source: lib/libtrace_parallel.h @ b3ff33b

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Last change on this file since b3ff33b was b3ff33b, checked in by Shane Alcock <salcock@…>, 6 years ago

Make parallel API work for C++ programs

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1/*
2 * This file is part of libtrace
3 *
4 * Copyright (c) 2007,2008,2009,2010 The University of Waikato, Hamilton,
5 * New Zealand.
6 *
7 * Authors: Richard Sanger
8 *
9 * All rights reserved.
10 *
11 * This code has been developed by the University of Waikato WAND
12 * research group. For further information please see http://www.wand.net.nz/
13 *
14 * libtrace is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * libtrace is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with libtrace; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
27 *
28 * $Id$
29 *
30 */
31
32/** @file
33 *
34 * @brief Header file containing definitions for structures and functions
35 * related to the parallel framework
36 *
37 * @author Richard Sanger
38 *
39 * @version $Id$
40 *
41 * The parallel libtrace framework is a replacement to the libtrace framework. XXX TODO MAKE MORE DOCS HERE.
42 */
43
44#ifndef LIBTRACE_PARALLEL_H
45#define LIBTRACE_PARALLEL_H
46
47#include "libtrace.h"
48#include <stdio.h>
49
50#ifdef __cplusplus
51extern "C" {
52#endif
53
54typedef struct libtrace_result_t libtrace_result_t;
55
56/**
57 * A collection of types for convenience used in place of a
58 * simple void* to allow a any type of data to be stored.
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
106typedef struct libtrace_message_t {
107        int code; /**< The message code see enum libtrace_messages */
108        libtrace_generic_t data; /**< Additional data related to the message */
109        libtrace_thread_t *sender; /**< The thread that sent the message */
110} libtrace_message_t;
111
112/** Structure holding information about a result */
113struct libtrace_result_t {
114        uint64_t key;
115        libtrace_generic_t value;
116        int type;
117};
118
119/** The libtrace_messages enum
120 * All libtrace messages are defined and documented here.
121 *
122 * Some messages can be sent to control the library while others
123 * are received by the per-packet and reporter functions to inform the libtrace
124 * application.
125 *
126 * If a user wishes to send there own custom messages they should use
127 * numbers greater than MESSAGE_USER (1000).
128 *
129 * @note Some messages are for internal use only
130 */
131enum libtrace_messages {
132        /** A libtrace packet is ready, this will only be sent to per
133         * packet threads.
134         * @param data Holds the packet in data.pkt. The packet belongs to
135         * libtrace and should either be returned from the per-packet function
136         * if no longer needed or free'd at some later time using the XXX
137         * function.
138         * @param sender The sender will be set as the current thread
139         */
140        MESSAGE_PACKET,
141        /** A libtrace result is ready, this will only be sent to the reporter
142         * thread.
143         * @param data Holds the result in data.res. The memory holding the
144         * result is allocated by libtrace and should not be free'd. However
145         * note that any data stored within the result might need to be free'd.
146         * @param sender The sender will be set as the current thread
147         */
148        MESSAGE_RESULT,
149
150        /** A message sent to each thread when it starts. This is sent
151         * to both the reporter and per-packet threads. This will be sent once
152         * after trace_pstart() (assuming no errors occurs).
153         *
154         * This can be used to allocate resources required by each thread.
155         *
156         * These can be free'd when MESSAGE_STOPPING is received.
157         *
158         * @param data unused, do not use this
159         * @param sender The sender will be set as the current thread
160         * @return When using a function callback for starting, the returned
161         * value is stored against the thread tls. Otherwise the return is ignored.
162         */
163        MESSAGE_STARTING,
164
165        /** A message sent to each thread when it stops. This is sent
166         * to both the reporter and per-packet threads. This will be sent once
167         * after MESSAGE_STARTING.
168         *
169         * This can be used to free any resources allocated with
170         * MESSAGE_STARTING.
171         *
172         * @param data unused, do not use this
173         * @param sender The sender will be set as the current thread
174         */
175        MESSAGE_STOPPING,
176
177        /** A message sent to each thread when a thread transitions between a
178         * paused (or unstarted) state to running state. This is sent
179         * to both the reporter and per-packet threads. This will be sent after
180         * MESSAGE_STARTING when a trace is first started and when a trace
181         * is started (trace_pstart()) after a pause (trace_ppause()).
182         *
183         * This can be used to allocate resources.
184         *
185         * @param data unused, do not use this
186         * @param sender The sender will be set as the current thread
187         */
188        MESSAGE_RESUMING,
189
190        /** A message sent to each thread when a thread transitions between a
191         * paused (or unstarted) state to running state. This is sent
192         * to both the reporter and per-packet threads. This will be sent after
193         * MESSAGE_STARTING when a trace is first started and when a trace
194         * is started (trace_pstart()) after a pause (trace_ppause()).
195         *
196         * This can be used to allocate resources.
197         *
198         * @param data unused, do not use this
199         * @param sender The sender will be set as the current thread
200         */
201        MESSAGE_PAUSING,
202
203        /** An internal message do not use this */
204        MESSAGE_DO_PAUSE,
205        /** An internal message do not use this */
206        MESSAGE_DO_STOP,
207
208        /** Sent to all per-packet threads (including the sender) and the
209         * reducer when the first packet is seen for a thread.
210         *
211         * @param data The first packet is stored in data.pkt. This packet is
212         * shared by all threads receiving the message and is valid until
213         * MESSAGE_PAUSING is received.
214         * @param sender The per-packet thread which received the packet
215         *
216         * @note Upon pausing and restarting a trace this will be reset and
217         * sent once a new packet is encountered
218         *
219         * @see trace_get_first_packet()
220         */
221        MESSAGE_FIRST_PACKET,
222
223        /** Notify the reporter thread more data is available.
