summaryrefslogtreecommitdiff
path: root/tools/tracing/rtla/src/osnoise.c
blob: 7b73d1eccd0e3d373e56b42ba873e87a7a95ce22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>

#include "osnoise.h"
#include "utils.h"

/*
 * osnoise_get_cpus - return the original "osnoise/cpus" content
 *
 * It also saves the value to be restored.
 */
char *osnoise_get_cpus(struct osnoise_context *context)
{
	if (context->curr_cpus)
		return context->curr_cpus;

	if (context->orig_cpus)
		return context->orig_cpus;

	context->orig_cpus = tracefs_instance_file_read(NULL, "osnoise/cpus", NULL);

	/*
	 * The error value (NULL) is the same for tracefs_instance_file_read()
	 * and this functions, so:
	 */
	return context->orig_cpus;
}

/*
 * osnoise_set_cpus - configure osnoise to run on *cpus
 *
 * "osnoise/cpus" file is used to set the cpus in which osnoise/timerlat
 * will run. This function opens this file, saves the current value,
 * and set the cpus passed as argument.
 */
int osnoise_set_cpus(struct osnoise_context *context, char *cpus)
{
	char *orig_cpus = osnoise_get_cpus(context);
	char buffer[1024];
	int retval;

	if (!orig_cpus)
		return -1;

	context->curr_cpus = strdup(cpus);
	if (!context->curr_cpus)
		return -1;

	snprintf(buffer, 1024, "%s\n", cpus);

	debug_msg("setting cpus to %s from %s", cpus, context->orig_cpus);

	retval = tracefs_instance_file_write(NULL, "osnoise/cpus", buffer);
	if (retval < 0) {
		free(context->curr_cpus);
		context->curr_cpus = NULL;
		return -1;
	}

	return 0;
}

/*
 * osnoise_restore_cpus - restore the original "osnoise/cpus"
 *
 * osnoise_set_cpus() saves the original data for the "osnoise/cpus"
 * file. This function restore the original config it was previously
 * modified.
 */
void osnoise_restore_cpus(struct osnoise_context *context)
{
	int retval;

	if (!context->orig_cpus)
		return;

	if (!context->curr_cpus)
		return;

	/* nothing to do? */
	if (!strcmp(context->orig_cpus, context->curr_cpus))
		goto out_done;

	debug_msg("restoring cpus to %s", context->orig_cpus);

	retval = tracefs_instance_file_write(NULL, "osnoise/cpus", context->orig_cpus);
	if (retval < 0)
		err_msg("could not restore original osnoise cpus\n");

out_done:
	free(context->curr_cpus);
	context->curr_cpus = NULL;
}

/*
 * osnoise_put_cpus - restore cpus config and cleanup data
 */
void osnoise_put_cpus(struct osnoise_context *context)
{
	osnoise_restore_cpus(context);

	if (!context->orig_cpus)
		return;

	free(context->orig_cpus);
	context->orig_cpus = NULL;
}

/*
 * osnoise_read_ll_config - read a long long value from a config
 *
 * returns -1 on error.
 */
static long long osnoise_read_ll_config(char *rel_path)
{
	long long retval;
	char *buffer;

	buffer = tracefs_instance_file_read(NULL, rel_path, NULL);
	if (!buffer)
		return -1;

	/* get_llong_from_str returns -1 on error */
	retval = get_llong_from_str(buffer);

	debug_msg("reading %s returned %lld\n", rel_path, retval);

	free(buffer);

	return retval;
}

/*
 * osnoise_write_ll_config - write a long long value to a config in rel_path
 *
 * returns -1 on error.
 */
static long long osnoise_write_ll_config(char *rel_path, long long value)
{
	char buffer[BUFF_U64_STR_SIZE];
	long long retval;

	snprintf(buffer, sizeof(buffer), "%lld\n", value);

	debug_msg("setting %s to %lld\n", rel_path, value);

