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         uint64_t tracefile_size;
  63         uint64_t tracefile_count;
  64 };
  65
  66 /* UST Metadata */
  67 struct ltt_ust_metadata {
  68         int handle;
  69         struct lttng_ust_object_data *obj;
  70         char pathname[PATH_MAX];              /* Trace file path name */
  71         struct lttng_ust_channel_attr attr;
  72         struct lttng_ust_object_data *stream_obj;
  73 };
  74
  75 /* UST domain global (LTTNG_DOMAIN_UST) */
  76 struct ltt_ust_domain_global {
  77         struct lttng_ht *channels;
  78         struct cds_list_head registry_buffer_uid_list;
  79 };
  80
  81 /* UST session */
  82 struct ltt_ust_session {
  83         int id;    /* Unique identifier of session */
  84         int start_trace;
  85         char pathname[PATH_MAX];
  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 };
 111
 112 /*
 113  * Validate that the id has reached the maximum allowed or not.
 114  *
 115  * Return 0 if NOT else 1.
 116  */
 117 static inline int trace_ust_is_max_id(uint64_t id)
 118 {
 119         return (id == UINT64_MAX) ? 1 : 0;
 120 }
 121
 122 /*
 123  * Return next available channel id and increment the used counter. The
 124  * trace_ust_is_max_id function MUST be called before in order to validate if
 125  * the maximum number of IDs have been reached. If not, it is safe to call this
 126  * function.
 127  *
 128  * Return a unique channel ID. If max is reached, the used_channel_id counter
 129  * is returned.
 130  */
 131 static inline uint64_t trace_ust_get_next_chan_id(struct ltt_ust_session *s)
 132 {
 133         if (trace_ust_is_max_id(s->used_channel_id)) {
 134                 return s->used_channel_id;
 135         }
 136
 137         s->used_channel_id++;
 138         return s->next_channel_id++;
 139 }
 140
 141 #ifdef HAVE_LIBLTTNG_UST_CTL
 142
 143 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key);
 144 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 145                 const void *_key);
 146
 147 /*
 148  * Lookup functions. NULL is returned if not found.
 149  */
 150 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 151                 char *name, struct lttng_filter_bytecode *filter, int loglevel);
 152 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 153                 char *name);
 154
 155 /*
 156  * Create functions malloc() the data structure.
 157  */
 158 struct ltt_ust_session *trace_ust_create_session(char *path,
 159                 unsigned int session_id);
 160 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr,
 161                 char *path);
 162 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 163                 struct lttng_filter_bytecode *filter);
 164 struct ltt_ust_metadata *trace_ust_create_metadata(char *path);
 165 struct ltt_ust_context *trace_ust_create_context(
 166                 struct lttng_event_context *ctx);
 167
 168 /*
 169  * Destroy functions free() the data structure and remove from linked list if
 170  * it's applies.
 171  */
 172 void trace_ust_destroy_session(struct ltt_ust_session *session);
 173 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata);
 174 void trace_ust_destroy_channel(struct ltt_ust_channel *channel);
 175 void trace_ust_destroy_event(struct ltt_ust_event *event);
 176
 177 #else /* HAVE_LIBLTTNG_UST_CTL */
 178
 179 static inline int trace_ust_ht_match_event(struct cds_lfht_node *node,
 180                 const void *_key)
 181 {
 182         return 0;
 183 }
 184 static inline int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 185                 const void *_key)
 186 {
 187         return 0;
 188 }
 189 static inline
 190 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 191                 char *name)
 192 {
 193         return NULL;
 194 }
 195
 196 static inline
 197 struct ltt_ust_session *trace_ust_create_session(char *path,
 198                 unsigned int session_id)
 199 {
 200         return NULL;
 201 }
 202 static inline
 203 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr,
 204                 char *path)
 205 {
 206         return NULL;
 207 }
 208 static inline
 209 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 210                 struct lttng_filter_bytecode *filter)
 211 {
 212         return NULL;
 213 }
 214 static inline
 215 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 216 {
 217         return NULL;
 218 }
 219
 220 static inline
 221 void trace_ust_destroy_session(struct ltt_ust_session *session)
 222 {
 223 }
 224
 225 static inline
 226 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 227 {
 228 }
 229
 230 static inline
 231 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 232 {
 233 }
 234
 235 static inline
 236 void trace_ust_destroy_event(struct ltt_ust_event *event)
 237 {
 238 }
 239 static inline
 240 struct ltt_ust_context *trace_ust_create_context(
 241                 struct lttng_event_context *ctx)
 242 {
 243         return NULL;
 244 }
 245 static inline struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 246                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 247 {
 248         return NULL;
 249 }
 250
 251 #endif /* HAVE_LIBLTTNG_UST_CTL */
 252
 253 #endif /* _LTT_TRACE_UST_H */