224         *
225         * Triggers the reporter to read as many results as possible.
226         *
227         * @param data unused
228         * @param sender the sending
229         *
230         * @note This message should not be sent directly instead call
231         * trace_post_reporter()
232         *
233         */
234        MESSAGE_POST_REPORTER,
235
236        /** Sent to per-packet threads periodically after the configured time
237         * interval has passed.
238         *
239         * This is sent out-of-band with respect to packets and as a result
240         * can appear after a packet with an later time-stamp, or before one
241         * with an earlier time-stamp.
242         *
243         * @param data data.uint64 holds the system time-stamp in the
244         * erf format
245         * @param sender should be ignored
246         */
247        MESSAGE_TICK_INTERVAL,
248
249        /** Sent to per-packet threads once the configured number of packets
250         * are read from a trace.
251         *
252         * This are sent in-band with respect to packets such that all
253         * threads will see it between the same packets.
254         *
255         * @param data data.uint64 holds the number of packets seen so far across all threads
256         * @param sender Set to the current per-packet thread
257         */
258        MESSAGE_TICK_COUNT,
259
260        /** For specific user defined messages use codes of MESSAGE_USER or above. */
261        MESSAGE_USER = 1000
262};
263
264/** The hasher types available to libtrace application.
265 * These can be selected using trace_set_hasher().
266 */
267enum hasher_types {
268        /** Balance load across per-packet threads as best as possible, this is
269         * basically to say I do not care about where packets are sent. This
270         * might still might be implemented using a hash or round robin etc.
271         * depending on the format and libtrace configuration.
272         */
273        HASHER_BALANCE,
274
275        /** Use a hash which is bi-directional for TCP and UDP flows, that is
276         * packets with the same 5-tuple are sent to the same per-packet thread.
277         * All non TCP/UDP packets will be sent to the same thread.
278         *
279         * @note it is possible that UDP packets may not be spread across
280         * per-packet threads, depending upon the format support. In this case
281         * they would be directed to a single per-packet thread.
282         */
283        HASHER_BIDIRECTIONAL,
284
285        /** Use a hash which is uni-directional across TCP and UDP flows, this
286         * means the opposing directions of the same 5-tuple might end up on
287         * different per-packet threads.
288         * Otherwise this is identical to HASHER_BIDIRECTIONAL
289         */
290        HASHER_UNIDIRECTIONAL,
291
292        /**
293         * Always use the user supplied hasher, this disables native
294         * support in and is likely significantly slower.
295         */
296        HASHER_CUSTOM
297};
298
299typedef struct libtrace_info_t {
300        /**
301         * True if a live format (i.e. packets have to be trace-time).
302         * Otherwise false, indicating packets can be read as fast
303         * as possible from the format.
304         */
305        bool live;
306
307        /**
308         * The maximum number of threads supported by a parallel trace. 1
309         * if parallel support is not native (in this case libtrace will simulate
310         * an unlimited number of threads), -1 means unlimited and 0 unknown.
311         */
312        int max_threads;
313
314        /* TODO hash fn supported list */
315
316        /* TODO consider time/clock details?? */
317} libtrace_info_t;
318
319/**
320 * The methods we use to combine multiple outputs into a single output
321 * This is not considered a stable API however is public.
322 * Where possible use built in combiners.
323 *
324 * @note this structure is duplicated per trace and as such can
325 * have functions rewritten, and in fact should if possible.
326 */
327typedef struct libtrace_combine libtrace_combine_t;
328struct libtrace_combine {
329
330        /**
331         * Called at the start of the trace to allow data-structures
332         * to be initialised and allow functions to be swapped if appropriate.
333         *
334         * Also factors such as whether the trace is live or not can
335         * be used to determine the functions used.
336         * @return 0 if successful, -1 if an error occurs
337         */
338        int (*initialise)(libtrace_t *,libtrace_combine_t *);
339
340        /**
341         * Called when the trace ends, clean up any memory here
342         * from libtrace_t * init.
343         */
344        void (*destroy)(libtrace_t *, libtrace_combine_t *);
345
346        /**
347         * Publish a result against it's a threads queue.
348         * If null publish directly, expected to be used
349         * as a single threaded optimisation and can be
350         * set to NULL by init if this case is detected.
351         *
352         * TODO this is old info
353         */
354        void (*publish)(libtrace_t *, int thread_id, libtrace_combine_t *, libtrace_result_t *);
355
356        /**
357         * Read as many results as possible from the trace.
358         * Directly calls the users code to handle results from here.
359         *
360         * THIS SHOULD BE NON-BLOCKING AND READ AS MANY AS POSSIBLE
361         * If publish is NULL, this probably should be NULL also otherwise
362         * it will not be called.
363         */
364        void (*read)(libtrace_t *, libtrace_combine_t *);
365
366        /**
367         * Called when the trace is finished to flush the final
368         * results to the reporter thread.
369         *
370         * There may be no results, in which case this should
371         * just return.
372         *
373         * Libtrace state:
374         * Called from reporter thread
375         * No perpkt threads will be running, i.e. publish will not be
376         * called again.
377         *
378         * If publish is NULL, this probably should be NULL also otherwise
379         * it will not be called.
380         */
381        void (*read_final)(libtrace_t *, libtrace_combine_t *);
382
383        /**
384         * Pause must make sure any results of the type packet are safe.
385         * That means trace_copy_packet() and destroy the original.
386         * This also should be NULL if publish is NULL.
387         */
388        void (*pause)(libtrace_t *, libtrace_combine_t *);
389
390        /**
391         * Data storage for all the combiner threads
392         */
393        void *queues;
394
395        /**
396         * Configuration options, what this does is up to the combiner
397         * chosen.
398         */
399        libtrace_generic_t configuration;
400};
401
402/**
403 * The definition for the main function that the user supplies to process
404 * messages.
