Add a packet sequence number
[lttng-modules.git] / lttng-ring-buffer-metadata-client.h
CommitLineData
881833e3 1/*
a90917c3 2 * lttng-ring-buffer-client.h
881833e3 3 *
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4 * LTTng lib ring buffer client template.
5 *
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6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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21 */
22
23#include <linux/module.h>
24#include <linux/types.h>
25#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
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26#include "lttng-events.h"
27#include "lttng-tracer.h"
881833e3 28
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29static struct lttng_transport lttng_relay_transport;
30
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31struct metadata_packet_header {
32 uint32_t magic; /* 0x75D11D57 */
1ec3f75a 33 uint8_t uuid[16]; /* Unique Universal Identifier */
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34 uint32_t checksum; /* 0 if unused */
35 uint32_t content_size; /* in bits */
36 uint32_t packet_size; /* in bits */
37 uint8_t compression_scheme; /* 0 if unused */
38 uint8_t encryption_scheme; /* 0 if unused */
39 uint8_t checksum_scheme; /* 0 if unused */
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40 uint8_t major; /* CTF spec major version number */
41 uint8_t minor; /* CTF spec minor version number */
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42 uint8_t header_end[0];
43};
44
45struct metadata_record_header {
46 uint8_t header_end[0]; /* End of header */
47};
48
49static const struct lib_ring_buffer_config client_config;
50
51static inline
52u64 lib_ring_buffer_clock_read(struct channel *chan)
53{
54 return 0;
55}
56
57static inline
58unsigned char record_header_size(const struct lib_ring_buffer_config *config,
59 struct channel *chan, size_t offset,
64c796d8 60 size_t *pre_header_padding,
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61 struct lib_ring_buffer_ctx *ctx)
62{
63 return 0;
64}
65
66#include "wrapper/ringbuffer/api.h"
67
68static u64 client_ring_buffer_clock_read(struct channel *chan)
69{
70 return 0;
71}
72
73static
74size_t client_record_header_size(const struct lib_ring_buffer_config *config,
75 struct channel *chan, size_t offset,
881833e3 76 size_t *pre_header_padding,
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77 struct lib_ring_buffer_ctx *ctx)
78{
79 return 0;
80}
81
82/**
83 * client_packet_header_size - called on buffer-switch to a new sub-buffer
84 *
85 * Return header size without padding after the structure. Don't use packed
86 * structure because gcc generates inefficient code on some architectures
87 * (powerpc, mips..)
88 */
89static size_t client_packet_header_size(void)
90{
91 return offsetof(struct metadata_packet_header, header_end);
92}
93
94static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
95 unsigned int subbuf_idx)
96{
97 struct channel *chan = buf->backend.chan;
98 struct metadata_packet_header *header =
99 (struct metadata_packet_header *)
100 lib_ring_buffer_offset_address(&buf->backend,
101 subbuf_idx * chan->backend.subbuf_size);
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102 struct lttng_metadata_cache *metadata_cache =
103 channel_get_private(chan);
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104
105 header->magic = TSDL_MAGIC_NUMBER;
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106 memcpy(header->uuid, metadata_cache->uuid.b,
107 sizeof(metadata_cache->uuid));
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108 header->checksum = 0; /* 0 if unused */
109 header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
110 header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
111 header->compression_scheme = 0; /* 0 if unused */
112 header->encryption_scheme = 0; /* 0 if unused */
113 header->checksum_scheme = 0; /* 0 if unused */
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114 header->major = CTF_SPEC_MAJOR;
115 header->minor = CTF_SPEC_MINOR;
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116}
117
118/*
119 * offset is assumed to never be 0 here : never deliver a completely empty
120 * subbuffer. data_size is between 1 and subbuf_size.
121 */
122static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
123 unsigned int subbuf_idx, unsigned long data_size)
124{
125 struct channel *chan = buf->backend.chan;
d793d5e1 126 struct metadata_packet_header *header =
1ec3f75a 127 (struct metadata_packet_header *)
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128 lib_ring_buffer_offset_address(&buf->backend,
129 subbuf_idx * chan->backend.subbuf_size);
130 unsigned long records_lost = 0;
131
132 header->content_size = data_size * CHAR_BIT; /* in bits */
133 header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
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134 /*
135 * We do not care about the records lost count, because the metadata
136 * channel waits and retry.
