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

   1 /*
   2  * ltt-ring-buffer-client.h
   3  *
   4  * LTTng lib ring buffer client template.
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <stdint.h>
  24 #include <lttng/ust-events.h>
  25 #include "lttng/bitfield.h"
  26 #include "ltt-tracer.h"
  27 #include "../libringbuffer/frontend_types.h"
  28
  29 struct metadata_packet_header {
  30         uint32_t magic;                 /* 0x75D11D57 */
  31         uint8_t  uuid[16];              /* Unique Universal Identifier */
  32         uint32_t checksum;              /* 0 if unused */
  33         uint32_t content_size;          /* in bits */
  34         uint32_t packet_size;           /* in bits */
  35         uint8_t  compression_scheme;    /* 0 if unused */
  36         uint8_t  encryption_scheme;     /* 0 if unused */
  37         uint8_t  checksum_scheme;       /* 0 if unused */
  38         uint8_t  major;                 /* CTF spec major version number */
  39         uint8_t  minor;                 /* CTF spec minor version number */
  40         uint8_t  header_end[0];
  41 };
  42
  43 struct metadata_record_header {
  44         uint8_t header_end[0];          /* End of header */
  45 };
  46
  47 static const struct lttng_ust_lib_ring_buffer_config client_config;
  48
  49 static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
  50 {
  51         return 0;
  52 }
  53
  54 static inline
  55 unsigned char record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
  56                                  struct channel *chan, size_t offset,
  57                                  size_t *pre_header_padding,
  58                                  struct lttng_ust_lib_ring_buffer_ctx *ctx)
  59 {
  60         return 0;
  61 }
  62
  63 #include "../libringbuffer/api.h"
  64
  65 static uint64_t client_ring_buffer_clock_read(struct channel *chan)
  66 {
  67         return 0;
  68 }
  69
  70 static
  71 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
  72                                  struct channel *chan, size_t offset,
  73                                  size_t *pre_header_padding,
  74                                  struct lttng_ust_lib_ring_buffer_ctx *ctx)
  75 {
  76         return 0;
  77 }
  78
  79 /**
  80  * client_packet_header_size - called on buffer-switch to a new sub-buffer
  81  *
  82  * Return header size without padding after the structure. Don't use packed
  83  * structure because gcc generates inefficient code on some architectures
  84  * (powerpc, mips..)
  85  */
  86 static size_t client_packet_header_size(void)
  87 {
  88         return offsetof(struct metadata_packet_header, header_end);
  89 }
  90
  91 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
  92                                 unsigned int subbuf_idx,
  93                                 struct lttng_ust_shm_handle *handle)
  94 {
  95         struct channel *chan = shmp(handle, buf->backend.chan);
  96         struct metadata_packet_header *header =
  97                 (struct metadata_packet_header *)
  98                         lib_ring_buffer_offset_address(&buf->backend,
  99                                 subbuf_idx * chan->backend.subbuf_size,
 100                                 handle);
 101         struct ltt_channel *ltt_chan = channel_get_private(chan);
 102
 103         header->magic = TSDL_MAGIC_NUMBER;
 104         memcpy(header->uuid, ltt_chan->uuid, sizeof(ltt_chan->uuid));
 105         header->checksum = 0;           /* 0 if unused */
 106         header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
 107         header->packet_size = 0xFFFFFFFF;  /* in bits, for debugging */
 108         header->compression_scheme = 0; /* 0 if unused */
 109         header->encryption_scheme = 0;  /* 0 if unused */
 110         header->checksum_scheme = 0;    /* 0 if unused */
 111         header->major = CTF_SPEC_MAJOR;
 112         header->minor = CTF_SPEC_MINOR;
 113
 114 }
 115
 116 /*
 117  * offset is assumed to never be 0 here : never deliver a completely empty
 118  * subbuffer. data_size is between 1 and subbuf_size.