	retval = tracefs_instance_file_write(NULL, rel_path, buffer);
	return retval;
}

/*
 * osnoise_get_runtime - return the original "osnoise/runtime_us" value
 *
 * It also saves the value to be restored.
 */
unsigned long long osnoise_get_runtime(struct osnoise_context *context)
{
	long long runtime_us;

	if (context->runtime_us != OSNOISE_TIME_INIT_VAL)
		return context->runtime_us;

	if (context->orig_runtime_us != OSNOISE_TIME_INIT_VAL)
		return context->orig_runtime_us;

	runtime_us = osnoise_read_ll_config("osnoise/runtime_us");
	if (runtime_us < 0)
		goto out_err;

	context->orig_runtime_us = runtime_us;
	return runtime_us;

out_err:
	return OSNOISE_TIME_INIT_VAL;
}

/*
 * osnoise_get_period - return the original "osnoise/period_us" value
 *
 * It also saves the value to be restored.
 */
unsigned long long osnoise_get_period(struct osnoise_context *context)
{
	long long period_us;

	if (context->period_us != OSNOISE_TIME_INIT_VAL)
		return context->period_us;

	if (context->orig_period_us != OSNOISE_TIME_INIT_VAL)
		return context->orig_period_us;

	period_us = osnoise_read_ll_config("osnoise/period_us");
	if (period_us < 0)
		goto out_err;

	context->orig_period_us = period_us;
	return period_us;

out_err:
	return OSNOISE_TIME_INIT_VAL;
}

static int __osnoise_write_runtime(struct osnoise_context *context,
				   unsigned long long runtime)
{
	int retval;

	if (context->orig_runtime_us == OSNOISE_TIME_INIT_VAL)
		return -1;

	retval = osnoise_write_ll_config("osnoise/runtime_us", runtime);
	if (retval < 0)
		return -1;

	context->runtime_us = runtime;
	return 0;
}

static int __osnoise_write_period(struct osnoise_context *context,
				  unsigned long long period)
{
	int retval;

	if (context->orig_period_us == OSNOISE_TIME_INIT_VAL)
		return -1;

	retval = osnoise_write_ll_config("osnoise/period_us", period);
	if (retval < 0)
		return -1;

	context->period_us = period;
	return 0;
}

/*
 * osnoise_set_runtime_period - set osnoise runtime and period
 *
 * Osnoise's runtime and period are related as runtime <= period.
 * Thus, this function saves the original values, and then tries
 * to set the runtime and period if they are != 0.
 */
int osnoise_set_runtime_period(struct osnoise_context *context,
			       unsigned long long runtime,
			       unsigned long long period)
{
	unsigned long long curr_runtime_us;
	unsigned long long curr_period_us;
	int retval;

	if (!period && !runtime)
		return 0;

	curr_runtime_us = osnoise_get_runtime(context);
	curr_period_us = osnoise_get_period(context);

	/* error getting any value? */
	if (curr_period_us == OSNOISE_TIME_INIT_VAL || curr_runtime_us == OSNOISE_TIME_INIT_VAL)
		return -1;

	if (!period) {
		if (runtime > curr_period_us)
			return -1;
		return __osnoise_write_runtime(context, runtime);
	} else if (!runtime) {
		if (period < curr_runtime_us)
			return -1;
		return __osnoise_write_period(context, period);
	}

	if (runtime > curr_period_us) {
		retval = __osnoise_write_period(context, period);
		if (retval)
			return -1;
		retval = __osnoise_write_runtime(context, runtime);
		if (retval)
			return -1;
	} else {
		retval = __osnoise_write_runtime(context, runtime);
		if (retval)
			return -1;
		retval = __osnoise_write_period(context, period);
		if (retval)
			return -1;
	}

	return 0;
}

/*
 * osnoise_restore_runtime_period - restore the original runtime and period
 */
void osnoise_restore_runtime_period(struct osnoise_context *context)
{
	unsigned long long orig_runtime = context->orig_runtime_us;
	unsigned long long orig_period = context->orig_period_us;
	unsigned long long curr_runtime = context->runtime_us;
	unsigned long long curr_period = context->period_us;
	int retval;

