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67337c4a MD |
1 | // SPDX-License-Identifier: MIT |
2 | /* | |
3 | * Copyright 2022 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | */ | |
5 | ||
6 | #include <side/trace.h> | |
7 | #include <string.h> | |
b1bf768c | 8 | #include <assert.h> |
67337c4a MD |
9 | |
10 | #include "rcu.h" | |
11 | #include "list.h" | |
873bbf16 | 12 | #include "rculist.h" |
67337c4a MD |
13 | |
14 | /* Top 8 bits reserved for kernel tracer use. */ | |
15 | #if SIDE_BITS_PER_LONG == 64 | |
16 | # define SIDE_EVENT_ENABLED_KERNEL_MASK 0xFF00000000000000ULL | |
17 | # define SIDE_EVENT_ENABLED_KERNEL_USER_EVENT_MASK 0x8000000000000000ULL | |
18 | ||
19 | /* Allow 2^56 tracer references on an event. */ | |
20 | # define SIDE_EVENT_ENABLED_USER_MASK 0x00FFFFFFFFFFFFFFULL | |
21 | #else | |
22 | # define SIDE_EVENT_ENABLED_KERNEL_MASK 0xFF000000UL | |
23 | # define SIDE_EVENT_ENABLED_KERNEL_USER_EVENT_MASK 0x80000000UL | |
24 | ||
25 | /* Allow 2^24 tracer references on an event. */ | |
26 | # define SIDE_EVENT_ENABLED_USER_MASK 0x00FFFFFFUL | |
27 | #endif | |
28 | ||
29 | struct side_events_register_handle { | |
30 | struct side_list_node node; | |
31 | struct side_event_description **events; | |
32 | uint32_t nr_events; | |
33 | }; | |
34 | ||
35 | struct side_tracer_handle { | |
36 | struct side_list_node node; | |
37 | void (*cb)(enum side_tracer_notification notif, | |
38 | struct side_event_description **events, uint32_t nr_events, void *priv); | |
39 | void *priv; | |
40 | }; | |
41 | ||
f0b01832 | 42 | struct side_statedump_request_handle { |
873bbf16 | 43 | struct side_list_node node; /* RCU list. */ |
f0b01832 MD |
44 | void (*cb)(void); |
45 | }; | |
46 | ||
867b4725 MD |
47 | struct side_callback { |
48 | union { | |
49 | void (*call)(const struct side_event_description *desc, | |
50 | const struct side_arg_vec *side_arg_vec, | |
51 | void *priv); | |
52 | void (*call_variadic)(const struct side_event_description *desc, | |
53 | const struct side_arg_vec *side_arg_vec, | |
54 | const struct side_arg_dynamic_struct *var_struct, | |
55 | void *priv); | |
56 | } u; | |
57 | void *priv; | |
92c377f9 | 58 | void *key; |
867b4725 MD |
59 | }; |
60 | ||
873bbf16 | 61 | static struct side_rcu_gp_state event_rcu_gp, statedump_rcu_gp; |
67337c4a MD |
62 | |
63 | /* | |
64 | * Lazy initialization for early use within library constructors. | |
65 | */ | |
66 | static bool initialized; | |
67 | /* | |
68 | * Do not register/unregister any more events after destructor. | |
69 | */ | |
70 | static bool finalized; | |
71 | ||
72 | /* | |
73 | * Recursive mutex to allow tracer callbacks to use the side API. | |
74 | */ | |
873bbf16 MD |
75 | static pthread_mutex_t side_event_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; |
76 | static pthread_mutex_t side_statedump_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; | |
67337c4a MD |
77 | |
78 | static DEFINE_SIDE_LIST_HEAD(side_events_list); | |
79 | static DEFINE_SIDE_LIST_HEAD(side_tracer_list); | |
