| .\" Copyright (C) 2004 Andries Brouwer (aeb@cwi.nl) |
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| .TH SIGPAUSE 3 2017-09-15 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| sigpause \- atomically release blocked signals and wait for interrupt |
| .SH SYNOPSIS |
| .nf |
| .B #include <signal.h> |
| .PP |
| .BI "int sigpause(int " sigmask "); /* BSD (but see NOTES) */" |
| .PP |
| .BI "int sigpause(int " sig "); /* System V / UNIX 95 */" |
| .fi |
| .SH DESCRIPTION |
| Don't use this function. |
| Use |
| .BR sigsuspend (2) |
| instead. |
| .PP |
| The function |
| .BR sigpause () |
| is designed to wait for some signal. |
| It changes the process's signal mask (set of blocked signals), |
| and then waits for a signal to arrive. |
| Upon arrival of a signal, the original signal mask is restored. |
| .SH RETURN VALUE |
| If |
| .BR sigpause () |
| returns, it was interrupted by a signal and the return value is \-1 |
| with |
| .I errno |
| set to |
| .BR EINTR . |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lb lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR sigpause () |
| T} Thread safety MT-Safe |
| .TE |
| .\" FIXME: The marking is different from that in the glibc manual, |
| .\" marking in glibc manual is more detailed: |
| .\" |
| .\" sigpause: MT-Unsafe race:sigprocmask/!bsd!linux |
| .\" |
| .\" glibc manual says /!linux!bsd indicate the preceding marker only applies |
| .\" when the underlying kernel is neither Linux nor a BSD kernel. |
| .\" So, it is safe in Linux kernel. |
| .SH CONFORMING TO |
| The System V version of |
| .BR sigpause () |
| is standardized in POSIX.1-2001. |
| It is also specified in POSIX.1-2008, where it is marked obsolete. |
| .SH NOTES |
| .SS History |
| The classical BSD version of this function appeared in 4.2BSD. |
| It sets the process's signal mask to |
| .IR sigmask . |
| UNIX 95 standardized the incompatible System V version of |
| this function, which removes only the specified signal |
| .I sig |
| from the process's signal mask. |
| .\" __xpg_sigpause: UNIX 95, spec 1170, SVID, SVr4, XPG |
| The unfortunate situation with two incompatible functions with the |
| same name was solved by the |
| .BR \%sigsuspend (2) |
| function, that takes a |
| .I "sigset_t\ *" |
| argument (instead of an |
| .IR int ). |
| .SS Linux notes |
| On Linux, this routine is a system call only on the Sparc (sparc64) |
| architecture. |
| .PP |
| .\" Libc4 and libc5 know only about the BSD version. |
| .\" |
| Glibc uses the BSD version if the |
| .B _BSD_SOURCE |
| feature test macro is defined and none of |
| .BR _POSIX_SOURCE , |
| .BR _POSIX_C_SOURCE , |
| .BR _XOPEN_SOURCE , |
| .BR _GNU_SOURCE , |
| or |
| .B _SVID_SOURCE |
| is defined. |
| Otherwise, the System V version is used, |
| and feature test macros must be defined as follows to obtain the declaration: |
| .IP * 3 |
| Since glibc 2.26: |
| _XOPEN_SOURCE >= 500 |
| .\" || (_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) |
| .IP * |
| Glibc 2.25 and earlier: _XOPEN_SOURCE |
| .PP |
| Since glibc 2.19, only the System V version is exposed by |
| .IR <signal.h> ; |
| applications that formerly used the BSD |
| .BR sigpause () |
| should be amended to use |
| .BR sigsuspend (2). |
| .\" |
| .\" For the BSD version, one usually uses a zero |
| .\" .I sigmask |
| .\" to indicate that no signals are to be blocked. |
| .SH SEE ALSO |
| .BR kill (2), |
| .BR sigaction (2), |
| .BR sigprocmask (2), |
| .BR sigsuspend (2), |
| .BR sigblock (3), |
| .BR sigvec (3), |
| .BR feature_test_macros (7) |