD_PROCESS_SHARED) , . 64- x86 x86-64 i386, , 32- 64- x86-64. . credentials(7), pthreads(7), signal(7), standards(7) Alex Nik , Azamat Hackimov , Dmitry Bolkhovskikh , Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 31 2023 . nptl(7)