f0b01832 | 80 | static DEFINE_SIDE_LIST_HEAD(side_statedump_list); |
67337c4a | 81 | |
74be90b7 MD |
82 | /* |
83 | * Callback filter key for state dump. | |
84 | */ | |
85 | static __thread void *filter_key; | |
86 | ||
67337c4a MD |
87 | /* |
88 | * The empty callback has a NULL function callback pointer, which stops | |
89 | * iteration on the array of callbacks immediately. | |
90 | */ | |
867b4725 | 91 | const char side_empty_callback[sizeof(struct side_callback)]; |
67337c4a | 92 | |
74be90b7 MD |
93 | static |
94 | void _side_call(const struct side_event_state *event_state, const struct side_arg_vec *side_arg_vec, void *key) | |
67337c4a MD |
95 | { |
96 | struct side_rcu_read_state rcu_read_state; | |
b2a84b9f | 97 | const struct side_event_state_0 *es0; |
67337c4a MD |
98 | const struct side_callback *side_cb; |
99 | uintptr_t enabled; | |
100 | ||
101 | if (side_unlikely(finalized)) | |
102 | return; | |
103 | if (side_unlikely(!initialized)) | |
104 | side_init(); | |
b2a84b9f MD |
105 | if (side_unlikely(event_state->version != 0)) |
106 | abort(); | |
49aea3ef | 107 | es0 = side_container_of(event_state, const struct side_event_state_0, parent); |
7269a8a3 | 108 | assert(!(es0->desc->flags & SIDE_EVENT_FLAG_VARIADIC)); |
b2a84b9f | 109 | enabled = __atomic_load_n(&es0->enabled, __ATOMIC_RELAXED); |
67337c4a MD |
110 | if (side_unlikely(enabled & SIDE_EVENT_ENABLED_KERNEL_USER_EVENT_MASK)) { |
111 | // TODO: call kernel write. | |
112 | } | |
873bbf16 | 113 | side_rcu_read_begin(&event_rcu_gp, &rcu_read_state); |
92c377f9 MD |
114 | for (side_cb = side_rcu_dereference(es0->callbacks); side_cb->u.call != NULL; side_cb++) { |
115 | /* A NULL key is always a match. */ | |
116 | if (key && side_cb->key && side_cb->key != key) | |
117 | continue; | |
7269a8a3 | 118 | side_cb->u.call(es0->desc, side_arg_vec, side_cb->priv); |
92c377f9 | 119 | } |
873bbf16 | 120 | side_rcu_read_end(&event_rcu_gp, &rcu_read_state); |
67337c4a MD |
121 | } |
122 | ||
92c377f9 MD |
123 | void side_call(const struct side_event_state *event_state, const struct side_arg_vec *side_arg_vec) |
124 | { | |
74be90b7 | 125 | _side_call(event_state, side_arg_vec, NULL); |
92c377f9 MD |
126 | } |
127 | ||
f0b01832 | 128 | void side_statedump_call(const struct side_event_state *event_state, const struct side_arg_vec *side_arg_vec) |
74be90b7 MD |
129 | { |
130 | _side_call(event_state, side_arg_vec, filter_key); | |
131 | } | |
132 | ||
133 | static | |
134 | void _side_call_variadic(const struct side_event_state *event_state, | |
67337c4a | 135 | const struct side_arg_vec *side_arg_vec, |
92c377f9 MD |
136 | const struct side_arg_dynamic_struct *var_struct, |
137 | void *key) | |
67337c4a MD |
138 | { |
139 | struct side_rcu_read_state rcu_read_state; | |
b2a84b9f | 140 | const struct side_event_state_0 *es0; |
67337c4a MD |
141 | const struct side_callback *side_cb; |
142 | uintptr_t enabled; | |
143 | ||
144 | if (side_unlikely(finalized)) | |
145 | return; | |
146 | if (side_unlikely(!initialized)) | |
