source: lib/libtrace_parallel.h @ 62b2d97

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Last change on this file since 62b2d97 was 62b2d97, checked in by Jacob Van Walraven <jcv9@…>, 22 months ago

Add callback for meta packets

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1/*
2 *
3 * Copyright (c) 2007-2016 The University of Waikato, Hamilton, New Zealand.
4 * All rights reserved.
5 *
6 * This file is part of libtrace.
7 *
8 * This code has been developed by the University of Waikato WAND
9 * research group. For further information please see http://www.wand.net.nz/
10 *
11 * libtrace is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU Lesser General Public License as published by
13 * the Free Software Foundation; either version 3 of the License, or
14 * (at your option) any later version.
15 *
16 * libtrace is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public License
22 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
23 *
24 *
25 */
26
27
28/** @file
29 *
30 * @brief Header file containing definitions for structures and functions
31 * related to the parallel framework
32 *
33 * @author Richard Sanger
34 *
35 * @version 4.0.0
36 *
37 * The parallel libtrace framework is a replacement to the libtrace framework
38 * that allows packet processing workload to be spread over multiple threads.
39 * It can also take advantage of native parallelism in the packet capture
40 * source.
41 */
42
43#ifndef LIBTRACE_PARALLEL_H
44#define LIBTRACE_PARALLEL_H
45
46#include "libtrace.h"
47#include <stdio.h>
48
49#ifdef __cplusplus
50extern "C" {
51#endif
52
53typedef struct libtrace_result_t libtrace_result_t;
54
55/**
56 * A collection of types for convenience used in place of a
57 * simple void* to allow any type of data to be stored and passed
58 * around easily.
59 *
60 * This is expected to be 8 bytes in length.
61 */
62typedef union {
63        /* Pointers */
64        void *ptr;
65        libtrace_packet_t *pkt;
66        libtrace_result_t *res;
67
68        /* C99 Integer types */
69        /* NOTE: Standard doesn't require 64-bit
70         * but x32 and x64 gcc does */
71        int64_t sint64;
72        uint64_t uint64;
73
74        uint32_t uint32s[2];
75        int32_t sint32s[2];
76        uint32_t uint32;
77        int32_t sint32;
78
79        uint16_t uint16s[4];
80        int16_t sint16s[4];
81        uint16_t uint16;
82        int16_t sint16;
83
84        uint8_t uint8s[8];
85        int8_t sint8s[8];
86        uint8_t uint8;
87        int8_t sint8;
88
89        size_t size;
90
91        /* C basic types - we cannot be certain of the size */
92        int sint;
93        unsigned int uint;
94
95        signed char schars[8];
96        unsigned char uchars[8];
97        signed char schar;
98        unsigned char uchar;
99
100        /* Real numbers */
101        float rfloat;
102        double rdouble;
103} libtrace_generic_t;
104ct_assert(sizeof(libtrace_generic_t) == 8);
105
106/**
107 * Structure describing a message that can be sent to a libtrace thread.
108 */
109typedef struct libtrace_message_t {
110        int code; /**< The message code, as defined in enum libtrace_messages */
111        libtrace_generic_t data; /**< Additional data related to the message */
112        libtrace_thread_t *sender; /**< The thread that sent the message */
113} libtrace_message_t;
114
115/** Structure holding information about a result */
116struct libtrace_result_t {
117        uint64_t key;   /**< The unique key for the result */
118        libtrace_generic_t value;  /**< The result value itself */
119        int type; /**< Describes the type of result, see enum result_types */
120};
121
122/** The libtrace_messages enum
123 * All libtrace messages are defined and documented here.
124 *
125 * Some messages can be sent to control the internal behaviour of the library
126 * while others are used to trigger the user-defined callback functions.
127 * If a user wishes to send their own custom messages, they should use
128 * numbers greater than MESSAGE_USER (1000).
129 *
130 * @note Some messages are for internal use only
131 */
132enum libtrace_messages {
133        /** A libtrace packet is ready, this will trigger the packet callback
134         *  for the processing threads.
135         */
136        MESSAGE_PACKET,
137
138        /** A libtrace meta packet is ready, this will trigger the meta packet
139         *  callback for the processing threads.
140         */
141        MESSAGE_META_PACKET,
142
143        /** A libtrace result is ready, this will trigger the result callback
144         *  for the reporter thread.
145         */
146        MESSAGE_RESULT,
147
148        /** This message is sent to each thread when it first starts and will
149         *  trigger the starting callback for the processing and reporter
150         *  threads. A starting message is sent when trace_pstart is called
151         *  for the first time on a trace.
152         */
153        MESSAGE_STARTING,
154
155        /** This message is sent to each thread when the thread ends and will
156         *  trigger the stopping callback for the processing and reporter
157         *  threads.
158         */
159        MESSAGE_STOPPING,
160
161        /** This message is sent to each thread when the thread transitions
162         *  from a paused state to a running state. It will trigger the
163         *  resuming callback for the processing and reporter threads.
164         *
165         *  A resuming message is sent whenever trace_pstart is called on a
166         *  trace (including the first time the trace is started).
167         */
168        MESSAGE_RESUMING,
169
170        /** This message is sent to each thread when the thread transitions
171         *  into a paused state from a running state. It will trigger the
172         *  pausing callback for the processing and reporter threads.
173         *
174         *  A pausing message is sent whenever trace_ppause is called on a
175         *  trace. It will also be sent when a trace is stopped, as all traces
176         *  are implicitly paused before they stop.
177         */
178        MESSAGE_PAUSING,
179
180        /** An internal message for forcing another thread to pause. Do not
181         *  use this in user-defined callbacks!
182         */
183        MESSAGE_DO_PAUSE,
184
185        /** An internal message for forcing another thread to stop. Do not
186         *  use this in user-defined callbacks!
187         */
188        MESSAGE_DO_STOP,
189
190        /** This message is sent to each processing thread as soon as the first
191         *  packet has been seen by any of the processing threads. This will
192         *  trigger the first_packet callback for the processing threads,
193         *  allowing the threads to perform any initialisation required based
194         *  on the properties of the first packet (e.g. the timestamp).
195         *
196         *  Threads should use trace_get_first_packet() to access the packet
197         *  that triggered this message.
198         *
199         *  @note Upon pausing and restarting a trace, this message will be
200         *  sent again when the first new packet is encountered.
201         */
202        MESSAGE_FIRST_PACKET,
203
204        /** An internal message for notifying the reporter thread that more
205         *  results are available.
206         *
207         *  Do not use this in user-defined callbacks -- call
208         *  trace_post_reporter() instead.
209         */
210        MESSAGE_POST_REPORTER,
211
212        /** Sent to per-packet threads periodically after the configured time
213         * interval has passed.
214         *
215         * This is sent out-of-band with respect to packets and as a result
216         * can appear after a packet with an later time-stamp, or before one
217         * with an earlier time-stamp.
