.sp 1
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008, SUSv2.
-.SH AVAILABILITY
+.PP
On POSIX systems on which these functions are available, the symbol
.B _POSIX_TIMERS
is defined in \fI<unistd.h>\fP to a value greater than 0.
storage space.
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008, 4.3BSD.
-.SH AVAILABILITY
+.PP
On POSIX systems on which
.BR fdatasync ()
is available,
.PP
.BR mlock2 ()
is Linux specific.
-.SH AVAILABILITY
+.PP
On POSIX systems on which
.BR mlock ()
and
POSIX.1-2001, POSIX.1-2008, SVr4, 4.4BSD.
.\" SVr4 documents additional error codes ENXIO and ENODEV.
.\" SUSv2 documents additional error codes EMFILE and EOVERFLOW.
-.SH AVAILABILITY
+.PP
On POSIX systems on which
.BR mmap (),
.BR msync (2),
.BR ENOMEM .
In Linux 2.4.19, this was changed to the POSIX value
.BR ENOMEM .
-.SH AVAILABILITY
+.PP
On POSIX systems on which
.BR msync ()
is available, both
that represent a large positive value, possibly positive infinity.
.SH CONFORMING TO
C99.
-.SH AVAILABILITY
+.PP
On a glibc system, the macro
.B HUGE_VAL
is always available.
.IR z .
.SH CONFORMING TO
These function names are reserved for future use in C99.
-.SH AVAILABILITY
+.PP
As at version 2.31, these functions are not provided in glibc.
.\" But reserved in NAMESPACE.
.SH SEE ALSO
close to zero will cause an overflow.
.SH CONFORMING TO
These function names are reserved for future use in C99.
-.SH AVAILABILITY
+.PP
Not yet in glibc, as at version 2.19.
.\" But reserved in NAMESPACE.
.SH SEE ALSO
.TE
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
-.SH AVAILABILITY
+.PP
These functions are available when
.B _POSIX_THREAD_SAFE_FUNCTIONS
is defined.