405 *
406 * @param trace The trace the packet is related to.
407 * @param thread The thread identifier.
408 * @param mesg_code The type of data ready, the most important being MESSAGE_PACKET.
409 * In this case data.pkt contains the packet.
410 * @param data A generic union of types that fit into 8 bytes, containing
411 * information dependent upon the mesg_code.
412 * @param sender The thread from which the message originated.
413 * @return If the message type is MESSAGE_PACKET a packet can be returned back
414 * to the library similar to trace_free_packet() otherwise this should be NULL.
415 *
416 * The values of data and sender depend upon the mesg_code. Please see the
417 * documentation for the message as to what value these will contain.
418 */
419typedef void* (*fn_cb_msg)(libtrace_t* trace,
420                           libtrace_thread_t *thread,
421                           int mesg_code,
422                           libtrace_generic_t data,
423                           libtrace_thread_t *sender);
424
425/**
426 * The definition for the main function that the user supplies to process
427 * results from trace_publish_result().
428 *
429 * @param trace The trace the packet is related to.
430 * @param mesg_code The type of data ready, the most important being MESSAGE_RESULT.
431 * In this case data.res contains the result.
432 * @param data A generic union of types that fit into 8 bytes, containing
433 * information dependent upon the mesg_code.
434 * @param sender The thread from which the message originated.
435 *
436 * The values of data and sender depend upon the mesg_code. Please see the
437 * documentation for the message as to what value these will contain.
438 */
439typedef void (*fn_reporter)(libtrace_t* trace,
440                            int mesg_code,
441                            libtrace_generic_t data,
442                            libtrace_thread_t *sender);
443
444/**
445 * The definition for a hasher function, allowing matching packets to be
446 * directed to the same per packet thread for processing.
447 *
448 * @param packet The packet to be hashed.
449 * @param data A void pointer which can contain additional information,
450 * such as configuration of the hasher function.
451 */
452typedef uint64_t (*fn_hasher)(const libtrace_packet_t* packet, void *data);
453
454
455/** Start or restart an input trace in the parallel libtrace framework.
456 *
457 * @param libtrace The input trace to start
458 * @param global_blob Global data related to this trace accessible using trace_get_global()
459 * @param per_msg A user supplied function called when a message is ready
460 * @param reporter A user supplied function called when a result is ready.
461 * Optional if NULL the reporter thread will not be started.
462 * @return 0 on success, otherwise -1 to indicate an error has occurred
463 *
464 * This can also be used to restart an existing parallel trace,
465 * that has previously been paused using trace_ppause().
466 * In this case global_blob,per_msg and reporter will only be updated
467 * if they are non-null. Otherwise their previous values will be maintained.
468 *
469 */
470DLLEXPORT int trace_pstart(libtrace_t *libtrace, void* global_blob,
471                           fn_cb_msg per_msg, fn_reporter reporter);
472
473/**
474 *
475 * @param libtrace The parallel trace
476 * @param t The thread that is running
477 * @param global The global storage
478 * @return The returned value is stored against the threads tls.
479 *         This is typically passed as tls argument to other messages.
480 */
481typedef void* (*fn_cb_starting)(libtrace_t *libtrace,
482                                     libtrace_thread_t *t,
483                                     void *global);
484
485/**
486 * @param libtrace The parallel trace
487 * @param t The thread that is running
488 * @param global The global storage
489 * @param tls The thread local storage
490 */
491typedef void (*fn_cb_dataless)(libtrace_t *libtrace,
492                                    libtrace_thread_t *t,
493                                    void *global,
494                                    void *tls);
495
496/**
497 * @param libtrace The parallel trace
498 * @param t The thread that is running
499 * @param global The global storage
500 * @param tls The thread local storage
501 */
502typedef void (*fn_cb_first_packet)(libtrace_t *libtrace,
503                                   libtrace_thread_t *t,
504                                   void *global,
505                                   void *tls,
506                                   libtrace_packet_t *first_packet,
507                                   libtrace_thread_t *sender);
508
509/**
510 * @param libtrace The parallel trace
511 * @param t The thread that is running
512 * @param global The global storage
513 * @param tls The thread local storage
514 * @param uint64_t Either the timestamp or packet count depending on message type
515 */
516typedef void (*fn_cb_tick)(libtrace_t *libtrace,
517                           libtrace_thread_t *t,
518                           void *global,
519                           void *tls,
520                           uint64_t order);
521
522/**
523 * @param libtrace The parallel trace
524 * @param t The thread
525 * @param packet The packet associated with the message
526 * @param global The global storage
527 * @param tls The thread local storage
528 *
529 * @return optionally a packet which is handed back to the library,
530 *         typically this is the packet supplied. Otherwise NULL.
531 */
532typedef libtrace_packet_t* (*fn_cb_packet)(libtrace_t *libtrace,
533                                           libtrace_thread_t *t,
534                                           void *global,
535                                           void *tls,
536                                           libtrace_packet_t *packet);
537
538/** Registers a built-in message with a handler.
539 * Note we do not include the sending thread as an argument to the reporter.
540 * If set to NULL, the message will be sent to default perpkt handler.
541 *
542 * @param libtrace The input trace to start
543 * @param handler the handler to be called when the message is received
544 * @return 0 if successful otherwise -1.