218         *
219         * @param data data.uint64 holds the system time-stamp in the
220         * erf format
221         * @param sender should be ignored
222         */
223
224        /** This message is sent to the processing threads periodically, after
225         *  the configured time interval has passed. This message will
226         *  trigger the tick_interval callback function for the processing
227         *  threads.
228         *
229         *  This message is sent out-of-band relative to packet messages and
230         *  therefore can appear after a packet with a later timestamp or
231         *  before a packet with an earlier timestamp.
232         */
233        MESSAGE_TICK_INTERVAL,
234
235        /** Sent to per-packet threads once the configured number of packets
236         * are read from a trace.
237         *
238         * This are sent in-band with respect to packets such that all
239         * threads will see it between the same packets.
240         *
241         * @param data data.uint64 holds the number of packets seen so far across all threads
242         * @param sender Set to the current per-packet thread
243         */
244        /** This message is sent to the processing threads periodically, after
245         *  the configured number of packets have been read from the input
246         *  trace. This message will trigger the tick_count callback function
247         *  for the processing threads.
248         *
249         *  This message is sent in-band relative to packet messages and
250         *  will always appear in the right place relative to the other packets
251         *  observed by the thread.
252         */
253        MESSAGE_TICK_COUNT,
254
255        /** All message codes at or above this value represent custom
256         *  user-defined messages and will trigger the usermessage callback
257         *  for the processing threads.
258         */
259        MESSAGE_USER = 1000
260};
261
262/** The hasher types that are available to libtrace applications.
263 *  These can be selected using trace_set_hasher().
264 */
265enum hasher_types {
266        /** Balance load across per-packet threads as best as possible, i.e
267         *  the program does not care which thread sees a given packet. This
268         *  will be implemented using a hash or round robin, depending on the
269         *  format and libtrace configuration.
270         */
271        HASHER_BALANCE,
272
273        /** Use a hash which is bi-directional for TCP and UDP flows, such that
274         * packets with the same 5-tuple are sent to the same processing thread.
275         * All non TCP/UDP packets will be sent to the same thread.
276         *
277         * @note it is possible that UDP packets may not be spread across
278         * processing threads, depending upon the format support. In this case
279         * they would be directed to a single thread.
280         */
281        HASHER_BIDIRECTIONAL,
282
283        /** Use a hash which is uni-directional across TCP and UDP flows, such
284         * that the opposing directions of the same 5-tuple may end up on
285         * different processing threads.
286         * Otherwise this is identical to HASHER_BIDIRECTIONAL.
287         */
288        HASHER_UNIDIRECTIONAL,
289
290        /**
291         * This value indicates that the hasher is a custom user-defined
292         * function.
293         */
294        HASHER_CUSTOM
295};
296
297typedef struct libtrace_info_t {
298        /**
299         * True if a live format (i.e. packets have to be trace-time).
300         * Otherwise false, indicating packets can be read as fast
301         * as possible from the format.
302         */
303        bool live;
304
305        /**
306         * The maximum number of threads supported by a parallel trace. 1
307         * if parallel support is not native (in this case libtrace will
308         * simulate an unlimited number of threads), -1 means unlimited and 0
309         * unknown.
310         */
311        int max_threads;
312
313        /* TODO hash fn supported list */
314
315        /* TODO consider time/clock details?? */
316} libtrace_info_t;
317
318typedef struct libtrace_combine libtrace_combine_t;
319/**
320 * The methods we use to combine the results from multiple processing
321 * threads into a single output. Users can write their own combiners, but
322 * we strongly recommend that you use one of the provided combiners.
323 *
324 */
325struct libtrace_combine {
326
327        /**
328         * Called at the start of the trace to allow data-structures
329         * to be initialised and allow functions to be swapped if appropriate.
330         *
331         * Also factors such as whether the trace is live or not can
332         * be used to determine the functions used.
333         * @return 0 if successful, -1 if an error occurs
334         */
335        int (*initialise)(libtrace_t *,libtrace_combine_t *);
336
337        /**
338         * Called when the trace ends, clean up any memory allocated
339         * by the initialise function.
340         */
341        void (*destroy)(libtrace_t *, libtrace_combine_t *);
342
343        /**
344         * Receive a result from a processing thread. Most implementations
345         * of this function will push the result into an appropriate
346         * queue. If this is NULL, the result will automatically be pushed
347         * to the reporter thread.
348         */
349        void (*publish)(libtrace_t *, int thread_id, libtrace_combine_t *, libtrace_result_t *);
350
351        /**
352         * Read as many results as possible from the trace. Each result
353         * that is read should cause a MESSAGE_RESULT to be sent to the
354         * reporter thread.
355         *
356         * THIS SHOULD BE NON-BLOCKING AND READ AS MANY AS POSSIBLE!
357         * If publish is NULL, this probably should be NULL as it will not be
358         * called in that case.
359         */
360        void (*read)(libtrace_t *, libtrace_combine_t *);
361
362        /**
363         * Called when the trace is finished to flush the final
364         * results to the reporter thread. Any leftover results should
365         * cause a MESSAGE_RESULT to be sent to the reporter thread.
366         *
367         * There may be no results, in which case this function should
368         * just return.
369         *
370         * Libtrace state:
371         * This function will be called from the reporter thread.
372         * No processing threads will be running, i.e. you can assume that
373         * publish will not be called again.
374         *
375         * If publish is NULL, this probably should be NULL as it will not be
376         * called in that case.
377         */
378        void (*read_final)(libtrace_t *, libtrace_combine_t *);
379
380        /**
381         * Pause must make sure any queued results that contain packets are
382         * safe. See libtrace_make_result_safe() for more details on what it
383         * means for a result to be safe.
384         * This function should be NULL if publish is NULL.
385         */
386        void (*pause)(libtrace_t *, libtrace_combine_t *);
387
388        /**
389         * Data storage for all the combiner threads
390         */
391        void *queues;
392
393        /** The last counter tick that we saw, so we can avoid duplicating
394         *  any ticks that are published.
395         */
396        uint64_t last_count_tick;
397
398        /** The last timestamp tick that we saw, so we can avoid duplicating
399         *  any ticks that are published.
400         */
401        uint64_t last_ts_tick;
402
403        /**
404         * Configuration options, what this does is up to the combiner
405         * chosen.
406         */
407        libtrace_generic_t configuration;
408};
409
410/**
411 * The definition for a hasher function, allowing matching packets to be
412 * directed to the correct thread for processing.
413 *
414 * @param packet The packet to be hashed.
415 * @param data A void pointer which can contain additional information,
416 * such as configuration for the hasher function.
417 *
418 * @return The id of the thread that should receive this packet.
419 */
420typedef uint64_t (*fn_hasher)(const libtrace_packet_t* packet, void *data);
421
422
423/** Start or restart an input trace in the parallel libtrace framework.
