2 * SPDX-License-Identifier: LGPL-2.1-only
4 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * LTTng lib ring buffer client template.
11 #include <lttng/ust-events.h>
12 #include "ust-bitfield.h"
13 #include "ust-compat.h"
14 #include "lttng-tracer.h"
15 #include "../libringbuffer/frontend_types.h"
17 struct metadata_packet_header
{
18 uint32_t magic
; /* 0x75D11D57 */
19 uint8_t uuid
[LTTNG_UST_UUID_LEN
]; /* Unique Universal Identifier */
20 uint32_t checksum
; /* 0 if unused */
21 uint32_t content_size
; /* in bits */
22 uint32_t packet_size
; /* in bits */
23 uint8_t compression_scheme
; /* 0 if unused */
24 uint8_t encryption_scheme
; /* 0 if unused */
25 uint8_t checksum_scheme
; /* 0 if unused */
26 uint8_t major
; /* CTF spec major version number */
27 uint8_t minor
; /* CTF spec minor version number */
28 uint8_t header_end
[0];
31 struct metadata_record_header
{
32 uint8_t header_end
[0]; /* End of header */
35 static const struct lttng_ust_lib_ring_buffer_config client_config
;
37 static inline uint64_t lib_ring_buffer_clock_read(struct channel
*chan
)
43 size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
44 struct channel
*chan
, size_t offset
,
45 size_t *pre_header_padding
,
46 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
52 #include "../libringbuffer/api.h"
53 #include "lttng-rb-clients.h"
55 static uint64_t client_ring_buffer_clock_read(struct channel
*chan
)
61 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
62 struct channel
*chan
, size_t offset
,
63 size_t *pre_header_padding
,
64 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
71 * client_packet_header_size - called on buffer-switch to a new sub-buffer
73 * Return header size without padding after the structure. Don't use packed
74 * structure because gcc generates inefficient code on some architectures
77 static size_t client_packet_header_size(void)
79 return offsetof(struct metadata_packet_header
, header_end
);
82 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
83 unsigned int subbuf_idx
,
84 struct lttng_ust_shm_handle
*handle
)
86 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
87 struct metadata_packet_header
*header
=
88 (struct metadata_packet_header
*)
89 lib_ring_buffer_offset_address(&buf
->backend
,
90 subbuf_idx
* chan
->backend
.subbuf_size
,
92 struct lttng_channel
*lttng_chan
= channel_get_private(chan
);
97 header
->magic
= TSDL_MAGIC_NUMBER
;
98 memcpy(header
->uuid
, lttng_chan
->uuid
, sizeof(lttng_chan
->uuid
));
99 header
->checksum
= 0; /* 0 if unused */
100 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
101 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
102 header
->compression_scheme
= 0; /* 0 if unused */
103 header
->encryption_scheme
= 0; /* 0 if unused */
104 header
->checksum_scheme
= 0; /* 0 if unused */
105 header
->major
= CTF_SPEC_MAJOR
;
106 header
->minor
= CTF_SPEC_MINOR
;
110 * offset is assumed to never be 0 here : never deliver a completely empty
111 * subbuffer. data_size is between 1 and subbuf_size.
113 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
114 unsigned int subbuf_idx
, unsigned long data_size
,
115 struct lttng_ust_shm_handle
*handle
)
117 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
118 struct metadata_packet_header
*header
=
119 (struct metadata_packet_header
*)
120 lib_ring_buffer_offset_address(&buf
->backend
,
121 subbuf_idx
* chan
->backend
.subbuf_size
,
123 unsigned long records_lost
= 0;
128 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
129 header
->packet_size
= LTTNG_UST_PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
131 * We do not care about the records lost count, because the metadata
132 * channel waits and retry.
