summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/thread_map.c
blob: 292ae2c90e063d958da5f5859787c4c1c70ccab5 (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
#include <dirent.h>
#include <limits.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "strlist.h"
#include <string.h>
#include <api/fs/fs.h>
#include "asm/bug.h"
#include "thread_map.h"
#include "util.h"
#include "debug.h"

/* Skip "." and ".." directories */
static int filter(const struct dirent *dir)
{
	if (dir->d_name[0] == '.')
		return 0;
	else
		return 1;
}

static void thread_map__reset(struct thread_map *map, int start, int nr)
{
	size_t size = (nr - start) * sizeof(map->map[0]);

	memset(&map->map[start], 0, size);
}

static struct thread_map *thread_map__realloc(struct thread_map *map, int nr)
{
	size_t size = sizeof(*map) + sizeof(map->map[0]) * nr;
	int start = map ? map->nr : 0;

	map = realloc(map, size);
	/*
	 * We only realloc to add more items, let's reset new items.
	 */
	if (map)
		thread_map__reset(map, start, nr);

	return map;
}

#define thread_map__alloc(__nr) thread_map__realloc(NULL, __nr)

struct thread_map *thread_map__new_by_pid(pid_t pid)
{
	struct thread_map *threads;
	char name[256];
	int items;
	struct dirent **namelist = NULL;
	int i;

	sprintf(name, "/proc/%d/task", pid);
	items = scandir(name, &namelist, filter, NULL);
	if (items <= 0)
		return NULL;

	threads = thread_map__alloc(items);
	if (threads != NULL) {
		for (i = 0; i < items; i++)
			thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));
		threads->nr = items;
		atomic_set(&threads->refcnt, 1);
	}

	for (i=0; i<items; i++)
		zfree(&namelist[i]);
	free(namelist);

	return threads;
}

struct thread_map *thread_map__new_by_tid(pid_t tid)
{
	struct thread_map *threads = thread_map__alloc(1);

	if (threads != NULL) {
		thread_map__set_pid(threads, 0, tid);
		threads->nr = 1;
		atomic_set(&threads->refcnt, 1);
	}

	return threads;
}

struct thread_map *thread_map__new_by_uid(uid_t uid)
{
	DIR *proc;
	int max_threads = 32, items, i;
	char path[256];
	struct dirent dirent, *next, **namelist = NULL;
	struct thread_map *threads = thread_map__alloc(max_threads);

	if (threads == NULL)
		goto out;

	proc = opendir("/proc");
	if (proc == NULL)
		goto out_free_threads;

	threads->nr = 0;
	atomic_set(&threads->refcnt, 1);

	while (!readdir_r(proc, &dirent, &next) && next) {
		char *end;
		bool grow = false;
		struct stat st;
		pid_t pid = strtol(dirent.d_name, &end, 10);

		if (*end) /* only interested in proper numerical dirents */
			continue;

		snprintf(path, sizeof(path), "/proc/%s", dirent.d_name);

		if (stat(path, &st) != 0)
			continue;

		if (st.st_uid != uid)
			continue;

		snprintf(path, sizeof(path), "/proc/%d/task", pid);
		items = scandir(path, &namelist, filter, NULL);
		if (items <= 0)
			goto out_free_closedir;

		while (threads->nr + items >= max_threads) {
			max_threads *= 2;
			grow = true;
		}

		if (grow) {
			struct thread_map *tmp;

			tmp = thread_map__realloc(threads, max_threads);
			if (tmp == NULL)
				goto out_free_namelist;

			threads = tmp;
		}

		for (i = 0; i < items; i++) {
			thread_map__set_pid(threads, threads->nr + i,
					    atoi(namelist[i]->d_name));
		}

		for (i = 0; i < items; i++)
			zfree(&namelist[i]);
		free(namelist);

		threads->nr += items;
	}

out_closedir:
	closedir(proc);
out:
	return threads;

out_free_threads:
	free(threads);
	return NULL;

out_free_namelist:
	for (i = 0; i < items; i++)
		zfree(&namelist[i]);
	free(namelist);

out_free_closedir:
	zfree(&threads);
	goto out_closedir;
}

struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
{
	if (pid != -1)
		return thread_map__new_by_pid(pid);

	if (tid == -1 && uid != UINT_MAX)
		return thread_map__new_by_uid(uid);

	return thread_map__new_by_tid(tid);
}

static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
{
	struct thread_map *threads = NULL, *nt;
	char name[256];
	int items, total_tasks = 0;
	struct dirent **namelist = NULL;
	int i, j = 0;
	pid_t pid, prev_pid = INT_MAX;
	char *end_ptr;
	struct str_node *pos;
	struct strlist *slist = strlist__new(false, pid_str);

	if (!slist)
		return NULL;

	strlist__for_each(pos, slist) {
		pid = strtol(pos->s, &end_ptr, 10);

		if (pid == INT_MIN || pid == INT_MAX ||
		    (*end_ptr != '\0' && *end_ptr != ','))
			goto out_free_threads;

