liblttng-ust/lttng-ring-buffer-metadata-client.h

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * LTTng lib ring buffer client template.
   7  */
   8
   9 #include <stddef.h>
  10 #include <stdint.h>
  11
  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"
  17
  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];
  30 };
  31
  32 struct metadata_record_header {
  33         uint8_t header_end[0];          /* End of header */
  34 };
  35
  36 static const struct lttng_ust_lib_ring_buffer_config client_config;
  37
  38 static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
  39 {
  40         return 0;
  41 }
  42
  43 static inline
  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,
  48                                  void *client_ctx)
  49 {
  50         return 0;
  51 }
  52
  53 #include "../libringbuffer/api.h"
  54 #include "lttng-rb-clients.h"
  55
  56 static uint64_t client_ring_buffer_clock_read(struct channel *chan)
  57 {
  58         return 0;
  59 }
  60
  61 static
  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,
  66                                  void *client_ctx)
  67 {
  68         return 0;
  69 }
  70
  71 /**
  72  * client_packet_header_size - called on buffer-switch to a new sub-buffer
  73  *
  74  * Return header size without padding after the structure. Don't use packed
  75  * structure because gcc generates inefficient code on some architectures
  76  * (powerpc, mips..)
  77  */
  78 static size_t client_packet_header_size(void)
  79 {
  80         return offsetof(struct metadata_packet_header, header_end);
  81 }
  82
  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)
  86 {
  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,
  92                                 handle);
  93         struct lttng_channel *lttng_chan = channel_get_private(chan);
  94
  95         assert(header);
  96         if (!header)
  97                 return;
  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;
 108 }
 109
 110 /*
 111  * offset is assumed to never be 0 here : never deliver a completely empty
 112  * subbuffer. data_size is between 1 and subbuf_size.
 113  */
 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)
 117 {
 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,
 123                                 handle);
 124         unsigned long records_lost = 0;
 125
 126         assert(header);
 127         if (!header)
 128                 return;
 129         header->content_size = data_size * CHAR_BIT;            /* in bits */
 130         header->packet_size = LTTNG_UST_PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
 131         /*
 132          * We do not care about the records lost count, because the metadata
 133          * channel waits and retry.
 134          */
 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);
 139 }
 140
 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)
 144 {
 145         return 0;
 146 }
 147
 148 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf,
 149                                    void *priv, int cpu,
 150                                    struct lttng_ust_shm_handle *handle)
 151 {
 152 }
 153
 154 static const
 155 struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
 156         .parent = {
 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,
 164         },
 165 };
 166
 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,
 175
 176         .tsc_bits = 0,
 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,
 186
 187          .cb_ptr = &client_cb.parent,
 188 };
 189
 190 static
 191 struct lttng_channel *_channel_create(const char *name,
 192                                 void *buf_addr,
 193                                 size_t subbuf_size, size_t num_subbuf,
 194                                 unsigned int switch_timer_interval,
 195                                 unsigned int read_timer_interval,
 196                                 unsigned char *uuid,
 197                                 uint32_t chan_id,
 198                                 const int *stream_fds, int nr_stream_fds,
 199                                 int64_t blocking_timeout)
 200 {
 201         struct lttng_channel chan_priv_init;
 202         struct lttng_ust_shm_handle *handle;
 203         struct lttng_channel *lttng_chan;
 204         void *priv;
 205
 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),
 212                         &chan_priv_init,
 213                         buf_addr, subbuf_size, num_subbuf,
 214                         switch_timer_interval, read_timer_interval,
 215                         stream_fds, nr_stream_fds, blocking_timeout);
 216         if (!handle)
 217                 return NULL;
 218         lttng_chan = priv;
 219         lttng_chan->handle = handle;
 220         lttng_chan->chan = shmp(handle, handle->chan);
 221         return lttng_chan;
 222 }
 223
 224 static
 225 void lttng_channel_destroy(struct lttng_channel *chan)
 226 {
 227         channel_destroy(chan->chan, chan->handle, 1);
 228 }
 229
 230 static
 231 int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx, uint32_t event_id)
 232 {
 233         int ret;
 234
 235         ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
 236         if (ret)
 237                 return ret;
 238         if (lib_ring_buffer_backend_get_pages(&client_config, ctx,
 239                         &ctx->backend_pages))
 240                 return -EPERM;
 241         return 0;
 242 }
 243
 244 static
 245 void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
 246 {
 247         lib_ring_buffer_commit(&client_config, ctx);
 248 }
 249
 250 static
 251 void lttng_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 252                      size_t len)
 253 {
 254         lib_ring_buffer_write(&client_config, ctx, src, len);
 255 }
 256
 257 static
 258 size_t lttng_packet_avail_size(struct channel *chan, struct lttng_ust_shm_handle *handle)
 259 {
 260         unsigned long o_begin;
 261         struct lttng_ust_lib_ring_buffer *buf;
 262
 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);
 267         } else {
 268                 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
 269                         - sizeof(struct metadata_packet_header);
 270         }
 271 }
 272
 273 #if 0
 274 static
 275 wait_queue_head_t *lttng_get_reader_wait_queue(struct channel *chan)
 276 {
 277         return &chan->read_wait;
 278 }
 279
 280 static
 281 wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
 282 {
 283         return &chan->hp_wait;
 284 }
 285 #endif //0
 286
 287 static
 288 int lttng_is_finalized(struct channel *chan)
 289 {
 290         return lib_ring_buffer_channel_is_finalized(chan);
 291 }
 292
 293 static
 294 int lttng_is_disabled(struct channel *chan)
 295 {
 296         return lib_ring_buffer_channel_is_disabled(chan);
 297 }
 298
 299 static
 300 int lttng_flush_buffer(struct channel *chan, struct lttng_ust_shm_handle *handle)
 301 {
 302         struct lttng_ust_lib_ring_buffer *buf;
 303         int shm_fd, wait_fd, wakeup_fd;
 304         uint64_t memory_map_size;
 305
 306         buf = channel_get_ring_buffer(&client_config, chan,
 307                         0, handle, &shm_fd, &wait_fd, &wakeup_fd,
 308                         &memory_map_size);
 309         lib_ring_buffer_switch(&client_config, buf,
 310                         SWITCH_ACTIVE, handle);
 311         return 0;
 312 }
 313
 314 static struct lttng_transport lttng_relay_transport = {
 315         .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
 316         .ops = {
 317                 .struct_size = sizeof(struct lttng_ust_channel_ops),
 318
 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,
 328         },
 329         .client_config = &client_config,
 330 };
 331
 332 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
 333 {
 334         DBG("LTT : ltt ring buffer client \"%s\" init\n",
 335                 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
 336         lttng_transport_register(&lttng_relay_transport);
 337 }
 338
 339 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
 340 {
 341         DBG("LTT : ltt ring buffer client \"%s\" exit\n",
 342                 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
 343         lttng_transport_unregister(&lttng_relay_transport);
 344 }