FD.io VPP  v19.08-27-gf4dcae4
Vector Packet Processing
svm_fifo.h
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1 /*
2  * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3  * Copyright (c) 2019 Arm Limited
4  * Copyright (c) 2010-2017 Intel Corporation and/or its affiliates.
5  * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
6  * Inspired from DPDK rte_ring.h (SPSC only) (derived from freebsd bufring.h).
7  * Licensed under the Apache License, Version 2.0 (the "License");
8  * you may not use this file except in compliance with the License.
9  * You may obtain a copy of the License at:
10  *
11  * http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing, software
14  * distributed under the License is distributed on an "AS IS" BASIS,
15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  * See the License for the specific language governing permissions and
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18  */
19 #ifndef __included_ssvm_fifo_h__
20 #define __included_ssvm_fifo_h__
21 
22 #include <vppinfra/clib.h>
23 #include <vppinfra/vec.h>
24 #include <vppinfra/pool.h>
25 #include <vppinfra/format.h>
26 #include <vppinfra/rbtree.h>
27 
28 /** Out-of-order segment */
29 typedef struct
30 {
31  u32 next; /**< Next linked-list element pool index */
32  u32 prev; /**< Previous linked-list element pool index */
33  u32 start; /**< Start of segment, normalized*/
34  u32 length; /**< Length of segment */
36 
37 #define SVM_FIFO_TRACE (0)
38 #define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
39 #define SVM_FIFO_INVALID_SESSION_INDEX ((u32)~0)
40 #define SVM_FIFO_INVALID_INDEX ((u32)~0)
41 #define SVM_FIFO_MAX_EVT_SUBSCRIBERS 7
42 
43 typedef enum svm_fifo_deq_ntf_
44 {
45  SVM_FIFO_NO_DEQ_NOTIF = 0, /**< No notification requested */
46  SVM_FIFO_WANT_DEQ_NOTIF = 1, /**< Notify on dequeue */
47  SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL = 2, /**< Notify on transition from full */
48  SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY = 4, /**< Notify on transition to empty */
50 
51 typedef struct
52 {
57 
58 typedef struct svm_fifo_chunk_
59 {
60  u32 start_byte; /**< chunk start byte */
61  u32 length; /**< length of chunk in bytes */
62  struct svm_fifo_chunk_ *next; /**< pointer to next chunk in linked-lists */
63  u8 data[0]; /**< start of chunk data */
65 
66 typedef enum svm_fifo_flag_
67 {
69  SVM_FIFO_F_GROW = 1 << 1,
74 
75 typedef struct _svm_fifo
76 {
77  CLIB_CACHE_LINE_ALIGN_MARK (shared_first);
78  u32 size; /**< size of the fifo in bytes */
79  u32 nitems; /**< usable size (size-1) */
80  u8 flags; /**< fifo flags */
81  svm_fifo_chunk_t *start_chunk;/**< first chunk in fifo chunk list */
82  svm_fifo_chunk_t *end_chunk; /**< end chunk in fifo chunk list */
83  svm_fifo_chunk_t *new_chunks; /**< chunks yet to be added to list */
84  rb_tree_t chunk_lookup;
85 
86  CLIB_CACHE_LINE_ALIGN_MARK (shared_second);
87  volatile u32 has_event; /**< non-zero if deq event exists */
88  u32 master_session_index; /**< session layer session index */
89  u32 client_session_index; /**< app session index */
90  u8 master_thread_index; /**< session layer thread index */
91  u8 client_thread_index; /**< app worker index */
92  i8 refcnt; /**< reference count */
93  u32 segment_manager; /**< session layer segment manager index */
94  u32 segment_index; /**< segment index in segment manager */
95  struct _svm_fifo *next; /**< next in freelist/active chain */
96  struct _svm_fifo *prev; /**< prev in active chain */
97  u32 size_decrement; /**< bytes to remove from fifo */
98 
99  CLIB_CACHE_LINE_ALIGN_MARK (consumer);
100  u32 head; /**< fifo head position/byte */
101  svm_fifo_chunk_t *head_chunk; /**< tracks chunk where head lands */
102  svm_fifo_chunk_t *ooo_deq; /**< last chunk used for ooo dequeue */
103  volatile u32 want_deq_ntf; /**< producer wants nudge */
104  volatile u32 has_deq_ntf;
105 
106  CLIB_CACHE_LINE_ALIGN_MARK (producer);
107  u32 tail; /**< fifo tail position/byte */
108  u32 ooos_list_head; /**< Head of out-of-order linked-list */
109  svm_fifo_chunk_t *tail_chunk; /**< tracks chunk where tail lands */
110  svm_fifo_chunk_t *ooo_enq; /**< last chunk used for ooo enqueue */
111  ooo_segment_t *ooo_segments; /**< Pool of ooo segments */
112  u32 ooos_newest; /**< Last segment to have been updated */
113  volatile u8 n_subscribers; /**< Number of subscribers for io events */
114  u8 subscribers[SVM_FIFO_MAX_EVT_SUBSCRIBERS];
115 
116 #if SVM_FIFO_TRACE
118 #endif
119 
120 } svm_fifo_t;
121 
122 typedef enum
123 {
127 
128 typedef struct svm_fifo_seg_
129 {
133 
134 #if SVM_FIFO_TRACE
135 #define svm_fifo_trace_add(_f, _s, _l, _t) \
136 { \
137  svm_fifo_trace_elem_t *trace_elt; \
138  vec_add2(_f->trace, trace_elt, 1); \
139  trace_elt->offset = _s; \
140  trace_elt->len = _l; \
141  trace_elt->action = _t; \
142 }
143 #else
144 #define svm_fifo_trace_add(_f, _s, _l, _t)
145 #endif
146 
147 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
148 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
149 
150 /**
151  * Load head and tail optimized for consumer
152  *
153  * Internal function.
