Implement file-backed ring buffer
[lttng-ust.git] / liblttng-ust / lttng-ring-buffer-metadata-client.h
CommitLineData
3d1fc7fd 1/*
7dd08bec 2 * lttng-ring-buffer-client.h
3d1fc7fd 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
9f3fdbc6 23#include <stdint.h>
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24#include <lttng/ust-events.h>
25#include "lttng/bitfield.h"
7dd08bec 26#include "lttng-tracer.h"
9f3fdbc6 27#include "../libringbuffer/frontend_types.h"
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28
29struct metadata_packet_header {
30 uint32_t magic; /* 0x75D11D57 */
19d8b1b3 31 uint8_t uuid[LTTNG_UST_UUID_LEN]; /* Unique Universal Identifier */
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32 uint32_t checksum; /* 0 if unused */
33 uint32_t content_size; /* in bits */
34 uint32_t packet_size; /* in bits */
35 uint8_t compression_scheme; /* 0 if unused */
36 uint8_t encryption_scheme; /* 0 if unused */
37 uint8_t checksum_scheme; /* 0 if unused */
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38 uint8_t major; /* CTF spec major version number */
39 uint8_t minor; /* CTF spec minor version number */
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40 uint8_t header_end[0];
41};
42
43struct metadata_record_header {
44 uint8_t header_end[0]; /* End of header */
45};
46
4cfec15c 47static const struct lttng_ust_lib_ring_buffer_config client_config;
3d1fc7fd 48
23c8854a 49static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
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50{
51 return 0;
52}
53
54static inline
4cfec15c 55unsigned char record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
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56 struct channel *chan, size_t offset,
57 size_t *pre_header_padding,
4cfec15c 58 struct lttng_ust_lib_ring_buffer_ctx *ctx)
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59{
60 return 0;
61}
62
9f3fdbc6 63#include "../libringbuffer/api.h"
82b9bde8 64#include "lttng-rb-clients.h"
3d1fc7fd 65
23c8854a 66static uint64_t client_ring_buffer_clock_read(struct channel *chan)
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67{
68 return 0;
69}
70
71static
4cfec15c 72size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
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73 struct channel *chan, size_t offset,
74 size_t *pre_header_padding,
4cfec15c 75 struct lttng_ust_lib_ring_buffer_ctx *ctx)
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76{
77 return 0;
78}
79
80/**
81 * client_packet_header_size - called on buffer-switch to a new sub-buffer
82 *
83 * Return header size without padding after the structure. Don't use packed
84 * structure because gcc generates inefficient code on some architectures
85 * (powerpc, mips..)
86 */
87static size_t client_packet_header_size(void)
88{
89 return offsetof(struct metadata_packet_header, header_end);
90}
91
23c8854a 92static void client_buffer_begin(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
1d498196 93 unsigned int subbuf_idx,
38fae1d3 94 struct lttng_ust_shm_handle *handle)
3d1fc7fd 95{
1d498196 96 struct channel *chan = shmp(handle, buf->backend.chan);
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97 struct metadata_packet_header *header =
98 (struct metadata_packet_header *)
99 lib_ring_buffer_offset_address(&buf->backend,
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100 subbuf_idx * chan->backend.subbuf_size,
101 handle);
7dd08bec 102 struct lttng_channel *lttng_chan = channel_get_private(chan);
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103
104 header->magic = TSDL_MAGIC_NUMBER;
7dd08bec 105 memcpy(header->uuid, lttng_chan->uuid, sizeof(lttng_chan->uuid));
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106 header->checksum = 0; /* 0 if unused */
107 header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
108 header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
109 header->compression_scheme = 0; /* 0 if unused */
110 header->encryption_scheme = 0; /* 0 if unused */
111 header->checksum_scheme = 0; /* 0 if unused */
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112 header->major = CTF_SPEC_MAJOR;
113 header->minor = CTF_SPEC_MINOR;
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114}
115
116/*
117 * offset is assumed to never be 0 here : never deliver a completely empty
118 * subbuffer. data_size is between 1 and subbuf_size.