424 *
425 * @param libtrace The input trace to start
426 * @param global_blob Global data related to this trace. This may be NULL if
427 *    no global data is required.
428 * @param per_packet_cbs A set of user supplied functions to be called in
429 *   response to messages that are observed by the processing threads.
430 * @param reporter_cbs A set of user supplied functions to be called in
431 *   response to messages being seen by the reporter thread.
432 * Optional if NULL, the reporter thread will not be started.
433 * @return 0 on success, otherwise -1 to indicate an error has occurred
434 *
435 * This can also be used to restart an existing parallel trace,
436 * that has previously been paused using trace_ppause().
437 * In this case global_blob, per_packet_cbs and reporter_cbs will only be
438 * updated if they are non-null. Otherwise their previous values will be
439 * maintained.
440 *
441 */
442DLLEXPORT int trace_pstart(libtrace_t *libtrace, void* global_blob,
443                           libtrace_callback_set_t *per_packet_cbs,
444                           libtrace_callback_set_t *reporter_cbs);
445
446/**
447 * The starting callback for a processing or reporting thread. Use this
448 * callback to allocate and initialise any thread-local storage that you
449 * would like to be available in other callbacks.
450 *
451 * @param libtrace The parallel trace.
452 * @param t The thread that has just started.
453 * @param global The global storage for the trace.
454 *
455 * @return The returned value is stored against the thread's local storage.
456 *         This is typically passed as the 'tls' argument to other callbacks.
457 */
458typedef void* (*fn_cb_starting)(libtrace_t *libtrace,
459                                     libtrace_thread_t *t,
460                                     void *global);
461
462/**
463 * A callback function for any message that does not require any specific
464 * data, e.g. stopping, pausing, or resuming callbacks.
465 *
466 * @param libtrace The parallel trace.
467 * @param t The thread that is running.
468 * @param global The global storage.
469 * @param tls The thread local storage.
470 */
471typedef void (*fn_cb_dataless)(libtrace_t *libtrace,
472                                    libtrace_thread_t *t,
473                                    void *global,
474                                    void *tls);
475
476/**
477 * A callback function for a first packet message seen by a processing thread.
478 * @param libtrace The parallel trace.
479 * @param t The thread that is running.
480 * @param global The global storage.
481 * @param tls The thread local storage.
482 * @param sender The thread that saw the first packet.
483 */
484typedef void (*fn_cb_first_packet)(libtrace_t *libtrace,
485                                   libtrace_thread_t *t,
486                                   void *global,
487                                   void *tls,
488                                   libtrace_thread_t *sender);
489
490/**
491 * A callback function for handling a tick message within a processing thread.
492 *
493 * @param libtrace The parallel trace.
494 * @param t The thread that is running.
495 * @param global The global storage.
496 * @param tls The thread local storage.
497 * @param uint64_t The value of the tick; either a timestamp or packet count
498 *    depending on the type of tick.
499 */
500typedef void (*fn_cb_tick)(libtrace_t *libtrace,
501                           libtrace_thread_t *t,
502                           void *global,
503                           void *tls,
504                           uint64_t order);
505
506/**
507 * A callback function triggered when a processing thread receives a packet.
508 *
509 * @param libtrace The parallel trace.
510 * @param t The thread that is running
511 * @param global The global storage.
512 * @param tls The thread local storage.
513 * @param packet The packet to be processed.
514 *
515 * @return either the packet itself if it is not being published as a result
516 *   or NULL otherwise. If returning NULL, it is the user's responsibility
517 *   to ensure the packet is freed when the reporter thread is finished with it.
518 */
519typedef libtrace_packet_t* (*fn_cb_packet)(libtrace_t *libtrace,
520                                           libtrace_thread_t *t,
521                                           void *global,
522                                           void *tls,
523                                           libtrace_packet_t *packet);
524
525/**
526 * A callback function triggered when a processing thread receives a meta packet.
527 *
528 * @param libtrace The parallel trace.
529 * @param t The thread that is running
530 * @param global The global storage.
531 * @param tls The thread local storage.
532 * @param packet The packet to be processed.
533 *
534 * @return either the packet itself if it is not being published as a result
535 *   or NULL otherwise. If returning NULL, it is the user's responsibility
536 *   to ensure the packet is freed when the reporter thread is finished with it.
537 */
538typedef libtrace_packet_t* (*fn_cb_meta_packet)(libtrace_t *libtrace,
539                                           libtrace_thread_t *t,
540                                           void *global,
541                                           void *tls,
542                                           libtrace_packet_t *packet);
543
544/**
545 * Callback for handling a result message. Should only be required by the
546 * reporter thread.
547 *
548 * @param libtrace The parallel trace.
549 * @param sender The thread that generated this result.
550 * @param global The global storage.
551 * @param tls The thread local storage.
552 * @param result The result associated with the message.
553 *
554 */
555typedef void (*fn_cb_result)(libtrace_t *libtrace, libtrace_thread_t *sender,
556                void *global, void *tls, libtrace_result_t *result);
557
558
559/**
560 * Callback for handling any user-defined message types. This will handle
561 * any messages with a type >= MESSAGE_USER.
562 *
563 * @param libtrace The parallel trace.
564 * @param t The thread.
565 * @param global The global storage.
566 * @param tls The thread local storage.
567 * @param mesg The code identifying the message type.
568 * @param data The data associated with the message.
569 *
570 */
571typedef void (*fn_cb_usermessage) (libtrace_t *libtrace, libtrace_thread_t *t,
572                void *global, void *tls, int mesg, libtrace_generic_t data,
573                libtrace_thread_t *sender);
574
575
576/**
577 * Registers a starting callback against a callback set.
578 *
579 * @param cbset The callback set.
580 * @param handler The starting callback function.
581 * @return 0 if successful, -1 otherwise.
582 */
583DLLEXPORT int trace_set_starting_cb(libtrace_callback_set_t *cbset,
584                fn_cb_starting handler);
585
586/**
587 * Registers a stopping callback against a callback set.
588 *
589 * @param cbset The callback set.
590 * @param handler The stopping callback function.
591 * @return 0 if successful, -1 otherwise.
592 */
593DLLEXPORT int trace_set_stopping_cb(libtrace_callback_set_t *cbset,
594                fn_cb_dataless handler);
595
596/**
597 * Registers a resuming callback against a callback set.
598 *
599 * @param cbset The callback set.
600 * @param handler The resuming callback function.
601 * @return 0 if successful, -1 otherwise.
602 */
603DLLEXPORT int trace_set_resuming_cb(libtrace_callback_set_t *cbset,
604                fn_cb_dataless handler);
605
606/**
607 * Registers a pausing callback against a callback set.
608 *
609 * @param cbset The callback set.
610 * @param handler The pausing callback function.
611 * @return 0 if successful, -1 otherwise.