545 */
546
547DLLEXPORT int trace_cb_starting(libtrace_t *libtrace, fn_cb_starting handler);
548DLLEXPORT int trace_cb_stopping(libtrace_t *libtrace, fn_cb_dataless handler);
549DLLEXPORT int trace_cb_resuming(libtrace_t *libtrace, fn_cb_dataless handler);
550DLLEXPORT int trace_cb_pausing(libtrace_t *libtrace, fn_cb_dataless handler);
551DLLEXPORT int trace_cb_packet(libtrace_t *libtrace, fn_cb_packet handler);
552DLLEXPORT int trace_cb_first_packet(libtrace_t *libtrace, fn_cb_first_packet handler);
553DLLEXPORT int trace_cb_tick_count(libtrace_t *libtrace, fn_cb_tick handler);
554DLLEXPORT int trace_cb_tick_interval(libtrace_t *libtrace, fn_cb_tick handler);
555
556/** Pauses a trace previously started with trace_pstart()
557 *
558 * @param libtrace The parallel trace to be paused
559 * @return 0 on success, otherwise -1 to indicate an error has occurred
560 *
561 */
562DLLEXPORT int trace_ppause(libtrace_t *libtrace);
563
564/** Stops a parallel trace, causing all threads to exit as if an EOF
565 * has occurred. This replaces trace_interrupt(), allowing
566 * a specified trace to be stopped.
567 *
568 * @param libtrace The parallel trace to be stopped
569 * @return 0 on success, otherwise -1 to indicate an error has occurred
570 *
571 * This should only be called by the main thread.
572 *
573 */
574DLLEXPORT int trace_pstop(libtrace_t *libtrace);
575
576/** Waits for a trace to finish and all threads to join.
577 *
578 * @param trace The parallel trace
579 *
580 * Waits for a trace to finish, whether this be due to
581 * an error occurring, an EOF or trace_pstop.
582 *
583 */
584DLLEXPORT void trace_join(libtrace_t * trace);
585
586/**
587 * @name User Data Storage
588 *
589 * These method provide a way for users to store data against a trace or
590 * a thread.
591 *
592 * Alternatively one could use global variables and thread local
593 * storage (__thread), respectively, which in many cases could be simpler.
594 *
595 * @note We do not lock on reads, instead we rely on the
596 * processor making any writes appear atomically.
597 *
598 * @{
599 */
600
601/** Returns the data stored against a trace.
602 *
603 * @param trace The parallel trace
604 * @return The stored data.
605 */
606DLLEXPORT void * trace_get_local(libtrace_t *trace);
607
608/** Store data against a trace so that all threads can access it
609 * using trace_get_global().
610 *
611 * @param trace The parallel trace.
612 * @param data The new value to save against the trace
613 * @return The previously stored value
614 *
615 * The update to the previous value is atomic and thread-safe.
616 *
617 * @note Although this is thread-safe another thread may still be
618 * using the previous data, as such further synchronisation is needed
619 * if a thread wanted to free the existing value.
620 */
621DLLEXPORT void * trace_set_local(libtrace_t *trace, void * data);
622
623/** Returns the users data stored against a thread.
624 *
625 * @param thread The thread
626 * @return The stored data
627 */
628DLLEXPORT void * trace_get_tls(libtrace_thread_t *thread);
629
630/** Store data against a thread.
631 *
632 * @param thread The thread
633 * @param data The new value to save against the thread
634 * @return The previously stored value
635 *
636 * This function is not thread-safe and is intended only to be
637 * called on the currently running thread.
638 */
639DLLEXPORT void * trace_set_tls(libtrace_thread_t *thread, void * data);
640
641/// @}
642
643
644/**
645 * @name Parallel Configuration
646 *
647 * These methods provide a way to configure the parallel libtrace library.
648 *
649 * Many of these options are typically unneeded by most applications as they
650 * control tuning aspects of the library and are more useful to the
651 * end user.
652 *
653 * To allow the end user to change this configuration libtrace will search for
654 * three environment variables and apply them to the configuration in the
655 * following order. Such that the first has the lowest priority.
656 *
657 * 1. LIBTRACE_CONF, The global environment configuration
658 * 2. LIBTRACE_CONF_<FORMAT>, Applied to a given format
659 * 3. LIBTRACE_CONF_<FORMAT_URI>, Applied the specified trace
660 *
661 * E.g.
662 * - int:eth0 would match LIBTRACE_CONF, LIBTRACE_CONF_INT, LIBTRACE_CONF_INT_ETH0
663 * - dag:/dev/dag0,0 would match LIBTRACE_CONF, LIBTRACE_CONF_DAG, LIBTRACE_CONF_DAG__DEV_DAG0_0
664 * - test.erf would match LIBTRACE_CONF, LIBTRACE_CONF_ERF, LIBTRACE_CONF_ERF_TEST_ERF
665 *
666 * @note All environment variables names MUST only contain
667 * [A-Z], [0-9] and [_] (underscore). Any characters
668 * outside of this range should be capitalised if possible or replaced with an
669 * underscore.
670 * @{
671 */
672
673/** Set the maximum number of perpkt threads to use in a trace.
674 *
675 * @param[in] trace The parallel input trace
676 * @param[in] nb The number of threads to use. If 0 use default.
677 * @return 0 if successful otherwise -1
678 */
679DLLEXPORT int trace_set_perpkt_threads(libtrace_t *trace, int nb);
680
681/** Set the interval between tick messages in milliseconds.
682 *
683 * @param[in] trace The parallel input trace
684 * @param[in] millisec The interval in milliseconds. If 0 this is disabled [default].
685 * @return 0 if successful otherwise -1
686 *
687 * When a underlying parallel live trace is used MESSAGE_TICK_INTERVAL is sent
688 * every tick interval to all per-packet threads to ensure data is received.
689 * This allows results to be printed even in cases flows are not being directed
690 * to a per-packet thread, while still maintaining order etc.
691 *
692 * @note Tick count is preferred over tick interval and will be used rather
693 * than tick interval if possible.
694 * @see MESSAGE_TICK_INTERVAL, trace_set_tick_count()
695 */
696DLLEXPORT int trace_set_tick_interval(libtrace_t *trace, size_t millisec);
697
698/** Set the count between tick messages.
699 *
700 * @param[in] trace The parallel input trace
701 * @param[in] count The tick count.  If 0 this is disabled [default].
