Add missing error handling
[lttng-ust.git] / libust / ltt-ring-buffer-metadata-client.h
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1/*
2 * ltt-ring-buffer-client.h
3 *
4 * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 *
6 * LTTng lib ring buffer client template.
7 *
8 * Dual LGPL v2.1/GPL v2 license.
9 */
10
9f3fdbc6 11#include <stdint.h>
f4681817 12#include <ust/lttng-events.h>
9f3fdbc6 13#include "ust/bitfield.h"
3d1fc7fd 14#include "ltt-tracer.h"
9f3fdbc6 15#include "../libringbuffer/frontend_types.h"
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16
17struct 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 header_end[0];
27};
28
29struct metadata_record_header {
30 uint8_t header_end[0]; /* End of header */
31};
32
33static const struct lib_ring_buffer_config client_config;
34
35static inline
36u64 lib_ring_buffer_clock_read(struct channel *chan)
37{
38 return 0;
39}
40
41static inline
42unsigned char record_header_size(const struct lib_ring_buffer_config *config,
43 struct channel *chan, size_t offset,
44 size_t *pre_header_padding,
45 struct lib_ring_buffer_ctx *ctx)
46{
47 return 0;
48}
49
9f3fdbc6 50#include "../libringbuffer/api.h"
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51
52static u64 client_ring_buffer_clock_read(struct channel *chan)
53{
54 return 0;
55}
56
57static
58size_t client_record_header_size(const struct lib_ring_buffer_config *config,
59 struct channel *chan, size_t offset,
60 size_t *pre_header_padding,
61 struct lib_ring_buffer_ctx *ctx)
62{
63 return 0;
64}
65
66/**
67 * client_packet_header_size - called on buffer-switch to a new sub-buffer
68 *
69 * Return header size without padding after the structure. Don't use packed
70 * structure because gcc generates inefficient code on some architectures
71 * (powerpc, mips..)
72 */
73static size_t client_packet_header_size(void)
74{
75 return offsetof(struct metadata_packet_header, header_end);
76}
77
78static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
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79 unsigned int subbuf_idx,
80 struct shm_handle *handle)
3d1fc7fd 81{
1d498196 82 struct channel *chan = shmp(handle, buf->backend.chan);
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83 struct metadata_packet_header *header =
84 (struct metadata_packet_header *)
85 lib_ring_buffer_offset_address(&buf->backend,
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86 subbuf_idx * chan->backend.subbuf_size,
87 handle);
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88 struct ltt_channel *ltt_chan = channel_get_private(chan);
89 struct ltt_session *session = ltt_chan->session;
90
91 header->magic = TSDL_MAGIC_NUMBER;
9f3fdbc6 92 memcpy(header->uuid, session->uuid, sizeof(session->uuid));
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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}
100
101/*
102 * offset is assumed to never be 0 here : never deliver a completely empty
103 * subbuffer. data_size is between 1 and subbuf_size.
104 */
105static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
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106 unsigned int subbuf_idx, unsigned long data_size,
107 struct shm_handle *handle)
3d1fc7fd 108{
1d498196 109 struct channel *chan = shmp(handle, buf->backend.chan);
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110 struct metadata_packet_header *header =
111 (struct metadata_packet_header *)
112 lib_ring_buffer_offset_address(&buf->backend,
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113 subbuf_idx * chan->backend.subbuf_size,
114 handle);
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115 unsigned long records_lost = 0;
116
117 header->content_size = data_size * CHAR_BIT; /* in bits */
118 header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
119 records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
120 records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
121 records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
122 WARN_ON_ONCE(records_lost != 0);
123}
124
125static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
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126 int cpu, const char *name,
127 struct shm_handle *handle)
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128{
129 return 0;
130}
131
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132static void client_buffer_finalize(struct lib_ring_buffer *buf,
133 void *priv, int cpu,
134 struct shm_handle *handle)
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135{
136}
137
138static const struct lib_ring_buffer_config client_config = {
139 .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
140 .cb.record_header_size = client_record_header_size,
141 .cb.subbuffer_header_size = client_packet_header_size,
142 .cb.buffer_begin = client_buffer_begin,
143 .cb.buffer_end = client_buffer_end,
144 .cb.buffer_create = client_buffer_create,
145 .cb.buffer_finalize = client_buffer_finalize,
146
147 .tsc_bits = 0,
148 .alloc = RING_BUFFER_ALLOC_GLOBAL,
149 .sync = RING_BUFFER_SYNC_GLOBAL,
150 .mode = RING_BUFFER_MODE_TEMPLATE,
151 .backend = RING_BUFFER_PAGE,
5d61a504 152 .output = RING_BUFFER_MMAP,