147 | side_init(); | |
b2a84b9f MD |
148 | if (side_unlikely(event_state->version != 0)) |
149 | abort(); | |
49aea3ef | 150 | es0 = side_container_of(event_state, const struct side_event_state_0, parent); |
7269a8a3 | 151 | assert(es0->desc->flags & SIDE_EVENT_FLAG_VARIADIC); |
b2a84b9f | 152 | enabled = __atomic_load_n(&es0->enabled, __ATOMIC_RELAXED); |
67337c4a MD |
153 | if (side_unlikely(enabled & SIDE_EVENT_ENABLED_KERNEL_USER_EVENT_MASK)) { |
154 | // TODO: call kernel write. | |
155 | } | |
873bbf16 | 156 | side_rcu_read_begin(&event_rcu_gp, &rcu_read_state); |
92c377f9 MD |
157 | for (side_cb = side_rcu_dereference(es0->callbacks); side_cb->u.call_variadic != NULL; side_cb++) { |
158 | /* A NULL key is always a match. */ | |
159 | if (key && side_cb->key && side_cb->key != key) | |
160 | continue; | |
7269a8a3 | 161 | side_cb->u.call_variadic(es0->desc, side_arg_vec, var_struct, side_cb->priv); |
92c377f9 | 162 | } |
873bbf16 | 163 | side_rcu_read_end(&event_rcu_gp, &rcu_read_state); |
67337c4a MD |
164 | } |
165 | ||
92c377f9 MD |
166 | void side_call_variadic(const struct side_event_state *event_state, |
167 | const struct side_arg_vec *side_arg_vec, | |
168 | const struct side_arg_dynamic_struct *var_struct) | |
169 | { | |
74be90b7 MD |
170 | _side_call_variadic(event_state, side_arg_vec, var_struct, NULL); |
171 | } | |
172 | ||
f0b01832 | 173 | void side_statedump_call_variadic(const struct side_event_state *event_state, |
74be90b7 MD |
174 | const struct side_arg_vec *side_arg_vec, |
175 | const struct side_arg_dynamic_struct *var_struct) | |
176 | { | |
177 | _side_call_variadic(event_state, side_arg_vec, var_struct, filter_key); | |
92c377f9 MD |
178 | } |
179 | ||
67337c4a MD |
180 | static |
181 | const struct side_callback *side_tracer_callback_lookup( | |
182 | const struct side_event_description *desc, | |
92c377f9 | 183 | void *call, void *priv, void *key) |
67337c4a | 184 | { |
0b9e59d6 | 185 | struct side_event_state *event_state = side_ptr_get(desc->state); |
b2a84b9f | 186 | const struct side_event_state_0 *es0; |
67337c4a MD |
187 | const struct side_callback *cb; |
188 | ||
b2a84b9f MD |
189 | if (side_unlikely(event_state->version != 0)) |
190 | abort(); | |
49aea3ef | 191 | es0 = side_container_of(event_state, const struct side_event_state_0, parent); |
7269a8a3 | 192 | for (cb = es0->callbacks; cb->u.call != NULL; cb++) { |
92c377f9 | 193 | if ((void *) cb->u.call == call && cb->priv == priv && cb->key == key) |
67337c4a MD |
194 | return cb; |
195 | } | |
196 | return NULL; | |
197 | } | |
198 | ||
199 | static | |
200 | int _side_tracer_callback_register(struct side_event_description *desc, | |
92c377f9 | 201 | void *call, void *priv, void *key) |
67337c4a | 202 | { |
0b9e59d6 | 203 | struct side_event_state *event_state; |
67337c4a | 204 | struct side_callback *old_cb, *new_cb; |
b2a84b9f | 205 | struct side_event_state_0 *es0; |
67337c4a MD |
206 | int ret = SIDE_ERROR_OK; |
207 | uint32_t old_nr_cb; | |
208 | ||
209 | if (!call) | |
210 | return SIDE_ERROR_INVAL; | |