702 * @return 0 if successful otherwise -1
703 *
704 * When an underlying trace is accessed internally by libtrace in a
705 * single-threaded manner MESSAGE_TICK_COUNT is sent to all per-packet threads
706 * after every count packets have been seen in the trace. This allows results
707 * to be printed even in cases flows are not being directed to a per-packet
708 * thread, while still maintaining order etc.
709 *
710 * @see MESSAGE_TICK_COUNT, trace_set_tick_interval()
711 */
712DLLEXPORT int trace_set_tick_count(libtrace_t *trace, size_t count);
713
714/**
715 * Delays packets so they are played back in trace-time rather than as fast
716 * as possible (real-time).
717 *
718 * @param trace A parallel input trace
719 * @param tracetime If true packets are released with time intervals matching
720 * the original trace. Otherwise packets are read as fast as possible.
721 * @return 0 if successful otherwise -1
722 */
723DLLEXPORT int trace_set_tracetime(libtrace_t *trace, bool tracetime);
724
725/** This sets the maximum size of the freelist used to store empty packets
726 * and their memory buffers.
727 *
728 * @param trace A parallel input trace
729 * @param size The number of empty packets to cache in memory. Set to the
730 * default, 0, to autoconfigure this value.
731 * @return 0 if successful otherwise -1
732 *
733 * Internally libtrace maintains a buffer of packet structures, this buffer
734 * includes a cache per thread and a shared main pool. This configures
735 * the size of the main pool. If an application is not passing packets
736 * through to the reducer step --- that is to say returns packets from
737 * the perpkt function --- this buffer will not need to be used.
738 *
739 * @note Setting this too low could cause performance issues or a deadlock. An
740 * unblockable warning will be printed.
741 *
742 * @see trace_set_thread_cache_size(), trace_set_fixed_count()
743 */
744DLLEXPORT int trace_set_cache_size(libtrace_t *trace, size_t size);
745
746/** This sets the maximum size of the freelist thread cache's used to provide
747 * faster access than the main shared pool.
748 *
749 * @param trace A parallel input trace
750 * @param size The number of empty packets to cache in memory. Set to the
751 * default, 0, to autoconfigure this value.
752 * @return 0 if successful otherwise -1
753 *
754 * @see trace_set_cache_size(), trace_set_fixed_count()
755 */
756DLLEXPORT int trace_set_thread_cache_size(libtrace_t *trace, size_t size);
757
758/** If true the total number of packets that can be created by a trace is limited
759 * to that set by trace_set_cache_size(), otherwise once exceeded malloc
760 * and free will be used to create and free packets, this will be slower than
761 * using the freelist and could run a machine out of memory.
762 *
763 * @param trace A parallel input trace
764 * @param fixed If true the total number of packets is limited, otherwise
765 * it is not. Defaults to false.
766 * @return 0 if successful otherwise -1
767 *
768 * @see trace_set_thread_cache_size(), trace_set_cache_size()
769 */
770DLLEXPORT int trace_set_fixed_count(libtrace_t *trace, bool fixed);
771
772/** The number of packets to batch together for processing internally
773 * by libtrace.
774 *
775 * @param trace A parallel input trace
776 * @param size The total number of packets to batch together. Set to the
777 * default, 0, to autoconfigure this value.
778 * @return 0 if successful otherwise -1
779 *
780 * Internally libtrace will attempt to read up to this number of packets from
781 * a format typically values of 10 will get good performance and increasing
782 * beyond that will should little difference.
783 *
784 * @note We still pass a single packet at a time to the perpkt function
785 */
786DLLEXPORT int trace_set_burst_size(libtrace_t *trace, size_t size);
787
788/**
789 * See diagrams, this sets the maximum size of buffers used between
790 * the single hasher thread and the buffer.
791 * NOTE setting this to less than recommend could cause deadlock a
792 * trace that manages its own packets.
793 * A unblockable warning message will be printed to stderr in this case.
794 */
795/** The number of packets that can queue per thread from hasher thread */
796DLLEXPORT int trace_set_hasher_queue_size(libtrace_t *trace, size_t size);
797
798/** If true use a polling hasher queue, that means that we will spin/or yield
799 * when data is not available rather than blocking on a condition.
800 *
801 * @param trace A parallel input trace
802 * @param polling If true the hasher will poll waiting for data, otherwise
803 * it is not. Defaults to false.
804 *
805 * We note this is likely to waste many CPU cycles and could even decrease
806 * performance.
807 *
808 * @return 0 if successful otherwise -1
809 */
810DLLEXPORT int trace_set_hasher_polling(libtrace_t *trace, bool polling);
811
812/** If true the reporter thread will continuously poll waiting for results
813 * if false they are only checked when a message is received, this message
814 * is controlled by reporter_thold.
815 *
816 * @param trace A parallel input trace
817 * @param polling If true the reporter will poll waiting for data, otherwise
818 * it is not. Defaults to false.
819 * @return 0 if successful otherwise -1
820 *
821 * We note this is likely to waste many CPU cycles and could even decrease
822 * performance.
823 *
824 * @note This setting could be ignored by some reporters.
825 */
826DLLEXPORT int trace_set_reporter_polling(libtrace_t *trace, bool polling);
827
828/** Set the perpkt thread result queue size before triggering the reporter
829 * to read results.
830 *
831 * @param trace A parallel input trace
832 * @param thold The threshold on the number of results to enqueue before
833 * notifying the reporter thread to read them.
834 * @return 0 if successful otherwise -1
835 *
836 *
837 * @note This setting is generally ignored if trace_set_reporter_polling() is
838 * set however some combiner functions might ignore trace_set_reporter_polling()
839 * and still require this to be set.
840 * @see trace_publish_result(), trace_post_reporter()
841 */
842DLLEXPORT int trace_set_reporter_thold(libtrace_t *trace, size_t thold);
843
844/** Prints a line to standard error for every state change
845 * for both the trace as a whole and for each thread.