612 */
613DLLEXPORT int trace_set_pausing_cb(libtrace_callback_set_t *cbset,
614                fn_cb_dataless handler);
615
616/**
617 * Registers a packet callback against a callback set.
618 *
619 * @param cbset The callback set.
620 * @param handler The packet callback function.
621 * @return 0 if successful, -1 otherwise.
622 */
623DLLEXPORT int trace_set_packet_cb(libtrace_callback_set_t *cbset,
624                fn_cb_packet handler);
625
626/**
627 * Registers a meta packet callback against a callback set.
628 *
629 * @param cbset The callback set.
630 * @param handler The meta packet callback funtion.
631 * @return 0 if successful, -1 otherwise.
632 */
633DLLEXPORT int trace_set_meta_packet_cb(libtrace_callback_set_t *cbset,
634                fn_cb_meta_packet handler);
635
636/**
637 * Registers a first packet callback against a callback set.
638 *
639 * @param cbset The callback set.
640 * @param handler The first packet callback function.
641 * @return 0 if successful, -1 otherwise.
642 */
643DLLEXPORT int trace_set_first_packet_cb(libtrace_callback_set_t *cbset,
644                fn_cb_first_packet handler);
645
646/**
647 * Registers a result callback against a callback set.
648 *
649 * @param cbset The callback set.
650 * @param handler The result callback function.
651 * @return 0 if successful, -1 otherwise.
652 */
653DLLEXPORT int trace_set_result_cb(libtrace_callback_set_t *cbset,
654                fn_cb_result handler);
655
656/**
657 * Registers a tick counter callback against a callback set.
658 *
659 * @param cbset The callback set.
660 * @param handler The tick callback function.
661 * @return 0 if successful, -1 otherwise.
662 */
663DLLEXPORT int trace_set_tick_count_cb(libtrace_callback_set_t *cbset,
664                fn_cb_tick handler);
665
666/**
667 * Registers a tick interval callback against a callback set.
668 *
669 * @param cbset The callback set.
670 * @param handler The tick callback function.
671 * @return 0 if successful, -1 otherwise.
672 */
673DLLEXPORT int trace_set_tick_interval_cb(libtrace_callback_set_t *cbset,
674                fn_cb_tick handler);
675
676/**
677 * Registers a callback for custom user messages against a callback set.
678 *
679 * @param cbset The callback set.
680 * @param handler The user message callback function.
681 * @return 0 if successful, -1 otherwise.
682 */
683DLLEXPORT int trace_set_user_message_cb(libtrace_callback_set_t *cbset,
684                fn_cb_usermessage handler);
685
686/** Create a callback set that can be used to define callbacks for parallel
687  * libtrace threads.
688  *
689  * @return A pointer to a freshly allocated callback set.
690  */
691DLLEXPORT libtrace_callback_set_t *trace_create_callback_set(void);
692
693/** Destroys a callback set, freeing up any resources it was using.
694 *
695 * @param cbset         The callback set to be destroyed.
696 */
697DLLEXPORT void trace_destroy_callback_set(libtrace_callback_set_t *cbset);
698
699
700/** Pauses a trace previously started with trace_pstart()
701 *
702 * @param libtrace The parallel trace to be paused
703 * @return 0 on success, otherwise -1 to indicate an error has occurred
704 *
705 */
706DLLEXPORT int trace_ppause(libtrace_t *libtrace);
707
708/** Stops a parallel trace, causing all threads to exit as if an EOF
709 * has occurred. This replaces trace_interrupt(), allowing
710 * a specified trace to be stopped.
711 *
712 * @param libtrace The parallel trace to be stopped
713 * @return 0 on success, otherwise -1 to indicate an error has occurred
714 *
715 * Ideally, this should only be called by the main thread (i.e. from a signal
716 * handler) but it can be called from within a reporter thread reasonably
717 * safely.
718 *
719 */
720DLLEXPORT int trace_pstop(libtrace_t *libtrace);
721
722/** Waits for a trace to finish and all threads to join.
723 *
724 * @param trace The parallel trace
725 *
726 * Waits for a trace to finish, whether this be due to
727 * an error occurring, an EOF or trace_pstop.
728 *
729 */
730DLLEXPORT void trace_join(libtrace_t * trace);
731
732
733/**
734 * @name Parallel Configuration
735 *
736 * These methods provide a way to configure the parallel libtrace library.
737 *
738 * Many of these options are typically unneeded by most applications as they
739 * control tuning aspects of the library and are more useful to the
740 * end user.
741 *
742 * To allow the end user to change this configuration libtrace will search for
743 * three environment variables and apply them to the configuration in the
744 * following order. Such that the first has the lowest priority.
745 *
746 * 1. LIBTRACE_CONF, The global environment configuration
747 * 2. LIBTRACE_CONF_<FORMAT>, Applied to a given format
748 * 3. LIBTRACE_CONF_<FORMAT_URI>, Applied the specified trace
749 *
750 * E.g.
751 * - int:eth0 would match LIBTRACE_CONF, LIBTRACE_CONF_INT,
752 *       LIBTRACE_CONF_INT_ETH0
753 * - dag:/dev/dag0,0 would match LIBTRACE_CONF, LIBTRACE_CONF_DAG,
754 *       LIBTRACE_CONF_DAG__DEV_DAG0_0
755 * - test.erf would match LIBTRACE_CONF, LIBTRACE_CONF_ERF,
756 *       LIBTRACE_CONF_ERF_TEST_ERF
757 *
758 * @note All environment variables names MUST only contain
759 * [A-Z], [0-9] and [_] (underscore). Any characters
760 * outside of this range should be capitalised if possible or replaced with an
761 * underscore.
762 * @{
763 */
764
765/** Set the maximum number of perpkt threads to use in a trace.
766 *
767 * Only valid on a new trace, that has not be started. Once started
768 * the number of threads cannot be changed without destroying the trace.
769 *
770 * @param[in] trace The parallel input trace
771 * @param[in] nb The number of threads to use. If set to 0, libtrace will
772 *    try to auto-detect how many threads it can use.
773 * @return 0 if successful otherwise -1
774 */
775DLLEXPORT int trace_set_perpkt_threads(libtrace_t *trace, int nb);
776
777/** Set the interval between tick messages in milliseconds.
778 *
779 * @param[in] trace The parallel input trace
780 * @param[in] millisec The interval in milliseconds. If 0 this is disabled
781 *     [default].
782 * @return 0 if successful, otherwise -1.
783 *
784 * When enabled, MESSAGE_TICK_INTERVAL will be sent every tick interval to all
785 * processing threads. This allows results to be published even in cases where
786 * new packets are not being directed to a processing thread, while still
787 * maintaining order etc.
788 *
789 * @see MESSAGE_TICK_INTERVAL, trace_set_tick_count()
790 */
791DLLEXPORT int trace_set_tick_interval(libtrace_t *trace, size_t millisec);
792
793/** Set the number of packets to be read between tick messages.