154  */
155 static inline void
157 {
158  /* load-relaxed: consumer owned index */
159  *head = f->head;
160  /* load-acq: consumer foreign index (paired with store-rel in producer) */
161  *tail = clib_atomic_load_acq_n (&f->tail);
162 }
163 
164 /** Load head and tail optimized for producer
165  *
166  * Internal function
167  */
168 static inline void
170 {
171  /* load relaxed: producer owned index */
172  *tail = f->tail;
173  /* load-acq: producer foreign index (paired with store-rel in consumer) */
174  *head = clib_atomic_load_acq_n (&f->head);
175 }
176 
177 /**
178  * Load head and tail independent of producer/consumer role
179  *
180  * Internal function.
181  */
182 static inline void
184 {
185  /* load-acq : consumer foreign index (paired with store-rel) */
186  *tail = clib_atomic_load_acq_n (&f->tail);
187  /* load-acq : producer foriegn index (paired with store-rel) */
188  *head = clib_atomic_load_acq_n (&f->head);
189 }
190 
191 /**
192  * Distance to a from b, i.e., a - b in the fifo
193  *
194  * Internal function.
195  */
196 static inline u32
198 {
199  return ((f->size + a - b) % f->size);
200 }
201 
202 /**
203  * Distance from a to b, i.e., b - a in the fifo
204  *
205  * Internal function.
206  */
207 static inline u32
209 {
210  return ((f->size + b - a) % f->size);
211 }
212 
213 /**
214  * Fifo current size, i.e., number of bytes enqueued
215  *
216  * Internal function.
217  */
218 static inline u32
219 f_cursize (svm_fifo_t * f, u32 head, u32 tail)
220 {
221  return (head <= tail ? tail - head : f->size + tail - head);
222 }
223 
224 /**
225  * Fifo free bytes, i.e., number of free bytes
226  *
227  * Internal function
228  */
229 static inline u32
230 f_free_count (svm_fifo_t * f, u32 head, u32 tail)
231 {
232  return (f->nitems - f_cursize (f, head, tail));
233 }
234 
235 /**
236  * Try to shrink fifo size.
237  *
238  * Internal function.
239  */
240 void svm_fifo_try_shrink (svm_fifo_t * f, u32 head, u32 tail);
241 
242 /**
243  * Create fifo of requested size
244  *
245  * Allocates fifo on current heap.
246  *
247  * @param size data size in bytes for fifo to be allocated. Will be
248  * rounded to the next highest power-of-two value.
249  * @return pointer to new fifo
250  */
252 /**
253  * Initialize fifo
254  *
255  * @param f fifo
256  * @param size size for fifo
257  */
258 void svm_fifo_init (svm_fifo_t * f, u32 size);
259 /**
260  * Initialize fifo chunks and rbtree
261  *
262  * @param f fifo
263  */
265 /**
266  * Allocate a fifo chunk on heap
267  *
268  * If the chunk is allocated on a fifo segment, this should be called
269  * with the segment's heap pushed.
270  *
271  * @param size chunk size in bytes. Will be rounded to the next highest
272  * power-of-two
273  * @return new chunk or 0 if alloc failed
274  */
276 /**
277  * Grow fifo size by adding chunk to chunk list
278  *
279  * If fifos are allocated on a segment, this should be called with
280  * the segment's heap pushed.
