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

   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
  11 #include <stdint.h>
  12 #include <lttng/ust-events.h>
  13 #include "lttng/bitfield.h"
  14 #include "ltt-tracer.h"
  15 #include "../libringbuffer/frontend_types.h"
  16
  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];
  29 };
  30
  31 struct metadata_record_header {
  32         uint8_t header_end[0];          /* End of header */
  33 };
  34
  35 static const struct lttng_ust_lib_ring_buffer_config client_config;
  36
  37 static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
  38 {
  39         return 0;
  40 }
  41
  42 static inline
  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)
  47 {
  48         return 0;
  49 }
  50
  51 #include "../libringbuffer/api.h"
  52
  53 static uint64_t client_ring_buffer_clock_read(struct channel *chan)
  54 {
  55         return 0;
  56 }
  57
  58 static
  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)
  63 {
  64         return 0;
  65 }
  66
  67 /**
  68  * client_packet_header_size - called on buffer-switch to a new sub-buffer
  69  *
  70  * Return header size without padding after the structure. Don't use packed
  71  * structure because gcc generates inefficient code on some architectures
  72  * (powerpc, mips..)
  73  */
  74 static size_t client_packet_header_size(void)
  75 {
  76         return offsetof(struct metadata_packet_header, header_end);
  77 }
  78
  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)
  82 {
  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,
  88                                 handle);
  89         struct ltt_channel *ltt_chan = channel_get_private(chan);
  90
  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;
 101
 102 }
 103
 104 /*
 105  * offset is assumed to never be 0 here : never deliver a completely empty
 106  * subbuffer. data_size is between 1 and subbuf_size.
 107  */
 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)
 111 {
 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,
 117                                 handle);
 118         unsigned long records_lost = 0;
 119
 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);
 126 }
 127
 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)
 131 {
 132         return 0;
 133 }
 134
 135 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf,
 136                                    void *priv, int cpu,
 137                                    struct lttng_ust_shm_handle *handle)
 138 {
 139 }
 140
 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,
 149
 150         .tsc_bits = 0,
 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,
 160 };
 161
 162 const struct lttng_ust_lib_ring_buffer_client_cb *LTTNG_CLIENT_CALLBACKS = &client_config.cb;
 163
 164 static
 165 struct ltt_channel *_channel_create(const char *name,
 166                                 void *buf_addr,
 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)
 173 {
 174         void *priv;
 175         struct ltt_channel *ltt_chan = NULL;
 176         struct lttng_ust_shm_handle *handle;
 177
 178         handle = channel_create(&client_config, name,
 179                         &priv, __alignof__(*ltt_chan), sizeof(*ltt_chan),
 180                         chan_priv_init,
 181                         buf_addr, subbuf_size, num_subbuf,
 182                         switch_timer_interval, read_timer_interval,
 183                         shm_fd, wait_fd, memory_map_size);
 184         if (!handle)
 185                 return NULL;
 186         ltt_chan = priv;
 187         ltt_chan->handle = handle;
 188         ltt_chan->chan = shmp(ltt_chan->handle, ltt_chan->handle->chan);
 189         return ltt_chan;
 190 }
 191
 192 static
 193 void ltt_channel_destroy(struct ltt_channel *ltt_chan)
 194 {
 195         channel_destroy(ltt_chan->chan, ltt_chan->handle, 0);
 196 }
 197
 198 static
 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)
 203 {
 204         struct lttng_ust_lib_ring_buffer *buf;
 205
 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))
 209                 return buf;
 210         return NULL;
 211 }
 212
 213 static
 214 void ltt_buffer_read_close(struct lttng_ust_lib_ring_buffer *buf,
 215                            struct lttng_ust_shm_handle *handle)
 216 {
 217         lib_ring_buffer_release_read(buf, handle, 0);
 218 }
 219
 220 static
 221 int ltt_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx, uint32_t event_id)
 222 {
 223         return lib_ring_buffer_reserve(&client_config, ctx);
 224 }
 225
 226 static
 227 void ltt_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
 228 {
 229         lib_ring_buffer_commit(&client_config, ctx);
 230 }
 231
 232 static
 233 void ltt_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 234                      size_t len)
 235 {
 236         lib_ring_buffer_write(&client_config, ctx, src, len);
 237 }
 238
 239 static
 240 size_t ltt_packet_avail_size(struct channel *chan, struct lttng_ust_shm_handle *handle)
 241
 242 {
 243         unsigned long o_begin;
 244         struct lttng_ust_lib_ring_buffer *buf;
 245
 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);
 250         } else {
 251                 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
 252                         - sizeof(struct metadata_packet_header);
 253         }
 254 }
 255
 256 #if 0
 257 static
 258 wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
 259 {
 260         return &chan->read_wait;
 261 }
 262
 263 static
 264 wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
 265 {
 266         return &chan->hp_wait;
 267 }
 268 #endif //0
 269
 270 static
 271 int ltt_is_finalized(struct channel *chan)
 272 {
 273         return lib_ring_buffer_channel_is_finalized(chan);
 274 }
 275
 276 static
 277 int ltt_is_disabled(struct channel *chan)
 278 {
 279         return lib_ring_buffer_channel_is_disabled(chan);
 280 }
 281
 282 static
 283 int ltt_flush_buffer(struct channel *chan, struct lttng_ust_shm_handle *handle)
 284 {
 285         struct lttng_ust_lib_ring_buffer *buf;
 286         int shm_fd, wait_fd;
 287         uint64_t memory_map_size;
 288
 289         buf = channel_get_ring_buffer(&client_config, chan,
 290                         0, handle, &shm_fd, &wait_fd,
 291                         &memory_map_size);
 292         lib_ring_buffer_switch(&client_config, buf,
 293                         SWITCH_ACTIVE, handle);
 294         return 0;
 295 }
 296
 297 static struct ltt_transport ltt_relay_transport = {
 298         .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
 299         .ops = {
 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,
 313         },
 314 };
 315
 316 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
 317 {
 318         DBG("LTT : ltt ring buffer client init\n");
 319         ltt_transport_register(&ltt_relay_transport);
 320 }
 321
 322 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
 323 {
 324         DBG("LTT : ltt ring buffer client exit\n");
 325         ltt_transport_unregister(&ltt_relay_transport);
 326 }