2 * lttng-ring-buffer-client.h
4 * LTTng lib ring buffer client template.
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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.
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.
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
25 #include <lttng/ust-events.h>
26 #include "lttng/bitfield.h"
27 #include "lttng-tracer.h"
28 #include "../libringbuffer/frontend_types.h"
30 struct metadata_packet_header
{
31 uint32_t magic
; /* 0x75D11D57 */
32 uint8_t uuid
[LTTNG_UST_UUID_LEN
]; /* Unique Universal Identifier */
33 uint32_t checksum
; /* 0 if unused */
34 uint32_t content_size
; /* in bits */
35 uint32_t packet_size
; /* in bits */
36 uint8_t compression_scheme
; /* 0 if unused */
37 uint8_t encryption_scheme
; /* 0 if unused */
38 uint8_t checksum_scheme
; /* 0 if unused */
39 uint8_t major
; /* CTF spec major version number */
40 uint8_t minor
; /* CTF spec minor version number */
41 uint8_t header_end
[0];
44 struct metadata_record_header
{
45 uint8_t header_end
[0]; /* End of header */
48 static const struct lttng_ust_lib_ring_buffer_config client_config
;
50 static inline uint64_t lib_ring_buffer_clock_read(struct channel
*chan
)
56 size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
57 struct channel
*chan
, size_t offset
,
58 size_t *pre_header_padding
,
59 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
65 #include "../libringbuffer/api.h"
66 #include "lttng-rb-clients.h"
68 static uint64_t client_ring_buffer_clock_read(struct channel
*chan
)
74 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
75 struct channel
*chan
, size_t offset
,
76 size_t *pre_header_padding
,
77 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
84 * client_packet_header_size - called on buffer-switch to a new sub-buffer
86 * Return header size without padding after the structure. Don't use packed
87 * structure because gcc generates inefficient code on some architectures
90 static size_t client_packet_header_size(void)
92 return offsetof(struct metadata_packet_header
, header_end
);
95 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
96 unsigned int subbuf_idx
,
97 struct lttng_ust_shm_handle
*handle
)
99 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
100 struct metadata_packet_header
*header
=
101 (struct metadata_packet_header
*)
102 lib_ring_buffer_offset_address(&buf
->backend
,
103 subbuf_idx
* chan
->backend
.subbuf_size
,
105 struct lttng_channel
*lttng_chan
= channel_get_private(chan
);
110 header
->magic
= TSDL_MAGIC_NUMBER
;
111 memcpy(header
->uuid
, lttng_chan
->uuid
, sizeof(lttng_chan
->uuid
));
112 header
->checksum
= 0; /* 0 if unused */
113 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
114 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
115 header
->compression_scheme
= 0; /* 0 if unused */
116 header
->encryption_scheme
= 0; /* 0 if unused */
117 header
->checksum_scheme
= 0; /* 0 if unused */
118 header
->major
= CTF_SPEC_MAJOR
;
119 header
->minor
= CTF_SPEC_MINOR
;
123 * offset is assumed to never be 0 here : never deliver a completely empty
124 * subbuffer. data_size is between 1 and subbuf_size.
126 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
127 unsigned int subbuf_idx
, unsigned long data_size
,
128 struct lttng_ust_shm_handle
*handle
)
130 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
131 struct metadata_packet_header
*header
=
132 (struct metadata_packet_header
*)
133 lib_ring_buffer_offset_address(&buf
->backend
,
134 subbuf_idx
* chan
->backend
.subbuf_size
,
136 unsigned long records_lost
= 0;
141 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
142 header
->packet_size
= LTTNG_UST_PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
144 * We do not care about the records lost count, because the metadata
145 * channel waits and retry.