281  *
282  * @param f fifo to be extended
283  * @param c chunk or linked list of chunks to be added
284  */
286 /**
287  * Request to reduce fifo size by amount of bytes
288  *
289  * Because the producer might be enqueuing data when this is called, the
290  * actual size update is only applied when producer tries to enqueue new
291  * data, unless @param try_shrink is set.
292  *
293  * @param f fifo
294  * @param len number of bytes to remove from fifo. The actual number
295  * of bytes to be removed will be less or equal to this
296  * value.
297  * @param try_shrink flg to indicate if it's safe to try to shrink fifo
298  * size. It should be set only if this is called by the
299  * producer of if the producer is not using the fifo
300  * @return actual length fifo size will be reduced by
301  */
302 int svm_fifo_reduce_size (svm_fifo_t * f, u32 len, u8 try_shrink);
303 /**
304  * Removes chunks that are after fifo end byte
305  *
306  * Needs to be called with segment heap pushed.
307  *
308  * @param f fifo
309  */
311 /**
312  * Free fifo and associated state
313  *
314  * @param f fifo
315  */
316 void svm_fifo_free (svm_fifo_t * f);
317 /**
318  * Cleanup fifo chunk lookup rb tree
319  *
320  * The rb tree is allocated in segment heap so this should be called
321  * with it pushed.
322  *
323  * @param f fifo to cleanup
324  */
326 /**
327  * Cleanup fifo ooo data
328  *
329  * The ooo data is allocated in producer process memory. The fifo
330  * segment heap should not be pushed.
331  *
332  * @param f fifo to cleanup
333  */
335 /**
336  * Init fifo head and tail
337  *
338  * @param f fifo
339  * @param head head value that will be matched to a chunk
340  * @param tail tail value that will be matched to a chunk
341  */
342 void svm_fifo_init_pointers (svm_fifo_t * f, u32 head, u32 tail);
343 /**
344  * Clone fifo
345  *
346  * Clones single/default chunk fifo. It does not work for fifos with
347  * multiple chunks.
348  */
349 void svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf);
350 /**
351  * Enqueue data to fifo
352  *
353  * Data is enqueued and tail pointer is updated atomically. If the new data
354  * enqueued partly overlaps or "touches" an out-of-order segment, said segment
355  * is "consumed" and the number of bytes returned is appropriately updated.
356  *
357  * @param f fifo
358  * @param len length of data to copy
359  * @param src buffer from where to copy the data
360  * @return number of contiguous bytes that can be consumed or error
361  */
362 int svm_fifo_enqueue (svm_fifo_t * f, u32 len, const u8 * src);
363 /**
364  * Enqueue data to fifo with offset
365  *
366  * Data is enqueued without updating tail pointer. Instead, an out-of-order
367  * list of segments is generated and maintained. Fifo takes care of coalescing
368  * contiguous or overlapping segments.
369  *
370  * @param f fifo
371  * @param offset offset at which to copy the data
372  * @param len len of data to copy
373  * @param src buffer from where to copy the data
374  * @return 0 if enqueue was successful, error otherwise
375  */
377  u8 * src);
378 
379 /**
380  * Advance tail pointer
381  *
382  * Useful for moving tail pointer after external enqueue.
383  *
384  * @param f fifo
385  * @param len number of bytes to add to tail
386  */
388 /**
389  * Overwrite fifo head with new data
390  *
391  * This should be typically used by dgram transport protocols that need
392  * to update the dgram header after dequeueing a chunk of data. It assumes
393  * that the dgram header is at most spread over two chunks.
394  *
395  * @param f fifo
396  * @param src src of new data
397  * @param len length of new data
398  */
400 /**
401  * Dequeue data from fifo
402  *
403  * Data is dequeued to consumer provided buffer and head is atomically
404  * updated.
405  *
406  * @param f fifo
407  * @param len length of data to dequeue
408  * @param dst buffer to where to dequeue the data
409  * @return number of bytes dequeued or error
410  */
411 int svm_fifo_dequeue (svm_fifo_t * f, u32 len, u8 * dst);
412 /**
413  * Peek data from fifo
414  *
415  * Data is copied from requested offset into provided dst buffer. Head is
416  * not updated.
417  *
418  * @param f fifo
419  * @param offset offset from which to copy the data
420  * @param len length of data to copy
421  * @param dst buffer to where to dequeue the data
422  * @return number of bytes peeked
423  */
424 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 len, u8 * dst);
425 /**
426  * Dequeue and drop bytes from fifo
427  *
428  * Advances fifo head by requested amount of bytes.
429  *
430  * @param f fifo
431  * @param len number of bytes to drop
432  * @return number of bytes dropped
433  */
435 /**
436  * Dequeue and drop all bytes from fifo
437  *
438  * Advances head to tail position.
