src/bin/lttng-sessiond/trace-ust.h

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #ifndef _LTT_TRACE_UST_H
  19 #define _LTT_TRACE_UST_H
  20
  21 #include <config.h>
  22 #include <limits.h>
  23 #include <urcu/list.h>
  24
  25 #include <lttng/lttng.h>
  26 #include <common/hashtable/hashtable.h>
  27 #include <common/defaults.h>
  28
  29 #include "consumer.h"
  30 #include "ust-ctl.h"
  31
  32 struct ltt_ust_ht_key {
  33         const char *name;
  34         const struct lttng_filter_bytecode *filter;
  35         enum lttng_ust_loglevel_type loglevel;
  36 };
  37
  38 /* Context hash table nodes */
  39 struct ltt_ust_context {
  40         struct lttng_ust_context ctx;
  41         struct lttng_ht_node_ulong node;
  42         struct cds_list_head list;
  43 };
  44
  45 /* UST event */
  46 struct ltt_ust_event {
  47         unsigned int enabled;
  48         struct lttng_ust_event attr;
  49         struct lttng_ht_node_str node;
  50         struct lttng_ust_filter_bytecode *filter;
  51 };
  52
  53 /* UST channel */
  54 struct ltt_ust_channel {
  55         uint64_t id;    /* unique id per session. */
  56         unsigned int enabled;
  57         char name[LTTNG_UST_SYM_NAME_LEN];
  58         struct lttng_ust_channel_attr attr;
  59         struct lttng_ht *ctx;
  60         struct cds_list_head ctx_list;
  61         struct lttng_ht *events;
  62         struct lttng_ht_node_str node;
  63         uint64_t tracefile_size;
  64         uint64_t tracefile_count;
  65 };
  66
  67 /* UST Metadata */
  68 struct ltt_ust_metadata {
  69         int handle;
  70         struct lttng_ust_object_data *obj;
  71         char pathname[PATH_MAX];              /* Trace file path name */
  72         struct lttng_ust_channel_attr attr;
  73         struct lttng_ust_object_data *stream_obj;
  74 };
  75
  76 /* UST domain global (LTTNG_DOMAIN_UST) */
  77 struct ltt_ust_domain_global {
  78         struct lttng_ht *channels;
  79         struct cds_list_head registry_buffer_uid_list;
  80 };
  81
  82 /* UST session */
  83 struct ltt_ust_session {
  84         uint64_t id;    /* Unique identifier of session */
  85         int start_trace;
  86         struct ltt_ust_domain_global domain_global;
  87         /* UID/GID of the user owning the session */
  88         uid_t uid;
  89         gid_t gid;
  90         /*
  91          * Two consumer_output object are needed where one is for the current
  92          * output object and the second one is the temporary object used to store
  93          * URI being set by the lttng_set_consumer_uri call. Once
  94          * lttng_enable_consumer is called, the two pointers are swapped.
  95          */
  96         struct consumer_output *consumer;
  97         struct consumer_output *tmp_consumer;
  98         /* Sequence number for filters so the tracer knows the ordering. */
  99         uint64_t filter_seq_num;
 100         /* This indicates which type of buffer this session is set for. */
 101         enum lttng_buffer_type buffer_type;
 102         /* If set to 1, the buffer_type can not be changed anymore. */
 103         int buffer_type_changed;
 104         /* For per UID buffer, every buffer reg object is kept of this session */
 105         struct cds_list_head buffer_reg_uid_list;
 106         /* Next channel ID available for a newly registered channel. */
 107         uint64_t next_channel_id;
 108         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
 109         uint64_t used_channel_id;
 110         /* Tell or not if the session has to output the traces. */
 111         unsigned int output_traces;
 112         unsigned int snapshot_mode;
 113         unsigned int has_non_default_channel;
 114         unsigned int live_timer_interval;       /* usec */
 115 };
 116
 117 /*
 118  * Validate that the id has reached the maximum allowed or not.
 119  *
 120  * Return 0 if NOT else 1.