794 *
795 * @param[in] trace The parallel input trace
796 * @param[in] count The tick count.  If 0 this is disabled [default].
797 * @return 0 if successful otherwise -1
798 *
799 * When enabled, MESSAGE_TICK_COUNT will be sent to all processing threads
800 * after every 'count' packets have been read from the trace. This allows
801 * results to be published even in cases where new packets are not being
802 * directed to a processing thread, while still maintaining order etc.
803 *
804 * @see MESSAGE_TICK_COUNT, trace_set_tick_interval()
805 */
806DLLEXPORT int trace_set_tick_count(libtrace_t *trace, size_t count);
807
808/**
809 * Delays packets so they are played back in trace-time rather than as fast
810 * as possible (real-time).
811 *
812 * @param trace A parallel input trace
813 * @param tracetime If true packets are released with time spacing that matches
814 * the original trace. Otherwise packets are read as fast as possible.
815 * @return 0 if successful otherwise -1
816 */
817DLLEXPORT int trace_set_tracetime(libtrace_t *trace, bool tracetime);
818
819/** Sets the maximum size of the freelist used to store empty packets
820 * and their memory buffers.
821 *
822 * @param trace A parallel input trace
823 * @param size The number of empty packets to cache in memory. Set to the
824 * default, 0, to autoconfigure this value.
825 * @return 0 if successful otherwise -1
826 *
827 * Internally libtrace maintains a buffer of packet structures which
828 * includes a cache per thread and a shared main pool. This option configures
829 * the size of the main pool. If an application is not passing packets
830 * through to the reporter thread, i.e. the packet callback always returns
831 * the packet, then the main pool is not used.
832 *
833 * @note Setting this too low could cause performance issues or a deadlock. An
834 * unblockable warning will be printed.
835 *
836 * @see trace_set_thread_cache_size(), trace_set_fixed_count()
837 */
838DLLEXPORT int trace_set_cache_size(libtrace_t *trace, size_t size);
839
840/** This sets the maximum size of the freelist cache owned by each thread
841 * used to provide faster access to empty packets than the main shared pool.
842 *
843 * @param trace A parallel input trace
844 * @param size The number of empty packets to cache in memory. Set to the
845 * default, 0, to autoconfigure this value.
846 * @return 0 if successful otherwise -1
847 *
848 * @see trace_set_cache_size(), trace_set_fixed_count()
849 */
850DLLEXPORT int trace_set_thread_cache_size(libtrace_t *trace, size_t size);
851
852/** Determines whether a trace is allowed to create additional packets
853 *  beyond the cache size.
854 *
855 *  If set to true, libtrace will cease reading packets once the cache is used
856 *  up until the other threads release some packets back to the cache.
857 *
858 *  If set to false (the default), libtrace will use malloc and free to create
859 *  additional packets when the cache is exhausted. This will be slower than
860 *  getting a packet from the cache and will eventually run the machine out
861 *  of memory if packets are allocated faster than they are released.
862 *
863 * @param trace A parallel input trace
864 * @param fixed If true the total number of packets is limited, otherwise
865 * it is not. Defaults to false.
866 * @return 0 if successful otherwise -1
867 *
868 * @see trace_set_thread_cache_size(), trace_set_cache_size()
869 */
870DLLEXPORT int trace_set_fixed_count(libtrace_t *trace, bool fixed);
871
872/** The number of packets to batch together for processing internally
873 * by libtrace.
874 *
875 * @param trace A parallel input trace
876 * @param size The total number of packets to batch together. Set to the
877 * default, 0, to autoconfigure this value.
878 * @return 0 if successful otherwise -1
879 *
880 * Internally libtrace will attempt to read up to this number of packets from
881 * a format at a time. Typically, values of 10 will get good performance and
882 * increasing beyond that will should little difference.
883 *
884 * @note We still pass a single packet at a time to the packet callback
885 * function.
886 */
887DLLEXPORT int trace_set_burst_size(libtrace_t *trace, size_t size);
888
889/**
890 * Sets the maximum size of the buffer used between the single hasher thread
891 * and the packet processing thread.
892 *
893 * Setting this to less than recommend could cause a deadlock for an input
894 * trace that manages its own packets.
895 * A unblockable warning message will be printed to stderr in this case.
896 */
897DLLEXPORT int trace_set_hasher_queue_size(libtrace_t *trace, size_t size);
898
899/**
900 * Enables or disables polling of the hasher queue.
901 *
902 * If enabled, the processing threads will poll on the hasher queue, yielding
903 * if no data is available.
904 *
905 * If disabled, the processing threads will block on a condition variable
906 * if there is no data available from the hasher.
907 *
908 * @param trace A parallel input trace
909 * @param polling If true the hasher will poll waiting for data, otherwise
910 * it will use a condition variable. Defaults to false.
911 *
912 * We note polling is likely to waste many CPU cycles and could even decrease
913 * performance.
914 *
915 * @return 0 if successful otherwise -1
916 */
917DLLEXPORT int trace_set_hasher_polling(libtrace_t *trace, bool polling);
918
919/**
920 * Enables or disables polling of the reporter result queue.
921 *
922 * If enabled, the reporter thread will continuously poll for results.
923 * If disabled, the reporter will only check for results if it receives a
924 * MESSAGE_POST_REPORTER.
925 *
926 * @param trace A parallel input trace
927 * @param polling If true the reporter will poll waiting for data, otherwise
928 * it will wait for a MESSAGE_POST_REPORTER. Defaults to false.
929 * @return 0 if successful otherwise -1
930 *
931 * We note polling is likely to waste many CPU cycles and could even decrease
932 * performance.
933 *
934 * @note This setting could be ignored by some reporters.
935 */
936DLLEXPORT int trace_set_reporter_polling(libtrace_t *trace, bool polling);
937
938/**
939 * Set the number of results that are required in the result queue before
940 * a MESSAGE_POST_REPORTER is sent to the reporter so that it can read the
941 * results.
942 *
943 * Set this to 1 to ensure if you require your results to reach the reporter
944 * as soon as possible.
945 *
946 * @param trace A parallel input trace
947 * @param thold The threshold on the number of results to enqueue before
948 * notifying the reporter thread to read them.
949 * @return 0 if successful otherwise -1
950 *
951 *
952 * @note This setting is generally ignored if the reporter is polling. However,
953 * some combiner functions might ignore the polling behaviour and still
954 * require this to be set.
955 * @see trace_publish_result(), trace_post_reporter()
956 */
957DLLEXPORT int trace_set_reporter_thold(libtrace_t *trace, size_t thold);
958
959/**
960 * Enable or disable debug output for parallel libtrace.
961
962 * If enabled, libtrace will print a line to standard error for every
963 * state change observed by both the trace as a whole and by each thread.
964 *
965 * You really shouldn't need to enable this....