439  *
440  * @param f fifo
441  */
445 /**
446  * Add io events subscriber to list
447  *
448  * @param f fifo
449  * @param sub subscriber opaque index (typically app worker index)
450  */
451 void svm_fifo_add_subscriber (svm_fifo_t * f, u8 sub);
452 /**
453  * Remove io events subscriber form list
454  *
455  * @param f fifo
456  * @param sub subscriber index to be removed
457  */
458 void svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber);
459 /**
460  * Number of out-of-order segments for fifo
461  *
462  * @param f fifo
463  * @return number of out of order segments
464  */
466 /**
467  * First out-of-order segment for fifo
468  *
469  * @param f fifo
470  * @return first out-of-order segment for fifo
471  */
473 /**
474  * Check if fifo is sane. Debug only.
475  *
476  * @param f fifo
477  * @return 1 if sane, 0 otherwise
478  */
481 
482 /**
483  * Fifo max bytes to dequeue optimized for consumer
484  *
485  * @param f fifo
486  * @return max number of bytes that can be dequeued
487  */
488 static inline u32
490 {
491  u32 tail, head;
492  f_load_head_tail_cons (f, &head, &tail);
493  return f_cursize (f, head, tail);
494 }
495 
496 /**
497  * Fifo max bytes to dequeue optimized for producer
498  *
499  * @param f fifo
500  * @return max number of bytes that can be dequeued
501  */
502 static inline u32
504 {
505  u32 tail, head;
506  f_load_head_tail_prod (f, &head, &tail);
507  return f_cursize (f, head, tail);
508 }
509 
510 /**
511  * Fifo max bytes to dequeue
512  *
513  * Note: use producer or consumer specific functions for performance:
514  * @ref svm_fifo_max_dequeue_cons (svm_fifo_t *f)
515  * @ref svm_fifo_max_dequeue_prod (svm_fifo_t *f)
516  */
517 static inline u32
519 {
520  u32 tail, head;
521  f_load_head_tail_all_acq (f, &head, &tail);
522  return f_cursize (f, head, tail);
523 }
524 
525 /**
526  * Check if fifo is full optimized for producer
527  *
528  * @param f fifo
529  * @return 1 if fifo is full 0 otherwise
530  */
531 static inline int
533 {
534  return (svm_fifo_max_dequeue_prod (f) == f->nitems);
535 }
536 
537 /* Check if fifo is full.
538  *
539  * Note: use producer or consumer specific functions for performance.
540  * @ref svm_fifo_is_full_prod (svm_fifo_t * f)
541  * add cons version if needed
542  */
543 static inline int
545 {
546  return (svm_fifo_max_dequeue (f) == f->nitems);
547 }
548 
549 /**
550  * Check if fifo is empty optimized for consumer
551  *
552  * @param f fifo
553  * @return 1 if fifo is empty 0 otherwise
554  */
555 static inline int
557 {
558  return (svm_fifo_max_dequeue_cons (f) == 0);
559 }
560 
561 /**
562  * Check if fifo is empty optimized for producer
563  *
564  * @param f fifo
565  * @return 1 if fifo is empty 0 otherwise
566  */
567 static inline int
569 {
570  return (svm_fifo_max_dequeue_prod (f) == 0);
571 }
572 
573 /**
574  * Check if fifo is empty
575  *
576  * Note: use producer or consumer specific functions for perfomance.
577  * @ref svm_fifo_is_empty_cons (svm_fifo_t * f)
578  * @ref svm_fifo_is_empty_prod (svm_fifo_t * f)
579  */
580 static inline int
582 {
583  return (svm_fifo_max_dequeue (f) == 0);
584 }
585 
586 /**
587  * Check if fifo is wrapped
588  *
589  * @param f fifo
590  * @return 1 if 'normalized' head is ahead of tail
591  */
592 static inline u8
594 {
595  u32 head, tail;
596  f_load_head_tail_all_acq (f, &head, &tail);
597  return head > tail;
598 }
599 
600 /**
601  * Maximum number of bytes that can be enqueued into fifo
602  *
603  * Optimized for producer
604  *
605  * @param f fifo
606  * @return max number of bytes that can be enqueued into fifo
607  */
608 static inline u32
610 {
611  u32 head, tail;
612  f_load_head_tail_prod (f, &head, &tail);
613  if (PREDICT_FALSE (f->flags & SVM_FIFO_F_SHRINK))
614  svm_fifo_try_shrink (f, head, tail);
615  return f_free_count (f, head, tail);
616 }
617 
618 /* Maximum number of bytes that can be enqueued into fifo
619  *
620  * Note: use producer or consumer specific functions for performance.
