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 };
  43
  44 /* UST event */
  45 struct ltt_ust_event {
  46         unsigned int enabled;
  47         struct lttng_ust_event attr;
  48         struct lttng_ht_node_str node;
  49         struct lttng_ust_filter_bytecode *filter;
  50 };
  51
  52 /* UST channel */
  53 struct ltt_ust_channel {
  54         uint64_t id;    /* unique id per session. */
  55         unsigned int enabled;
  56         char name[LTTNG_UST_SYM_NAME_LEN];
  57         char pathname[PATH_MAX];
  58         struct lttng_ust_channel_attr attr;
  59         struct lttng_ht *ctx;
  60         struct lttng_ht *events;
  61         struct lttng_ht_node_str node;
  62 };
  63
  64 /* UST Metadata */
  65 struct ltt_ust_metadata {
  66         int handle;
  67         struct lttng_ust_object_data *obj;
  68         char pathname[PATH_MAX];              /* Trace file path name */
  69         struct lttng_ust_channel_attr attr;
  70         struct lttng_ust_object_data *stream_obj;
  71 };
  72
  73 /* UST domain global (LTTNG_DOMAIN_UST) */
  74 struct ltt_ust_domain_global {
  75         struct lttng_ht *channels;
  76         struct cds_list_head registry_buffer_uid_list;
  77 };
  78
  79 /* UST session */
  80 struct ltt_ust_session {
  81         int id;    /* Unique identifier of session */
  82         int start_trace;
  83         char pathname[PATH_MAX];
  84         struct ltt_ust_domain_global domain_global;
  85         /* UID/GID of the user owning the session */
  86         uid_t uid;
  87         gid_t gid;
  88         /*
  89          * Two consumer_output object are needed where one is for the current
  90          * output object and the second one is the temporary object used to store
  91          * URI being set by the lttng_set_consumer_uri call. Once
  92          * lttng_enable_consumer is called, the two pointers are swapped.
  93          */
  94         struct consumer_output *consumer;
  95         struct consumer_output *tmp_consumer;
  96         /* Sequence number for filters so the tracer knows the ordering. */
  97         uint64_t filter_seq_num;
  98         /* This indicates which type of buffer this session is set for. */
  99         enum lttng_buffer_type buffer_type;
 100         /* If set to 1, the buffer_type can not be changed anymore. */
 101         int buffer_type_changed;
 102         /* For per UID buffer, every buffer reg object is kept of this session */
 103         struct cds_list_head buffer_reg_uid_list;
 104         /* Next channel ID available for a newly registered channel. */
 105         uint64_t next_channel_id;
 106         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
 107         uint64_t used_channel_id;
 108 };
 109
 110 /*
 111  * Validate that the id has reached the maximum allowed or not.
 112  *
 113  * Return 0 if NOT else 1.
 114  */
 115 static inline int trace_ust_is_max_id(uint64_t id)
 116 {
 117         return (id == UINT64_MAX) ? 1 : 0;
 118 }
 119
 120 /*
 121  * Return next available channel id and increment the used counter. The
 122  * trace_ust_is_max_id function MUST be called before in order to validate if
 123  * the maximum number of IDs have been reached. If not, it is safe to call this
 124  * function.
 125  *
 126  * Return a unique channel ID. If max is reached, the used_channel_id counter
 127  * is returned.
 128  */
 129 static inline uint64_t trace_ust_get_next_chan_id(struct ltt_ust_session *s)
 130 {
 131         if (trace_ust_is_max_id(s->used_channel_id)) {
 132                 return s->used_channel_id;
 133         }
 134
 135         s->used_channel_id++;
 136         return s->next_channel_id++;
 137 }
 138
 139 #ifdef HAVE_LIBLTTNG_UST_CTL
 140
 141 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key);
 142 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 143                 const void *_key);
 144
 145 /*
 146  * Lookup functions. NULL is returned if not found.
 147  */
 148 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 149                 char *name, struct lttng_filter_bytecode *filter, int loglevel);
 150 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 151                 char *name);
 152
 153 /*
 154  * Create functions malloc() the data structure.
 155  */
 156 struct ltt_ust_session *trace_ust_create_session(char *path,
 157                 unsigned int session_id);
 158 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr,
 159                 char *path);
 160 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 161                 struct lttng_filter_bytecode *filter);
 162 struct ltt_ust_metadata *trace_ust_create_metadata(char *path);
 163 struct ltt_ust_context *trace_ust_create_context(
 164                 struct lttng_event_context *ctx);
 165
 166 /*
 167  * Destroy functions free() the data structure and remove from linked list if
 168  * it's applies.
 169  */
 170 void trace_ust_destroy_session(struct ltt_ust_session *session);
 171 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata);
 172 void trace_ust_destroy_channel(struct ltt_ust_channel *channel);
 173 void trace_ust_destroy_event(struct ltt_ust_event *event);
 174
 175 #else /* HAVE_LIBLTTNG_UST_CTL */
 176
 177 static inline int trace_ust_ht_match_event(struct cds_lfht_node *node,
 178                 const void *_key)
 179 {
 180         return 0;
 181 }
 182 static inline int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 183                 const void *_key)
 184 {
 185         return 0;
 186 }
 187 static inline
 188 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 189                 char *name)
 190 {
 191         return NULL;
 192 }
 193
 194 static inline
 195 struct ltt_ust_session *trace_ust_create_session(char *path,
 196                 unsigned int session_id)
 197 {
 198         return NULL;
 199 }
 200 static inline
 201 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr,
 202                 char *path)
 203 {
 204         return NULL;
 205 }
 206 static inline
 207 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 208                 struct lttng_filter_bytecode *filter)
 209 {
 210         return NULL;
 211 }
 212 static inline
 213 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 214 {
 215         return NULL;
 216 }
 217
 218 static inline
 219 void trace_ust_destroy_session(struct ltt_ust_session *session)
 220 {
 221 }
 222
 223 static inline
 224 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 225 {
 226 }
 227
 228 static inline
 229 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 230 {
 231 }
 232
 233 static inline
 234 void trace_ust_destroy_event(struct ltt_ust_event *event)
 235 {
 236 }
 237 static inline
 238 struct ltt_ust_context *trace_ust_create_context(
 239                 struct lttng_event_context *ctx)
 240 {
 241         return NULL;
 242 }
 243 static inline struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 244                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 245 {
 246         return NULL;
 247 }
 248
 249 #endif /* HAVE_LIBLTTNG_UST_CTL */
 250
 251 #endif /* _LTT_TRACE_UST_H */