846 *
847 * @param trace A parallel input trace
848 * @param debug_state If true debug is printed. Defaults false.
849 * @return 0 if successful otherwise -1.
850 *
851 */
852DLLEXPORT int trace_set_debug_state(libtrace_t *trace, bool debug_state);
853
854/** Set the hasher function for a parallel trace.
855 *
856 * @param[in] trace The parallel trace to apply the hasher to
857 * @param[in] type The type of hashing to apply, see enum hasher_types
858 * @param[in] hasher A hasher function to use [Optional]
859 * @param[in] data Data passed to the hasher function [Optional]
860 *
861 * @return 0 if successful otherwise -1 on error
862 *
863 * The hasher function in a parallel trace can be used to control which
864 * per-packet thread a packets is processed by.
865 *
866 * HASHER_BALANCE is the default and will dispatch packets as fast as possible
867 * to all threads arbitrarily. As such when called the hasher and
868 * data parameters must be set to NULL.
869 *
870 * HASHER_CUSTOM will force the libtrace to use the user defined function. As
871 * such the hasher parameter must be supplied.
872 *
873 * With other defined hasher types we will try to push the hashing into the format
874 * by default. In this case the hasher parameter is optional and will be
875 * preferred over the default supplied by libtrace.
876 *
877 * @note When supplying a hasher function it should be thread-safe so it can
878 * be run in parallel by libtrace. Ideally this should rely upon no state, other
879 * than some form of seed value supplied in data.
880 */
881DLLEXPORT int trace_set_hasher(libtrace_t *trace, enum hasher_types type,
882                               fn_hasher hasher, void *data);
883
884/// @}
885
886
887/** Types of results.
888 * Some result types require special handling by combiners
889 * as such making use of built-in types is important.
890 *
891 * Custom result types users should be defined as RESULT_USER(1000) or greater.
892 *
893 */
894enum result_types {
895        /**
896         * The result is a packet in some circumstances special handling needs
897         * to be performed. As such packets should always be published as so.
898         *
899         * @param key (Typically) The packets order, see trace_packet_get_order()
900         */
901        RESULT_PACKET,
902
903        /** The result is a tick message
904         *
905         * @param key The erf time-stamp of the tick
906         */
907        RESULT_TICK_INTERVAL,
908
909        /** The result is a tick message
910         *
911         * @param key The sequence number of the tick message
912         */
913        RESULT_TICK_COUNT,
914
915        /** Any user specific codes should be above this.
916         *
917         */
918        RESULT_USER = 1000
919
920};
921
922/** Publish a result for to the combiner destined for the reporter thread
923 *
924 * @param[in] libtrace The parallel input trace
925 * @param[in] t The current per-packet thread
926 * @param[in] key The key of the result (used for sorting by the combiner)
927 * @param[in] value The value of the result
928 * @param[in] type The type of result see the documentation for the result_types enum
929 */
930DLLEXPORT void trace_publish_result(libtrace_t *libtrace,
931                                    libtrace_thread_t *t,
932                                    uint64_t key,
933                                    libtrace_generic_t value,
934                                    int type);
935
936/** Check if a dedicated hasher thread is being used.
937 *
938 * @param[in] libtrace The parallel input trace
939 * @return True if the trace has dedicated hasher thread otherwise false.
940 *
941 * This is valid once the trace is running after calling trace_pstart().
942 */
943DLLEXPORT bool trace_has_dedicated_hasher(libtrace_t * libtrace);
944
945/** Checks if a trace is using a reporter
946 *
947 * @param[in] libtrace The parallel input trace
948 * @return True if the trace is using a reporter otherwise false
949 */
950DLLEXPORT bool trace_has_reporter(libtrace_t * libtrace);
951
952/** Post a message to the reporter thread requesting it to check for more
953 * results.
954 *
955 * @param[in] The parallel input trace
956 * @return -1 upon error indicating the message has not been sent otherwise a
957 * backlog indicator (the number of messages the reporter has not yet read).
958 */
959DLLEXPORT int trace_post_reporter(libtrace_t *libtrace);
960
961/** Check the number of messages waiting in a queue
962 *
963 * @param[in] libtrace The input trace
964 * @param[in] t The thread to check, if NULL the current thread will be used [Optional]
965 *
966 * @return packets in the queue otherwise -1 upon error.
967 *
968 * @note For best performance it is recommended to supply the thread argument
969 * even if it is the current thread.
970 */
971DLLEXPORT int libtrace_thread_get_message_count(libtrace_t * libtrace,
972                                                libtrace_thread_t *t);
973
974/** Read a message from a thread in a blocking fashion
975 *
976 * @param[in] libtrace The input trace
977 * @param[in] t The thread to check, if NULL the current thread will be used [Optional]
978 * @param[out] message A pointer to libtrace_message_t structure which will be
979 * filled with the retrieved message.
980 *
981 * @return The number of messages remaining otherwise -1 upon error.
982 *
983 *
984 * @note For best performance it is recommended to supply the thread argument
985 * even if it is the current thread.
986 */
987DLLEXPORT int libtrace_thread_get_message(libtrace_t * libtrace,
988                                          libtrace_thread_t *t,
989                                          libtrace_message_t * message);
990
991/** Read a message from a thread in a blocking fashion
992 *
993 * @param[in] libtrace The input trace
994 * @param[in] t The thread to check, if NULL the current thread will be used [Optional]
995 * @param[out] message A pointer to libtrace_message_t structure which will be
996 * filled with the retrieved message.
997 *
998 * @return 0 if successful otherwise -1 upon error or if no packets were available.
999 *
1000 *
1001 * @note For best performance it is recommended to supply the thread argument
1002 * even if it is the current thread.