621  * @ref svm_fifo_max_enqueue_prod (svm_fifo_t *f)
622  * add consumer specific version if needed.
623  */
624 static inline u32
626 {
627  u32 head, tail;
628  f_load_head_tail_all_acq (f, &head, &tail);
629  if (PREDICT_FALSE (f->flags & SVM_FIFO_F_SHRINK))
630  svm_fifo_try_shrink (f, head, tail);
631  return f_free_count (f, head, tail);
632 }
633 
634 /**
635  * Max contiguous chunk of data that can be read
636  */
637 static inline u32
639 {
640  u32 head, tail;
641  f_load_head_tail_cons (f, &head, &tail);
642  return tail >= head ? (tail - head) : (f->size - head);
643 }
644 
645 /**
646  * Max contiguous chunk of data that can be written
647  */
648 static inline u32
650 {
651  u32 head, tail;
652  f_load_head_tail_prod (f, &head, &tail);
653  return tail >= head ? f->size - tail : f_free_count (f, head, tail);
654 }
655 
656 static inline u8 *
658 {
659  /* load-relaxed: consumer owned index */
660  return (f->head_chunk->data + (f->head - f->head_chunk->start_byte));
661 }
662 
663 static inline u8 *
665 {
666  /* load-relaxed: producer owned index */
667  return (f->tail_chunk->data + (f->tail - f->tail_chunk->start_byte));
668 }
669 
670 static inline u8
672 {
673  return f->n_subscribers;
674 }
675 
676 /**
677  * Check if fifo has out-of-order data
678  *
679  * @param f fifo
680  * @return 1 if fifo has ooo data, 0 otherwise
681  */
682 static inline u8
684 {
685  return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
686 }
687 
688 static inline ooo_segment_t *
690 {
691  if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
692  return 0;
693  return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
694 }
695 
696 static inline void
698 {
699  f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
700 }
701 
702 static inline u32
704 {
705  u32 tail;
706  /* load-relaxed: producer owned index */
707  tail = f->tail;
708 
709  return f_distance_to (f, s->start, tail);
710 }
711 
712 static inline u32
714 {
715  return s->length;
716 }
717 
718 /**
719  * Check if fifo has io event
720  *
721  * @param f fifo
722  * @return 1 if fifo has event, 0 otherwise
723  */
724 static inline int
726 {
727  return f->has_event;
728 }
729 
730 /**
731  * Set fifo event flag.
732  *
733  * Forces release semantics.
734  *
735  * @param f fifo
736  * @return 1 if flag was not set, 0 otherwise
737  */
740 {
741  return !clib_atomic_swap_rel_n (&f->has_event, 1);
742 }
743 
744 /**
745  * Unset fifo event flag.
746  *
747  * Forces acquire semantics
748  *
749  * @param f fifo
750  */
751 always_inline void
753 {
754  clib_atomic_swap_acq_n (&f->has_event, 0);
755 }
756 
757 /**
758  * Set specific want notification flag
759  *
760  * For list of flags see @ref svm_fifo_deq_ntf_t
761  *
762  * @param f fifo
763  * @param ntf_type type of notification requested
764  */
765 static inline void
767 {
768  f->want_deq_ntf |= ntf_type;
769 }
770 
771 /**
772  * Clear specific want notification flag
773  *
774  * For list of flags see @ref svm_fifo_ntf_t
775  *
776  * @param f fifo
777  * @param ntf_type type of notification to be cleared
778  */
779 static inline void
781 {
782  f->want_deq_ntf &= ~ntf_type;
783 }
784 
785 /**
786  * Clear the want notification flag and set has notification
787  *
788  * Should be used after enqueuing an event. This clears the
789  * SVM_FIFO_WANT_NOTIF flag but it does not clear
790  * SVM_FIFO_WANT_NOTIF_IF_FULL. If the latter was set, has_ntf is
791  * set to avoid enqueueing events for for all dequeue operations until
792  * it is manually cleared.
793  *
794  * @param f fifo
795  */
796 static inline void
798 {
799  /* Set the flag if want_notif_if_full was the only ntf requested */
800  f->has_deq_ntf = f->want_deq_ntf == SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL;
802 }
803 
804 /**
805  * Clear has notification flag
806  *
807  * The fifo generates only one event per SVM_FIFO_WANT_NOTIF_IF_FULL
808  * request and sets has_ntf. To received new events the flag must be
809  * cleared using this function.
810  *
811  * @param f fifo
812  */
813 static inline void
815 {
816  f->has_deq_ntf = 0;
817 }
818 
819 /**
820  * Check if fifo needs dequeue notification
821  *
822  * Determines based on notification request flags and state of the fifo if
823  * an event should be generated.
