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Diffstat (limited to 'man2/sigwaitinfo.2')
| -rw-r--r-- | man2/sigwaitinfo.2 | 90 |
1 files changed, 46 insertions, 44 deletions
diff --git a/man2/sigwaitinfo.2 b/man2/sigwaitinfo.2 index 42209c1806..fb797e8036 100644 --- a/man2/sigwaitinfo.2 +++ b/man2/sigwaitinfo.2 @@ -110,8 +110,53 @@ The wait was interrupted by a signal handler; see .B EINVAL .I timeout was invalid. +.SH VERSIONS +.SS C library/kernel differences +On Linux, +.BR sigwaitinfo () +is a library function implemented on top of +.BR sigtimedwait (). +.PP +The glibc wrapper functions for +.BR sigwaitinfo () +and +.BR sigtimedwait () +silently ignore attempts to wait for the two real-time signals that +are used internally by the NPTL threading implementation. +See +.BR nptl (7) +for details. +.PP +The original Linux system call was named +.BR sigtimedwait (). +However, with the addition of real-time signals in Linux 2.2, +the fixed-size, 32-bit +.I sigset_t +type supported by that system call was no longer fit for purpose. +Consequently, a new system call, +.BR rt_sigtimedwait (), +was added to support an enlarged +.I sigset_t +type. +The new system call takes a fourth argument, +.IR "size_t sigsetsize" , +which specifies the size in bytes of the signal set in +.IR set . +This argument is currently required to have the value +.I sizeof(sigset_t) +(or the error +.B EINVAL +results). +The glibc +.BR sigtimedwait () +wrapper function hides these details from us, transparently calling +.BR rt_sigtimedwait () +when the kernel provides it. +.\" .SH STANDARDS -POSIX.1-2001, POSIX.1-2008. +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001. .SH NOTES In normal usage, the calling program blocks the signals in .I set @@ -171,49 +216,6 @@ unspecified, permitting the possibility that this has the same meaning as a call to .BR sigwaitinfo (), and indeed this is what is done on Linux. -.\" -.SS C library/kernel differences -On Linux, -.BR sigwaitinfo () -is a library function implemented on top of -.BR sigtimedwait (). -.PP -The glibc wrapper functions for -.BR sigwaitinfo () -and -.BR sigtimedwait () -silently ignore attempts to wait for the two real-time signals that -are used internally by the NPTL threading implementation. -See -.BR nptl (7) -for details. -.PP -The original Linux system call was named -.BR sigtimedwait (). -However, with the addition of real-time signals in Linux 2.2, -the fixed-size, 32-bit -.I sigset_t -type supported by that system call was no longer fit for purpose. -Consequently, a new system call, -.BR rt_sigtimedwait (), -was added to support an enlarged -.I sigset_t -type. -The new system call takes a fourth argument, -.IR "size_t sigsetsize" , -which specifies the size in bytes of the signal set in -.IR set . -This argument is currently required to have the value -.I sizeof(sigset_t) -(or the error -.B EINVAL -results). -The glibc -.BR sigtimedwait () -wrapper function hides these details from us, transparently calling -.BR rt_sigtimedwait () -when the kernel provides it. -.\" .SH SEE ALSO .BR kill (2), .BR sigaction (2), |