1003 */
1004DLLEXPORT int libtrace_thread_try_get_message(libtrace_t * libtrace,
1005                                              libtrace_thread_t *t,
1006                                              libtrace_message_t * message);
1007
1008/** Send a message to the reporter thread
1009 *
1010 * @param[in] libtrace The parallel trace
1011 * @param[in] message The message to be sent, if sender is NULL libtrace will
1012 * attempt to fill this in. It is faster to assign this if it is known.
1013 *
1014 * @return -1 upon error indicating the message has not been sent otherwise a
1015 * backlog indicator (the number of messages the reporter has not yet read).
1016 */
1017DLLEXPORT int trace_message_reporter(libtrace_t * libtrace,
1018                                     libtrace_message_t * message);
1019
1020/** Send a message to all per-packet threads
1021 *
1022 * @param[in] libtrace The parallel trace
1023 * @param[in] message The message to be sent, if sender is NULL libtrace will
1024 * attempt to fill this in. It is faster to assign this if it is known.
1025 *
1026 * @return 0 if successful otherwise a negative number indicating the number
1027 * of per-packet threads the message was not sent to (i.e. -1 means one thread
1028 * could not be sent the message).
1029 */
1030DLLEXPORT int trace_message_perpkts(libtrace_t * libtrace,
1031                                    libtrace_message_t * message);
1032
1033/** Send a message to a thread
1034 *
1035 * @param[in] libtrace The parallel trace
1036 * @param[in] t The thread to message
1037 * @param[in] message The message to be sent, if sender is NULL libtrace will
1038 * attempt to fill this in. It is faster to assign this if it is known.
1039 *
1040 * @return -1 upon error indicating the message has not been sent otherwise a
1041 * backlog indicator (the number of messages the thread has not yet read).
1042 */
1043DLLEXPORT int trace_message_thread(libtrace_t * libtrace,
1044                                   libtrace_thread_t *t,
1045                                   libtrace_message_t * message);
1046
1047/** Check if a parallel trace has finished reading packets
1048 *
1049 * @return True if the trace has finished reading packets (even if all results
1050 * have not yet been processed). Otherwise false.
1051 *
1052 * @note This returns true even if all results have not yet been processed.
1053 */
1054DLLEXPORT bool trace_has_finished(libtrace_t * libtrace);
1055
1056
1057/** Check if libtrace is directly reading from multiple queues
1058 * from the format (such as a NICs hardware queues).
1059 *
1060 * When a parallel trace is running, or if checked after its completion
1061 * this returns true if a trace was able to run natively parallel
1062 * from the format. Otherwise false is returned, meaning libtrace is
1063 * distibuting packets across multiple threads from a single source.
1064 *
1065 * Factors that may stop this happening despite the format supporting
1066 * native parallel reads include: the choice of hasher function,
1067 * the number of threads choosen (such as 1 or more than the trace supports)
1068 * or another error when trying to start the parallel format.
1069 *
1070 * If this is called before the trace is started. I.e. before pstart
1071 * this returns an indication that the trace has the possiblity to support
1072 * native parallel reads. After trace pstart is called this should be
1073 * checked again to confirm this has happened.
1074 *
1075 *
1076 * @return true if the trace is parallel or false if the library is splitting
1077 * the trace into multiple threads.
1078 */
1079DLLEXPORT bool trace_is_parallel(libtrace_t * libtrace);
1080
1081/** Returns either the sequence number or erf timestamp of a packet.
1082 *
1083 * @param[in] packet
1084 * @return A 64bit sequence number or erf timestamp.
1085 *
1086 * The returned value can be used to compare if packets come before or after
1087 * others.
1088 */
1089DLLEXPORT uint64_t trace_packet_get_order(libtrace_packet_t * packet);
1090
1091/** Returns the hash of a packet.
1092 *
1093 * @param[in] packet
1094 * @return A 64-bit hash
1095 *
1096 * @note In many cases this might not be filled in, only in cases where
1097 * a custom hash is being used. You can use trace_has_dedicated_hasher()
1098 * to check if this will be valid.
1099 */
1100DLLEXPORT uint64_t trace_packet_get_hash(libtrace_packet_t * packet);
1101
1102/** Sets the order of a packet.
1103 *
1104 * @param[in] packet
1105 * @param[in] order the new order of a packet
1106 *
1107 * @note many combiners rely on this value, ensure changing this conforms to
1108 * the combiners requirements.
1109 */
1110DLLEXPORT void trace_packet_set_order(libtrace_packet_t * packet, uint64_t order);
1111
1112/** Sets the hash of a packet.
1113 *
1114 * @param[in] packet
1115 * @param[in] hash the new hash
1116 *
1117 * Once handed to the user the libtrace library has little use for this field
1118 * and as such this can essentially be used for any storage the user requires.
1119 */
1120DLLEXPORT void trace_packet_set_hash(libtrace_packet_t * packet, uint64_t hash);
1121
1122/** TODO WHAT TO DO WITH THIS ? */
1123DLLEXPORT uint64_t tv_to_usec(const struct timeval *tv);
1124
1125
1126/** Returns the first packet of a parallel trace since it was started or
1127 * restarted.
1128 *
1129 * @param[in] libtrace the parallel input trace
1130 * @param[in] t Either a per packet thread or NULL to retrieve the first packet
1131 * of across all per packet threads.
1132 * @param[out] packet A pointer to the first packet in the trace. [Optional]
1133 * @param[out] tv The system time-stamp when this packet was received. [Optional]
1134 * @return 1 if we are confident this is the first packet. Otherwise 0 if this
1135 * is a best guess (this is only possible int the case t=NULL)
1136 * in which case we recommend calling this at a later time.
1137 * -1 is returned if an error occurs, such as supplied a invalid thread.
1138 *
1139 * The packet and timeval returned by this function is shared by all threads
1140 * and remain valid until MESSAGE_PAUSING is received.
