atomic_queue.h

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#pragma once
/*
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: bd00b1f00a94ca7a476aa84c001b28a19c8a90fe $
 *
 * @file io/atomic_queue.h
 * @brief Thread-safe queues.
 *
 * @copyright 2016 Alan DeKok (aland@freeradius.org)
 */
RCSIDH(atomic_queue_h, "$Id: bd00b1f00a94ca7a476aa84c001b28a19c8a90fe $")
 
 
#ifdef HAVE_STDATOMIC_H
#  include <stdatomic.h>
#else
#  include <freeradius-devel/util/stdatomic.h>
#endif
#include <freeradius-devel/util/talloc.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
typedef struct fr_atomic_queue_s fr_atomic_queue_t;
 
fr_atomic_queue_t       *fr_atomic_queue_talloc(TALLOC_CTX *ctx, size_t num, size_t elem_len);
fr_atomic_queue_t       *fr_atomic_queue_malloc(TALLOC_CTX *ctx, size_t num, size_t elem_len);
fr_atomic_queue_t       *fr_atomic_queue_mmap(TALLOC_CTX *ctx, int *fd, size_t num,
                                              size_t elem_len) CC_HINT(nonnull(2));
void                    fr_atomic_queue_free(fr_atomic_queue_t **aq);
 
bool                    fr_atomic_queue_mpmc_push(fr_atomic_queue_t *aq, void const *data) CC_HINT(nonnull);
bool                    fr_atomic_queue_mpmc_pop(fr_atomic_queue_t *aq, void *data) CC_HINT(nonnull);
 
bool                    fr_atomic_queue_spsc_push(fr_atomic_queue_t *aq, void const *data) CC_HINT(nonnull);
bool                    fr_atomic_queue_spsc_pop(fr_atomic_queue_t *aq, void *data) CC_HINT(nonnull);
size_t                  fr_atomic_queue_size(fr_atomic_queue_t *aq);
 
/** Unbounded segmented single-producer / single-consumer queue
 *
 * Internally a linked list of fixed-size `fr_atomic_queue_t` segments.
 * When the producer's current segment fills, a new segment is malloc'd
 * and linked in; the consumer drains segments in order and frees them
 * as it advances.  Allocation on the producer side uses raw malloc
 * (not talloc), so the producer thread is free to be one that cannot
 * safely use talloc (e.g. a library-owned callback thread).
 *
 * Exactly one producer and one consumer.  Not safe for MPMC use.
 */
typedef struct fr_atomic_ring_s fr_atomic_ring_t;
 
fr_atomic_ring_t        *fr_atomic_ring_alloc(TALLOC_CTX *ctx, size_t seg_size);
void                    fr_atomic_ring_free(fr_atomic_ring_t **ring);
bool                    fr_atomic_ring_push(fr_atomic_ring_t *ring, void *data);
bool                    fr_atomic_ring_pop(fr_atomic_ring_t *ring, void **p_data);
 
#ifdef WITH_VERIFY_PTR
void                    fr_atomic_queue_verify(fr_atomic_queue_t *aq);
#endif
 
#ifndef NDEBUG
void                    fr_atomic_queue_debug(FILE *fp, fr_atomic_queue_t *aq);
#endif
 
 
#ifdef __cplusplus
}
#endif