	if ((orig_runtime == OSNOISE_TIME_INIT_VAL) && (orig_period == OSNOISE_TIME_INIT_VAL))
		return;

	if ((orig_period == curr_period) && (orig_runtime == curr_runtime))
		goto out_done;

	retval = osnoise_set_runtime_period(context, orig_runtime, orig_period);
	if (retval)
		err_msg("Could not restore original osnoise runtime/period\n");

out_done:
	context->runtime_us = OSNOISE_TIME_INIT_VAL;
	context->period_us = OSNOISE_TIME_INIT_VAL;
}

/*
 * osnoise_put_runtime_period - restore original values and cleanup data
 */
void osnoise_put_runtime_period(struct osnoise_context *context)
{
	osnoise_restore_runtime_period(context);

	if (context->orig_runtime_us != OSNOISE_TIME_INIT_VAL)
		context->orig_runtime_us = OSNOISE_TIME_INIT_VAL;

	if (context->orig_period_us != OSNOISE_TIME_INIT_VAL)
		context->orig_period_us = OSNOISE_TIME_INIT_VAL;
}

/*
 * osnoise_get_timerlat_period_us - read and save the original "timerlat_period_us"
 */
static long long
osnoise_get_timerlat_period_us(struct osnoise_context *context)
{
	long long timerlat_period_us;

	if (context->timerlat_period_us != OSNOISE_TIME_INIT_VAL)
		return context->timerlat_period_us;

	if (context->orig_timerlat_period_us != OSNOISE_TIME_INIT_VAL)
		return context->orig_timerlat_period_us;

	timerlat_period_us = osnoise_read_ll_config("osnoise/timerlat_period_us");
	if (timerlat_period_us < 0)
		goto out_err;

	context->orig_timerlat_period_us = timerlat_period_us;
	return timerlat_period_us;

out_err:
	return OSNOISE_TIME_INIT_VAL;
}

/*
 * osnoise_set_timerlat_period_us - set "timerlat_period_us"
 */
int osnoise_set_timerlat_period_us(struct osnoise_context *context, long long timerlat_period_us)
{
	long long curr_timerlat_period_us = osnoise_get_timerlat_period_us(context);
	int retval;

	if (curr_timerlat_period_us == OSNOISE_TIME_INIT_VAL)
		return -1;

	retval = osnoise_write_ll_config("osnoise/timerlat_period_us", timerlat_period_us);
	if (retval < 0)
		return -1;

	context->timerlat_period_us = timerlat_period_us;

	return 0;
}

/*
 * osnoise_restore_timerlat_period_us - restore "timerlat_period_us"
 */
void osnoise_restore_timerlat_period_us(struct osnoise_context *context)
{
	int retval;

	if (context->orig_timerlat_period_us == OSNOISE_TIME_INIT_VAL)
		return;

	if (context->orig_timerlat_period_us == context->timerlat_period_us)
		goto out_done;

	retval = osnoise_write_ll_config("osnoise/timerlat_period_us", context->orig_timerlat_period_us);
	if (retval < 0)
		err_msg("Could not restore original osnoise timerlat_period_us\n");

out_done:
	context->timerlat_period_us = OSNOISE_TIME_INIT_VAL;
}

/*
 * osnoise_put_timerlat_period_us - restore original values and cleanup data
 */
void osnoise_put_timerlat_period_us(struct osnoise_context *context)
{
	osnoise_restore_timerlat_period_us(context);

	if (context->orig_timerlat_period_us == OSNOISE_TIME_INIT_VAL)
		return;

	context->orig_timerlat_period_us = OSNOISE_TIME_INIT_VAL;
}

/*
 * osnoise_get_stop_us - read and save the original "stop_tracing_us"
 */
static long long
osnoise_get_stop_us(struct osnoise_context *context)
{
	long long stop_us;

