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
24 #include <lttng/ust-events.h>
25 #include "lttng/bitfield.h"
26 #include "lttng-tracer.h"
27 #include "../libringbuffer/frontend_types.h"
29 struct metadata_packet_header
{
30 uint32_t magic
; /* 0x75D11D57 */
31 uint8_t uuid
[LTTNG_UST_UUID_LEN
]; /* Unique Universal Identifier */
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 */
38 uint8_t major
; /* CTF spec major version number */
39 uint8_t minor
; /* CTF spec minor version number */
40 uint8_t header_end
[0];
43 struct metadata_record_header
{
44 uint8_t header_end
[0]; /* End of header */
47 static const struct lttng_ust_lib_ring_buffer_config client_config
;
49 static inline uint64_t lib_ring_buffer_clock_read(struct channel
*chan
)
55 unsigned char record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
56 struct channel
*chan
, size_t offset
,
57 size_t *pre_header_padding
,
58 struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
63 #include "../libringbuffer/api.h"
65 static uint64_t client_ring_buffer_clock_read(struct channel
*chan
)
71 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
72 struct channel
*chan
, size_t offset
,
73 size_t *pre_header_padding
,
74 struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
80 * client_packet_header_size - called on buffer-switch to a new sub-buffer
82 * Return header size without padding after the structure. Don't use packed
83 * structure because gcc generates inefficient code on some architectures
86 static size_t client_packet_header_size(void)
88 return offsetof(struct metadata_packet_header
, header_end
);
91 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
92 unsigned int subbuf_idx
,
93 struct lttng_ust_shm_handle
*handle
)
95 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
96 struct metadata_packet_header
*header
=
97 (struct metadata_packet_header
*)
98 lib_ring_buffer_offset_address(&buf
->backend
,
99 subbuf_idx
* chan
->backend
.subbuf_size
,
101 struct lttng_channel
*lttng_chan
= channel_get_private(chan
);
103 header
->magic
= TSDL_MAGIC_NUMBER
;
104 memcpy(header
->uuid
, lttng_chan
->uuid
, sizeof(lttng_chan
->uuid
));
105 header
->checksum
= 0; /* 0 if unused */
106 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
107 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
108 header
->compression_scheme
= 0; /* 0 if unused */
109 header
->encryption_scheme
= 0; /* 0 if unused */
110 header
->checksum_scheme
= 0; /* 0 if unused */
111 header
->major
= CTF_SPEC_MAJOR
;
112 header
->minor
= CTF_SPEC_MINOR
;
116 * offset is assumed to never be 0 here : never deliver a completely empty
117 * subbuffer. data_size is between 1 and subbuf_size.
119 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
120 unsigned int subbuf_idx
, unsigned long data_size
,
121 struct lttng_ust_shm_handle
*handle
)
123 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
124 struct metadata_packet_header
*header
=
125 (struct metadata_packet_header
*)
126 lib_ring_buffer_offset_address(&buf
->backend
,
127 subbuf_idx
* chan
->backend
.subbuf_size
,
129 unsigned long records_lost
= 0;
131 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
132 header
->packet_size
= PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
134 * We do not care about the records lost count, because the metadata
135 * channel waits and retry.