119 */
23c8854a 120static void client_buffer_end(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
1d498196 121 unsigned int subbuf_idx, unsigned long data_size,
38fae1d3 122 struct lttng_ust_shm_handle *handle)
3d1fc7fd 123{
1d498196 124 struct channel *chan = shmp(handle, buf->backend.chan);
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125 struct metadata_packet_header *header =
126 (struct metadata_packet_header *)
127 lib_ring_buffer_offset_address(&buf->backend,
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128 subbuf_idx * chan->backend.subbuf_size,
129 handle);
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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
4cfec15c 144static int client_buffer_create(struct lttng_ust_lib_ring_buffer *buf, void *priv,
1d498196 145 int cpu, const char *name,
38fae1d3 146 struct lttng_ust_shm_handle *handle)
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147{
148 return 0;
149}
150
4cfec15c 151static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf,
1d498196 152 void *priv, int cpu,
38fae1d3 153 struct lttng_ust_shm_handle *handle)
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154{
155}
156
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157static const
158struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
159 .parent = {
160 .ring_buffer_clock_read = client_ring_buffer_clock_read,
161 .record_header_size = client_record_header_size,
162 .subbuffer_header_size = client_packet_header_size,
163 .buffer_begin = client_buffer_begin,
164 .buffer_end = client_buffer_end,
165 .buffer_create = client_buffer_create,
166 .buffer_finalize = client_buffer_finalize,
167 },
168};
169
4cfec15c 170static const struct lttng_ust_lib_ring_buffer_config client_config = {
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171 .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
172 .cb.record_header_size = client_record_header_size,
173 .cb.subbuffer_header_size = client_packet_header_size,
174 .cb.buffer_begin = client_buffer_begin,
175 .cb.buffer_end = client_buffer_end,
176 .cb.buffer_create = client_buffer_create,
177 .cb.buffer_finalize = client_buffer_finalize,
178
179 .tsc_bits = 0,
180 .alloc = RING_BUFFER_ALLOC_GLOBAL,
181 .sync = RING_BUFFER_SYNC_GLOBAL,
182 .mode = RING_BUFFER_MODE_TEMPLATE,
183 .backend = RING_BUFFER_PAGE,
5d61a504 184 .output = RING_BUFFER_MMAP,
3d1fc7fd 185 .oops = RING_BUFFER_OOPS_CONSISTENCY,
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186 .ipi = RING_BUFFER_NO_IPI_BARRIER,
187 .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
c1fca457 188 .client_type = LTTNG_CLIENT_TYPE,
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189
190 .cb_ptr = &client_cb.parent,
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191};
192
82b9bde8 193const struct lttng_ust_client_lib_ring_buffer_client_cb *LTTNG_CLIENT_CALLBACKS = &client_cb;
c1fca457 194
3d1fc7fd 195static
7dd08bec 196struct lttng_channel *_channel_create(const char *name,
a3f61e7f 197 void *buf_addr,
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198 size_t subbuf_size, size_t num_subbuf,
199 unsigned int switch_timer_interval,
193183fb 200 unsigned int read_timer_interval,
6ca18e66 201 unsigned char *uuid,
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202 uint32_t chan_id,
203 const char *shm_path)
3d1fc7fd 204{
74d81a6c 205 struct lttng_channel chan_priv_init;
a3f61e7f 206 struct lttng_ust_shm_handle *handle;
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207 struct lttng_channel *lttng_chan;
208 void *priv;
a3f61e7f 209
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210 memset(&chan_priv_init, 0, sizeof(chan_priv_init));
211 memcpy(chan_priv_init.uuid, uuid, LTTNG_UST_UUID_LEN);
6ca18e66 212 chan_priv_init.id = chan_id;
a3f61e7f 213 handle = channel_create(&client_config, name,
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214 &priv, __alignof__(struct lttng_channel),
215 sizeof(struct lttng_channel),
74d81a6c 216 &chan_priv_init,
a3f61e7f 217 buf_addr, subbuf_size, num_subbuf,
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218 switch_timer_interval, read_timer_interval,
219 shm_path);
a3f61e7f 220 if (!handle)
1b2c2540 221 return NULL;
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222 lttng_chan = priv;
223 lttng_chan->handle = handle;
74d81a6c 224 lttng_chan->chan = shmp(handle, handle->chan);
7dd08bec 225 return lttng_chan;
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226}
227
228static
74d81a6c 229void lttng_channel_destroy(struct lttng_channel *chan)