211 | if (finalized) | |
212 | return SIDE_ERROR_EXITING; | |
213 | if (!initialized) | |
214 | side_init(); | |
873bbf16 | 215 | pthread_mutex_lock(&side_event_lock); |
0b9e59d6 | 216 | event_state = side_ptr_get(desc->state); |
b2a84b9f MD |
217 | if (side_unlikely(event_state->version != 0)) |
218 | abort(); | |
49aea3ef | 219 | es0 = side_container_of(event_state, struct side_event_state_0, parent); |
3cac1780 | 220 | old_nr_cb = es0->nr_callbacks; |
67337c4a MD |
221 | if (old_nr_cb == UINT32_MAX) { |
222 | ret = SIDE_ERROR_INVAL; | |
223 | goto unlock; | |
224 | } | |
225 | /* Reject duplicate (call, priv) tuples. */ | |
92c377f9 | 226 | if (side_tracer_callback_lookup(desc, call, priv, key)) { |
67337c4a MD |
227 | ret = SIDE_ERROR_EXIST; |
228 | goto unlock; | |
229 | } | |
7269a8a3 | 230 | old_cb = (struct side_callback *) es0->callbacks; |
67337c4a MD |
231 | /* old_nr_cb + 1 (new cb) + 1 (NULL) */ |
232 | new_cb = (struct side_callback *) calloc(old_nr_cb + 2, sizeof(struct side_callback)); | |
233 | if (!new_cb) { | |
234 | ret = SIDE_ERROR_NOMEM; | |
235 | goto unlock; | |
236 | } | |
237 | memcpy(new_cb, old_cb, old_nr_cb); | |
238 | if (desc->flags & SIDE_EVENT_FLAG_VARIADIC) | |
239 | new_cb[old_nr_cb].u.call_variadic = | |
240 | (side_tracer_callback_variadic_func) call; | |
241 | else | |
242 | new_cb[old_nr_cb].u.call = | |
243 | (side_tracer_callback_func) call; | |
244 | new_cb[old_nr_cb].priv = priv; | |
92c377f9 | 245 | new_cb[old_nr_cb].key = key; |
f60d8121 | 246 | /* High order bits are already zeroed. */ |
7269a8a3 | 247 | side_rcu_assign_pointer(es0->callbacks, new_cb); |
873bbf16 | 248 | side_rcu_wait_grace_period(&event_rcu_gp); |
67337c4a MD |
249 | if (old_nr_cb) |
250 | free(old_cb); | |
3cac1780 | 251 | es0->nr_callbacks++; |
67337c4a MD |
252 | /* Increment concurrently with kernel setting the top bits. */ |
253 | if (!old_nr_cb) | |
b2a84b9f | 254 | (void) __atomic_add_fetch(&es0->enabled, 1, __ATOMIC_RELAXED); |
67337c4a | 255 | unlock: |
873bbf16 | 256 | pthread_mutex_unlock(&side_event_lock); |
67337c4a MD |
257 | return ret; |
258 | } | |
259 | ||
260 | int side_tracer_callback_register(struct side_event_description *desc, | |
261 | side_tracer_callback_func call, | |
92c377f9 | 262 | void *priv, void *key) |
67337c4a MD |
263 | { |
264 | if (desc->flags & SIDE_EVENT_FLAG_VARIADIC) | |
265 | return SIDE_ERROR_INVAL; | |
92c377f9 | 266 | return _side_tracer_callback_register(desc, (void *) call, priv, key); |
67337c4a MD |
267 | } |
268 | ||
269 | int side_tracer_callback_variadic_register(struct side_event_description *desc, | |
270 | side_tracer_callback_variadic_func call_variadic, | |
92c377f9 | 271 | void *priv, void *key) |
67337c4a MD |
272 | { |
273 | if (!(desc->flags & SIDE_EVENT_FLAG_VARIADIC)) | |
274 | return SIDE_ERROR_INVAL; | |
92c377f9 | 275 | return _side_tracer_callback_register(desc, (void *) call_variadic, priv, key); |
67337c4a MD |
276 | } |
277 | ||
278 | static int _side_tracer_callback_unregister(struct side_event_description *desc, | |