		if (pid == prev_pid)
			continue;

		sprintf(name, "/proc/%d/task", pid);
		items = scandir(name, &namelist, filter, NULL);
		if (items <= 0)
			goto out_free_threads;

		total_tasks += items;
		nt = thread_map__realloc(threads, total_tasks);
		if (nt == NULL)
			goto out_free_namelist;

		threads = nt;

		for (i = 0; i < items; i++) {
			thread_map__set_pid(threads, j++, atoi(namelist[i]->d_name));
			zfree(&namelist[i]);
		}
		threads->nr = total_tasks;
		free(namelist);
	}

out:
	strlist__delete(slist);
	if (threads)
		atomic_set(&threads->refcnt, 1);
	return threads;

out_free_namelist:
	for (i = 0; i < items; i++)
		zfree(&namelist[i]);
	free(namelist);

out_free_threads:
	zfree(&threads);
	goto out;
}

struct thread_map *thread_map__new_dummy(void)
{
	struct thread_map *threads = thread_map__alloc(1);

	if (threads != NULL) {
		thread_map__set_pid(threads, 0, -1);
		threads->nr = 1;
		atomic_set(&threads->refcnt, 1);
	}
	return threads;
}

static struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
{
	struct thread_map *threads = NULL, *nt;
	int ntasks = 0;
	pid_t tid, prev_tid = INT_MAX;
	char *end_ptr;
	struct str_node *pos;
	struct strlist *slist;

	/* perf-stat expects threads to be generated even if tid not given */
	if (!tid_str)
		return thread_map__new_dummy();

	slist = strlist__new(false, tid_str);
	if (!slist)
		return NULL;

	strlist__for_each(pos, slist) {
		tid = strtol(pos->s, &end_ptr, 10);

		if (tid == INT_MIN || tid == INT_MAX ||
		    (*end_ptr != '\0' && *end_ptr != ','))
			goto out_free_threads;

		if (tid == prev_tid)
			continue;

		ntasks++;
		nt = thread_map__realloc(threads, ntasks);

		if (nt == NULL)
			goto out_free_threads;

		threads = nt;
		thread_map__set_pid(threads, ntasks - 1, tid);
		threads->nr = ntasks;
	}
out:
	if (threads)
		atomic_set(&threads->refcnt, 1);
	return threads;

out_free_threads:
	zfree(&threads);
	goto out;
}

struct thread_map *thread_map__new_str(const char *pid, const char *tid,
				       uid_t uid)
{
	if (pid)
		return thread_map__new_by_pid_str(pid);

	if (!tid && uid != UINT_MAX)
		return thread_map__new_by_uid(uid);

	return thread_map__new_by_tid_str(tid);
}

static void thread_map__delete(struct thread_map *threads)
{
	if (threads) {
		int i;

		WARN_ONCE(atomic_read(&threads->refcnt) != 0,
			  "thread map refcnt unbalanced\n");
		for (i = 0; i < threads->nr; i++)
			free(thread_map__comm(threads, i));
		free(threads);
	}
}

struct thread_map *thread_map__get(struct thread_map *map)
{
	if (map)
		atomic_inc(&map->refcnt);
	return map;
}

void thread_map__put(struct thread_map *map)
{
	if (map && atomic_dec_and_test(&map->refcnt))
		thread_map__delete(map);
}

size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)
{
	int i;
	size_t printed = fprintf(fp, "%d thread%s: ",
				 threads->nr, threads->nr > 1 ? "s" : "");
	for (i = 0; i < threads->nr; ++i)
		printed += fprintf(fp, "%s%d", i ? ", " : "", thread_map__pid(threads, i));

	return printed + fprintf(fp, "\n");
}

static int get_comm(char **comm, pid_t pid)
{
	char *path;
	size_t size;
	int err;

	if (asprintf(&path, "%s/%d/comm", procfs__mountpoint(), pid) == -1)
		return -ENOMEM;

	err = filename__read_str(path, comm, &size);
	if (!err) {
		/*
		 * We're reading 16 bytes, while filename__read_str
		 * allocates data per BUFSIZ bytes, so we can safely
		 * mark the end of the string.
		 */
		(*comm)[size] = 0;
		rtrim(*comm);
	}

	free(path);
	return err;
}

static void comm_init(struct thread_map *map, int i)
{
	pid_t pid = thread_map__pid(map, i);
	char *comm = NULL;

	/* dummy pid comm initialization */
	if (pid == -1) {
		map->map[i].comm = strdup("dummy");
		return;
	}

	/*
	 * The comm name is like extra bonus ;-),
	 * so just warn if we fail for any reason.
	 */
	if (get_comm(&comm, pid))
		pr_warning("Couldn't resolve comm name for pid %d\n", pid);

	map->map[i].comm = comm;
}

void thread_map__read_comms(struct thread_map *threads)
{
	int i;

	for (i = 0; i < threads->nr; ++i)
		comm_init(threads, i);
}
OpenPOWER on IntegriCloud