966 *
967 * @param trace A parallel input trace
968 * @param debug_state If true debug is printed. Defaults false.
969 * @return 0 if successful otherwise -1.
970 *
971 */
972DLLEXPORT int trace_set_debug_state(libtrace_t *trace, bool debug_state);
973
974/** Set the hasher function for a parallel trace.
975 *
976 * @param[in] trace The parallel trace to apply the hasher to
977 * @param[in] type The type of hashing to apply, see enum hasher_types
978 * @param[in] hasher A hasher function to use [Optional]
979 * @param[in] data Data passed to the hasher function [Optional]
980 *
981 * @return 0 if successful otherwise -1 on error
982 *
983 * The hasher function in a parallel trace can be used to control which
984 * processing thread will receive each packet.
985 *
986 * See hasher_types for a list of hashers supported natively by libtrace.
987 *
988 * HASHER_BALANCE is the default and will dispatch packets as fast as possible
989 * to all threads arbitrarily.
990 *
991 * HASHER_CUSTOM will force the libtrace to use the user defined function. In
992 * this case, the hasher parameter must be supplied.
993 *
994 * With other defined hasher types libtrace will try to push the hashing into
995 * the capture format wherever possible. In this case, the hasher parameter is
996 * optional; if a hasher is provided then it will be preferred over the
997 * libtrace implementation.
998 *
999 * @note When supplying a hasher function it should be thread-safe so it can
1000 * be run in parallel by libtrace. Ideally this should rely upon no state, other
1001 * than some form of seed value supplied in data.
1002 */
1003DLLEXPORT int trace_set_hasher(libtrace_t *trace, enum hasher_types type,
1004                               fn_hasher hasher, void *data);
1005
1006/// @}
1007
1008
1009/** Types of results.
1010 *
1011 * Custom result types users should be defined as RESULT_USER(1000) or greater.
1012 *
1013 */
1014enum result_types {
1015        /**
1016         * The result contains a pointer to a libtrace_packet_t. This
1017         * packet should be freed using trace_free_packet() once the result
1018         * is processed by the reporter thread.
1019         *
1020         * The key for a RESULT_PACKET is the packet order (see
1021         * trace_get_packet_order() for more about ordering).
1022         *
1023         */
1024        RESULT_PACKET,
1025
1026        /**
1027         * The result is a tick timestamp. The key is an ERF timestamp.
1028         */
1029        RESULT_TICK_INTERVAL,
1030
1031        /**
1032         * The result is a tick counter. The key is the sequence number of
1033         * the tick, relative to the packets read so far.
1034         */
1035        RESULT_TICK_COUNT,
1036
1037        /**
1038         * Any user-defined result codes should be at or above this value.
1039         */
1040        RESULT_USER = 1000
1041
1042};
1043
1044/** Publish a result to the reporter thread (via the combiner)
1045 *
1046 * @param[in] libtrace The parallel input trace
1047 * @param[in] t The current per-packet thread
1048 * @param[in] key The key of the result (used for sorting by the combiner)
1049 * @param[in] value The value of the result
1050 * @param[in] type The type of result (see result_types)
1051 */
1052DLLEXPORT void trace_publish_result(libtrace_t *libtrace,
1053                                    libtrace_thread_t *t,
1054                                    uint64_t key,
1055                                    libtrace_generic_t value,
1056                                    int type);
1057
1058/** Check if a dedicated hasher thread is being used.
1059 *
1060 * @param[in] libtrace The parallel input trace
1061 * @return true if the trace has dedicated hasher thread otherwise false.
1062 *
1063 * This should only be called after the trace has been started with
1064 * trace_pstart().
1065 */
1066DLLEXPORT bool trace_has_dedicated_hasher(libtrace_t * libtrace);
1067
1068/** Checks if a trace is using a reporter thread.
1069 *
1070 * @param[in] libtrace The parallel input trace
1071 * @return True if the trace is using a reporter otherwise false
1072 */
1073DLLEXPORT bool trace_has_reporter(libtrace_t * libtrace);
1074
1075/** Post a message to the reporter thread requesting that it check for more
1076 * results.
1077 *
1078 * @param[in] The parallel input trace
1079 * @return -1 upon error indicating the message has not been sent otherwise a
1080 * backlog indicator (the number of messages the reporter has not yet read).
1081 */
1082DLLEXPORT int trace_post_reporter(libtrace_t *libtrace);
1083
1084/** Check the number of messages waiting in a thread's message queue
1085 *
1086 * @param[in] libtrace The input trace
1087 * @param[in] t The thread to check; if NULL the current thread will be used.
1088 *
1089 * @return packets in the queue otherwise -1 upon error.
1090 *
1091 * @note For best performance it is recommended to supply the thread argument
1092 * even if it is the current thread.
1093 */
1094DLLEXPORT int libtrace_thread_get_message_count(libtrace_t * libtrace,
1095                                                libtrace_thread_t *t);
1096
1097/** Read a message from a thread in a blocking fashion.
1098 *
1099 * @param[in] libtrace The input trace
1100 * @param[in] t The thread to check, if NULL the current thread will be used.
1101 * @param[out] message A pointer to a libtrace_message_t structure which will
1102 * be filled with the retrieved message.
1103 *
1104 * @return The number of messages remaining otherwise -1 upon error.
1105 *
1106 * @note For best performance it is recommended to supply the thread argument
1107 * even if it is the current thread.
1108 */
1109DLLEXPORT int libtrace_thread_get_message(libtrace_t * libtrace,
1110                                          libtrace_thread_t *t,
1111                                          libtrace_message_t * message);
1112
1113/** Read a message from a thread in a non-blocking fashion.
1114 *
1115 * @param[in] libtrace The input trace
1116 * @param[in] t The thread to check, if NULL the current thread will be used.
1117 * @param[out] message A pointer to a libtrace_message_t structure which will
1118 * be filled with the retrieved message.
1119 *
1120 * @return 0 if successful otherwise -1 upon error or if no message were
1121 * available.
1122 *
1123 * @note For best performance it is recommended to supply the thread argument
1124 * even if it is the current thread.
1125 */
1126DLLEXPORT int libtrace_thread_try_get_message(libtrace_t * libtrace,
1127                                              libtrace_thread_t *t,
1128                                              libtrace_message_t * message);
1129
1130/** Send a message to the reporter thread.
1131 *
1132 * @param[in] libtrace The parallel trace
1133 * @param[in] message The message to be sent. If the sender field is NULL,
1134 * libtrace will attempt to fill this in. It is faster to assign this if it is
1135 * known.
1136 *
1137 * @return -1 upon error indicating the message has not been sent. Otherwise,
1138 * will return the number of messages the reporter has not yet read.
1139 */
1140DLLEXPORT int trace_message_reporter(libtrace_t * libtrace,
1141                                     libtrace_message_t * message);
1142
1143/** Send a message to all processing threads.