92c377f9 | 279 | void *call, void *priv, void *key) |
67337c4a | 280 | { |
0b9e59d6 | 281 | struct side_event_state *event_state; |
67337c4a MD |
282 | struct side_callback *old_cb, *new_cb; |
283 | const struct side_callback *cb_pos; | |
b2a84b9f | 284 | struct side_event_state_0 *es0; |
67337c4a MD |
285 | uint32_t pos_idx; |
286 | int ret = SIDE_ERROR_OK; | |
287 | uint32_t old_nr_cb; | |
288 | ||
289 | if (!call) | |
290 | return SIDE_ERROR_INVAL; | |
291 | if (finalized) | |
292 | return SIDE_ERROR_EXITING; | |
293 | if (!initialized) | |
294 | side_init(); | |
873bbf16 | 295 | pthread_mutex_lock(&side_event_lock); |
0b9e59d6 | 296 | event_state = side_ptr_get(desc->state); |
b2a84b9f MD |
297 | if (side_unlikely(event_state->version != 0)) |
298 | abort(); | |
49aea3ef | 299 | es0 = side_container_of(event_state, struct side_event_state_0, parent); |
92c377f9 | 300 | cb_pos = side_tracer_callback_lookup(desc, call, priv, key); |
67337c4a MD |
301 | if (!cb_pos) { |
302 | ret = SIDE_ERROR_NOENT; | |
303 | goto unlock; | |
304 | } | |
3cac1780 | 305 | old_nr_cb = es0->nr_callbacks; |
7269a8a3 | 306 | old_cb = (struct side_callback *) es0->callbacks; |
67337c4a MD |
307 | if (old_nr_cb == 1) { |
308 | new_cb = (struct side_callback *) &side_empty_callback; | |
309 | } else { | |
7269a8a3 | 310 | pos_idx = cb_pos - es0->callbacks; |
67337c4a MD |
311 | /* Remove entry at pos_idx. */ |
312 | /* old_nr_cb - 1 (removed cb) + 1 (NULL) */ | |
313 | new_cb = (struct side_callback *) calloc(old_nr_cb, sizeof(struct side_callback)); | |
314 | if (!new_cb) { | |
315 | ret = SIDE_ERROR_NOMEM; | |
316 | goto unlock; | |
317 | } | |
318 | memcpy(new_cb, old_cb, pos_idx); | |
319 | memcpy(&new_cb[pos_idx], &old_cb[pos_idx + 1], old_nr_cb - pos_idx - 1); | |
320 | } | |
f60d8121 | 321 | /* High order bits are already zeroed. */ |
7269a8a3 | 322 | side_rcu_assign_pointer(es0->callbacks, new_cb); |
873bbf16 | 323 | side_rcu_wait_grace_period(&event_rcu_gp); |
67337c4a | 324 | free(old_cb); |
3cac1780 | 325 | es0->nr_callbacks--; |
67337c4a MD |
326 | /* Decrement concurrently with kernel setting the top bits. */ |
327 | if (old_nr_cb == 1) | |
b2a84b9f | 328 | (void) __atomic_add_fetch(&es0->enabled, -1, __ATOMIC_RELAXED); |
67337c4a | 329 | unlock: |
873bbf16 | 330 | pthread_mutex_unlock(&side_event_lock); |
67337c4a MD |
331 | return ret; |
332 | } | |
333 | ||
334 | int side_tracer_callback_unregister(struct side_event_description *desc, | |
335 | side_tracer_callback_func call, | |
92c377f9 | 336 | void *priv, void *key) |
67337c4a MD |
337 | { |
338 | if (desc->flags & SIDE_EVENT_FLAG_VARIADIC) | |
339 | return SIDE_ERROR_INVAL; | |
92c377f9 | 340 | return _side_tracer_callback_unregister(desc, (void *) call, priv, key); |
67337c4a MD |
341 | } |
342 | ||
343 | int side_tracer_callback_variadic_unregister(struct side_event_description *desc, | |
344 | side_tracer_callback_variadic_func call_variadic, | |
92c377f9 | 345 | void *priv, void *key) |
67337c4a MD |
346 | { |
