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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
commit | 399644e47874bff147afb19c89228901ac39340e (patch) | |
tree | 1c4c0b733f4c16b5783b41bebb19194a9ef62ad1 /man2/sigsuspend.2 | |
parent | Initial commit. (diff) | |
download | manpages-399644e47874bff147afb19c89228901ac39340e.tar.xz manpages-399644e47874bff147afb19c89228901ac39340e.zip |
Adding upstream version 6.05.01.upstream/6.05.01
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man2/sigsuspend.2')
-rw-r--r-- | man2/sigsuspend.2 | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/man2/sigsuspend.2 b/man2/sigsuspend.2 new file mode 100644 index 0000000..f89a6ca --- /dev/null +++ b/man2/sigsuspend.2 @@ -0,0 +1,131 @@ +.\" Copyright (c) 2005 Michael Kerrisk +.\" based on earlier work by faith@cs.unc.edu and +.\" Mike Battersby <mib@deakin.edu.au> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" 2005-09-15, mtk, Created new page by splitting off from sigaction.2 +.\" +.TH sigsuspend 2 2023-03-30 "Linux man-pages 6.05.01" +.SH NAME +sigsuspend, rt_sigsuspend \- wait for a signal +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <signal.h> +.PP +.BI "int sigsuspend(const sigset_t *" mask ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR sigsuspend (): +.nf + _POSIX_C_SOURCE +.fi +.SH DESCRIPTION +.BR sigsuspend () +temporarily replaces the signal mask of the calling thread with the +mask given by +.I mask +and then suspends the thread until delivery of a signal whose +action is to invoke a signal handler or to terminate a process. +.PP +If the signal terminates the process, then +.BR sigsuspend () +does not return. +If the signal is caught, then +.BR sigsuspend () +returns after the signal handler returns, +and the signal mask is restored to the state before the call to +.BR sigsuspend (). +.PP +It is not possible to block +.B SIGKILL +or +.BR SIGSTOP ; +specifying these signals in +.IR mask , +has no effect on the thread's signal mask. +.SH RETURN VALUE +.BR sigsuspend () +always returns \-1, with +.I errno +set to indicate the error (normally, +.BR EINTR ). +.SH ERRORS +.TP +.B EFAULT +.I mask +points to memory which is not a valid part of the process address space. +.TP +.B EINTR +The call was interrupted by a signal; +.BR signal (7). +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001. +.SS C library/kernel differences +The original Linux system call was named +.BR sigsuspend (). +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_sigsuspend (), +was added to support an enlarged +.I sigset_t +type. +The new system call takes a second argument, +.IR "size_t sigsetsize" , +which specifies the size in bytes of the signal set in +.IR mask . +This argument is currently required to have the value +.I sizeof(sigset_t) +(or the error +.B EINVAL +results). +The glibc +.BR sigsuspend () +wrapper function hides these details from us, transparently calling +.BR rt_sigsuspend () +when the kernel provides it. +.\" +.SH NOTES +Normally, +.BR sigsuspend () +is used in conjunction with +.BR sigprocmask (2) +in order to prevent delivery of a signal during the execution of a +critical code section. +The caller first blocks the signals with +.BR sigprocmask (2). +When the critical code has completed, the caller then waits for the +signals by calling +.BR sigsuspend () +with the signal mask that was returned by +.BR sigprocmask (2) +(in the +.I oldset +argument). +.PP +See +.BR sigsetops (3) +for details on manipulating signal sets. +.SH SEE ALSO +.BR kill (2), +.BR pause (2), +.BR sigaction (2), +.BR signal (2), +.BR sigprocmask (2), +.BR sigwaitinfo (2), +.BR sigsetops (3), +.BR sigwait (3), +.BR signal (7) |