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
;
37 static inline uint64_t lib_ring_buffer_clock_read(struct channel
*chan
)
43 unsigned char 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
)
51 #include "../libringbuffer/api.h"
53 static uint64_t client_ring_buffer_clock_read(struct channel
*chan
)
59 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config
*config
,
60 struct channel
*chan
, size_t offset
,
61 size_t *pre_header_padding
,
62 struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
68 * client_packet_header_size - called on buffer-switch to a new sub-buffer
70 * Return header size without padding after the structure. Don't use packed
71 * structure because gcc generates inefficient code on some architectures
74 static size_t client_packet_header_size(void)
76 return offsetof(struct metadata_packet_header
, header_end
);
79 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
80 unsigned int subbuf_idx
,
81 struct lttng_ust_shm_handle
*handle
)
83 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
84 struct metadata_packet_header
*header
=
85 (struct metadata_packet_header
*)
86 lib_ring_buffer_offset_address(&buf
->backend
,
87 subbuf_idx
* chan
->backend
.subbuf_size
,
89 struct ltt_channel
*ltt_chan
= channel_get_private(chan
);
91 header
->magic
= TSDL_MAGIC_NUMBER
;
92 memcpy(header
->uuid
, ltt_chan
->uuid
, sizeof(ltt_chan
->uuid
));
93 header
->checksum
= 0; /* 0 if unused */
94 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
95 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
96 header
->compression_scheme
= 0; /* 0 if unused */
97 header
->encryption_scheme
= 0; /* 0 if unused */
98 header
->checksum_scheme
= 0; /* 0 if unused */
99 header
->major
= CTF_SPEC_MAJOR
;
100 header
->minor
= CTF_SPEC_MINOR
;
105 * offset is assumed to never be 0 here : never deliver a completely empty
106 * subbuffer. data_size is between 1 and subbuf_size.
108 static void client_buffer_end(struct lttng_ust_lib_ring_buffer
*buf
, uint64_t tsc
,
109 unsigned int subbuf_idx
, unsigned long data_size
,
110 struct lttng_ust_shm_handle
*handle
)
112 struct channel
*chan
= shmp(handle
, buf
->backend
.chan
);
113 struct metadata_packet_header
*header
=
114 (struct metadata_packet_header
*)
115 lib_ring_buffer_offset_address(&buf
->backend
,
116 subbuf_idx
* chan
->backend
.subbuf_size
,
118 unsigned long records_lost
= 0;
120 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
121 header
->packet_size
= PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
122 records_lost
+= lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
123 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
124 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
125 WARN_ON_ONCE(records_lost
!= 0);
128 static int client_buffer_create(struct lttng_ust_lib_ring_buffer
*buf
, void *priv
,
129 int cpu
, const char *name
,
130 struct lttng_ust_shm_handle
*handle
)
135 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer
*buf
,
137 struct lttng_ust_shm_handle
*handle
)
141 static const struct lttng_ust_lib_ring_buffer_config client_config
= {
142 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
143 .cb
.record_header_size
= client_record_header_size
,
144 .cb
.subbuffer_header_size
= client_packet_header_size
,
145 .cb
.buffer_begin
= client_buffer_begin
,
146 .cb
.buffer_end
= client_buffer_end
,
147 .cb
.buffer_create
= client_buffer_create
,
148 .cb
.buffer_finalize
= client_buffer_finalize
,
151 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
152 .sync
= RING_BUFFER_SYNC_GLOBAL
,
153 .mode
= RING_BUFFER_MODE_TEMPLATE
,
154 .backend
= RING_BUFFER_PAGE
,
155 .output
= RING_BUFFER_MMAP
,
156 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
157 .ipi
= RING_BUFFER_NO_IPI_BARRIER
,
158 .wakeup
= RING_BUFFER_WAKEUP_BY_WRITER
,
159 .client_type
= LTTNG_CLIENT_TYPE
,
162 const struct lttng_ust_lib_ring_buffer_client_cb
*LTTNG_CLIENT_CALLBACKS
= &client_config
.cb
;
165 struct ltt_channel
*_channel_create(const char *name