347 | if (!(desc->flags & SIDE_EVENT_FLAG_VARIADIC)) | |
348 | return SIDE_ERROR_INVAL; | |
92c377f9 | 349 | return _side_tracer_callback_unregister(desc, (void *) call_variadic, priv, key); |
67337c4a MD |
350 | } |
351 | ||
352 | struct side_events_register_handle *side_events_register(struct side_event_description **events, uint32_t nr_events) | |
353 | { | |
354 | struct side_events_register_handle *events_handle = NULL; | |
355 | struct side_tracer_handle *tracer_handle; | |
356 | ||
357 | if (finalized) | |
358 | return NULL; | |
359 | if (!initialized) | |
360 | side_init(); | |
361 | events_handle = (struct side_events_register_handle *) | |
362 | calloc(1, sizeof(struct side_events_register_handle)); | |
363 | if (!events_handle) | |
364 | return NULL; | |
365 | events_handle->events = events; | |
366 | events_handle->nr_events = nr_events; | |
367 | ||
873bbf16 | 368 | pthread_mutex_lock(&side_event_lock); |
67337c4a MD |
369 | side_list_insert_node_tail(&side_events_list, &events_handle->node); |
370 | side_list_for_each_entry(tracer_handle, &side_tracer_list, node) { | |
371 | tracer_handle->cb(SIDE_TRACER_NOTIFICATION_INSERT_EVENTS, | |
372 | events, nr_events, tracer_handle->priv); | |
373 | } | |
873bbf16 | 374 | pthread_mutex_unlock(&side_event_lock); |
67337c4a MD |
375 | //TODO: call event batch register ioctl |
376 | return events_handle; | |
377 | } | |
378 | ||
379 | static | |
380 | void side_event_remove_callbacks(struct side_event_description *desc) | |
381 | { | |
0b9e59d6 | 382 | struct side_event_state *event_state = side_ptr_get(desc->state); |
b2a84b9f | 383 | struct side_event_state_0 *es0; |
67337c4a | 384 | struct side_callback *old_cb; |
3cac1780 | 385 | uint32_t nr_cb; |
67337c4a | 386 | |
b2a84b9f MD |
387 | if (side_unlikely(event_state->version != 0)) |
388 | abort(); | |
49aea3ef | 389 | es0 = side_container_of(event_state, struct side_event_state_0, parent); |
3cac1780 MD |
390 | nr_cb = es0->nr_callbacks; |
391 | if (!nr_cb) | |
392 | return; | |
7269a8a3 | 393 | old_cb = (struct side_callback *) es0->callbacks; |
b2a84b9f | 394 | (void) __atomic_add_fetch(&es0->enabled, -1, __ATOMIC_RELAXED); |
67337c4a MD |
395 | /* |
396 | * Setting the state back to 0 cb and empty callbacks out of | |
397 | * caution. This should not matter because instrumentation is | |
398 | * unreachable. | |
399 | */ | |
3cac1780 | 400 | es0->nr_callbacks = 0; |
7269a8a3 | 401 | side_rcu_assign_pointer(es0->callbacks, &side_empty_callback); |
67337c4a MD |
402 | /* |
403 | * No need to wait for grace period because instrumentation is | |
404 | * unreachable. | |
405 | */ | |
406 | free(old_cb); | |
407 | } | |
408 | ||
409 | /* | |
410 | * Unregister event handle. At this point, all side events in that | |
411 | * handle should be unreachable. | |
412 | */ | |
413 | void side_events_unregister(struct side_events_register_handle *events_handle) | |
414 | { | |
415 | struct side_tracer_handle *tracer_handle; | |
416 | uint32_t i; | |
417 | ||
418 | if (!events_handle) | |
419 | return; | |