	if (context->stop_us != OSNOISE_OPTION_INIT_VAL)
		return context->stop_us;

	if (context->orig_stop_us != OSNOISE_OPTION_INIT_VAL)
		return context->orig_stop_us;

	stop_us = osnoise_read_ll_config("osnoise/stop_tracing_us");
	if (stop_us < 0)
		goto out_err;

	context->orig_stop_us = stop_us;
	return stop_us;

out_err:
	return OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_set_stop_us - set "stop_tracing_us"
 */
int osnoise_set_stop_us(struct osnoise_context *context, long long stop_us)
{
	long long curr_stop_us = osnoise_get_stop_us(context);
	int retval;

	if (curr_stop_us == OSNOISE_OPTION_INIT_VAL)
		return -1;

	retval = osnoise_write_ll_config("osnoise/stop_tracing_us", stop_us);
	if (retval < 0)
		return -1;

	context->stop_us = stop_us;

	return 0;
}

/*
 * osnoise_restore_stop_us - restore the original "stop_tracing_us"
 */
void osnoise_restore_stop_us(struct osnoise_context *context)
{
	int retval;

	if (context->orig_stop_us == OSNOISE_OPTION_INIT_VAL)
		return;

	if (context->orig_stop_us == context->stop_us)
		goto out_done;

	retval = osnoise_write_ll_config("osnoise/stop_tracing_us", context->orig_stop_us);
	if (retval < 0)
		err_msg("Could not restore original osnoise stop_us\n");

out_done:
	context->stop_us = OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_put_stop_us - restore original values and cleanup data
 */
void osnoise_put_stop_us(struct osnoise_context *context)
{
	osnoise_restore_stop_us(context);

	if (context->orig_stop_us == OSNOISE_OPTION_INIT_VAL)
		return;

	context->orig_stop_us = OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_get_stop_total_us - read and save the original "stop_tracing_total_us"
 */
static long long
osnoise_get_stop_total_us(struct osnoise_context *context)
{
	long long stop_total_us;

	if (context->stop_total_us != OSNOISE_OPTION_INIT_VAL)
		return context->stop_total_us;

	if (context->orig_stop_total_us != OSNOISE_OPTION_INIT_VAL)
		return context->orig_stop_total_us;

	stop_total_us = osnoise_read_ll_config("osnoise/stop_tracing_total_us");
	if (stop_total_us < 0)
		goto out_err;

	context->orig_stop_total_us = stop_total_us;
	return stop_total_us;

out_err:
	return OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_set_stop_total_us - set "stop_tracing_total_us"
 */
int osnoise_set_stop_total_us(struct osnoise_context *context, long long stop_total_us)
{
	long long curr_stop_total_us = osnoise_get_stop_total_us(context);
	int retval;

	if (curr_stop_total_us == OSNOISE_OPTION_INIT_VAL)
		return -1;

	retval = osnoise_write_ll_config("osnoise/stop_tracing_total_us", stop_total_us);
	if (retval < 0)
		return -1;

	context->stop_total_us = stop_total_us;

	return 0;
}

/*
 * osnoise_restore_stop_total_us - restore the original "stop_tracing_total_us"
 */
void osnoise_restore_stop_total_us(struct osnoise_context *context)
{
	int retval;

	if (context->orig_stop_total_us == OSNOISE_OPTION_INIT_VAL)
		return;

	if (context->orig_stop_total_us == context->stop_total_us)
		goto out_done;

	retval = osnoise_write_ll_config("osnoise/stop_tracing_total_us",
			context->orig_stop_total_us);
	if (retval < 0)
		err_msg("Could not restore original osnoise stop_total_us\n");

out_done:
	context->stop_total_us = OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_put_stop_total_us - restore original values and cleanup data
 */
void osnoise_put_stop_total_us(struct osnoise_context *context)
{
	osnoise_restore_stop_total_us(context);