137 (void) lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
138 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
139 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
140 WARN_ON_ONCE(records_lost
!= 0);
143 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
144 int cpu
, const char *name
,
145 struct lttng_ust_shm_handle
*handle
)
150 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
152 struct lttng_ust_shm_handle
*handle
)
156 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
157 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
158 .cb
.record_header_size
= client_record_header_size
,
159 .cb
.subbuffer_header_size
= client_packet_header_size
,
160 .cb
.buffer_begin
= client_buffer_begin
,
161 .cb
.buffer_end
= client_buffer_end
,
162 .cb
.buffer_create
= client_buffer_create
,
163 .cb
.buffer_finalize
= client_buffer_finalize
,
166 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
167 .sync
= RING_BUFFER_SYNC_GLOBAL
,
168 .mode
= RING_BUFFER_MODE_TEMPLATE
,
169 .backend
= RING_BUFFER_PAGE
,
170 .output
= RING_BUFFER_MMAP
,
171 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
172 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
173 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
174 .client_type
= LTTNG_CLIENT_TYPE
,
177 const struct lttng_ust_lib_ring_buffer_client_cb
*LTTNG_CLIENT_CALLBACKS
= &client_config
.cb
;
180 struct lttng_channel
*_channel_create(const char *name
,
182 size_t subbuf_size
, size_t num_subbuf
,
183 unsigned int switch_timer_interval
,
184 unsigned int read_timer_interval
,
188 struct lttng_channel chan_priv_init
;
189 struct lttng_ust_shm_handle
*handle
;
190 struct lttng_channel
*lttng_chan
;
193 memset(&chan_priv_init
, 0, sizeof(chan_priv_init
));
194 memcpy(chan_priv_init
.uuid
, uuid
, LTTNG_UST_UUID_LEN
);
195 chan_priv_init
.id
= chan_id
;
196 handle
= channel_create(&client_config
, name
,
197 &priv
, __alignof__(struct lttng_channel
),
198 sizeof(struct lttng_channel
),
200 buf_addr
, subbuf_size
, num_subbuf
,
201 switch_timer_interval
, read_timer_interval
);
205 lttng_chan
->handle
= handle
;
206 lttng_chan
->chan
= shmp(handle
, handle
->chan
);
211 void lttng_channel_destroy(struct lttng_channel
*chan
)
213 channel_destroy(chan
->chan
, chan
->handle
, 1);
217 int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
219 return lib_ring_buffer_reserve(&client_config
, ctx
);
223 void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
225 lib_ring_buffer_commit(&client_config
, ctx
);
229 void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
232 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
236 size_t lttng_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
239 unsigned long o_begin
;
240 struct lttng_ust_lib_ring_buffer
*buf
;
242 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
243 o_begin
= v_read(&client_config
, &buf
->offset
);
244 if (subbuf_offset(o_begin
, chan
) != 0) {
245 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
247 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
248 - sizeof(struct metadata_packet_header
);
254 wait_queue_head_t
*lttng_get_reader_wait_queue(struct channel
*chan
)
256 return &chan
->read_wait
;
260 wait_queue_head_t
*lttng_get_hp_wait_queue(struct channel
*chan
)
262 return &chan
->hp_wait
;
267 int lttng_is_finalized(struct channel
*chan
)
269 return lib_ring_buffer_channel_is_finalized(chan
);
273 int lttng_is_disabled(struct channel
*chan
)
275 return lib_ring_buffer_channel_is_disabled(chan
);
279 int lttng_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
281 struct lttng_ust_lib_ring_buffer
*buf
;
282 int shm_fd
, wait_fd
, wakeup_fd
;
283 uint64_t memory_map_size
;
285 buf
= channel_get_ring_buffer(&client_config
, chan
,
286 0, handle
, &shm_fd
, &wait_fd
, &wakeup_fd
,
288 lib_ring_buffer_switch(&client_config
, buf
,
289 SWITCH_ACTIVE
, handle
);
293 static struct lttng_transport lttng_relay_transport
= {
294 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
296 .channel_create
= _channel_create
,
297 .channel_destroy
= lttng_channel_destroy
,
298 .event_reserve
= lttng_event_reserve
,
299 .event_commit
= lttng_event_commit
,
300 .event_write
= lttng_event_write
,
301 .packet_avail_size
= lttng_packet_avail_size
,
302 //.get_reader_wait_queue = lttng_get_reader_wait_queue,
303 //.get_hp_wait_queue = lttng_get_hp_wait_queue,
304 .is_finalized
= lttng_is_finalized
,
305 .is_disabled
= lttng_is_disabled
,
306 .flush_buffer
= lttng_flush_buffer
,
308 .client_config
= &client_config
,
311 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
313 DBG("LTT : ltt ring buffer client \"%s\" init\n",
314 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
315 lttng_transport_register(<tng_relay_transport
);
318 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
320 DBG("LTT : ltt ring buffer client \"%s\" exit\n",
321 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
322 lttng_transport_unregister(<tng_relay_transport
);