147 (void) lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
148 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
149 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
150 WARN_ON_ONCE(records_lost
!= 0);
153 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
154 int cpu
, const char *name
,
155 struct lttng_ust_shm_handle
*handle
)
160 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
162 struct lttng_ust_shm_handle
*handle
)
167 struct lttng_ust_client_lib_ring_buffer_client_cb client_cb
= {
169 .ring_buffer_clock_read
= client_ring_buffer_clock_read
,
170 .record_header_size
= client_record_header_size
,
171 .subbuffer_header_size
= client_packet_header_size
,
172 .buffer_begin
= client_buffer_begin
,
173 .buffer_end
= client_buffer_end
,
174 .buffer_create
= client_buffer_create
,
175 .buffer_finalize
= client_buffer_finalize
,
179 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
180 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
181 .cb
.record_header_size
= client_record_header_size
,
182 .cb
.subbuffer_header_size
= client_packet_header_size
,
183 .cb
.buffer_begin
= client_buffer_begin
,
184 .cb
.buffer_end
= client_buffer_end
,
185 .cb
.buffer_create
= client_buffer_create
,
186 .cb
.buffer_finalize
= client_buffer_finalize
,
189 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
190 .sync
= RING_BUFFER_SYNC_GLOBAL
,
191 .mode
= RING_BUFFER_MODE_TEMPLATE
,
192 .backend
= RING_BUFFER_PAGE
,
193 .output
= RING_BUFFER_MMAP
,
194 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
195 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
196 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
197 .client_type
= LTTNG_CLIENT_TYPE
,
199 .cb_ptr
= &client_cb
.parent
,
202 const struct lttng_ust_client_lib_ring_buffer_client_cb
*LTTNG_CLIENT_CALLBACKS
= &client_cb
;
205 struct lttng_channel
*_channel_create(const char *name
,
207 size_t subbuf_size
, size_t num_subbuf
,
208 unsigned int switch_timer_interval
,
209 unsigned int read_timer_interval
,
212 const int *stream_fds
, int nr_stream_fds
,
213 int64_t blocking_timeout
)
215 struct lttng_channel chan_priv_init
;
216 struct lttng_ust_shm_handle
*handle
;
217 struct lttng_channel
*lttng_chan
;
220 memset(&chan_priv_init
, 0, sizeof(chan_priv_init
));
221 memcpy(chan_priv_init
.uuid
, uuid
, LTTNG_UST_UUID_LEN
);
222 chan_priv_init
.id
= chan_id
;
223 handle
= channel_create(&client_config
, name
,
224 &priv
, __alignof__(struct lttng_channel
),
225 sizeof(struct lttng_channel
),
227 buf_addr
, subbuf_size
, num_subbuf
,
228 switch_timer_interval
, read_timer_interval
,
229 stream_fds
, nr_stream_fds
, blocking_timeout
);
233 lttng_chan
->handle
= handle
;
234 lttng_chan
->chan
= shmp(handle
, handle
->chan
);
239 void lttng_channel_destroy(struct lttng_channel
*chan
)
241 channel_destroy(chan
->chan
, chan
->handle
, 1);
245 int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
249 ret
= lib_ring_buffer_reserve(&client_config
, ctx
, NULL
);
252 if (caa_likely(ctx
->ctx_len
253 >= sizeof(struct lttng_ust_lib_ring_buffer_ctx
))) {
254 if (lib_ring_buffer_backend_get_pages(&client_config
, ctx
,
255 &ctx
->backend_pages
))
262 void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
264 lib_ring_buffer_commit(&client_config
, ctx
);
268 void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
271 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
275 size_t lttng_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
277 unsigned long o_begin
;
278 struct lttng_ust_lib_ring_buffer
*buf
;
280 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
281 o_begin
= v_read(&client_config
, &buf
->offset
);
282 if (subbuf_offset(o_begin
, chan
) != 0) {
283 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
285 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
286 - sizeof(struct metadata_packet_header
);
292 wait_queue_head_t
*lttng_get_reader_wait_queue(struct channel
*chan
)
294 return &chan
->read_wait
;
298 wait_queue_head_t
*lttng_get_hp_wait_queue(struct channel
*chan
)
300 return &chan
->hp_wait
;
305 int lttng_is_finalized(struct channel
*chan
)
307 return lib_ring_buffer_channel_is_finalized(chan
);
311 int lttng_is_disabled(struct channel
*chan
)
313 return lib_ring_buffer_channel_is_disabled(chan
);
317 int lttng_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
319 struct lttng_ust_lib_ring_buffer
*buf
;
320 int shm_fd
, wait_fd
, wakeup_fd
;
321 uint64_t memory_map_size
;
323 buf
= channel_get_ring_buffer(&client_config
, chan
,
324 0, handle
, &shm_fd
, &wait_fd
, &wakeup_fd
,
326 lib_ring_buffer_switch(&client_config
, buf
,
327 SWITCH_ACTIVE
, handle
);
331 static struct lttng_transport lttng_relay_transport
= {
332 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
334 .channel_create
= _channel_create
,
335 .channel_destroy
= lttng_channel_destroy
,
336 .event_reserve
= lttng_event_reserve
,
337 .event_commit
= lttng_event_commit
,
338 .event_write
= lttng_event_write
,
339 .packet_avail_size
= lttng_packet_avail_size
,
340 //.get_reader_wait_queue = lttng_get_reader_wait_queue,
341 //.get_hp_wait_queue = lttng_get_hp_wait_queue,
342 .is_finalized
= lttng_is_finalized
,
343 .is_disabled
= lttng_is_disabled
,
344 .flush_buffer
= lttng_flush_buffer
,
346 .client_config
= &client_config
,
349 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
351 DBG("LTT : ltt ring buffer client \"%s\" init\n",
352 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
353 lttng_transport_register(<tng_relay_transport
);
356 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
358 DBG("LTT : ltt ring buffer client \"%s\" exit\n",
359 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
360 lttng_transport_unregister(<tng_relay_transport
);