824  *
825  * @param f fifo
826  * @param n_last_deq number of bytes last dequeued
827  * @return 1 if event should be generated, 0 otherwise
828  */
829 static inline u8
831 {
832  u8 want_ntf = f->want_deq_ntf;
833 
834  if (PREDICT_TRUE (want_ntf == SVM_FIFO_NO_DEQ_NOTIF))
835  return 0;
836  else if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF)
837  return 1;
838  if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL)
839  {
840  u32 max_deq = svm_fifo_max_dequeue_cons (f);
841  u32 nitems = f->nitems;
842  if (!f->has_deq_ntf && max_deq < nitems
843  && max_deq + n_last_deq >= nitems)
844  return 1;
845  }
846  if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY)
847  {
848  if (!f->has_deq_ntf && svm_fifo_is_empty (f))
849  return 1;
850  }
851  return 0;
852 }
853 
854 #endif /* __included_ssvm_fifo_h__ */
855 
856 /*
857  * fd.io coding-style-patch-verification: ON
858  *
859  * Local Variables:
860  * eval: (c-set-style "gnu")
861  * End:
862  */
void svm_fifo_add_subscriber(svm_fifo_t *f, u8 sub)
Add io events subscriber to list.
Definition: svm_fifo.c:1094
u32 length
length of chunk in bytes
Definition: svm_fifo.h:61
static void f_load_head_tail_all_acq(svm_fifo_t *f, u32 *head, u32 *tail)
Load head and tail independent of producer/consumer role.
Definition: svm_fifo.h:183
static vlib_cli_command_t trace
(constructor) VLIB_CLI_COMMAND (trace)
Definition: vlib_api_cli.c:870
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:60
u32 flags
Definition: vhost_user.h:141
struct svm_fifo_chunk_ svm_fifo_chunk_t
int svm_fifo_enqueue(svm_fifo_t *f, u32 len, const u8 *src)
Enqueue data to fifo.
Definition: svm_fifo.c:807
static u32 svm_fifo_max_enqueue_prod(svm_fifo_t *f)
Maximum number of bytes that can be enqueued into fifo.
Definition: svm_fifo.h:609
a
Definition: bitmap.h:538
void svm_fifo_clone(svm_fifo_t *df, svm_fifo_t *sf)
Clone fifo.
Definition: svm_fifo.c:1049
void svm_fifo_try_shrink(svm_fifo_t *f, u32 head, u32 tail)
Try to shrink fifo size.
Definition: svm_fifo.c:653
static int svm_fifo_is_full(svm_fifo_t *f)
Definition: svm_fifo.h:544
Notify on dequeue.
Definition: svm_fifo.h:46
u8 * svm_fifo_replay(u8 *s, svm_fifo_t *f, u8 no_read, u8 verbose)
Definition: svm_fifo.c:1192
static u8 svm_fifo_has_ooo_data(svm_fifo_t *f)
Check if fifo has out-of-order data.
Definition: svm_fifo.h:683
format_function_t format_svm_fifo
Definition: svm_fifo.h:480
void svm_fifo_free_ooo_data(svm_fifo_t *f)
Cleanup fifo ooo data.
Definition: svm_fifo.c:132
#define PREDICT_TRUE(x)
Definition: clib.h:112
svm_fifo_flag_
Definition: svm_fifo.h:66
static u32 f_free_count(svm_fifo_t *f, u32 head, u32 tail)
Fifo free bytes, i.e., number of free bytes.
Definition: svm_fifo.h:230
Fixed length block allocator.
static int svm_fifo_is_empty_prod(svm_fifo_t *f)
Check if fifo is empty optimized for producer.
Definition: svm_fifo.h:568
u32 prev
Previous linked-list element pool index.
Definition: svm_fifo.h:32
static void f_load_head_tail_cons(svm_fifo_t *f, u32 *head, u32 *tail)
Load head and tail optimized for consumer.
Definition: svm_fifo.h:156
vl_api_address_t src
Definition: gre.api:51
static int svm_fifo_is_empty_cons(svm_fifo_t *f)
Check if fifo is empty optimized for consumer.
Definition: svm_fifo.h:556
static void svm_fifo_reset_has_deq_ntf(svm_fifo_t *f)
Clear has notification flag.
Definition: svm_fifo.h:814
static u32 svm_fifo_max_enqueue(svm_fifo_t *f)
Definition: svm_fifo.h:625
int svm_fifo_reduce_size(svm_fifo_t *f, u32 len, u8 try_shrink)
Request to reduce fifo size by amount of bytes.
