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 };
 115
 116 /*
 117  * Validate that the id has reached the maximum allowed or not.
 118  *
 119  * Return 0 if NOT else 1.
 120  */
 121 static inline int trace_ust_is_max_id(uint64_t id)
 122 {
 123         return (id == UINT64_MAX) ? 1 : 0;
 124 }
 125
 126 /*
 127  * Return next available channel id and increment the used counter. The
 128  * trace_ust_is_max_id function MUST be called before in order to validate if
 129  * the maximum number of IDs have been reached. If not, it is safe to call this
 130  * function.
 131  *
 132  * Return a unique channel ID. If max is reached, the used_channel_id counter
 133  * is returned.
 134  */
 135 static inline uint64_t trace_ust_get_next_chan_id(struct ltt_ust_session *s)
 136 {
 137         if (trace_ust_is_max_id(s->used_channel_id)) {
 138                 return s->used_channel_id;
 139         }
 140
 141         s->used_channel_id++;
 142         return s->next_channel_id++;
 143 }
 144
 145 #ifdef HAVE_LIBLTTNG_UST_CTL
 146
 147 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key);
 148 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 149                 const void *_key);
 150
 151 /*
 152  * Lookup functions. NULL is returned if not found.
 153  */
 154 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 155                 char *name, struct lttng_filter_bytecode *filter, int loglevel);
 156 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 157                 char *name);
 158
 159 /*
 160  * Create functions malloc() the data structure.
 161  */
 162 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id);
 163 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr);
 164 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 165                 struct lttng_filter_bytecode *filter);
 166 struct ltt_ust_metadata *trace_ust_create_metadata(char *path);
 167 struct ltt_ust_context *trace_ust_create_context(
 168                 struct lttng_event_context *ctx);
 169 void trace_ust_delete_channel(struct lttng_ht *ht,
 170                 struct ltt_ust_channel *channel);
 171
 172 /*
 173  * Destroy functions free() the data structure and remove from linked list if
 174  * it's applies.
 175  */
 176 void trace_ust_destroy_session(struct ltt_ust_session *session);
 177 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata);
 178 void trace_ust_destroy_channel(struct ltt_ust_channel *channel);
 179 void trace_ust_destroy_event(struct ltt_ust_event *event);
 180
 181 #else /* HAVE_LIBLTTNG_UST_CTL */
 182
 183 static inline int trace_ust_ht_match_event(struct cds_lfht_node *node,
 184                 const void *_key)
 185 {
 186         return 0;
 187 }
 188 static inline int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 189                 const void *_key)
 190 {
 191         return 0;
 192 }
 193 static inline
 194 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 195                 char *name)
 196 {
 197         return NULL;
 198 }
 199
 200 static inline
 201 struct ltt_ust_session *trace_ust_create_session(unsigned int session_id)
 202 {
 203         return NULL;
 204 }
 205 static inline
 206 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr)
 207 {
 208         return NULL;
 209 }
 210 static inline
 211 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 212                 struct lttng_filter_bytecode *filter)
 213 {
 214         return NULL;
 215 }
 216 static inline
 217 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 218 {
 219         return NULL;
 220 }
 221
 222 static inline
 223 void trace_ust_destroy_session(struct ltt_ust_session *session)
 224 {
 225 }
 226
 227 static inline
 228 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 229 {
 230 }
 231
 232 static inline
 233 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 234 {
 235 }
 236
 237 static inline
 238 void trace_ust_destroy_event(struct ltt_ust_event *event)
 239 {
 240 }
 241 static inline
 242 struct ltt_ust_context *trace_ust_create_context(
 243                 struct lttng_event_context *ctx)
 244 {
 245         return NULL;
 246 }
 247 static inline struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 248                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 249 {
 250         return NULL;
 251 }
 252 static inline
 253 void trace_ust_delete_channel(struct lttng_ht *ht,
 254                 struct ltt_ust_channel *channel)
 255 {
 256         return;
 257 }
 258
 259 #endif /* HAVE_LIBLTTNG_UST_CTL */
 260
 261 #endif /* _LTT_TRACE_UST_H */