420 | if (finalized) | |
421 | return; | |
422 | if (!initialized) | |
423 | side_init(); | |
873bbf16 | 424 | pthread_mutex_lock(&side_event_lock); |
67337c4a MD |
425 | side_list_remove_node(&events_handle->node); |
426 | side_list_for_each_entry(tracer_handle, &side_tracer_list, node) { | |
427 | tracer_handle->cb(SIDE_TRACER_NOTIFICATION_REMOVE_EVENTS, | |
428 | events_handle->events, events_handle->nr_events, | |
429 | tracer_handle->priv); | |
430 | } | |
431 | for (i = 0; i < events_handle->nr_events; i++) { | |
432 | struct side_event_description *event = events_handle->events[i]; | |
433 | ||
434 | /* Skip NULL pointers */ | |
435 | if (!event) | |
436 | continue; | |
437 | side_event_remove_callbacks(event); | |
438 | } | |
873bbf16 | 439 | pthread_mutex_unlock(&side_event_lock); |
67337c4a MD |
440 | //TODO: call event batch unregister ioctl |
441 | free(events_handle); | |
442 | } | |
443 | ||
444 | struct side_tracer_handle *side_tracer_event_notification_register( | |
445 | void (*cb)(enum side_tracer_notification notif, | |
446 | struct side_event_description **events, uint32_t nr_events, void *priv), | |
447 | void *priv) | |
448 | { | |
449 | struct side_tracer_handle *tracer_handle; | |
450 | struct side_events_register_handle *events_handle; | |
451 | ||
452 | if (finalized) | |
453 | return NULL; | |
454 | if (!initialized) | |
455 | side_init(); | |
456 | tracer_handle = (struct side_tracer_handle *) | |
457 | calloc(1, sizeof(struct side_tracer_handle)); | |
458 | if (!tracer_handle) | |
459 | return NULL; | |
873bbf16 | 460 | pthread_mutex_lock(&side_event_lock); |
67337c4a MD |
461 | tracer_handle->cb = cb; |
462 | tracer_handle->priv = priv; | |
463 | side_list_insert_node_tail(&side_tracer_list, &tracer_handle->node); | |
464 | side_list_for_each_entry(events_handle, &side_events_list, node) { | |
465 | cb(SIDE_TRACER_NOTIFICATION_INSERT_EVENTS, | |
466 | events_handle->events, events_handle->nr_events, priv); | |
467 | } | |
873bbf16 | 468 | pthread_mutex_unlock(&side_event_lock); |
67337c4a MD |
469 | return tracer_handle; |
470 | } | |
471 | ||
472 | void side_tracer_event_notification_unregister(struct side_tracer_handle *tracer_handle) | |
473 | { | |
474 | struct side_events_register_handle *events_handle; | |
475 | ||
476 | if (finalized) | |
477 | return; | |
478 | if (!initialized) | |
479 | side_init(); | |
873bbf16 | 480 | pthread_mutex_lock(&side_event_lock); |
67337c4a MD |
481 | side_list_for_each_entry(events_handle, &side_events_list, node) { |
482 | tracer_handle->cb(SIDE_TRACER_NOTIFICATION_REMOVE_EVENTS, | |
483 | events_handle->events, events_handle->nr_events, | |
484 | tracer_handle->priv); | |
485 | } | |
486 | side_list_remove_node(&tracer_handle->node); | |
873bbf16 | 487 | pthread_mutex_unlock(&side_event_lock); |
be787080 | 488 | free(tracer_handle); |
67337c4a MD |
489 | } |
490 | ||
f0b01832 MD |
491 | struct side_statedump_request_handle *side_statedump_request_notification_register(void (*statedump_cb)(void)) |
492 | { | |