Definition: svm_fifo.c:726
void svm_fifo_add_chunk(svm_fifo_t *f, svm_fifo_chunk_t *c)
Grow fifo size by adding chunk to chunk list.
Definition: svm_fifo.c:579
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
static u8 * svm_fifo_tail(svm_fifo_t *f)
Definition: svm_fifo.h:664
unsigned char u8
Definition: types.h:56
struct _svm_fifo svm_fifo_t
static int svm_fifo_is_empty(svm_fifo_t *f)
Check if fifo is empty.
Definition: svm_fifo.h:581
int svm_fifo_segments(svm_fifo_t *f, svm_fifo_seg_t *fs)
Definition: svm_fifo.c:996
#define always_inline
Definition: clib.h:98
static u32 svm_fifo_max_dequeue(svm_fifo_t *f)
Fifo max bytes to dequeue.
Definition: svm_fifo.h:518
static u32 svm_fifo_max_dequeue_cons(svm_fifo_t *f)
Fifo max bytes to dequeue optimized for consumer.
Definition: svm_fifo.h:489
static u32 svm_fifo_max_write_chunk(svm_fifo_t *f)
Max contiguous chunk of data that can be written.
Definition: svm_fifo.h:649
static u32 ooo_segment_length(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:713
u8 * svm_fifo_dump_trace(u8 *s, svm_fifo_t *f)
Definition: svm_fifo.c:1168
unsigned int u32
Definition: types.h:88
struct svm_fifo_seg_ svm_fifo_seg_t
svm_fifo_deq_ntf_
Definition: svm_fifo.h:43
static u8 * svm_fifo_head(svm_fifo_t *f)
Definition: svm_fifo.h:657
static u32 svm_fifo_max_read_chunk(svm_fifo_t *f)
Max contiguous chunk of data that can be read.
Definition: svm_fifo.h:638
static int svm_fifo_is_full_prod(svm_fifo_t *f)
Check if fifo is full optimized for producer.
Definition: svm_fifo.h:532
static void svm_fifo_newest_ooo_segment_reset(svm_fifo_t *f)
Definition: svm_fifo.h:697
int svm_fifo_peek(svm_fifo_t *f, u32 offset, u32 len, u8 *dst)
Peek data from fifo.
Definition: svm_fifo.c:926
u8 svm_fifo_is_sane(svm_fifo_t *f)
Check if fifo is sane.
Definition: svm_fifo.c:1117
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:514
uword size
void svm_fifo_dequeue_drop_all(svm_fifo_t *f)
Dequeue and drop all bytes from fifo.
Definition: svm_fifo.c:980
u32 svm_fifo_n_ooo_segments(svm_fifo_t *f)
Number of out-of-order segments for fifo.
Definition: svm_fifo.c:1060
struct svm_fifo_chunk_ * next
pointer to next chunk in linked-lists
Definition: svm_fifo.h:62
#define PREDICT_FALSE(x)
Definition: clib.h:111
static void svm_fifo_unset_event(svm_fifo_t *f)
Unset fifo event flag.
Definition: svm_fifo.h:752
void svm_fifo_init_chunks(svm_fifo_t *f)
Initialize fifo chunks and rbtree.
Definition: svm_fifo.c:408
signed char i8
Definition: types.h:45
svm_fifo_t * svm_fifo_create(u32 size)
Create fifo of requested size.
Definition: svm_fifo.c:436
static u32 svm_fifo_max_dequeue_prod(svm_fifo_t *f)
Fifo max bytes to dequeue optimized for producer.
Definition: svm_fifo.h:503
vl_api_address_t dst
Definition: gre.api:52
static ooo_segment_t * svm_fifo_newest_ooo_segment(svm_fifo_t *f)
Definition: svm_fifo.h:689
u8 len
Definition: ip_types.api:90
static u8 svm_fifo_set_event(svm_fifo_t *f)
Set fifo event flag.
Definition: svm_fifo.h:739
svm_fifo_chunk_t * svm_fifo_chunk_alloc(u32 size)
Allocate a fifo chunk on heap.
Definition: svm_fifo.c:471
#define SVM_FIFO_MAX_EVT_SUBSCRIBERS
Definition: svm_fifo.h:41
static u8 svm_fifo_needs_deq_ntf(svm_fifo_t *f, u32 n_last_deq)
Check if fifo needs dequeue notification.
Definition: svm_fifo.h:830
static u32 f_cursize(svm_fifo_t *f, u32 head, u32 tail)
Fifo current size, i.e., number of bytes enqueued.
Definition: svm_fifo.h:219
int svm_fifo_dequeue(svm_fifo_t *f, u32 len, u8 *dst)
Dequeue data from fifo.
