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
  38 u64 lib_ring_buffer_clock_read(struct channel *chan)
  39 {
  40         return 0;
  41 }
  42
  43 static inline
  44 unsigned char 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 {
  49         return 0;
  50 }
  51
  52 #include "../libringbuffer/api.h"
  53
  54 static u64 client_ring_buffer_clock_read(struct channel *chan)
  55 {
  56         return 0;
  57 }
  58
  59 static
  60 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
  61                                  struct channel *chan, size_t offset,
  62                                  size_t *pre_header_padding,
  63                                  struct lttng_ust_lib_ring_buffer_ctx *ctx)
  64 {
  65         return 0;
  66 }
  67
  68 /**
  69  * client_packet_header_size - called on buffer-switch to a new sub-buffer
  70  *
  71  * Return header size without padding after the structure. Don't use packed
  72  * structure because gcc generates inefficient code on some architectures
  73  * (powerpc, mips..)
  74  */
  75 static size_t client_packet_header_size(void)
  76 {
  77         return offsetof(struct metadata_packet_header, header_end);
  78 }
  79
  80 static void client_buffer_begin(struct lttng_ust_lib_ring_buffer *buf, u64 tsc,
  81                                 unsigned int subbuf_idx,
  82                                 struct lttng_ust_shm_handle *handle)
  83 {
  84         struct channel *chan = shmp(handle, buf->backend.chan);
  85         struct metadata_packet_header *header =
  86                 (struct metadata_packet_header *)
  87                         lib_ring_buffer_offset_address(&buf->backend,
  88                                 subbuf_idx * chan->backend.subbuf_size,
  89                                 handle);
  90         struct ltt_channel *ltt_chan = channel_get_private(chan);
  91         struct ltt_session *session = ltt_chan->session;
  92
  93         header->magic = TSDL_MAGIC_NUMBER;
  94         memcpy(header->uuid, session->uuid, sizeof(session->uuid));
  95         header->checksum = 0;           /* 0 if unused */
  96         header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
  97         header->packet_size = 0xFFFFFFFF;  /* in bits, for debugging */
  98         header->compression_scheme = 0; /* 0 if unused */
  99         header->encryption_scheme = 0;  /* 0 if unused */
 100         header->checksum_scheme = 0;    /* 0 if unused */
 101         header->major = CTF_SPEC_MAJOR;
 102         header->minor = CTF_SPEC_MINOR;
 103
 104 }
 105
 106 /*
 107  * offset is assumed to never be 0 here : never deliver a completely empty
 108  * subbuffer. data_size is between 1 and subbuf_size.
 109  */
 110 static void client_buffer_end(struct lttng_ust_lib_ring_buffer *buf, u64 tsc,
 111                               unsigned int subbuf_idx, unsigned long data_size,
 112                               struct lttng_ust_shm_handle *handle)
 113 {
 114         struct channel *chan = shmp(handle, buf->backend.chan);
 115         struct metadata_packet_header *header =
 116                 (struct metadata_packet_header *)
 117                         lib_ring_buffer_offset_address(&buf->backend,
 118                                 subbuf_idx * chan->backend.subbuf_size,
 119                                 handle);
 120         unsigned long records_lost = 0;
 121
 122         header->content_size = data_size * CHAR_BIT;            /* in bits */
 123         header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
 124         records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
 125         records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
 126         records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
 127         WARN_ON_ONCE(records_lost != 0);
 128 }
 129
 130 static int client_buffer_create(struct lttng_ust_lib_ring_buffer *buf, void *priv,
 131                                 int cpu, const char *name,
 132                                 struct lttng_ust_shm_handle *handle)
 133 {
 134         return 0;
 135 }
 136
 137 static void client_buffer_finalize(struct lttng_ust_lib_ring_buffer *buf,
 138                                    void *priv, int cpu,
 139                                    struct lttng_ust_shm_handle *handle)
 140 {
 141 }
 142
 143 static const struct lttng_ust_lib_ring_buffer_config client_config = {
 144         .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
 145         .cb.record_header_size = client_record_header_size,
 146         .cb.subbuffer_header_size = client_packet_header_size,
 147         .cb.buffer_begin = client_buffer_begin,
 148         .cb.buffer_end = client_buffer_end,
 149         .cb.buffer_create = client_buffer_create,
 150         .cb.buffer_finalize = client_buffer_finalize,
 151
 152         .tsc_bits = 0,
 153         .alloc = RING_BUFFER_ALLOC_GLOBAL,
 154         .sync = RING_BUFFER_SYNC_GLOBAL,
 155         .mode = RING_BUFFER_MODE_TEMPLATE,
 156         .backend = RING_BUFFER_PAGE,
 157         .output = RING_BUFFER_MMAP,
 158         .oops = RING_BUFFER_OOPS_CONSISTENCY,
 159         .ipi = RING_BUFFER_NO_IPI_BARRIER,
 160         .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
 161         .client_type = LTTNG_CLIENT_TYPE,
 162 };
 163
 164 const struct lttng_ust_lib_ring_buffer_config *LTTNG_CLIENT_CALLBACKS = &client_config;
 165
 166 static
 167 struct ltt_channel *_channel_create(const char *name,
 168                                 struct ltt_channel *ltt_chan, void *buf_addr,