137 */
138 (void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
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139 records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
140 records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
141 WARN_ON_ONCE(records_lost != 0);
142}
143
144static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
145 int cpu, const char *name)
146{
147 return 0;
148}
149
150static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
151{
152}
153
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154static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
155 struct lib_ring_buffer *buf, uint64_t *timestamp_begin)
156{
157 return -ENOSYS;
158}
159
160static int client_timestamp_end(const struct lib_ring_buffer_config *config,
161 struct lib_ring_buffer *bufb,
162 uint64_t *timestamp_end)
163{
164 return -ENOSYS;
165}
166
167static int client_events_discarded(const struct lib_ring_buffer_config *config,
168 struct lib_ring_buffer *bufb,
169 uint64_t *events_discarded)
170{
171 return -ENOSYS;
172}
173
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174static int client_current_timestamp(const struct lib_ring_buffer_config *config,
175 struct lib_ring_buffer *bufb,
176 uint64_t *ts)
177{
178 return -ENOSYS;
179}
180
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181static int client_content_size(const struct lib_ring_buffer_config *config,
182 struct lib_ring_buffer *bufb,
183 uint64_t *content_size)
184{
185 return -ENOSYS;
186}
187
188static int client_packet_size(const struct lib_ring_buffer_config *config,
189 struct lib_ring_buffer *bufb,
190 uint64_t *packet_size)
191{
192 return -ENOSYS;
193}
194
195static int client_stream_id(const struct lib_ring_buffer_config *config,
196 struct lib_ring_buffer *bufb,
197 uint64_t *stream_id)
198{
199 return -ENOSYS;
200}
201
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202static int client_sequence_number(const struct lib_ring_buffer_config *config,
203 struct lib_ring_buffer *bufb,
204 uint64_t *seq)
205{
206 return -ENOSYS;
207}
208
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209static const struct lib_ring_buffer_config client_config = {
210 .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
211 .cb.record_header_size = client_record_header_size,
212 .cb.subbuffer_header_size = client_packet_header_size,
213 .cb.buffer_begin = client_buffer_begin,
214 .cb.buffer_end = client_buffer_end,
215 .cb.buffer_create = client_buffer_create,
216 .cb.buffer_finalize = client_buffer_finalize,
217
218 .tsc_bits = 0,
219 .alloc = RING_BUFFER_ALLOC_GLOBAL,
220 .sync = RING_BUFFER_SYNC_GLOBAL,
221 .mode = RING_BUFFER_MODE_TEMPLATE,
222 .backend = RING_BUFFER_PAGE,
2db1399a 223 .output = RING_BUFFER_OUTPUT_TEMPLATE,
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224 .oops = RING_BUFFER_OOPS_CONSISTENCY,
225 .ipi = RING_BUFFER_IPI_BARRIER,
226 .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
227};
228
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229static
230void release_priv_ops(void *priv_ops)
231{
232 module_put(THIS_MODULE);
233}
234
235static
236void lttng_channel_destroy(struct channel *chan)
237{
238 channel_destroy(chan);
239}
240
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241static
242struct channel *_channel_create(const char *name,
a90917c3 243 struct lttng_channel *lttng_chan, void *buf_addr,
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244 size_t subbuf_size, size_t num_subbuf,
245 unsigned int switch_timer_interval,
246 unsigned int read_timer_interval)
247{
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248 struct channel *chan;
249
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250 chan = channel_create(&client_config, name,
251 lttng_chan->session->metadata_cache, buf_addr,
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252 subbuf_size, num_subbuf, switch_timer_interval,
253 read_timer_interval);
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254 if (chan) {
255 /*
256 * Ensure this module is not unloaded before we finish
257 * using lttng_relay_transport.ops.