 119  */
 120 static void client_buffer_end(struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
 121                               unsigned int subbuf_idx, unsigned long data_size,
 122                               struct lttng_ust_shm_handle *handle)
 123 {
 124         struct channel *chan = shmp(handle, buf->backend.chan);
 125         struct metadata_packet_header *header =
 126                 (struct metadata_packet_header *)
 127                         lib_ring_buffer_offset_address(&buf->backend,
 128                                 subbuf_idx * chan->backend.subbuf_size,
 129                                 handle);
 130         unsigned long records_lost = 0;
 131
 132         header->content_size = data_size * CHAR_BIT;            /* in bits */
 133         header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
 134         records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
 135         records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
 136         records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
 137         WARN_ON_ONCE(records_lost != 0);
 138 }
 139
 140 static int client_buffer_create(struct lttng_ust_lib_ring_buffer *buf, void *priv,
 141                                 int cpu, const char *name,
 142                                 struct lttng_ust_shm_handle *handle)
 143 {
 144         return 0;
 145 }
 146
 147 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf,
 148                                    void *priv, int cpu,
 149                                    struct lttng_ust_shm_handle *handle)
 150 {
 151 }
 152
 153 static const struct lttng_ust_lib_ring_buffer_config client_config = {
 154         .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
 155         .cb.record_header_size = client_record_header_size,
 156         .cb.subbuffer_header_size = client_packet_header_size,
 157         .cb.buffer_begin = client_buffer_begin,
 158         .cb.buffer_end = client_buffer_end,
 159         .cb.buffer_create = client_buffer_create,
 160         .cb.buffer_finalize = client_buffer_finalize,
 161
 162         .tsc_bits = 0,
 163         .alloc = RING_BUFFER_ALLOC_GLOBAL,
 164         .sync = RING_BUFFER_SYNC_GLOBAL,
 165         .mode = RING_BUFFER_MODE_TEMPLATE,
 166         .backend = RING_BUFFER_PAGE,
 167         .output = RING_BUFFER_MMAP,
 168         .oops = RING_BUFFER_OOPS_CONSISTENCY,
 169         .ipi = RING_BUFFER_NO_IPI_BARRIER,
 170         .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
 171         .client_type = LTTNG_CLIENT_TYPE,
 172 };
 173
 174 const struct lttng_ust_lib_ring_buffer_client_cb *LTTNG_CLIENT_CALLBACKS = &client_config.cb;
 175
 176 static
 177 struct ltt_channel *_channel_create(const char *name,
 178                                 void *buf_addr,
 179                                 size_t subbuf_size, size_t num_subbuf,
 180                                 unsigned int switch_timer_interval,
 181                                 unsigned int read_timer_interval,
 182                                 int **shm_fd, int **wait_fd,
 183                                 uint64_t **memory_map_size,
 184                                 struct ltt_channel *chan_priv_init)
 185 {
 186         void *priv;
 187         struct ltt_channel *ltt_chan = NULL;
 188         struct lttng_ust_shm_handle *handle;
 189
 190         handle = channel_create(&client_config, name,
 191                         &priv, __alignof__(*ltt_chan), sizeof(*ltt_chan),
 192                         chan_priv_init,
 193                         buf_addr, subbuf_size, num_subbuf,
 194                         switch_timer_interval, read_timer_interval,
 195                         shm_fd, wait_fd, memory_map_size);
 196         if (!handle)
 197                 return NULL;
 198         ltt_chan = priv;
 199         ltt_chan->handle = handle;
 200         ltt_chan->chan = shmp(ltt_chan->handle, ltt_chan->handle->chan);
 201         return ltt_chan;
 202 }
 203
 204 static
 205 void ltt_channel_destroy(struct ltt_channel *ltt_chan)
 206 {
 207         channel_destroy(ltt_chan->chan, ltt_chan->handle, 0);
 208 }
 209
 210 static
 211 struct lttng_ust_lib_ring_buffer *ltt_buffer_read_open(struct channel *chan,
 212                                              struct lttng_ust_shm_handle *handle,
