diff options
Diffstat (limited to 'src/svm/svm_fifo.h')
| -rw-r--r-- | src/svm/svm_fifo.h | 79 |
1 files changed, 55 insertions, 24 deletions
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h index 390e1170e27..417b0ecb672 100644 --- a/src/svm/svm_fifo.h +++ b/src/svm/svm_fifo.h @@ -64,9 +64,11 @@ typedef struct svm_fifo_chunk_ typedef enum svm_fifo_flag_ { - SVM_FIFO_F_SIZE_UPDATE = 1 << 0, - SVM_FIFO_F_MULTI_CHUNK = 1 << 1, - SVM_FIFO_F_LL_TRACKED = 1 << 2, + SVM_FIFO_F_MULTI_CHUNK = 1 << 0, + SVM_FIFO_F_GROW = 1 << 1, + SVM_FIFO_F_SHRINK = 1 << 2, + SVM_FIFO_F_COLLECT_CHUNKS = 1 << 3, + SVM_FIFO_F_LL_TRACKED = 1 << 4, } svm_fifo_flag_t; typedef struct _svm_fifo @@ -86,12 +88,13 @@ typedef struct _svm_fifo u32 client_session_index; /**< app session index */ u8 master_thread_index; /**< session layer thread index */ u8 client_thread_index; /**< app worker index */ + i8 refcnt; /**< reference count */ u32 segment_manager; /**< session layer segment manager index */ u32 segment_index; /**< segment index in segment manager */ u32 freelist_index; /**< aka log2(allocated_size) - const. */ - i8 refcnt; /**< reference count */ struct _svm_fifo *next; /**< next in freelist/active chain */ struct _svm_fifo *prev; /**< prev in active chain */ + u32 size_decrement; /**< bytes to remove from fifo */ CLIB_CACHE_LINE_ALIGN_MARK (consumer); u32 head; /**< fifo head position/byte */ @@ -172,7 +175,8 @@ f_load_head_tail_prod (svm_fifo_t * f, u32 * head, u32 * tail) *head = clib_atomic_load_acq_n (&f->head); } -/* Load head and tail independent of producer/consumer role +/** + * Load head and tail independent of producer/consumer role * * Internal function. */ @@ -230,6 +234,13 @@ f_free_count (svm_fifo_t * f, u32 head, u32 tail) } /** + * Try to shrink fifo size. + * + * Internal function. + */ +void svm_fifo_try_shrink (svm_fifo_t * f, u32 head, u32 tail); + +/** * Create fifo of requested size * * Allocates fifo on current heap. @@ -267,6 +278,31 @@ svm_fifo_chunk_t *svm_fifo_chunk_alloc (u32 size); */ void svm_fifo_add_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c); /** + * Request to reduce fifo size by amount of bytes + * + * Because the producer might be enqueuing data when this is called, the + * actual size update is only applied when producer tries to enqueue new + * data, unless @param try_shrink is set. + * + * @param f fifo + * @param len number of bytes to remove from fifo. The actual number + * of bytes to be removed will be less or equal to this + * value. + * @param try_shrink flg to indicate if it's safe to try to shrink fifo + * size. It should be set only if this is called by the + * producer of if the producer is not using the fifo + * @return actual length fifo size will be reduced by + */ +int svm_fifo_reduce_size (svm_fifo_t * f, u32 len, u8 try_shrink); +/** + * Removes chunks that are after fifo end byte + * + * Needs to be called with segment heap pushed. + * + * @param f fifo + */ +svm_fifo_chunk_t *svm_fifo_collect_chunks (svm_fifo_t * f); +/** * Free fifo and associated state * * @param f fifo @@ -333,6 +369,16 @@ int svm_fifo_enqueue (svm_fifo_t * f, u32 len, const u8 * src); */ int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 len, u8 * src); + +/** + * Advance tail pointer + * + * Useful for moving tail pointer after external enqueue. + * + * @param f fifo + * @param len number of bytes to add to tail + */ +void svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 len); /** * Overwrite fifo head with new data * @@ -551,6 +597,8 @@ svm_fifo_max_enqueue_prod (svm_fifo_t * f) { u32 head, tail; f_load_head_tail_prod (f, &head, &tail); + if (PREDICT_FALSE (f->flags & SVM_FIFO_F_SHRINK)) + svm_fifo_try_shrink (f, head, tail); return f_free_count (f, head, tail); } @@ -565,6 +613,8 @@ svm_fifo_max_enqueue (svm_fifo_t * f) { u32 head, tail; f_load_head_tail_all_acq (f, &head, &tail); + if (PREDICT_FALSE (f->flags & SVM_FIFO_F_SHRINK)) + svm_fifo_try_shrink (f, head, tail); return f_free_count (f, head, tail); } @@ -590,25 +640,6 @@ svm_fifo_max_write_chunk (svm_fifo_t * f) return tail > head ? f->size - tail : f_free_count (f, head, tail); } -/** - * Advance tail pointer - * - * Useful for moving tail pointer after external enqueue. - * - * @param f fifo - * @param len number of bytes to add to tail - */ -static inline void -svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 len) -{ - ASSERT (len <= svm_fifo_max_enqueue_prod (f)); - /* load-relaxed: producer owned index */ - u32 tail = f->tail; - tail = (tail + len) % f->size; - /* store-rel: producer owned index (paired with load-acq in consumer) */ - clib_atomic_store_rel_n (&f->tail, tail); -} - static inline u8 * svm_fifo_head (svm_fifo_t * f) { |