Definition: svm_fifo.c:900
void svm_fifo_overwrite_head(svm_fifo_t *f, u8 *src, u32 len)
Overwrite fifo head with new data.
Definition: svm_fifo.c:785
static void f_load_head_tail_prod(svm_fifo_t *f, u32 *head, u32 *tail)
Load head and tail optimized for producer.
Definition: svm_fifo.h:169
u32 start_byte
chunk start byte
Definition: svm_fifo.h:60
svm_fifo_chunk_t * svm_fifo_collect_chunks(svm_fifo_t *f)
Removes chunks that are after fifo end byte.
Definition: svm_fifo.c:634
#define OOO_SEGMENT_INVALID_INDEX
Definition: svm_fifo.h:38
void svm_fifo_free_chunk_lookup(svm_fifo_t *f)
Cleanup fifo chunk lookup rb tree.
Definition: svm_fifo.c:766
#define clib_atomic_swap_acq_n(a, b)
Definition: atomics.h:51
int svm_fifo_dequeue_drop(svm_fifo_t *f, u32 len)
Dequeue and drop bytes from fifo.
Definition: svm_fifo.c:948
Notify on transition to empty.
Definition: svm_fifo.h:48
u8 data[0]
start of chunk data
Definition: svm_fifo.h:63
void svm_fifo_free(svm_fifo_t *f)
Free fifo and associated state.
Definition: svm_fifo.c:772
static void svm_fifo_clear_deq_ntf(svm_fifo_t *f)
Clear the want notification flag and set has notification.
Definition: svm_fifo.h:797
static void svm_fifo_add_want_deq_ntf(svm_fifo_t *f, u8 ntf_type)
Set specific want notification flag.
Definition: svm_fifo.h:766
static u8 svm_fifo_is_wrapped(svm_fifo_t *f)
Check if fifo is wrapped.
Definition: svm_fifo.h:593
Out-of-order segment.
Definition: svm_fifo.h:29
Notify on transition from full.
Definition: svm_fifo.h:47
static u32 f_distance_to(svm_fifo_t *f, u32 a, u32 b)
Distance to a from b, i.e., a - b in the fifo.
Definition: svm_fifo.h:197
u32 length
Length of segment.
Definition: svm_fifo.h:34
void svm_fifo_enqueue_nocopy(svm_fifo_t *f, u32 len)
Advance tail pointer.
Definition: svm_fifo.c:883
void svm_fifo_init(svm_fifo_t *f, u32 size)
Initialize fifo.
Definition: svm_fifo.c:392
u32 next
Next linked-list element pool index.
Definition: svm_fifo.h:31
template key/value backing page structure
Definition: bihash_doc.h:44
#define clib_atomic_swap_rel_n(a, b)
Definition: atomics.h:52
enum svm_fifo_deq_ntf_ svm_fifo_deq_ntf_t
No notification requested.
Definition: svm_fifo.h:45
enum svm_fifo_flag_ svm_fifo_flag_t
static void svm_fifo_del_want_deq_ntf(svm_fifo_t *f, u8 ntf_type)
Clear specific want notification flag.
Definition: svm_fifo.h:780
static u32 f_distance_from(svm_fifo_t *f, u32 a, u32 b)
Distance from a to b, i.e., b - a in the fifo.
Definition: svm_fifo.h:208
static u32 ooo_segment_offset_prod(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:703
static u8 svm_fifo_n_subscribers(svm_fifo_t *f)
Definition: svm_fifo.h:671
void svm_fifo_init_pointers(svm_fifo_t *f, u32 head, u32 tail)
Init fifo head and tail.
Definition: svm_fifo.c:1075
void svm_fifo_segments_free(svm_fifo_t *f, svm_fifo_seg_t *fs)
Definition: svm_fifo.c:1028
svm_fifo_err_t
Definition: svm_fifo.h:122
static int svm_fifo_has_event(svm_fifo_t *f)
Check if fifo has io event.
Definition: svm_fifo.h:725
#define clib_atomic_load_acq_n(a)
Definition: atomics.h:48
void svm_fifo_del_subscriber(svm_fifo_t *f, u8 subscriber)
Remove io events subscriber form list.
Definition: svm_fifo.c:1102
int svm_fifo_enqueue_with_offset(svm_fifo_t *f, u32 offset, u32 len, u8 *src)
Enqueue data to fifo with offset.
Definition: svm_fifo.c:850
u32 start
Start of segment, normalized.
Definition: svm_fifo.h:33
ooo_segment_t * svm_fifo_first_ooo_segment(svm_fifo_t *f)
First out-of-order segment for fifo.
Definition: svm_fifo.c:1066
CLIB vectors are ubiquitous dynamically resized arrays with by user defined "headers".