493 | struct side_statedump_request_handle *handle; | |
494 | ||
495 | if (finalized) | |
496 | return NULL; | |
497 | if (!initialized) | |
498 | side_init(); | |
499 | /* | |
500 | * The statedump request notification should not be registered | |
501 | * from a notification callback. | |
502 | */ | |
503 | assert(filter_key == NULL); | |
504 | handle = (struct side_statedump_request_handle *) | |
505 | calloc(1, sizeof(struct side_statedump_request_handle)); | |
506 | if (!handle) | |
507 | return NULL; | |
f0b01832 | 508 | handle->cb = statedump_cb; |
873bbf16 MD |
509 | |
510 | pthread_mutex_lock(&side_statedump_lock); | |
511 | side_list_insert_node_tail_rcu(&side_statedump_list, &handle->node); | |
512 | pthread_mutex_unlock(&side_statedump_lock); | |
513 | ||
f0b01832 MD |
514 | /* Invoke callback for all tracers. */ |
515 | statedump_cb(); | |
873bbf16 | 516 | |
f0b01832 MD |
517 | return handle; |
518 | } | |
519 | ||
520 | void side_statedump_request_notification_unregister(struct side_statedump_request_handle *handle) | |
521 | { | |
522 | if (finalized) | |
523 | return; | |
524 | if (!initialized) | |
525 | side_init(); | |
526 | assert(filter_key == NULL); | |
873bbf16 MD |
527 | |
528 | pthread_mutex_lock(&side_statedump_lock); | |
529 | side_list_remove_node_rcu(&handle->node); | |
530 | pthread_mutex_unlock(&side_statedump_lock); | |
531 | ||
532 | side_rcu_wait_grace_period(&statedump_rcu_gp); | |
f0b01832 MD |
533 | free(handle); |
534 | } | |
535 | ||
536 | void side_tracer_statedump_request(void *key) | |
537 | { | |
538 | struct side_statedump_request_handle *handle; | |
873bbf16 | 539 | struct side_rcu_read_state rcu_read_state; |
f0b01832 MD |
540 | |
541 | /* Invoke the state dump callback specifically for the tracer key. */ | |
542 | filter_key = key; | |
873bbf16 MD |
543 | side_rcu_read_begin(&statedump_rcu_gp, &rcu_read_state); |
544 | side_list_for_each_entry_rcu(handle, &side_statedump_list, node) | |
f0b01832 | 545 | handle->cb(); |
873bbf16 | 546 | side_rcu_read_end(&statedump_rcu_gp, &rcu_read_state); |
f0b01832 MD |
547 | filter_key = NULL; |
548 | } | |
549 | ||
67337c4a MD |
550 | void side_init(void) |
551 | { | |
552 | if (initialized) | |
553 | return; | |
873bbf16 MD |
554 | side_rcu_gp_init(&event_rcu_gp); |
555 | side_rcu_gp_init(&statedump_rcu_gp); | |
67337c4a MD |
556 | initialized = true; |
557 | } | |
558 | ||
559 | /* | |
560 | * side_exit() is executed from a library destructor. It can be called | |
561 | * explicitly at application exit as well. Concurrent side API use is | |
562 | * not expected at that point. | |
563 | */ | |
564 | void side_exit(void) | |
565 | { | |
566 | struct side_events_register_handle *handle, *tmp; | |
567 | ||
568 | if (finalized) | |
569 | return; | |
570 | side_list_for_each_entry_safe(handle, tmp, &side_events_list, node) | |
571 | side_events_unregister(handle); | |
873bbf16 MD |
572 | side_rcu_gp_exit(&event_rcu_gp); |
573 | side_rcu_gp_exit(&statedump_rcu_gp); | |
67337c4a MD |
574 | finalized = true; |
575 | } |