diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
commit | 399644e47874bff147afb19c89228901ac39340e (patch) | |
tree | 1c4c0b733f4c16b5783b41bebb19194a9ef62ad1 /man3/sem_post.3 | |
parent | Initial commit. (diff) | |
download | manpages-ac8a94b90d5cf454cd6648203aaf1c44d642788f.tar.xz manpages-ac8a94b90d5cf454cd6648203aaf1c44d642788f.zip |
Adding upstream version 6.05.01.upstream/6.05.01
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man3/sem_post.3')
-rw-r--r-- | man3/sem_post.3 | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/man3/sem_post.3 b/man3/sem_post.3 new file mode 100644 index 0000000..5406484 --- /dev/null +++ b/man3/sem_post.3 @@ -0,0 +1,74 @@ +'\" t +.\" Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH sem_post 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +sem_post \- unlock a semaphore +.SH LIBRARY +POSIX threads library +.RI ( libpthread ", " \-lpthread ) +.SH SYNOPSIS +.nf +.B #include <semaphore.h> +.PP +.BI "int sem_post(sem_t *" sem ); +.fi +.SH DESCRIPTION +.BR sem_post () +increments (unlocks) the semaphore pointed to by +.IR sem . +If the semaphore's value consequently becomes greater than zero, +then another process or thread blocked in a +.BR sem_wait (3) +call will be woken up and proceed to lock the semaphore. +.SH RETURN VALUE +.BR sem_post () +returns 0 on success; +on error, the value of the semaphore is left unchanged, +\-1 is returned, and +.I errno +is set to indicate the error. +.SH ERRORS +.TP +.B EINVAL +.I sem +is not a valid semaphore. +.TP +.B EOVERFLOW +.\" Added in POSIX.1-2008 TC1 (Austin Interpretation 213) +The maximum allowable value for a semaphore would be exceeded. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR sem_post () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001. +.SH NOTES +.BR sem_post () +is async-signal-safe: +it may be safely called within a signal handler. +.SH EXAMPLES +See +.BR sem_wait (3) +and +.BR shm_open (3). +.SH SEE ALSO +.BR sem_getvalue (3), +.BR sem_wait (3), +.BR sem_overview (7), +.BR signal\-safety (7) |