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.
12 #include <ust-events-internal.h>
13 #include "ust-bitfield.h"
14 #include "ust-compat.h"
15 #include "lttng-tracer.h"
16 #include "../libringbuffer/frontend_types.h"
18 struct metadata_packet_header
{
19 uint32_t magic
; /* 0x75D11D57 */
20 uint8_t uuid
[LTTNG_UST_UUID_LEN
]; /* Unique Universal Identifier */
21 uint32_t checksum
; /* 0 if unused */
22 uint32_t content_size
; /* in bits */
23 uint32_t packet_size
; /* in bits */
24 uint8_t compression_scheme
; /* 0 if unused */
25 uint8_t encryption_scheme
; /* 0 if unused */
26 uint8_t checksum_scheme
; /* 0 if unused */
27 uint8_t major
; /* CTF spec major version number */
28 uint8_t minor
; /* CTF spec minor version number */
29 uint8_t header_end
[0];
32 struct metadata_record_header
{
33 uint8_t header_end
[0]; /* End of header */
36 static const struct lttng_ust_lib_ring_buffer_config client_config
;
38 static inline uint64_t lib_ring_buffer_clock_read(struct channel
*chan
)
44 size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
45 struct channel
*chan
, size_t offset
,
46 size_t *pre_header_padding
,
47 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
53 #include "../libringbuffer/api.h"
54 #include "lttng-rb-clients.h"
56 static uint64_t client_ring_buffer_clock_read(struct channel
*chan
)
62 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
63 struct channel
*chan
, size_t offset
,
64 size_t *pre_header_padding
,
65 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
72 * client_packet_header_size - called on buffer-switch to a new sub-buffer
74 * Return header size without padding after the structure. Don't use packed
75 * structure because gcc generates inefficient code on some architectures
78 static size_t client_packet_header_size(void)
80 return offsetof(struct metadata_packet_header
, header_end
);
83 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
84 unsigned int subbuf_idx
,
85 struct lttng_ust_shm_handle
*handle
)
87 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
88 struct metadata_packet_header
*header
=
89 (struct metadata_packet_header
*)
90 lib_ring_buffer_offset_address(&buf
->backend
,
91 subbuf_idx
* chan
->backend
.subbuf_size
,
93 struct lttng_channel
*lttng_chan
= channel_get_private(chan
);
98 header
->magic
= TSDL_MAGIC_NUMBER
;
99 memcpy(header
->uuid
, lttng_chan
->uuid
, sizeof(lttng_chan
->uuid
));
100 header
->checksum
= 0; /* 0 if unused */
101 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
102 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
103 header
->compression_scheme
= 0; /* 0 if unused */
104 header
->encryption_scheme
= 0; /* 0 if unused */
105 header
->checksum_scheme
= 0; /* 0 if unused */
106 header
->major
= CTF_SPEC_MAJOR
;
107 header
->minor
= CTF_SPEC_MINOR
;
111 * offset is assumed to never be 0 here : never deliver a completely empty
112 * subbuffer. data_size is between 1 and subbuf_size.
114 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
115 unsigned int subbuf_idx
, unsigned long data_size
,
116 struct lttng_ust_shm_handle
*handle
)
118 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
119 struct metadata_packet_header
*header
=
120 (struct metadata_packet_header
*)
121 lib_ring_buffer_offset_address(&buf
->backend
,
122 subbuf_idx
* chan
->backend
.subbuf_size
,
124 unsigned long records_lost
= 0;
129 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
130 header
->packet_size
= LTTNG_UST_PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
132 * We do not care about the records lost count, because the metadata
133 * channel waits and retry.
