2 * ltt-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 "ltt-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 ltt_channel
*ltt_chan
= channel_get_private(chan
);
103 header
->magic
= TSDL_MAGIC_NUMBER
;
104 memcpy(header
->uuid
, ltt_chan
->uuid
, sizeof(ltt_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
;
117 * offset is assumed to never be 0 here : never deliver a completely empty
118 * subbuffer. data_size is between 1 and subbuf_size.
120 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
121 unsigned int subbuf_idx
, unsigned long data_size
,
122 struct lttng_ust_shm_handle
*handle
)
124 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
125 struct metadata_packet_header
*header
=
126 (struct metadata_packet_header
*)
127 lib_ring_buffer_offset_address(&buf
->backend
,
128 subbuf_idx
* chan
->backend
.subbuf_size
,
130 unsigned long records_lost
= 0;
132 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
133 header
->packet_size
= PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
135 * We do not care about the records lost count, because the metadata
136 * channel waits and retry.
138 (void) lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
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);
144 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
145 int cpu
, const char *name
,
146 struct lttng_ust_shm_handle
*handle
)
151 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
153 struct lttng_ust_shm_handle
*handle
)
157 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
158 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
159 .cb
.record_header_size
= client_record_header_size
,
160 .cb
.subbuffer_header_size
= client_packet_header_size
,
161 .cb
.buffer_begin
= client_buffer_begin
,
162 .cb
.buffer_end
= client_buffer_end
,
163 .cb
.buffer_create
= client_buffer_create
,
164 .cb
.buffer_finalize
= client_buffer_finalize
,
167 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
168 .sync
= RING_BUFFER_SYNC_GLOBAL
,
169 .mode
= RING_BUFFER_MODE_TEMPLATE
,
170 .backend
= RING_BUFFER_PAGE
,
171 .output
= RING_BUFFER_MMAP
,
172 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
173 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
174 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
175 .client_type
= LTTNG_CLIENT_TYPE
,
178 const struct lttng_ust_lib_ring_buffer_client_cb
*LTTNG_CLIENT_CALLBACKS
= &client_config
.cb
;
181 struct ltt_channel
*_channel_create(const char *name
,
183 size_t subbuf_size
, size_t num_subbuf
,
184 unsigned int switch_timer_interval
,
185 unsigned int read_timer_interval
,
186 int **shm_fd
, int **wait_fd
,
187 uint64_t **memory_map_size
,
188 struct ltt_channel
*chan_priv_init
)
191 struct ltt_channel
*ltt_chan
= NULL
;
192 struct lttng_ust_shm_handle
*handle
;
194 handle
= channel_create(&client_config
, name
,
195 &priv
, __alignof__(*ltt_chan
), sizeof(*ltt_chan
),
197 buf_addr
, subbuf_size
, num_subbuf
,
198 switch_timer_interval
, read_timer_interval
,
199 shm_fd
, wait_fd
, memory_map_size
);
203 ltt_chan
->handle
= handle
;
204 ltt_chan
->chan
= shmp(ltt_chan
->handle
, ltt_chan
->handle
->chan
);
209 void ltt_channel_destroy(struct ltt_channel
*ltt_chan
)
211 channel_destroy(ltt_chan
->chan
, ltt_chan
->handle
, 0);
215 struct lttng_ust_lib_ring_buffer
*ltt_buffer_read_open(struct channel
*chan
,
216 struct lttng_ust_shm_handle
*handle
,
217 int **shm_fd
, int **wait_fd
,
218 uint64_t **memory_map_size
)
220 struct lttng_ust_lib_ring_buffer
*buf
;
222 buf
= channel_get_ring_buffer(&client_config
, chan
,
223 0, handle
, shm_fd
, wait_fd
, memory_map_size
);
224 if (!lib_ring_buffer_open_read(buf
, handle
, 0))
230 void ltt_buffer_read_close(struct lttng_ust_lib_ring_buffer
*buf
,
231 struct lttng_ust_shm_handle
*handle
)
233 lib_ring_buffer_release_read(buf
, handle
, 0);
237 int ltt_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
239 return lib_ring_buffer_reserve(&client_config
, ctx
);
243 void ltt_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
245 lib_ring_buffer_commit(&client_config
, ctx
);
249 void ltt_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
252 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
256 size_t ltt_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
259 unsigned long o_begin
;
260 struct lttng_ust_lib_ring_buffer
*buf
;
262 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
263 o_begin
= v_read(&client_config
, &buf
->offset
);
264 if (subbuf_offset(o_begin
, chan
) != 0) {
265 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
267 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
268 - sizeof(struct metadata_packet_header
);
274 wait_queue_head_t
*ltt_get_reader_wait_queue(struct channel
*chan
)
276 return &chan
->read_wait
;
280 wait_queue_head_t
*ltt_get_hp_wait_queue(struct channel
*chan
)
282 return &chan
->hp_wait
;
287 int ltt_is_finalized(struct channel
*chan
)
289 return lib_ring_buffer_channel_is_finalized(chan
);
293 int ltt_is_disabled(struct channel
*chan
)
295 return lib_ring_buffer_channel_is_disabled(chan
);
299 int ltt_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
301 struct lttng_ust_lib_ring_buffer
*buf
;
302 int *shm_fd
, *wait_fd
;
303 uint64_t *memory_map_size
;
305 buf
= channel_get_ring_buffer(&client_config
, chan
,
306 0, handle
, &shm_fd
, &wait_fd
,
308 lib_ring_buffer_switch(&client_config
, buf
,
309 SWITCH_ACTIVE
, handle
);
313 static struct ltt_transport ltt_relay_transport
= {
314 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
316 .channel_create
= _channel_create
,
317 .channel_destroy
= ltt_channel_destroy
,
318 .buffer_read_open
= ltt_buffer_read_open
,
319 .buffer_read_close
= ltt_buffer_read_close
,
320 .event_reserve
= ltt_event_reserve
,
321 .event_commit
= ltt_event_commit
,
322 .event_write
= ltt_event_write
,
323 .packet_avail_size
= ltt_packet_avail_size
,
324 //.get_reader_wait_queue = ltt_get_reader_wait_queue,
325 //.get_hp_wait_queue = ltt_get_hp_wait_queue,
326 .is_finalized
= ltt_is_finalized
,
327 .is_disabled
= ltt_is_disabled
,
328 .flush_buffer
= ltt_flush_buffer
,
332 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
334 DBG("LTT : ltt ring buffer client init\n");
335 ltt_transport_register(<t_relay_transport
);
338 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
340 DBG("LTT : ltt ring buffer client exit\n");
341 ltt_transport_unregister(<t_relay_transport
);