	if (context->orig_stop_total_us == OSNOISE_OPTION_INIT_VAL)
		return;

	context->orig_stop_total_us = OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_get_print_stack - read and save the original "print_stack"
 */
static long long
osnoise_get_print_stack(struct osnoise_context *context)
{
	long long print_stack;

	if (context->print_stack != OSNOISE_OPTION_INIT_VAL)
		return context->print_stack;

	if (context->orig_print_stack != OSNOISE_OPTION_INIT_VAL)
		return context->orig_print_stack;

	print_stack = osnoise_read_ll_config("osnoise/print_stack");
	if (print_stack < 0)
		goto out_err;

	context->orig_print_stack = print_stack;
	return print_stack;

out_err:
	return OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_set_print_stack - set "print_stack"
 */
int osnoise_set_print_stack(struct osnoise_context *context, long long print_stack)
{
	long long curr_print_stack = osnoise_get_print_stack(context);
	int retval;

	if (curr_print_stack == OSNOISE_OPTION_INIT_VAL)
		return -1;

	retval = osnoise_write_ll_config("osnoise/print_stack", print_stack);
	if (retval < 0)
		return -1;

	context->print_stack = print_stack;

	return 0;
}

/*
 * osnoise_restore_print_stack - restore the original "print_stack"
 */
void osnoise_restore_print_stack(struct osnoise_context *context)
{
	int retval;

	if (context->orig_print_stack == OSNOISE_OPTION_INIT_VAL)
		return;

	if (context->orig_print_stack == context->print_stack)
		goto out_done;

	retval = osnoise_write_ll_config("osnoise/print_stack", context->orig_print_stack);
	if (retval < 0)
		err_msg("Could not restore original osnoise print_stack\n");

out_done:
	context->print_stack = OSNOISE_OPTION_INIT_VAL;
}

/*
 * osnoise_put_print_stack - restore original values and cleanup data
 */
void osnoise_put_print_stack(struct osnoise_context *context)
{
	osnoise_restore_print_stack(context);

	if (context->orig_print_stack == OSNOISE_OPTION_INIT_VAL)
		return;

	context->orig_print_stack = OSNOISE_OPTION_INIT_VAL;
}

/*
 * enable_osnoise - enable osnoise tracer in the trace_instance
 */
int enable_osnoise(struct trace_instance *trace)
{
	return enable_tracer_by_name(trace->inst, "osnoise");
}

/*
 * enable_timerlat - enable timerlat tracer in the trace_instance
 */
int enable_timerlat(struct trace_instance *trace)
{
	return enable_tracer_by_name(trace->inst, "timerlat");
}

enum {
	FLAG_CONTEXT_NEWLY_CREATED	= (1 << 0),
	FLAG_CONTEXT_DELETED		= (1 << 1),
};

/*
 * osnoise_get_context - increase the usage of a context and return it
 */
int osnoise_get_context(struct osnoise_context *context)
{
	int ret;

	if (context->flags & FLAG_CONTEXT_DELETED) {
		ret = -1;
	} else {
		context->ref++;
		ret = 0;
	}

	return ret;
}

/*
 * osnoise_context_alloc - alloc an osnoise_context
 *
 * The osnoise context contains the information of the "osnoise/" configs.
 * It is used to set and restore the config.
 */
struct osnoise_context *osnoise_context_alloc(void)
{
	struct osnoise_context *context;

	context = calloc(1, sizeof(*context));
	if (!context)
		return NULL;

	context->orig_stop_us		= OSNOISE_OPTION_INIT_VAL;
	context->stop_us		= OSNOISE_OPTION_INIT_VAL;

	context->orig_stop_total_us	= OSNOISE_OPTION_INIT_VAL;
	context->stop_total_us		= OSNOISE_OPTION_INIT_VAL;

	context->orig_print_stack	= OSNOISE_OPTION_INIT_VAL;
	context->print_stack		= OSNOISE_OPTION_INIT_VAL;