 213                                              int **shm_fd, int **wait_fd,
 214                                              uint64_t **memory_map_size)
 215 {
 216         struct lttng_ust_lib_ring_buffer *buf;
 217
 218         buf = channel_get_ring_buffer(&client_config, chan,
 219                         0, handle, shm_fd, wait_fd, memory_map_size);
 220         if (!lib_ring_buffer_open_read(buf, handle, 0))
 221                 return buf;
 222         return NULL;
 223 }
 224
 225 static
 226 void ltt_buffer_read_close(struct lttng_ust_lib_ring_buffer *buf,
 227                            struct lttng_ust_shm_handle *handle)
 228 {
 229         lib_ring_buffer_release_read(buf, handle, 0);
 230 }
 231
 232 static
 233 int ltt_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx, uint32_t event_id)
 234 {
 235         return lib_ring_buffer_reserve(&client_config, ctx);
 236 }
 237
 238 static
 239 void ltt_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
 240 {
 241         lib_ring_buffer_commit(&client_config, ctx);
 242 }
 243
 244 static
 245 void ltt_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 246                      size_t len)
 247 {
 248         lib_ring_buffer_write(&client_config, ctx, src, len);
 249 }
 250
 251 static
 252 size_t ltt_packet_avail_size(struct channel *chan, struct lttng_ust_shm_handle *handle)
 253
 254 {
 255         unsigned long o_begin;
 256         struct lttng_ust_lib_ring_buffer *buf;
 257
 258         buf = shmp(handle, chan->backend.buf[0].shmp);  /* Only for global buffer ! */
 259         o_begin = v_read(&client_config, &buf->offset);
 260         if (subbuf_offset(o_begin, chan) != 0) {
 261                 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
 262         } else {
 263                 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
 264                         - sizeof(struct metadata_packet_header);
 265         }
 266 }
 267
 268 #if 0
 269 static
 270 wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
 271 {
 272         return &chan->read_wait;
 273 }
 274
 275 static
 276 wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
 277 {
 278         return &chan->hp_wait;
 279 }
 280 #endif //0
 281
 282 static
 283 int ltt_is_finalized(struct channel *chan)
 284 {
 285         return lib_ring_buffer_channel_is_finalized(chan);
 286 }
 287
 288 static
 289 int ltt_is_disabled(struct channel *chan)
 290 {
 291         return lib_ring_buffer_channel_is_disabled(chan);
 292 }
 293
 294 static
 295 int ltt_flush_buffer(struct channel *chan, struct lttng_ust_shm_handle *handle)
 296 {
 297         struct lttng_ust_lib_ring_buffer *buf;
 298         int *shm_fd, *wait_fd;
 299         uint64_t *memory_map_size;
 300
 301         buf = channel_get_ring_buffer(&client_config, chan,
 302                         0, handle, &shm_fd, &wait_fd,
 303                         &memory_map_size);
 304         lib_ring_buffer_switch(&client_config, buf,
 305                         SWITCH_ACTIVE, handle);
 306         return 0;
 307 }
 308
 309 static struct ltt_transport ltt_relay_transport = {
 310         .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
 311         .ops = {
 312                 .channel_create = _channel_create,
 313                 .channel_destroy = ltt_channel_destroy,
 314                 .buffer_read_open = ltt_buffer_read_open,
 315                 .buffer_read_close = ltt_buffer_read_close,
 316                 .event_reserve = ltt_event_reserve,
 317                 .event_commit = ltt_event_commit,
 318                 .event_write = ltt_event_write,
 319                 .packet_avail_size = ltt_packet_avail_size,
 320                 //.get_reader_wait_queue = ltt_get_reader_wait_queue,
 321                 //.get_hp_wait_queue = ltt_get_hp_wait_queue,
 322                 .is_finalized = ltt_is_finalized,
 323                 .is_disabled = ltt_is_disabled,
 324                 .flush_buffer = ltt_flush_buffer,
 325         },
 326 };
 327
 328 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
 329 {
 330         DBG("LTT : ltt ring buffer client init\n");
 331         ltt_transport_register(&ltt_relay_transport);
 332 }
 333
 334 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
 335 {
 336         DBG("LTT : ltt ring buffer client exit\n");
 337         ltt_transport_unregister(&ltt_relay_transport);
 338 }