1141 */
1142DLLEXPORT int trace_get_first_packet(libtrace_t *libtrace,
1143                                     libtrace_thread_t *t,
1144                                     const libtrace_packet_t **packet,
1145                                     const struct timeval **tv);
1146
1147/** Makes a packet safe, a packet will become invalid after a
1148 * pausing a trace.
1149 *
1150 * @param[in,out] pkt The packet to make safe
1151 *
1152 * This copies a packet in such a way that it will be able to survive a pause.
1153 * However this will not allow the packet to be used after
1154 * the format is destroyed.
1155 */
1156DLLEXPORT void libtrace_make_packet_safe(libtrace_packet_t *pkt);
1157
1158/** Makes a result safe if a result contains a packet.
1159 *
1160 * @param[in,out] res The result to make safe.
1161 *
1162 * This ensures the internal content of a result is safe to survive a pause.
1163 * See libtrace_make_packet_safe().
1164 */
1165DLLEXPORT void libtrace_make_result_safe(libtrace_result_t *res);
1166
1167/** In a parallel trace, free a packet back to libtrace.
1168 *
1169 * @param[in] libtrace A parallel input trace
1170 * @param[in] packet The packet to be released back to libtrace
1171 *
1172 * The packet should not be used after calling this function.
1173 *
1174 * @note All packets should be free'd before a trace is destroyed.
1175 */
1176DLLEXPORT void trace_free_packet(libtrace_t * libtrace, libtrace_packet_t * packet);
1177
1178
1179DLLEXPORT libtrace_info_t *trace_get_information(libtrace_t * libtrace);
1180
1181/** Sets the configuration of a trace based upon a comma separated list of
1182 * key value pairs.
1183 *
1184 * @param trace A parallel trace which is not running or destroyed
1185 * @param str A comma separated list of key=value pairs.
1186 * E.g. \em "burst_size=20,perpkt_threads=2,fixed_count=true"
1187 * @return 0 if successful otherwise -1. If bad options are passed we will
1188 * print the error to stderr but still return successful.
1189 *
1190 * List of keys:
1191 * * \b cache_size,\b cs see trace_set_cache_size() [size_t]
1192 * * \b thread_cache_size,\b tcs see trace_set_thread_cache_size() [size_t]
1193 * * \b fixed_count,\b fc see trace_set_fixed_count() [bool]
1194 * * \b burst_size,\b bs see trace_set_burst_size() [size_t]
1195 * * \b tick_interval,\b ti see trace_set_tick_interval() [size_t]
1196 * * \b tick_count,\b tc see trace_set_tick_count() [size_t]
1197 * * \b perpkt_threads,\b pt see trace_set_perpkt_threads() [XXX TBA XXX]
1198 * * \b hasher_queue_size,\b hqs see trace_set_hasher_queue_size() [size_t]
1199 * * \b hasher_polling,\b hp see trace_set_hasher_polling() [bool]
1200 * * \b reporter_polling,\b rp see trace_set_reporter_polling() [bool]
1201 * * \b reporter_thold,\b rt see trace_set_reporter_thold() [size_t]
1202 * * \b debug_state,\b ds see trace_set_debug_state() [bool]
1203 *
1204 * Booleans can be set as 0/1 or false/true.
1205 *
1206 * @note a environment variable interface is provided by default to users via
1207 * LIBTRACE_CONF, see Parallel Configuration for more information.
1208 *
1209 * @note this interface is provided to allow a user to configure an application
1210 * if a libtrace applicate wishes to configure a setting it should use a
1211 * trace_set_*() function with the same name.
1212 */
1213DLLEXPORT int trace_set_configuration(libtrace_t *trace, const char * str);
1214
1215/** Sets configuration from a file. This reads every line from the file and
1216 * interprets each line with trace_set_configuration().
1217 *
1218 * @param trace A parallel trace which is not running or destroyed
1219 * @param file A file pointer which we read each line from
1220 * @return 0 if successful otherwise -1. If bad options are passed we will
1221 * print the error to stderr but still return successful.
1222 *
1223 * @note We do not close the file pointer upon completion
1224 */
1225DLLEXPORT int trace_set_configuration_file(libtrace_t *trace, FILE *file);
1226
1227DLLEXPORT int libtrace_get_perpkt_count(libtrace_t* t); // TODO MATCH WITH THE SET_PERPKT
1228
1229/**
1230 * Sets a combiner function against the trace.
1231 *
1232 * @param trace The input trace
1233 * @combiner The combiner to use
1234 * @config config Configuration information. Dependent upon the combiner in use
1235 *
1236 * Sets a combiner against a trace, this should only be called on a
1237 * non-started or paused trace.  By default combiner_unordered
1238 * will be used.
1239 */
1240DLLEXPORT void trace_set_combiner(libtrace_t *trace, const libtrace_combine_t *combiner, libtrace_generic_t config);
1241
1242/**
1243 * Takes unordered (or ordered) input and produces unordered output.
1244 * Basically you get the result quickly but in no particular order.
1245 */
1246extern const libtrace_combine_t combiner_unordered;
1247
1248/**
1249 * Takes ordered input and produces ordered output. Perpkt threads
1250 * the output results must be ordered for this to work correctly!!
1251 */
1252extern const libtrace_combine_t combiner_ordered;
1253
1254/**
1255 * Like classic Google Map/Reduce, the results are sorted
1256 * in ascending order, this is only done when the trace finishes.
1257 *
1258 * This only works with a limited number of results, otherwise
1259 * we will just run out of memory and crash!! You should always
1260 * use combiner_ordered if you can.
1261 */
1262extern const libtrace_combine_t combiner_sorted;
1263
1264#ifdef __cplusplus
1265}
1266#endif
1267
1268#endif // LIBTRACE_PARALLEL_H
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