	osnoise_get_context(context);

	return context;
}

/*
 * osnoise_put_context - put the osnoise_put_context
 *
 * If there is no other user for the context, the original data
 * is restored.
 */
void osnoise_put_context(struct osnoise_context *context)
{
	if (--context->ref < 1)
		context->flags |= FLAG_CONTEXT_DELETED;

	if (!(context->flags & FLAG_CONTEXT_DELETED))
		return;

	osnoise_put_cpus(context);
	osnoise_put_runtime_period(context);
	osnoise_put_stop_us(context);
	osnoise_put_stop_total_us(context);
	osnoise_put_timerlat_period_us(context);
	osnoise_put_print_stack(context);

	free(context);
}

/*
 * osnoise_destroy_tool - disable trace, restore configs and free data
 */
void osnoise_destroy_tool(struct osnoise_tool *top)
{
	trace_instance_destroy(&top->trace);

	if (top->context)
		osnoise_put_context(top->context);

	free(top);
}

/*
 * osnoise_init_tool - init an osnoise tool
 *
 * It allocs data, create a context to store data and
 * creates a new trace instance for the tool.
 */
struct osnoise_tool *osnoise_init_tool(char *tool_name)
{
	struct osnoise_tool *top;
	int retval;

	top = calloc(1, sizeof(*top));
	if (!top)
		return NULL;

	top->context = osnoise_context_alloc();
	if (!top->context)
		goto out_err;

	retval = trace_instance_init(&top->trace, tool_name);
	if (retval)
		goto out_err;

	return top;
out_err:
	osnoise_destroy_tool(top);
	return NULL;
}

/*
 * osnoise_init_trace_tool - init a tracer instance to trace osnoise events
 */
struct osnoise_tool *osnoise_init_trace_tool(char *tracer)
{
	struct osnoise_tool *trace;
	int retval;

	trace = osnoise_init_tool("osnoise_trace");
	if (!trace)
		return NULL;

	retval = tracefs_event_enable(trace->trace.inst, "osnoise", NULL);
	if (retval < 0 && !errno) {
		err_msg("Could not find osnoise events\n");
		goto out_err;
	}

	retval = enable_tracer_by_name(trace->trace.inst, tracer);
	if (retval) {
		err_msg("Could not enable osnoiser tracer for tracing\n");
		goto out_err;
	}

	return trace;
out_err:
	osnoise_destroy_tool(trace);
	return NULL;
}

static void osnoise_usage(void)
{
	int i;

	static const char *msg[] = {
		"",
		"osnoise version " VERSION,
		"",
		"  usage: [rtla] osnoise [MODE] ...",
		"",
		"  modes:",
		"     top   - prints the summary from osnoise tracer",
		"     hist  - prints a histogram of osnoise samples",
		"",
		"if no MODE is given, the top mode is called, passing the arguments",
		NULL,
	};

	for (i = 0; msg[i]; i++)
		fprintf(stderr, "%s\n", msg[i]);
	exit(1);
}

int osnoise_main(int argc, char *argv[])
{
	if (argc == 0)
		goto usage;

	/*
	 * if osnoise was called without any argument, run the
	 * default cmdline.
	 */
	if (argc == 1) {
		osnoise_top_main(argc, argv);
		exit(0);
	}

	if ((strcmp(argv[1], "-h") == 0) || (strcmp(argv[1], "--help") == 0)) {
		osnoise_usage();
		exit(0);
	} else if (strncmp(argv[1], "-", 1) == 0) {
		/* the user skipped the tool, call the default one */
		osnoise_top_main(argc, argv);
		exit(0);
	} else if (strcmp(argv[1], "top") == 0) {
		osnoise_top_main(argc-1, &argv[1]);
		exit(0);
	} else if (strcmp(argv[1], "hist") == 0) {
		osnoise_hist_main(argc-1, &argv[1]);
		exit(0);
	}

usage:
	osnoise_usage();
	exit(1);
}