1144 *
1145 * @param[in] libtrace The parallel trace
1146 * @param[in] message The message to be sent. If the sender field is NULL,
1147 * libtrace will attempt to fill this in. It is faster to assign this if it is
1148 * known.
1149 *
1150 * @return 0 if successful. Otherwise, a negative number is returned that
1151 * indicates the number of processing threads that the message was not sent
1152 * to (i.e. -1 means one thread could not be sent the message).
1153 */
1154DLLEXPORT int trace_message_perpkts(libtrace_t * libtrace,
1155                                    libtrace_message_t * message);
1156
1157/** Send a message to a specific thread.
1158 *
1159 * @param[in] libtrace The parallel trace
1160 * @param[in] t The thread to message
1161 * @param[in] message The message to be sent. If the sender field is NULL,
1162 * libtrace will attempt to fill this in. It is faster to assign this if it is
1163 * known.
1164 *
1165 * @return -1 upon error indicating the message has not been sent. Otherwise,
1166 * will return the number of messages the recipient has not yet read.
1167 */
1168DLLEXPORT int trace_message_thread(libtrace_t * libtrace,
1169                                   libtrace_thread_t *t,
1170                                   libtrace_message_t * message);
1171
1172/** Checks if a parallel trace has finished reading packets.
1173 *
1174 * @return true if the trace has finished reading packets (even if all results
1175 * have not yet been processed). Otherwise false.
1176 *
1177 * @note This returns true even if all results have not yet been processed by
1178 * the reporter thread.
1179 */
1180DLLEXPORT bool trace_has_finished(libtrace_t * libtrace);
1181
1182
1183/** Check if libtrace is directly reading from multiple queues
1184 * from within the capture format (such as a NICs hardware queues).
1185 *
1186 * A trace is considered to be parallel if the input format for the trace
1187 * allows the packets to be read in a natively parallel fashion, i.e. packets
1188 * can be read using multiple pipelines. If this function returns false, the
1189 * packets are instead being read from a single input source and then
1190 * distributed amongst the processing threads.
1191 *
1192 * Factors that may cause this function to return false despite the format
1193 * normally supporting native parallel reads include: the choice of hasher
1194 * function, the number of threads choosen (such as 1 or more than the trace
1195 * supports) or another error when trying to start the parallel format.
1196 *
1197 * If called before the trace is started, i.e. before trace_pstart(), this
1198 * function returns an indication whether the trace has the possiblity to
1199 * support native parallel reads. After trace_pstart() is called this should be
1200 * checked again to confirm that this has happened.
1201 *
1202 * @return true if the trace is parallel or false if the library is splitting
1203 * the trace into multiple threads.
1204 */
1205DLLEXPORT bool trace_is_parallel(libtrace_t * libtrace);
1206
1207/** Returns either the sequence number or erf timestamp of a packet.
1208 *
1209 * @param[in] packet
1210 * @return A 64bit sequence number or erf timestamp.
1211 *
1212 * The returned value can be used to compare the relative ordering of packets.
1213 * Formats that are not natively parallel will typically return a sequence
1214 * number. Natively parallel formats will return a timestamp.
1215 */
1216DLLEXPORT uint64_t trace_packet_get_order(libtrace_packet_t * packet);
1217
1218/** Returns the hash of a packet.
1219 *
1220 * @param[in] packet
1221 * @return A 64-bit hash
1222 *
1223 * @note This function will only work in situations where
1224 * a custom hash is being used. You can use trace_has_dedicated_hasher()
1225 * to check if this is the case.
1226 */
1227DLLEXPORT uint64_t trace_packet_get_hash(libtrace_packet_t * packet);
1228
1229/** Sets the order of a packet.
1230 *
1231 * @param[in] packet
1232 * @param[in] order the new order of a packet
1233 *
1234 * @note Many combiners rely on this value, so please ensure that changing this
1235 * conforms to the expectations of the combiner.
1236 *
1237 * Generally speaking, you probably shouldn't be changing the order of packets!
1238 */
1239DLLEXPORT void trace_packet_set_order(libtrace_packet_t * packet, uint64_t order);
1240
1241/** Sets the hash of a packet.
1242 *
1243 * @param[in] packet
1244 * @param[in] hash the new hash
1245 *
1246 * Once a packet reaches the processing thread, the libtrace library has
1247 * little use for this field and as such this can essentially be used for any
1248 * storage that the user requires.
1249 */
1250DLLEXPORT void trace_packet_set_hash(libtrace_packet_t * packet, uint64_t hash);
1251
1252
1253/** Returns the first packet read by a processing thread since the source
1254 * trace was last started or restarted.
1255 *
1256 * @param[in] libtrace the parallel input trace.
1257 * @param[in] t Either a per packet thread or NULL to retrieve the earliest
1258 * packet across all per packet threads.
1259 * @param[out] packet A pointer to the requested packet. [Optional]
1260 * @param[out] tv The system time-stamp when the packet was received. [Optional]
1261 * @return 1 if we are confident this is the first packet. Otherwise 0 if this
1262 * is a best guess (this is only possible int the case t=NULL) in which case
1263 * we recommend trying again at a later time.
1264 * -1 is returned if an error occurs, such as when this function is supplied
1265 * an invalid thread.
1266 *
1267 * The packet and timeval returned by this function is shared by all threads
1268 * and remain valid until MESSAGE_PAUSING is received.
1269 */
1270DLLEXPORT int trace_get_first_packet(libtrace_t *libtrace,
1271                                     libtrace_thread_t *t,
1272                                     const libtrace_packet_t **packet,
1273                                     const struct timeval **tv);
1274
1275/** Makes a packet safe, preventing the packet from becoming invalid after a
1276 * pausing a trace.
1277 *
1278 * @param[in,out] pkt The packet to make safe
1279 *
1280 * This copies a packet in such a way that it will be able to survive a pause.
1281 * However this will not allow the packet to be used after the format is
1282 * destroyed.
1283 */
1284DLLEXPORT void libtrace_make_packet_safe(libtrace_packet_t *pkt);
1285
1286/** Makes a result safe, preventing the result from becoming invalid after
1287 * pausing a trace.
1288 *
1289 * @param[in,out] res The result to make safe.
1290 *
1291 * This ensures the internal content of a result is safe to survive a pause.
1292 * Note that this is only an issue if the result contains a packet.
1293 * See libtrace_make_packet_safe().
1294 */
1295DLLEXPORT void libtrace_make_result_safe(libtrace_result_t *res);
1296
1297/** In a parallel trace, free a packet back to libtrace.
1298 *
1299 * @param[in] libtrace A parallel input trace
1300 * @param[in] packet The packet to be released back to libtrace
1301 *
1302 * The packet should not be used after calling this function.
1303 *
1304 * @note Don't use this inside a packet callback function -- just return
1305 * the packet instead, as this will be faster.
