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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2021-07-23 11:24:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2021-07-23 11:24:09 +0000 |
commit | e36b37583bebd229102f46c4ed7d2f6fad8697d4 (patch) | |
tree | 73937b6f051fcaaa1ccbdfbaa9f3a1f36bbedb9e /include/ck_fifo.h | |
parent | Initial commit. (diff) | |
download | ck-e36b37583bebd229102f46c4ed7d2f6fad8697d4.tar.xz ck-e36b37583bebd229102f46c4ed7d2f6fad8697d4.zip |
Adding upstream version 0.6.0.upstream/0.6.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/ck_fifo.h')
-rw-r--r-- | include/ck_fifo.h | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/include/ck_fifo.h b/include/ck_fifo.h new file mode 100644 index 0000000..6d50070 --- /dev/null +++ b/include/ck_fifo.h @@ -0,0 +1,478 @@ +/* + * Copyright 2010-2015 Samy Al Bahra. + * Copyright 2011 David Joseph. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef CK_FIFO_H +#define CK_FIFO_H + +#include <ck_cc.h> +#include <ck_md.h> +#include <ck_pr.h> +#include <ck_spinlock.h> +#include <ck_stddef.h> + +#ifndef CK_F_FIFO_SPSC +#define CK_F_FIFO_SPSC +struct ck_fifo_spsc_entry { + void *value; + struct ck_fifo_spsc_entry *next; +}; +typedef struct ck_fifo_spsc_entry ck_fifo_spsc_entry_t; + +struct ck_fifo_spsc { + ck_spinlock_t m_head; + struct ck_fifo_spsc_entry *head; + char pad[CK_MD_CACHELINE - sizeof(struct ck_fifo_spsc_entry *) - sizeof(ck_spinlock_t)]; + ck_spinlock_t m_tail; + struct ck_fifo_spsc_entry *tail; + struct ck_fifo_spsc_entry *head_snapshot; + struct ck_fifo_spsc_entry *garbage; +}; +typedef struct ck_fifo_spsc ck_fifo_spsc_t; + +CK_CC_INLINE static bool +ck_fifo_spsc_enqueue_trylock(struct ck_fifo_spsc *fifo) +{ + + return ck_spinlock_trylock(&fifo->m_tail); +} + +CK_CC_INLINE static void +ck_fifo_spsc_enqueue_lock(struct ck_fifo_spsc *fifo) +{ + + ck_spinlock_lock(&fifo->m_tail); + return; +} + +CK_CC_INLINE static void +ck_fifo_spsc_enqueue_unlock(struct ck_fifo_spsc *fifo) +{ + + ck_spinlock_unlock(&fifo->m_tail); + return; +} + +CK_CC_INLINE static bool +ck_fifo_spsc_dequeue_trylock(struct ck_fifo_spsc *fifo) +{ + + return ck_spinlock_trylock(&fifo->m_head); +} + +CK_CC_INLINE static void +ck_fifo_spsc_dequeue_lock(struct ck_fifo_spsc *fifo) +{ + + ck_spinlock_lock(&fifo->m_head); + return; +} + +CK_CC_INLINE static void +ck_fifo_spsc_dequeue_unlock(struct ck_fifo_spsc *fifo) +{ + + ck_spinlock_unlock(&fifo->m_head); + return; +} + +CK_CC_INLINE static void +ck_fifo_spsc_init(struct ck_fifo_spsc *fifo, struct ck_fifo_spsc_entry *stub) +{ + + ck_spinlock_init(&fifo->m_head); + ck_spinlock_init(&fifo->m_tail); + + stub->next = NULL; + fifo->head = fifo->tail = fifo->head_snapshot = fifo->garbage = stub; + return; +} + +CK_CC_INLINE static void +ck_fifo_spsc_deinit(struct ck_fifo_spsc *fifo, struct ck_fifo_spsc_entry **garbage) +{ + + *garbage = fifo->head; + fifo->head = fifo->tail = NULL; + return; +} + +CK_CC_INLINE static void +ck_fifo_spsc_enqueue(struct ck_fifo_spsc *fifo, + struct ck_fifo_spsc_entry *entry, + void *value) +{ + + entry->value = value; + entry->next = NULL; + + /* If stub->next is visible, guarantee that entry is consistent. */ + ck_pr_fence_store(); + ck_pr_store_ptr(&fifo->tail->next, entry); + fifo->tail = entry; + return; +} + +CK_CC_INLINE static bool +ck_fifo_spsc_dequeue(struct ck_fifo_spsc *fifo, void *value) +{ + struct ck_fifo_spsc_entry *entry; + + /* + * The head pointer is guaranteed to always point to a stub entry. + * If the stub entry does not point to an entry, then the queue is + * empty. + */ + entry = ck_pr_load_ptr(&fifo->head->next); + if (entry == NULL) + return false; + + /* If entry is visible, guarantee store to value is visible. */ + ck_pr_store_ptr_unsafe(value, entry->value); + ck_pr_fence_store(); + ck_pr_store_ptr(&fifo->head, entry); + return true; +} + +/* + * Recycle a node. This technique for recycling nodes is based on + * Dmitriy Vyukov's work. + */ +CK_CC_INLINE static struct ck_fifo_spsc_entry * +ck_fifo_spsc_recycle(struct ck_fifo_spsc *fifo) +{ + struct ck_fifo_spsc_entry *garbage; + + if (fifo->head_snapshot == fifo->garbage) { + fifo->head_snapshot = ck_pr_load_ptr(&fifo->head); + if (fifo->head_snapshot == fifo->garbage) + return NULL; + } + + garbage = fifo->garbage; + fifo->garbage = garbage->next; + return garbage; +} + +CK_CC_INLINE static bool +ck_fifo_spsc_isempty(struct ck_fifo_spsc *fifo) +{ + struct ck_fifo_spsc_entry *head = ck_pr_load_ptr(&fifo->head); + return ck_pr_load_ptr(&head->next) == NULL; +} + +#define CK_FIFO_SPSC_ISEMPTY(f) ((f)->head->next == NULL) +#define CK_FIFO_SPSC_FIRST(f) ((f)->head->next) +#define CK_FIFO_SPSC_NEXT(m) ((m)->next) +#define CK_FIFO_SPSC_SPARE(f) ((f)->head) +#define CK_FIFO_SPSC_FOREACH(fifo, entry) \ + for ((entry) = CK_FIFO_SPSC_FIRST(fifo); \ + (entry) != NULL; \ + (entry) = CK_FIFO_SPSC_NEXT(entry)) +#define CK_FIFO_SPSC_FOREACH_SAFE(fifo, entry, T) \ + for ((entry) = CK_FIFO_SPSC_FIRST(fifo); \ + (entry) != NULL && ((T) = (entry)->next, 1); \ + (entry) = (T)) + +#endif /* CK_F_FIFO_SPSC */ + +#ifdef CK_F_PR_CAS_PTR_2 +#ifndef CK_F_FIFO_MPMC +#define CK_F_FIFO_MPMC +struct ck_fifo_mpmc_entry; +struct ck_fifo_mpmc_pointer { + struct ck_fifo_mpmc_entry *pointer; + char *generation CK_CC_PACKED; +} CK_CC_ALIGN(16); + +struct ck_fifo_mpmc_entry { + void *value; + struct ck_fifo_mpmc_pointer next; +}; +typedef struct ck_fifo_mpmc_entry ck_fifo_mpmc_entry_t; + +struct ck_fifo_mpmc { + struct ck_fifo_mpmc_pointer head; + char pad[CK_MD_CACHELINE - sizeof(struct ck_fifo_mpmc_pointer)]; + struct ck_fifo_mpmc_pointer tail; +}; +typedef struct ck_fifo_mpmc ck_fifo_mpmc_t; + +CK_CC_INLINE static void +ck_fifo_mpmc_init(struct ck_fifo_mpmc *fifo, struct ck_fifo_mpmc_entry *stub) +{ + + stub->next.pointer = NULL; + stub->next.generation = NULL; + fifo->head.pointer = fifo->tail.pointer = stub; + fifo->head.generation = fifo->tail.generation = NULL; + return; +} + +CK_CC_INLINE static void +ck_fifo_mpmc_deinit(struct ck_fifo_mpmc *fifo, struct ck_fifo_mpmc_entry **garbage) +{ + + *garbage = fifo->head.pointer; + fifo->head.pointer = fifo->tail.pointer = NULL; + return; +} + +CK_CC_INLINE static void +ck_fifo_mpmc_enqueue(struct ck_fifo_mpmc *fifo, + struct ck_fifo_mpmc_entry *entry, + void *value) +{ + struct ck_fifo_mpmc_pointer tail, next, update; + + /* + * Prepare the upcoming node and make sure to commit the updates + * before publishing. + */ + entry->value = value; + entry->next.pointer = NULL; + entry->next.generation = 0; + ck_pr_fence_store_atomic(); + + for (;;) { + tail.generation = ck_pr_load_ptr(&fifo->tail.generation); + ck_pr_fence_load(); + tail.pointer = ck_pr_load_ptr(&fifo->tail.pointer); + next.generation = ck_pr_load_ptr(&tail.pointer->next.generation); + ck_pr_fence_load(); + next.pointer = ck_pr_load_ptr(&tail.pointer->next.pointer); + + if (ck_pr_load_ptr(&fifo->tail.generation) != tail.generation) + continue; + + if (next.pointer != NULL) { + /* + * If the tail pointer has an entry following it then + * it needs to be forwarded to the next entry. This + * helps us guarantee we are always operating on the + * last entry. + */ + update.pointer = next.pointer; + update.generation = tail.generation + 1; + ck_pr_cas_ptr_2(&fifo->tail, &tail, &update); + } else { + /* + * Attempt to commit new entry to the end of the + * current tail. + */ + update.pointer = entry; + update.generation = next.generation + 1; + if (ck_pr_cas_ptr_2(&tail.pointer->next, &next, &update) == true) + break; + } + } + + ck_pr_fence_atomic(); + + /* After a successful insert, forward the tail to the new entry. */ + update.generation = tail.generation + 1; + ck_pr_cas_ptr_2(&fifo->tail, &tail, &update); + return; +} + +CK_CC_INLINE static bool +ck_fifo_mpmc_tryenqueue(struct ck_fifo_mpmc *fifo, + struct ck_fifo_mpmc_entry *entry, + void *value) +{ + struct ck_fifo_mpmc_pointer tail, next, update; + + entry->value = value; + entry->next.pointer = NULL; + entry->next.generation = 0; + + ck_pr_fence_store_atomic(); + + tail.generation = ck_pr_load_ptr(&fifo->tail.generation); + ck_pr_fence_load(); + tail.pointer = ck_pr_load_ptr(&fifo->tail.pointer); + next.generation = ck_pr_load_ptr(&tail.pointer->next.generation); + ck_pr_fence_load(); + next.pointer = ck_pr_load_ptr(&tail.pointer->next.pointer); + + if (ck_pr_load_ptr(&fifo->tail.generation) != tail.generation) + return false; + + if (next.pointer != NULL) { + /* + * If the tail pointer has an entry following it then + * it needs to be forwarded to the next entry. This + * helps us guarantee we are always operating on the + * last entry. + */ + update.pointer = next.pointer; + update.generation = tail.generation + 1; + ck_pr_cas_ptr_2(&fifo->tail, &tail, &update); + return false; + } else { + /* + * Attempt to commit new entry to the end of the + * current tail. + */ + update.pointer = entry; + update.generation = next.generation + 1; + if (ck_pr_cas_ptr_2(&tail.pointer->next, &next, &update) == false) + return false; + } + + ck_pr_fence_atomic(); + + /* After a successful insert, forward the tail to the new entry. */ + update.generation = tail.generation + 1; + ck_pr_cas_ptr_2(&fifo->tail, &tail, &update); + return true; +} + +CK_CC_INLINE static bool +ck_fifo_mpmc_dequeue(struct ck_fifo_mpmc *fifo, + void *value, + struct ck_fifo_mpmc_entry **garbage) +{ + struct ck_fifo_mpmc_pointer head, tail, next, update; + + for (;;) { + head.generation = ck_pr_load_ptr(&fifo->head.generation); + ck_pr_fence_load(); + head.pointer = ck_pr_load_ptr(&fifo->head.pointer); + tail.generation = ck_pr_load_ptr(&fifo->tail.generation); + ck_pr_fence_load(); + tail.pointer = ck_pr_load_ptr(&fifo->tail.pointer); + + next.generation = ck_pr_load_ptr(&head.pointer->next.generation); + ck_pr_fence_load(); + next.pointer = ck_pr_load_ptr(&head.pointer->next.pointer); + + update.pointer = next.pointer; + if (head.pointer == tail.pointer) { + /* + * The head is guaranteed to always point at a stub + * entry. If the stub entry has no references then the + * queue is empty. + */ + if (next.pointer == NULL) + return false; + + /* Forward the tail pointer if necessary. */ + update.generation = tail.generation + 1; + ck_pr_cas_ptr_2(&fifo->tail, &tail, &update); + } else { + /* + * It is possible for head snapshot to have been + * re-used. Avoid deferencing during enqueue + * re-use. + */ + if (next.pointer == NULL) + continue; + + /* Save value before commit. */ + *(void **)value = ck_pr_load_ptr(&next.pointer->value); + + /* Forward the head pointer to the next entry. */ + update.generation = head.generation + 1; + if (ck_pr_cas_ptr_2(&fifo->head, &head, &update) == true) + break; + } + } + + *garbage = head.pointer; + return true; +} + +CK_CC_INLINE static bool +ck_fifo_mpmc_trydequeue(struct ck_fifo_mpmc *fifo, + void *value, + struct ck_fifo_mpmc_entry **garbage) +{ + struct ck_fifo_mpmc_pointer head, tail, next, update; + + head.generation = ck_pr_load_ptr(&fifo->head.generation); + ck_pr_fence_load(); + head.pointer = ck_pr_load_ptr(&fifo->head.pointer); + + tail.generation = ck_pr_load_ptr(&fifo->tail.generation); + ck_pr_fence_load(); + tail.pointer = ck_pr_load_ptr(&fifo->tail.pointer); + + next.generation = ck_pr_load_ptr(&head.pointer->next.generation); + ck_pr_fence_load(); + next.pointer = ck_pr_load_ptr(&head.pointer->next.pointer); + + update.pointer = next.pointer; + if (head.pointer == tail.pointer) { + /* + * The head is guaranteed to always point at a stub + * entry. If the stub entry has no references then the + * queue is empty. + */ + if (next.pointer == NULL) + return false; + + /* Forward the tail pointer if necessary. */ + update.generation = tail.generation + 1; + ck_pr_cas_ptr_2(&fifo->tail, &tail, &update); + return false; + } else { + /* + * It is possible for head snapshot to have been + * re-used. Avoid deferencing during enqueue. + */ + if (next.pointer == NULL) + return false; + + /* Save value before commit. */ + *(void **)value = ck_pr_load_ptr(&next.pointer->value); + + /* Forward the head pointer to the next entry. */ + update.generation = head.generation + 1; + if (ck_pr_cas_ptr_2(&fifo->head, &head, &update) == false) + return false; + } + + *garbage = head.pointer; + return true; +} + +#define CK_FIFO_MPMC_ISEMPTY(f) ((f)->head.pointer->next.pointer == NULL) +#define CK_FIFO_MPMC_FIRST(f) ((f)->head.pointer->next.pointer) +#define CK_FIFO_MPMC_NEXT(m) ((m)->next.pointer) +#define CK_FIFO_MPMC_FOREACH(fifo, entry) \ + for ((entry) = CK_FIFO_MPMC_FIRST(fifo); \ + (entry) != NULL; \ + (entry) = CK_FIFO_MPMC_NEXT(entry)) +#define CK_FIFO_MPMC_FOREACH_SAFE(fifo, entry, T) \ + for ((entry) = CK_FIFO_MPMC_FIRST(fifo); \ + (entry) != NULL && ((T) = (entry)->next.pointer, 1); \ + (entry) = (T)) + +#endif /* CK_F_FIFO_MPMC */ +#endif /* CK_F_PR_CAS_PTR_2 */ + +#endif /* CK_FIFO_H */ |