258 */
259 if (!try_module_get(THIS_MODULE)) {
260 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
261 goto error;
262 }
263 chan->backend.priv_ops = &lttng_relay_transport.ops;
264 chan->backend.release_priv_ops = release_priv_ops;
265 }
266 return chan;
881833e3 267
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268error:
269 lttng_channel_destroy(chan);
270 return NULL;
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271}
272
273static
a90917c3 274struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan)
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275{
276 struct lib_ring_buffer *buf;
881833e3 277
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278 buf = channel_get_ring_buffer(&client_config, chan, 0);
279 if (!lib_ring_buffer_open_read(buf))
280 return buf;
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281 return NULL;
282}
283
f71ecafa 284static
a90917c3 285int lttng_buffer_has_read_closed_stream(struct channel *chan)
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286{
287 struct lib_ring_buffer *buf;
288 int cpu;
289
290 for_each_channel_cpu(cpu, chan) {
291 buf = channel_get_ring_buffer(&client_config, chan, cpu);
292 if (!atomic_long_read(&buf->active_readers))
293 return 1;
294 }
295 return 0;
296}
297
881833e3 298static
a90917c3 299void lttng_buffer_read_close(struct lib_ring_buffer *buf)
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300{
301 lib_ring_buffer_release_read(buf);
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302}
303
c099397a 304static
a90917c3 305int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
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306{
307 return lib_ring_buffer_reserve(&client_config, ctx);
308}
309
c099397a 310static
a90917c3 311void lttng_event_commit(struct lib_ring_buffer_ctx *ctx)
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312{
313 lib_ring_buffer_commit(&client_config, ctx);
314}
315
c099397a 316static
a90917c3 317void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
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318 size_t len)
319{
320 lib_ring_buffer_write(&client_config, ctx, src, len);
321}
322
4ea00e4f 323static
a90917c3 324void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
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325 const void __user *src, size_t len)
326{
7b8ea3a5 327 lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
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328}
329
58aa5d24 330static
a90917c3 331void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
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332 int c, size_t len)
333{
334 lib_ring_buffer_memset(&client_config, ctx, c, len);
335}
336
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337static
338void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src,
339 size_t len)
340{
341 lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
342}
343
1ec3f75a 344static
a90917c3 345size_t lttng_packet_avail_size(struct channel *chan)
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346
347{
348 unsigned long o_begin;
349 struct lib_ring_buffer *buf;
350
351 buf = chan->backend.buf; /* Only for global buffer ! */
352 o_begin = v_read(&client_config, &buf->offset);
353 if (subbuf_offset(o_begin, chan) != 0) {
354 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
355 } else {
356 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
357 - sizeof(struct metadata_packet_header);
358 }
359}
360
c099397a 361static
a90917c3 362wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu)
c099397a 363{
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364 struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
365 chan, cpu);
366 return &buf->write_wait;
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367}
368
369static
a90917c3 370wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
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371{
372 return &chan->hp_wait;
373}
374
375static
a90917c3 376int lttng_is_finalized(struct channel *chan)
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377{
378 return lib_ring_buffer_channel_is_finalized(chan);
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379}
380
254ec7bc 381static
a90917c3 382int lttng_is_disabled(struct channel *chan)
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383{
384 return lib_ring_buffer_channel_is_disabled(chan);
385}
386
a90917c3 387static struct lttng_transport lttng_relay_transport = {
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388 .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
389 .owner = THIS_MODULE,
390 .ops = {
391 .channel_create = _channel_create,
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392 .channel_destroy = lttng_channel_destroy,
393 .buffer_read_open = lttng_buffer_read_open,
f71ecafa 394 .buffer_has_read_closed_stream =
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395 lttng_buffer_has_read_closed_stream,
396 .buffer_read_close = lttng_buffer_read_close,
397 .event_reserve = lttng_event_reserve,
398 .event_commit = lttng_event_commit,
399 .event_write_from_user = lttng_event_write_from_user,
400 .event_memset = lttng_event_memset,
401 .event_write = lttng_event_write,
16f78f3a 402 .event_strcpy = lttng_event_strcpy,
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403 .packet_avail_size = lttng_packet_avail_size,
404 .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
405 .get_hp_wait_queue = lttng_get_hp_wait_queue,
406 .is_finalized = lttng_is_finalized,
407 .is_disabled = lttng_is_disabled,
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408 .timestamp_begin = client_timestamp_begin,
409 .timestamp_end = client_timestamp_end,
410 .events_discarded = client_events_discarded,
411 .content_size = client_content_size,
412 .packet_size = client_packet_size,
413 .stream_id = client_stream_id,
414 .current_timestamp = client_current_timestamp,
5b3cf4f9 415 .sequence_number = client_sequence_number,
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416 },
417};
418
a90917c3 419static int __init lttng_ring_buffer_client_init(void)
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420{
421 /*
422 * This vmalloc sync all also takes care of the lib ring buffer
423 * vmalloc'd module pages when it is built as a module into LTTng.
424 */
425 wrapper_vmalloc_sync_all();
a90917c3 426 lttng_transport_register(&lttng_relay_transport);
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427 return 0;
428}
429
a90917c3 430module_init(lttng_ring_buffer_client_init);
881833e3 431
a90917c3 432static void __exit lttng_ring_buffer_client_exit(void)
881833e3 433{
a90917c3 434 lttng_transport_unregister(&lttng_relay_transport);
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435}
436
a90917c3 437module_exit(lttng_ring_buffer_client_exit);
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438
439MODULE_LICENSE("GPL and additional rights");
440MODULE_AUTHOR("Mathieu Desnoyers");
441MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
442 " client");
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