135 (void) lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
136 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
137 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
138 WARN_ON_ONCE(records_lost
!= 0);
141 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
142 int cpu
, const char *name
,
143 struct lttng_ust_shm_handle
*handle
)
148 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
150 struct lttng_ust_shm_handle
*handle
)
155 struct lttng_ust_client_lib_ring_buffer_client_cb client_cb
= {
157 .ring_buffer_clock_read
= client_ring_buffer_clock_read
,
158 .record_header_size
= client_record_header_size
,
159 .subbuffer_header_size
= client_packet_header_size
,
160 .buffer_begin
= client_buffer_begin
,
161 .buffer_end
= client_buffer_end
,
162 .buffer_create
= client_buffer_create
,
163 .buffer_finalize
= client_buffer_finalize
,
167 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
168 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
169 .cb
.record_header_size
= client_record_header_size
,
170 .cb
.subbuffer_header_size
= client_packet_header_size
,
171 .cb
.buffer_begin
= client_buffer_begin
,
172 .cb
.buffer_end
= client_buffer_end
,
173 .cb
.buffer_create
= client_buffer_create
,
174 .cb
.buffer_finalize
= client_buffer_finalize
,
177 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
178 .sync
= RING_BUFFER_SYNC_GLOBAL
,
179 .mode
= RING_BUFFER_MODE_TEMPLATE
,
180 .backend
= RING_BUFFER_PAGE
,
181 .output
= RING_BUFFER_MMAP
,
182 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
183 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
184 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
185 .client_type
= LTTNG_CLIENT_TYPE
,
187 .cb_ptr
= &client_cb
.parent
,
191 struct lttng_channel
*_channel_create(const char *name
,
193 size_t subbuf_size
, size_t num_subbuf
,
194 unsigned int switch_timer_interval
,
195 unsigned int read_timer_interval
,
198 const int *stream_fds
, int nr_stream_fds
,
199 int64_t blocking_timeout
)
201 struct lttng_channel chan_priv_init
;
202 struct lttng_ust_shm_handle
*handle
;
203 struct lttng_channel
*lttng_chan
;
206 memset(&chan_priv_init
, 0, sizeof(chan_priv_init
));
207 memcpy(chan_priv_init
.uuid
, uuid
, LTTNG_UST_UUID_LEN
);
208 chan_priv_init
.id
= chan_id
;
209 handle
= channel_create(&client_config
, name
,
210 &priv
, __alignof__(struct lttng_channel
),
211 sizeof(struct lttng_channel
),
213 buf_addr
, subbuf_size
, num_subbuf
,
214 switch_timer_interval
, read_timer_interval
,
215 stream_fds
, nr_stream_fds
, blocking_timeout
);
219 lttng_chan
->handle
= handle
;
220 lttng_chan
->chan
= shmp(handle
, handle
->chan
);
225 void lttng_channel_destroy(struct lttng_channel
*chan
)
227 channel_destroy(chan
->chan
, chan
->handle
, 1);
231 int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
235 ret
= lib_ring_buffer_reserve(&client_config
, ctx
, NULL
);
238 if (lib_ring_buffer_backend_get_pages(&client_config
, ctx
,
239 &ctx
->backend_pages
))
245 void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
247 lib_ring_buffer_commit(&client_config
, ctx
);
251 void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
254 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
258 size_t lttng_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
260 unsigned long o_begin
;
261 struct lttng_ust_lib_ring_buffer
*buf
;
263 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
264 o_begin
= v_read(&client_config
, &buf
->offset
);
265 if (subbuf_offset(o_begin
, chan
) != 0) {
266 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
268 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
269 - sizeof(struct metadata_packet_header
);
275 wait_queue_head_t
*lttng_get_reader_wait_queue(struct channel
*chan
)
277 return &chan
->read_wait
;
281 wait_queue_head_t
*lttng_get_hp_wait_queue(struct channel
*chan
)
283 return &chan
->hp_wait
;
288 int lttng_is_finalized(struct channel
*chan
)
290 return lib_ring_buffer_channel_is_finalized(chan
);
294 int lttng_is_disabled(struct channel
*chan
)
296 return lib_ring_buffer_channel_is_disabled(chan
);
300 int lttng_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
302 struct lttng_ust_lib_ring_buffer
*buf
;
303 int shm_fd
, wait_fd
, wakeup_fd
;
304 uint64_t memory_map_size
;
306 buf
= channel_get_ring_buffer(&client_config
, chan
,
307 0, handle
, &shm_fd
, &wait_fd
, &wakeup_fd
,
309 lib_ring_buffer_switch(&client_config
, buf
,
310 SWITCH_ACTIVE
, handle
);
314 static struct lttng_transport lttng_relay_transport
= {
315 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
317 .struct_size
= sizeof(struct lttng_ust_channel_ops
),
319 .channel_create
= _channel_create
,
320 .channel_destroy
= lttng_channel_destroy
,
321 .event_reserve
= lttng_event_reserve
,
322 .event_commit
= lttng_event_commit
,
323 .event_write
= lttng_event_write
,
324 .packet_avail_size
= lttng_packet_avail_size
,
325 .is_finalized
= lttng_is_finalized
,
326 .is_disabled
= lttng_is_disabled
,
327 .flush_buffer
= lttng_flush_buffer
,
329 .client_config
= &client_config
,
332 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
334 DBG("LTT : ltt ring buffer client \"%s\" init\n",
335 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
336 lttng_transport_register(<tng_relay_transport
);
339 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
341 DBG("LTT : ltt ring buffer client \"%s\" exit\n",
342 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap");
343 lttng_transport_unregister(<tng_relay_transport
);