 121  */
 122 static inline int trace_ust_is_max_id(uint64_t id)
 123 {
 124         return (id == UINT64_MAX) ? 1 : 0;
 125 }
 126
 127 /*
 128  * Return next available channel id and increment the used counter. The
 129  * trace_ust_is_max_id function MUST be called before in order to validate if
 130  * the maximum number of IDs have been reached. If not, it is safe to call this
 131  * function.
 132  *
 133  * Return a unique channel ID. If max is reached, the used_channel_id counter
 134  * is returned.
 135  */
 136 static inline uint64_t trace_ust_get_next_chan_id(struct ltt_ust_session *s)
 137 {
 138         if (trace_ust_is_max_id(s->used_channel_id)) {
 139                 return s->used_channel_id;
 140         }
 141
 142         s->used_channel_id++;
 143         return s->next_channel_id++;
 144 }
 145
 146 #ifdef HAVE_LIBLTTNG_UST_CTL
 147
 148 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key);
 149 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 150                 const void *_key);
 151
 152 /*
 153  * Lookup functions. NULL is returned if not found.
 154  */
 155 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 156                 char *name, struct lttng_filter_bytecode *filter, int loglevel);
 157 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 158                 char *name);
 159
 160 /*
 161  * Create functions malloc() the data structure.
 162  */
 163 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id);
 164 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr);
 165 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 166                 struct lttng_filter_bytecode *filter);
 167 struct ltt_ust_metadata *trace_ust_create_metadata(char *path);
 168 struct ltt_ust_context *trace_ust_create_context(
 169                 struct lttng_event_context *ctx);
 170 void trace_ust_delete_channel(struct lttng_ht *ht,
 171                 struct ltt_ust_channel *channel);
 172
 173 /*
 174  * Destroy functions free() the data structure and remove from linked list if
 175  * it's applies.
 176  */
 177 void trace_ust_destroy_session(struct ltt_ust_session *session);
 178 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata);
 179 void trace_ust_destroy_channel(struct ltt_ust_channel *channel);
 180 void trace_ust_destroy_event(struct ltt_ust_event *event);
 181
 182 #else /* HAVE_LIBLTTNG_UST_CTL */
 183
 184 static inline int trace_ust_ht_match_event(struct cds_lfht_node *node,
 185                 const void *_key)
 186 {
 187         return 0;
 188 }
 189 static inline int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 190                 const void *_key)
 191 {
 192         return 0;
 193 }
 194 static inline
 195 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 196                 char *name)
 197 {
 198         return NULL;
 199 }
 200
 201 static inline
 202 struct ltt_ust_session *trace_ust_create_session(unsigned int session_id)
 203 {
 204         return NULL;
 205 }
 206 static inline
 207 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr)
 208 {
 209         return NULL;
 210 }
 211 static inline
 212 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 213                 struct lttng_filter_bytecode *filter)
 214 {
 215         return NULL;
 216 }
 217 static inline
 218 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 219 {
 220         return NULL;
 221 }
 222
 223 static inline
 224 void trace_ust_destroy_session(struct ltt_ust_session *session)
 225 {
 226 }
 227
 228 static inline
 229 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 230 {
 231 }
 232
 233 static inline
 234 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 235 {
 236 }
 237
 238 static inline
 239 void trace_ust_destroy_event(struct ltt_ust_event *event)
 240 {
 241 }
 242 static inline
 243 struct ltt_ust_context *trace_ust_create_context(
 244                 struct lttng_event_context *ctx)
 245 {
 246         return NULL;
 247 }
 248 static inline struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 249                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 250 {
 251         return NULL;
 252 }
 253 static inline
 254 void trace_ust_delete_channel(struct lttng_ht *ht,
 255                 struct ltt_ust_channel *channel)
 256 {
 257         return;
 258 }
 259
 260 #endif /* HAVE_LIBLTTNG_UST_CTL */
 261
 262 #endif /* _LTT_TRACE_UST_H */