3d1fc7fd 230{
74d81a6c 231 channel_destroy(chan->chan, chan->handle, 1);
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232}
233
234static
7dd08bec 235int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx, uint32_t event_id)
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236{
237 return lib_ring_buffer_reserve(&client_config, ctx);
238}
239
240static
7dd08bec 241void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
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242{
243 lib_ring_buffer_commit(&client_config, ctx);
244}
245
246static
7dd08bec 247void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
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248 size_t len)
249{
250 lib_ring_buffer_write(&client_config, ctx, src, len);
251}
252
253static
7dd08bec 254size_t lttng_packet_avail_size(struct channel *chan, struct lttng_ust_shm_handle *handle)
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255
256{
257 unsigned long o_begin;
4cfec15c 258 struct lttng_ust_lib_ring_buffer *buf;
3d1fc7fd 259
1d498196 260 buf = shmp(handle, chan->backend.buf[0].shmp); /* Only for global buffer ! */
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261 o_begin = v_read(&client_config, &buf->offset);
262 if (subbuf_offset(o_begin, chan) != 0) {
263 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
264 } else {
265 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
266 - sizeof(struct metadata_packet_header);
267 }
268}
269
9f3fdbc6 270#if 0
3d1fc7fd 271static
7dd08bec 272wait_queue_head_t *lttng_get_reader_wait_queue(struct channel *chan)
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273{
274 return &chan->read_wait;
275}
276
277static
7dd08bec 278wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
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279{
280 return &chan->hp_wait;
281}
9f3fdbc6 282#endif //0
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283
284static
7dd08bec 285int lttng_is_finalized(struct channel *chan)
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286{
287 return lib_ring_buffer_channel_is_finalized(chan);
288}
289
290static
7dd08bec 291int lttng_is_disabled(struct channel *chan)
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292{
293 return lib_ring_buffer_channel_is_disabled(chan);
294}
295
43861eab 296static
7dd08bec 297int lttng_flush_buffer(struct channel *chan, struct lttng_ust_shm_handle *handle)
43861eab 298{
4cfec15c 299 struct lttng_ust_lib_ring_buffer *buf;
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300 int shm_fd, wait_fd, wakeup_fd;
301 uint64_t memory_map_size;
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302
303 buf = channel_get_ring_buffer(&client_config, chan,
74d81a6c 304 0, handle, &shm_fd, &wait_fd, &wakeup_fd,
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305 &memory_map_size);
306 lib_ring_buffer_switch(&client_config, buf,
307 SWITCH_ACTIVE, handle);
308 return 0;
309}
310
7dd08bec 311static struct lttng_transport lttng_relay_transport = {
818173b9 312 .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
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313 .ops = {
314 .channel_create = _channel_create,
7dd08bec 315 .channel_destroy = lttng_channel_destroy,
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316 .event_reserve = lttng_event_reserve,
317 .event_commit = lttng_event_commit,
318 .event_write = lttng_event_write,
319 .packet_avail_size = lttng_packet_avail_size,
320 //.get_reader_wait_queue = lttng_get_reader_wait_queue,
321 //.get_hp_wait_queue = lttng_get_hp_wait_queue,
322 .is_finalized = lttng_is_finalized,
323 .is_disabled = lttng_is_disabled,
324 .flush_buffer = lttng_flush_buffer,
3d1fc7fd 325 },
74d81a6c 326 .client_config = &client_config,
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327};
328
edaa1431 329void RING_BUFFER_MODE_TEMPLATE_INIT(void)
3d1fc7fd 330{
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331 DBG("LTT : ltt ring buffer client \"%s\" init\n",
332 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
7dd08bec 333 lttng_transport_register(&lttng_relay_transport);
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334}
335
edaa1431 336void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
3d1fc7fd 337{
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338 DBG("LTT : ltt ring buffer client \"%s\" exit\n",
339 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
7dd08bec 340 lttng_transport_unregister(&lttng_relay_transport);
3d1fc7fd 341}
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