3d1fc7fd 153 .oops = RING_BUFFER_OOPS_CONSISTENCY,
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154 .ipi = RING_BUFFER_NO_IPI_BARRIER,
155 .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
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156};
157
158static
1d498196 159struct ltt_channel *_channel_create(const char *name,
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160 struct ltt_channel *ltt_chan, void *buf_addr,
161 size_t subbuf_size, size_t num_subbuf,
162 unsigned int switch_timer_interval,
8d8a24c8 163 unsigned int read_timer_interval)
3d1fc7fd 164{
1d498196 165 ltt_chan->handle = channel_create(&client_config, name, ltt_chan, buf_addr,
3d1fc7fd 166 subbuf_size, num_subbuf, switch_timer_interval,
8d8a24c8 167 read_timer_interval);
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168 ltt_chan->chan = shmp(handle, handle->chan);
169 return ltt_chan;
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170}
171
172static
1d498196 173void ltt_channel_destroy(struct ltt_channel *ltt_chan)
3d1fc7fd 174{
1d498196 175 channel_destroy(ltt_chan->chan, ltt_chan->handle);
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176}
177
178static
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179struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan,
180 struct shm_handle *handle)
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181{
182 struct lib_ring_buffer *buf;
183
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184 buf = channel_get_ring_buffer(&client_config, chan, 0, handle);
185 if (!lib_ring_buffer_open_read(buf, handle))
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186 return buf;
187 return NULL;
188}
189
190static
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191void ltt_buffer_read_close(struct lib_ring_buffer *buf,
192 struct shm_handle *handle)
3d1fc7fd 193{
1d498196 194 lib_ring_buffer_release_read(buf, handle);
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195}
196
197static
198int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
199{
200 return lib_ring_buffer_reserve(&client_config, ctx);
201}
202
203static
204void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
205{
206 lib_ring_buffer_commit(&client_config, ctx);
207}
208
209static
210void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
211 size_t len)
212{
213 lib_ring_buffer_write(&client_config, ctx, src, len);
214}
215
216static
1d498196 217size_t ltt_packet_avail_size(struct channel *chan, struct shm_handle *handle)
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218
219{
220 unsigned long o_begin;
221 struct lib_ring_buffer *buf;
222
1d498196 223 buf = shmp(handle, chan->backend.buf[0].shmp); /* Only for global buffer ! */
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224 o_begin = v_read(&client_config, &buf->offset);
225 if (subbuf_offset(o_begin, chan) != 0) {
226 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
227 } else {
228 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
229 - sizeof(struct metadata_packet_header);
230 }
231}
232
9f3fdbc6 233#if 0
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234static
235wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
236{
237 return &chan->read_wait;
238}
239
240static
241wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
242{
243 return &chan->hp_wait;
244}
9f3fdbc6 245#endif //0
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246
247static
248int ltt_is_finalized(struct channel *chan)
249{
250 return lib_ring_buffer_channel_is_finalized(chan);
251}
252
253static
254int ltt_is_disabled(struct channel *chan)
255{
256 return lib_ring_buffer_channel_is_disabled(chan);
257}
258
259static struct ltt_transport ltt_relay_transport = {
818173b9 260 .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
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261 .ops = {
262 .channel_create = _channel_create,
263 .channel_destroy = ltt_channel_destroy,
264 .buffer_read_open = ltt_buffer_read_open,
265 .buffer_read_close = ltt_buffer_read_close,
266 .event_reserve = ltt_event_reserve,
267 .event_commit = ltt_event_commit,
268 .event_write = ltt_event_write,
269 .packet_avail_size = ltt_packet_avail_size,
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270 //.get_reader_wait_queue = ltt_get_reader_wait_queue,
271 //.get_hp_wait_queue = ltt_get_hp_wait_queue,
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272 .is_finalized = ltt_is_finalized,
273 .is_disabled = ltt_is_disabled,
274 },
275};
276
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277static
278void __attribute__((constructor)) ltt_ring_buffer_client_init(void)
3d1fc7fd 279{
18c1cd87 280 DBG("LTT : ltt ring buffer client init\n");
3d1fc7fd 281 ltt_transport_register(&ltt_relay_transport);
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282}
283
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284static
285void __attribute__((destructor)) ltt_ring_buffer_client_exit(void)
3d1fc7fd 286{
18c1cd87 287 DBG("LTT : ltt ring buffer client exit\n");
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288 ltt_transport_unregister(&ltt_relay_transport);
289}
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