2 * ltt-ring-buffer-client.h
4 * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * LTTng lib ring buffer client template.
8 * Dual LGPL v2.1/GPL v2 license.
12 #include <lttng/ust-events.h>
13 #include "lttng/bitfield.h"
14 #include "ltt-tracer.h"
15 #include "../libringbuffer/frontend_types.h"
17 struct metadata_packet_header
{
18 uint32_t magic
; /* 0x75D11D57 */
19 uint8_t uuid
[16]; /* 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
;
38 u64
lib_ring_buffer_clock_read(struct channel
*chan
)
44 unsigned char 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
)
52 #include "../libringbuffer/api.h"
54 static u64
client_ring_buffer_clock_read(struct channel
*chan
)
60 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
61 struct channel
*chan
, size_t offset
,
62 size_t *pre_header_padding
,
63 struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
69 * client_packet_header_size - called on buffer-switch to a new sub-buffer
71 * Return header size without padding after the structure. Don't use packed
72 * structure because gcc generates inefficient code on some architectures
75 static size_t client_packet_header_size(void)
77 return offsetof(struct metadata_packet_header
, header_end
);
80 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer
*buf
, u64 tsc
,
81 unsigned int subbuf_idx
,
82 struct lttng_ust_shm_handle
*handle
)
84 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
85 struct metadata_packet_header
*header
=
86 (struct metadata_packet_header
*)
87 lib_ring_buffer_offset_address(&buf
->backend
,
88 subbuf_idx
* chan
->backend
.subbuf_size
,
90 struct ltt_channel
*ltt_chan
= channel_get_private(chan
);
91 struct ltt_session
*session
= ltt_chan
->session
;
93 header
->magic
= TSDL_MAGIC_NUMBER
;
94 memcpy(header
->uuid
, session
->uuid
, sizeof(session
->uuid
));
95 header
->checksum
= 0; /* 0 if unused */
96 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
97 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
98 header
->compression_scheme
= 0; /* 0 if unused */
99 header
->encryption_scheme
= 0; /* 0 if unused */
100 header
->checksum_scheme
= 0; /* 0 if unused */
101 header
->major
= CTF_SPEC_MAJOR
;
102 header
->minor
= CTF_SPEC_MINOR
;
107 * offset is assumed to never be 0 here : never deliver a completely empty
108 * subbuffer. data_size is between 1 and subbuf_size.
110 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, u64 tsc
,
111 unsigned int subbuf_idx
, unsigned long data_size
,
112 struct lttng_ust_shm_handle
*handle
)
114 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
115 struct metadata_packet_header
*header
=
116 (struct metadata_packet_header
*)
117 lib_ring_buffer_offset_address(&buf
->backend
,
118 subbuf_idx
* chan
->backend
.subbuf_size
,
120 unsigned long records_lost
= 0;
122 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
123 header
->packet_size
= PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
124 records_lost
+= lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
125 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
126 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
127 WARN_ON_ONCE(records_lost
!= 0);
130 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
131 int cpu
, const char *name
,
132 struct lttng_ust_shm_handle
*handle
)
137 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
139 struct lttng_ust_shm_handle
*handle
)
143 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
144 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
145 .cb
.record_header_size
= client_record_header_size
,
146 .cb
.subbuffer_header_size
= client_packet_header_size
,
147 .cb
.buffer_begin
= client_buffer_begin
,
148 .cb
.buffer_end
= client_buffer_end
,
149 .cb
.buffer_create
= client_buffer_create
,
150 .cb
.buffer_finalize
= client_buffer_finalize
,
153 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
154 .sync
= RING_BUFFER_SYNC_GLOBAL
,
155 .mode
= RING_BUFFER_MODE_TEMPLATE
,
156 .backend
= RING_BUFFER_PAGE
,
157 .output
= RING_BUFFER_MMAP
,
158 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