 169                                 size_t subbuf_size, size_t num_subbuf,
 170                                 unsigned int switch_timer_interval,
 171                                 unsigned int read_timer_interval,
 172                                 int *shm_fd, int *wait_fd,
 173                                 uint64_t *memory_map_size)
 174 {
 175         ltt_chan->handle = channel_create(&client_config, name, ltt_chan, buf_addr,
 176                               subbuf_size, num_subbuf, switch_timer_interval,
 177                               read_timer_interval, shm_fd, wait_fd,
 178                               memory_map_size);
 179         if (!ltt_chan->handle)
 180                 return NULL;
 181         ltt_chan->chan = shmp(ltt_chan->handle, ltt_chan->handle->chan);
 182         return ltt_chan;
 183 }
 184
 185 static
 186 void ltt_channel_destroy(struct ltt_channel *ltt_chan)
 187 {
 188         channel_destroy(ltt_chan->chan, ltt_chan->handle, 0);
 189 }
 190
 191 static
 192 struct lttng_ust_lib_ring_buffer *ltt_buffer_read_open(struct channel *chan,
 193                                              struct lttng_ust_shm_handle *handle,
 194                                              int *shm_fd, int *wait_fd,
 195                                              uint64_t *memory_map_size)
 196 {
 197         struct lttng_ust_lib_ring_buffer *buf;
 198
 199         buf = channel_get_ring_buffer(&client_config, chan,
 200                         0, handle, shm_fd, wait_fd, memory_map_size);
 201         if (!lib_ring_buffer_open_read(buf, handle, 0))
 202                 return buf;
 203         return NULL;
 204 }
 205
 206 static
 207 void ltt_buffer_read_close(struct lttng_ust_lib_ring_buffer *buf,
 208                            struct lttng_ust_shm_handle *handle)
 209 {
 210         lib_ring_buffer_release_read(buf, handle, 0);
 211 }
 212
 213 static
 214 int ltt_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx, uint32_t event_id)
 215 {
 216         return lib_ring_buffer_reserve(&client_config, ctx);
 217 }
 218
 219 static
 220 void ltt_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
 221 {
 222         lib_ring_buffer_commit(&client_config, ctx);
 223 }
 224
 225 static
 226 void ltt_event_write(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 227                      size_t len)
 228 {
 229         lib_ring_buffer_write(&client_config, ctx, src, len);
 230 }
 231
 232 static
 233 size_t ltt_packet_avail_size(struct channel *chan, struct lttng_ust_shm_handle *handle)
 234
 235 {
 236         unsigned long o_begin;
 237         struct lttng_ust_lib_ring_buffer *buf;
 238
 239         buf = shmp(handle, chan->backend.buf[0].shmp);  /* Only for global buffer ! */
 240         o_begin = v_read(&client_config, &buf->offset);
 241         if (subbuf_offset(o_begin, chan) != 0) {
 242                 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
 243         } else {
 244                 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
 245                         - sizeof(struct metadata_packet_header);
 246         }
 247 }
 248
 249 #if 0
 250 static
 251 wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
 252 {
 253         return &chan->read_wait;
 254 }
 255
 256 static
 257 wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
 258 {
 259         return &chan->hp_wait;
 260 }
 261 #endif //0
 262
 263 static
 264 int ltt_is_finalized(struct channel *chan)
 265 {
 266         return lib_ring_buffer_channel_is_finalized(chan);
 267 }
 268
 269 static
 270 int ltt_is_disabled(struct channel *chan)
 271 {
 272         return lib_ring_buffer_channel_is_disabled(chan);
 273 }
 274
 275 static
 276 int ltt_flush_buffer(struct channel *chan, struct lttng_ust_shm_handle *handle)
 277 {
 278         struct lttng_ust_lib_ring_buffer *buf;
 279         int shm_fd, wait_fd;
 280         uint64_t memory_map_size;
 281
 282         buf = channel_get_ring_buffer(&client_config, chan,
 283                         0, handle, &shm_fd, &wait_fd,
 284                         &memory_map_size);
 285         lib_ring_buffer_switch(&client_config, buf,
 286                         SWITCH_ACTIVE, handle);
 287         return 0;
 288 }
 289
 290 static struct ltt_transport ltt_relay_transport = {
 291         .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
 292         .ops = {
 293                 .channel_create = _channel_create,
 294                 .channel_destroy = ltt_channel_destroy,
 295                 .buffer_read_open = ltt_buffer_read_open,
 296                 .buffer_read_close = ltt_buffer_read_close,
 297                 .event_reserve = ltt_event_reserve,
 298                 .event_commit = ltt_event_commit,
 299                 .event_write = ltt_event_write,
 300                 .packet_avail_size = ltt_packet_avail_size,
 301                 //.get_reader_wait_queue = ltt_get_reader_wait_queue,
 302                 //.get_hp_wait_queue = ltt_get_hp_wait_queue,
 303                 .is_finalized = ltt_is_finalized,
 304                 .is_disabled = ltt_is_disabled,
 305                 .flush_buffer = ltt_flush_buffer,
 306         },
 307 };
 308
 309 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
 310 {
 311         DBG("LTT : ltt ring buffer client init\n");
 312         ltt_transport_register(&ltt_relay_transport);
 313 }
 314
 315 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
 316 {
 317         DBG("LTT : ltt ring buffer client exit\n");
 318         ltt_transport_unregister(&ltt_relay_transport);
 319 }