From b045529c40c83601909dca7b76a53498e9a70f33 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 10 Apr 2024 21:05:44 +0200 Subject: Adding upstream version 3.3.4. Signed-off-by: Daniel Baumann --- src/contrib/semaphore.h | 82 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 src/contrib/semaphore.h (limited to 'src/contrib/semaphore.h') diff --git a/src/contrib/semaphore.h b/src/contrib/semaphore.h new file mode 100644 index 0000000..5eadecf --- /dev/null +++ b/src/contrib/semaphore.h @@ -0,0 +1,82 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + */ + +#pragma once + +#include +#include + +typedef struct { + pthread_mutex_t mutex; + pthread_cond_t cond; +} knot_sem_nonposix_t; + +typedef struct { + int status; + union { + sem_t semaphore; + knot_sem_nonposix_t *status_lock; + }; +} knot_sem_t; + +/*! + * \brief Initialize semaphore by using POSIX sem_t if possible, custom value/mutex/cond structure otherwise. + */ +void knot_sem_init(knot_sem_t *sem, int value); + +/*! + * \brief Initialize semaphore, force using nonposix variant. + */ +void knot_sem_init_nonposix(knot_sem_t *sem, int value); + +/*! + * \brief Set semaphore value to specified value. + * \note This can be only used with nonposix semaphore. + */ +void knot_sem_reset(knot_sem_t *sem, int value); + +/*! + * \brief Lock the semaphore (decrement), block until it's non-negative. + */ +void knot_sem_wait(knot_sem_t *sem); + +/*! + * \brief Block until the semaphore could decrement, but keep the value unchanged. + * \note This can be only used with nonposix semaphore. + */ +void knot_sem_wait_post(knot_sem_t *sem); + +/*! + * \brief Force-lock the semaphore without blocking, it might get negative. + * \note This can be only used with nonposix semaphore. + */ +void knot_sem_get_ahead(knot_sem_t *sem); + +/*! + * \brief Lock the semaphore, abort() if it would block. + * \note This can be only used with nonposix semaphore. + */ +void knot_sem_get_assert(knot_sem_t *sem); + +/*! + * \brief Unlock the semaphore (increment). + */ +void knot_sem_post(knot_sem_t *sem); + +/*! + * \brief Uninitialize the semaphore. Calls knot_sem_wait once at the beginning. + */ +void knot_sem_destroy(knot_sem_t *sem); -- cgit v1.2.3