159 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
160 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
161 .client_type
= LTTNG_CLIENT_TYPE
,
164 const struct lttng_ust_lib_ring_buffer_client_cb
*LTTNG_CLIENT_CALLBACKS
= &client_config
.cb
;
167 struct ltt_channel
*_channel_create(const char *name
,
168 struct ltt_channel
*ltt_chan
, void *buf_addr
,
169 size_t subbuf_size
, size_t num_subbuf
,
170 unsigned int switch_timer_interval
,
171 unsigned int read_timer_interval
,
172 int *shm_fd
, int *wait_fd
,
173 uint64_t *memory_map_size
)
175 ltt_chan
->handle
= channel_create(&client_config
, name
, ltt_chan
, buf_addr
,
176 subbuf_size
, num_subbuf
, switch_timer_interval
,
177 read_timer_interval
, shm_fd
, wait_fd
,
179 if (!ltt_chan
->handle
)
181 ltt_chan
->chan
= shmp(ltt_chan
->handle
, ltt_chan
->handle
->chan
);
186 void ltt_channel_destroy(struct ltt_channel
*ltt_chan
)
188 channel_destroy(ltt_chan
->chan
, ltt_chan
->handle
, 0);
192 struct lttng_ust_lib_ring_buffer
*ltt_buffer_read_open(struct channel
*chan
,
193 struct lttng_ust_shm_handle
*handle
,
194 int *shm_fd
, int *wait_fd
,
195 uint64_t *memory_map_size
)
197 struct lttng_ust_lib_ring_buffer
*buf
;
199 buf
= channel_get_ring_buffer(&client_config
, chan
,
200 0, handle
, shm_fd
, wait_fd
, memory_map_size
);
201 if (!lib_ring_buffer_open_read(buf
, handle
, 0))
207 void ltt_buffer_read_close(struct lttng_ust_lib_ring_buffer
*buf
,
208 struct lttng_ust_shm_handle
*handle
)
210 lib_ring_buffer_release_read(buf
, handle
, 0);
214 int ltt_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
216 return lib_ring_buffer_reserve(&client_config
, ctx
);
220 void ltt_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
222 lib_ring_buffer_commit(&client_config
, ctx
);
226 void ltt_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
229 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
233 size_t ltt_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
236 unsigned long o_begin
;
237 struct lttng_ust_lib_ring_buffer
*buf
;
239 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
240 o_begin
= v_read(&client_config
, &buf
->offset
);
241 if (subbuf_offset(o_begin
, chan
) != 0) {
242 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
244 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
245 - sizeof(struct metadata_packet_header
);
251 wait_queue_head_t
*ltt_get_reader_wait_queue(struct channel
*chan
)
253 return &chan
->read_wait
;
257 wait_queue_head_t
*ltt_get_hp_wait_queue(struct channel
*chan
)
259 return &chan
->hp_wait
;
264 int ltt_is_finalized(struct channel
*chan
)
266 return lib_ring_buffer_channel_is_finalized(chan
);
270 int ltt_is_disabled(struct channel
*chan
)
272 return lib_ring_buffer_channel_is_disabled(chan
);
276 int ltt_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
278 struct lttng_ust_lib_ring_buffer
*buf
;
280 uint64_t memory_map_size
;
282 buf
= channel_get_ring_buffer(&client_config
, chan
,
283 0, handle
, &shm_fd
, &wait_fd
,
285 lib_ring_buffer_switch(&client_config
, buf
,
286 SWITCH_ACTIVE
, handle
);
290 static struct ltt_transport ltt_relay_transport
= {
291 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
293 .channel_create
= _channel_create
,
294 .channel_destroy
= ltt_channel_destroy
,
295 .buffer_read_open
= ltt_buffer_read_open
,
296 .buffer_read_close
= ltt_buffer_read_close
,
297 .event_reserve
= ltt_event_reserve
,
298 .event_commit
= ltt_event_commit
,
299 .event_write
= ltt_event_write
,
300 .packet_avail_size
= ltt_packet_avail_size
,
301 //.get_reader_wait_queue = ltt_get_reader_wait_queue,
302 //.get_hp_wait_queue = ltt_get_hp_wait_queue,
303 .is_finalized
= ltt_is_finalized
,
304 .is_disabled
= ltt_is_disabled
,
305 .flush_buffer
= ltt_flush_buffer
,
309 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
311 DBG("LTT : ltt ring buffer client init\n");
312 ltt_transport_register(<t_relay_transport
);
315 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
317 DBG("LTT : ltt ring buffer client exit\n");
318 ltt_transport_unregister(<t_relay_transport
);