,
167 size_t subbuf_size
, size_t num_subbuf
,
168 unsigned int switch_timer_interval
,
169 unsigned int read_timer_interval
,
170 int *shm_fd
, int *wait_fd
,
171 uint64_t *memory_map_size
,
172 struct ltt_channel
*chan_priv_init
)
175 struct ltt_channel
*ltt_chan
= NULL
;
176 struct lttng_ust_shm_handle
*handle
;
178 handle
= channel_create(&client_config
, name
,
179 &priv
, __alignof__(*ltt_chan
), sizeof(*ltt_chan
),
181 buf_addr
, subbuf_size
, num_subbuf
,
182 switch_timer_interval
, read_timer_interval
,
183 shm_fd
, wait_fd
, memory_map_size
);
187 ltt_chan
->handle
= handle
;
188 ltt_chan
->chan
= shmp(ltt_chan
->handle
, ltt_chan
->handle
->chan
);
193 void ltt_channel_destroy(struct ltt_channel
*ltt_chan
)
195 channel_destroy(ltt_chan
->chan
, ltt_chan
->handle
, 0);
199 struct lttng_ust_lib_ring_buffer
*ltt_buffer_read_open(struct channel
*chan
,
200 struct lttng_ust_shm_handle
*handle
,
201 int *shm_fd
, int *wait_fd
,
202 uint64_t *memory_map_size
)
204 struct lttng_ust_lib_ring_buffer
*buf
;
206 buf
= channel_get_ring_buffer(&client_config
, chan
,
207 0, handle
, shm_fd
, wait_fd
, memory_map_size
);
208 if (!lib_ring_buffer_open_read(buf
, handle
, 0))
214 void ltt_buffer_read_close(struct lttng_ust_lib_ring_buffer
*buf
,
215 struct lttng_ust_shm_handle
*handle
)
217 lib_ring_buffer_release_read(buf
, handle
, 0);
221 int ltt_event_reserve(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
223 return lib_ring_buffer_reserve(&client_config
, ctx
);
227 void ltt_event_commit(struct lttng_ust_lib_ring_buffer_ctx
*ctx
)
229 lib_ring_buffer_commit(&client_config
, ctx
);
233 void ltt_event_write(struct lttng_ust_lib_ring_buffer_ctx
*ctx
, const void *src
,
236 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
240 size_t ltt_packet_avail_size(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
243 unsigned long o_begin
;
244 struct lttng_ust_lib_ring_buffer
*buf
;
246 buf
= shmp(handle
, chan
->backend
.buf
[0].shmp
); /* Only for global buffer ! */
247 o_begin
= v_read(&client_config
, &buf
->offset
);
248 if (subbuf_offset(o_begin
, chan
) != 0) {
249 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
251 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
252 - sizeof(struct metadata_packet_header
);
258 wait_queue_head_t
*ltt_get_reader_wait_queue(struct channel
*chan
)
260 return &chan
->read_wait
;
264 wait_queue_head_t
*ltt_get_hp_wait_queue(struct channel
*chan
)
266 return &chan
->hp_wait
;
271 int ltt_is_finalized(struct channel
*chan
)
273 return lib_ring_buffer_channel_is_finalized(chan
);
277 int ltt_is_disabled(struct channel
*chan
)
279 return lib_ring_buffer_channel_is_disabled(chan
);
283 int ltt_flush_buffer(struct channel
*chan
, struct lttng_ust_shm_handle
*handle
)
285 struct lttng_ust_lib_ring_buffer
*buf
;
287 uint64_t memory_map_size
;
289 buf
= channel_get_ring_buffer(&client_config
, chan
,
290 0, handle
, &shm_fd
, &wait_fd
,
292 lib_ring_buffer_switch(&client_config
, buf
,
293 SWITCH_ACTIVE
, handle
);
297 static struct ltt_transport ltt_relay_transport
= {
298 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
"-mmap",
300 .channel_create
= _channel_create
,
301 .channel_destroy
= ltt_channel_destroy
,
302 .buffer_read_open
= ltt_buffer_read_open
,
303 .buffer_read_close
= ltt_buffer_read_close
,
304 .event_reserve
= ltt_event_reserve
,
305 .event_commit
= ltt_event_commit
,
306 .event_write
= ltt_event_write
,
307 .packet_avail_size
= ltt_packet_avail_size
,
308 //.get_reader_wait_queue = ltt_get_reader_wait_queue,
309 //.get_hp_wait_queue = ltt_get_hp_wait_queue,
310 .is_finalized
= ltt_is_finalized
,
311 .is_disabled
= ltt_is_disabled
,
312 .flush_buffer
= ltt_flush_buffer
,
316 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
318 DBG("LTT : ltt ring buffer client init\n");
319 ltt_transport_register(<t_relay_transport
);
322 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
324 DBG("LTT : ltt ring buffer client exit\n");
325 ltt_transport_unregister(<t_relay_transport
);