134 (void) lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
135 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
136 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
137 WARN_ON_ONCE(records_lost
!= 0);
140 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
141 int cpu
, const char *name
,
142 struct lttng_ust_shm_handle
*handle
)
147 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
149 struct lttng_ust_shm_handle
*handle
)
154 struct lttng_ust_client_lib_ring_buffer_client_cb client_cb
= {
156 .ring_buffer_clock_read
= client_ring_buffer_clock_read
,
157 .record_header_size
= client_record_header_size
,
158 .subbuffer_header_size
= client_packet_header_size
,
159 .buffer_begin
= client_buffer_begin
,
160 .buffer_end
= client_buffer_end
,
161 .buffer_create
= client_buffer_create
,
162 .buffer_finalize
= client_buffer_finalize
,
166 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
167 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
168 .cb
.record_header_size
= client_record_header_size
,
169 .cb
.subbuffer_header_size
= client_packet_header_size
,
170 .cb
.buffer_begin
= client_buffer_begin
,
171 .cb
.buffer_end
= client_buffer_end
,
172 .cb
.buffer_create
= client_buffer_create
,
173 .cb
.buffer_finalize
= client_buffer_finalize
,
176 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
177 .sync
= RING_BUFFER_SYNC_GLOBAL
,
178 .mode
= RING_BUFFER_MODE_TEMPLATE
,
179 .backend
= RING_BUFFER_PAGE
,
180 .output
= RING_BUFFER_MMAP
,
181 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
182 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
183 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
184 .client_type
= LTTNG_CLIENT_TYPE
,
186 .cb_ptr
= &client_cb
.parent
,
189 const struct lttng_ust_client_lib_ring_buffer_client_cb
*LTTNG_CLIENT_CALLBACKS
= &client_cb
;
192 struct lttng_channel
*_channel_create(const char *name
,
194 size_t subbuf_size
, size_t num_subbuf
,
195 unsigned int switch_timer_interval
,
196 unsigned int read_timer_interval
,
199 const int *stream_fds
, int nr_stream_fds
,
200 int64_t blocking_timeout
)
202 struct lttng_channel chan_priv_init
;
203 struct lttng_ust_shm_handle
*handle
;
204 struct lttng_channel
*lttng_chan
;
207 memset(&chan_priv_init
, 0, sizeof(chan_priv_init
));
208 memcpy(chan_priv_init
.uuid
, uuid
, LTTNG_UST_UUID_LEN
);
209 chan_priv_init
.id
= chan_id
;
210 handle
= channel_create(&client_config
, name
,
211 &priv
, __alignof__(struct lttng_channel
),
212 sizeof(struct lttng_channel
),
214 buf_addr
, subbuf_size
, num_subbuf
,
215 switch_timer_interval
, read_timer_interval
,
216 stream_fds
, nr_stream_fds
, blocking_timeout
);
220 lttng_chan
->handle
= handle
;
221 lttng_chan
->chan
= shmp(handle
, handle
->chan
);
226 void lttng_channel_destroy(struct lttng_channel
*chan
)
228 channel_destroy(chan
->chan
, chan
->handle
, 1);
232 int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
236 ret
= lib_ring_buffer_reserve(&client_config
, ctx
, NULL
);
239 if (caa_likely(ctx
->ctx_len
240 >= sizeof(struct lttng_ust_lib_ring_buffer_ctx
))) {
241 if (lib_ring_buffer_backend_get_pages(&client_config
, ctx
,
242 &ctx
->backend_pages
))
249 void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
251 lib_ring_buffer_commit(&client_config
, ctx
);
255 void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
258 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
262 size_t lttng_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
264 unsigned long o_begin
;
265 struct lttng_ust_lib_ring_buffer
*buf
;
267 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
268 o_begin
= v_read(&client_config
, &buf
->offset
);
269 if (subbuf_offset(o_begin
, chan
) != 0) {
270 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
272 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
273 - sizeof(struct metadata_packet_header
);
279 wait_queue_head_t
*lttng_get_reader_wait_queue(struct channel
*chan
)
281 return &chan
->read_wait
;
285 wait_queue_head_t
*lttng_get_hp_wait_queue(struct channel
*chan
)
287 return &chan
->hp_wait
;
292 int lttng_is_finalized(struct channel
*chan
)
294 return lib_ring_buffer_channel_is_finalized(chan
);
298 int lttng_is_disabled(struct channel
*chan
)
300 return lib_ring_buffer_channel_is_disabled(chan
);
304 int lttng_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
306 struct lttng_ust_lib_ring_buffer
*buf
;
307 int shm_fd
, wait_fd
, wakeup_fd
;
308 uint64_t memory_map_size
;
310 buf
= channel_get_ring_buffer(&client_config
, chan
,
311 0, handle
, &shm_fd
, &wait_fd
, &wakeup_fd
,
313 lib_ring_buffer_switch(&client_config
, buf
,
314 SWITCH_ACTIVE
, handle
);
318 static struct lttng_transport lttng_relay_transport
= {
319 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
321 .channel_create
= _channel_create
,
322 .channel_destroy
= lttng_channel_destroy
,
323 .event_reserve
= lttng_event_reserve
,
324 .event_commit
= lttng_event_commit
,
325 .event_write
= lttng_event_write
,
326 .packet_avail_size
= lttng_packet_avail_size
,
327 //.get_reader_wait_queue = lttng_get_reader_wait_queue,
328 //.get_hp_wait_queue = lttng_get_hp_wait_queue,
329 .is_finalized
= lttng_is_finalized
,
330 .is_disabled
= lttng_is_disabled
,
331 .flush_buffer
= lttng_flush_buffer
,
333 .client_config
= &client_config
,
336 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
338 DBG("LTT : ltt ring buffer client \"%s\" init\n",
339 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
340 lttng_transport_register(<tng_relay_transport
);
343 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
345 DBG("LTT : ltt ring buffer client \"%s\" exit\n",
346 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
347 lttng_transport_unregister(<tng_relay_transport
);