1306 *
1307 * @note All packets should be free'd before a trace is destroyed.
1308 */
1309DLLEXPORT void trace_free_packet(libtrace_t * libtrace, libtrace_packet_t * packet);
1310
1311/** Increments the internal reference counter for a packet.
1312 * @param packet        The packet opaque pointer
1313 *
1314 * You may wish to use this function (and its decrementing counterpart)
1315 * in situations where you are retaining multiple references to a packet
1316 * outside of the core packet processing function. This will ensure that
1317 * the packet is not released until there are no more outstanding references
1318 * to the packet anywhere in your program.
1319 */
1320DLLEXPORT void trace_increment_packet_refcount(libtrace_packet_t *packet);
1321
1322/** Decrements the internal reference counter for a packet.
1323 * @param packet        The packet opaque pointer
1324 *
1325 * If the reference counter goes below one, trace_fin_packet() will be
1326 * called on the packet.
1327 *
1328 * You may wish to use this function (and its incrementing counterpart)
1329 * in situations where you are retaining multiple references to a packet
1330 * outside of the core packet processing function. This will ensure that
1331 * the packet is not released until there are no more outstanding references
1332 * to the packet anywhere in your program.
1333 */
1334DLLEXPORT void trace_decrement_packet_refcount(libtrace_packet_t *packet);
1335
1336
1337/** Provides some basic information about a trace based on its input format.
1338 *
1339 * @param libtrace  The trace that is being inquired about.
1340 * @return a libtrace_info_t structure that contains information about the
1341 * trace format, i.e. is it live or not, how many threads it supports.
1342 *
1343 * See trace_is_parallel(), trace_get_perpkt_threads().
1344 */
1345DLLEXPORT libtrace_info_t *trace_get_information(libtrace_t * libtrace);
1346
1347/** Sets the configuration of a trace based upon a comma separated list of
1348 * key value pairs.
1349 *
1350 * @param trace A parallel trace which is not running or destroyed.
1351 * @param str A comma separated list of key=value pairs:
1352 *   e.g. \em "burst_size=20,perpkt_threads=2,fixed_count=true"
1353 * @return 0 if successful otherwise -1. If bad options are passed we will
1354 * print the error to stderr but still return successful.
1355 *
1356 * List of keys:
1357 * * \b cache_size,\b cs see trace_set_cache_size() [size_t]
1358 * * \b thread_cache_size,\b tcs see trace_set_thread_cache_size() [size_t]
1359 * * \b fixed_count,\b fc see trace_set_fixed_count() [bool]
1360 * * \b burst_size,\b bs see trace_set_burst_size() [size_t]
1361 * * \b tick_interval,\b ti see trace_set_tick_interval() [size_t]
1362 * * \b tick_count,\b tc see trace_set_tick_count() [size_t]
1363 * * \b perpkt_threads,\b pt see trace_set_perpkt_threads() [XXX TBA XXX]
1364 * * \b hasher_queue_size,\b hqs see trace_set_hasher_queue_size() [size_t]
1365 * * \b hasher_polling,\b hp see trace_set_hasher_polling() [bool]
1366 * * \b reporter_polling,\b rp see trace_set_reporter_polling() [bool]
1367 * * \b reporter_thold,\b rt see trace_set_reporter_thold() [size_t]
1368 * * \b debug_state,\b ds see trace_set_debug_state() [bool]
1369 *
1370 * Booleans can be set as 0/1 or false/true.
1371 *
1372 * @note a environment variable interface is provided by default to users via
1373 * LIBTRACE_CONF, see Parallel Configuration for more information.
1374 *
1375 * @note This interface is provided to allow a user to quickly configure an
1376 * application using a single API call. A nicer programatic method for
1377 * configuration would be to use the appropriate trace_set_*() function for
1378 * each option.
1379 */
1380DLLEXPORT int trace_set_configuration(libtrace_t *trace, const char * str);
1381
1382/** Sets configuration from a file. This reads every line from the file and
1383 * interprets each line with trace_set_configuration().
1384 *
1385 * @param trace A parallel trace which is not running or destroyed
1386 * @param file A file pointer which we read each line from
1387 * @return 0 if successful otherwise -1. If bad options are passed we will
1388 * print the error to stderr but still return successful.
1389 *
1390 * @note We do not close the file pointer upon completion
1391 */
1392DLLEXPORT int trace_set_configuration_file(libtrace_t *trace, FILE *file);
1393
1394/** Returns the number of processing threads that have been created for
1395 * a given trace.
1396 *
1397 * @param t A parallel trace.
1398 * @return The number of processing threads owned by that trace.
1399 */
1400DLLEXPORT int trace_get_perpkt_threads(libtrace_t* t); 
1401
1402/** Returns the internal unique ID for a packet processing thread.
1403 *
1404 * @param thread The thread being queried.
1405 * @return The ID number of the thread or -1 if the thread is not a processing
1406 * thread or is otherwise invalid.
1407 */
1408DLLEXPORT int trace_get_perpkt_thread_id(libtrace_thread_t *thread);
1409
1410/**
1411 * Sets a combiner function for an input trace.
1412 *
1413 * @param trace The input trace
1414 * @param combiner The combiner to use
1415 * @param config Configuration information. Dependent upon the combiner.
1416 *
1417 * Sets a combiner against a trace, this should only be called on a
1418 * non-started or paused trace.  By default, combiner_unordered
1419 * will be used if this function is not called before starting the trace.
1420 */
1421DLLEXPORT void trace_set_combiner(libtrace_t *trace, const libtrace_combine_t *combiner, libtrace_generic_t config);
1422
1423/**
1424 * Takes unordered (or ordered) input and produces unordered output.
1425 * This is the fastest combiner but makes no attempt to ensure you get
1426 * results in a particular order.
1427 */
1428extern const libtrace_combine_t combiner_unordered;
1429
1430/**
1431 * Takes ordered input and produces ordered output. Each processing thread
1432 * must produce results that are strictly ordered for this combiner to
1433 * work correctly.
1434 *
1435 * For example, a thread may publish a series of results with the keys
1436 * (in order) of 1,4,10,11,15,20 as the keys are all in order. It must not
1437 * publish the results in the order 1,4,11,10,15,20 -- 10 comes after 11,
1438 * which is out-of-order.
1439 */
1440extern const libtrace_combine_t combiner_ordered;
1441
1442/**
1443 * Like classic Google Map/Reduce, the results are sorted
1444 * in ascending order based on their key. The sorting is only done when the
1445 * trace finishes and all results are stored internally until then.
1446 *
1447 * This only works with a very limited number of results, otherwise
1448 * libtrace will just run out of memory and crash. You should always
1449 * use combiner_ordered if you can.
1450 */
1451extern const libtrace_combine_t combiner_sorted;
1452
1453#ifdef __cplusplus
1454}
1455#endif
1456
1457#endif // LIBTRACE_PARALLEL_H
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