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 "jul.h"
  31 #include "ust-ctl.h"
  32
  33 struct ltt_ust_ht_key {
  34         const char *name;
  35         const struct lttng_filter_bytecode *filter;
  36         enum lttng_ust_loglevel_type loglevel;
  37 };
  38
  39 /* Context hash table nodes */
  40 struct ltt_ust_context {
  41         struct lttng_ust_context ctx;
  42         struct lttng_ht_node_ulong node;
  43         struct cds_list_head list;
  44 };
  45
  46 /* UST event */
  47 struct ltt_ust_event {
  48         unsigned int enabled;
  49         struct lttng_ust_event attr;
  50         struct lttng_ht_node_str node;
  51         struct lttng_ust_filter_bytecode *filter;
  52 };
  53
  54 /* UST channel */
  55 struct ltt_ust_channel {
  56         uint64_t id;    /* unique id per session. */
  57         unsigned int enabled;
  58         char name[LTTNG_UST_SYM_NAME_LEN];
  59         struct lttng_ust_channel_attr attr;
  60         struct lttng_ht *ctx;
  61         struct cds_list_head ctx_list;
  62         struct lttng_ht *events;
  63         struct lttng_ht_node_str node;
  64         uint64_t tracefile_size;
  65         uint64_t tracefile_count;
  66 };
  67
  68 /* UST Metadata */
  69 struct ltt_ust_metadata {
  70         int handle;
  71         struct lttng_ust_object_data *obj;
  72         char pathname[PATH_MAX];              /* Trace file path name */
  73         struct lttng_ust_channel_attr attr;
  74         struct lttng_ust_object_data *stream_obj;
  75 };
  76
  77 /* UST domain global (LTTNG_DOMAIN_UST) */
  78 struct ltt_ust_domain_global {
  79         struct lttng_ht *channels;
  80         struct cds_list_head registry_buffer_uid_list;
  81 };
  82
  83 /* UST session */
  84 struct ltt_ust_session {
  85         uint64_t id;    /* Unique identifier of session */
  86         int start_trace;
  87         struct ltt_ust_domain_global domain_global;
  88         struct jul_domain domain_jul;
  89         /* UID/GID of the user owning the session */
  90         uid_t uid;
  91         gid_t gid;
  92         /*
  93          * Two consumer_output object are needed where one is for the current
  94          * output object and the second one is the temporary object used to store
  95          * URI being set by the lttng_set_consumer_uri call. Once
  96          * lttng_enable_consumer is called, the two pointers are swapped.
  97          */
  98         struct consumer_output *consumer;
  99         struct consumer_output *tmp_consumer;
 100         /* Sequence number for filters so the tracer knows the ordering. */
 101         uint64_t filter_seq_num;
 102         /* This indicates which type of buffer this session is set for. */
 103         enum lttng_buffer_type buffer_type;
 104         /* If set to 1, the buffer_type can not be changed anymore. */
 105         int buffer_type_changed;
 106         /* For per UID buffer, every buffer reg object is kept of this session */
 107         struct cds_list_head buffer_reg_uid_list;
 108         /* Next channel ID available for a newly registered channel. */
 109         uint64_t next_channel_id;
 110         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
 111         uint64_t used_channel_id;
 112         /* Tell or not if the session has to output the traces. */
 113         unsigned int output_traces;
 114         unsigned int snapshot_mode;
 115         unsigned int has_non_default_channel;
 116         unsigned int live_timer_interval;       /* usec */
 117 };
 118
 119 /*
 120  * Validate that the id has reached the maximum allowed or not.
 121  *
 122  * Return 0 if NOT else 1.
 123  */
 124 static inline int trace_ust_is_max_id(uint64_t id)
 125 {
 126         return (id == UINT64_MAX) ? 1 : 0;
 127 }
 128
 129 /*
 130  * Return next available channel id and increment the used counter. The
 131  * trace_ust_is_max_id function MUST be called before in order to validate if
 132  * the maximum number of IDs have been reached. If not, it is safe to call this
 133  * function.
 134  *
 135  * Return a unique channel ID. If max is reached, the used_channel_id counter
 136  * is returned.
 137  */
 138 static inline uint64_t trace_ust_get_next_chan_id(struct ltt_ust_session *s)
 139 {
 140         if (trace_ust_is_max_id(s->used_channel_id)) {
 141                 return s->used_channel_id;
 142         }
 143
 144         s->used_channel_id++;
 145         return s->next_channel_id++;
 146 }
 147
 148 #ifdef HAVE_LIBLTTNG_UST_CTL
 149
 150 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key);
 151 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 152                 const void *_key);
 153
 154 /*
 155  * Lookup functions. NULL is returned if not found.
 156  */
 157 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 158                 char *name, struct lttng_filter_bytecode *filter, int loglevel);
 159 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 160                 char *name);
 161
 162 /*
 163  * Create functions malloc() the data structure.
 164  */
 165 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id);
 166 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr);
 167 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 168                 struct lttng_filter_bytecode *filter);
 169 struct ltt_ust_metadata *trace_ust_create_metadata(char *path);
 170 struct ltt_ust_context *trace_ust_create_context(
 171                 struct lttng_event_context *ctx);
 172 void trace_ust_delete_channel(struct lttng_ht *ht,
 173                 struct ltt_ust_channel *channel);
 174
 175 /*
 176  * Destroy functions free() the data structure and remove from linked list if
 177  * it's applies.
 178  */
 179 void trace_ust_destroy_session(struct ltt_ust_session *session);
 180 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata);
 181 void trace_ust_destroy_channel(struct ltt_ust_channel *channel);
 182 void trace_ust_destroy_event(struct ltt_ust_event *event);
 183
 184 #else /* HAVE_LIBLTTNG_UST_CTL */
 185
 186 static inline int trace_ust_ht_match_event(struct cds_lfht_node *node,
 187                 const void *_key)
 188 {
 189         return 0;
 190 }
 191 static inline int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 192                 const void *_key)
 193 {
 194         return 0;
 195 }
 196 static inline
 197 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 198                 char *name)
 199 {
 200         return NULL;
 201 }
 202
 203 static inline
 204 struct ltt_ust_session *trace_ust_create_session(unsigned int session_id)
 205 {
 206         return NULL;
 207 }
 208 static inline
 209 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr)
 210 {
 211         return NULL;
 212 }
 213 static inline
 214 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 215                 struct lttng_filter_bytecode *filter)
 216 {
 217         return NULL;
 218 }
 219 static inline
 220 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 221 {
 222         return NULL;
 223 }
 224
 225 static inline
 226 void trace_ust_destroy_session(struct ltt_ust_session *session)
 227 {
 228 }
 229
 230 static inline
 231 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 232 {
 233 }
 234
 235 static inline
 236 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 237 {
 238 }
 239
 240 static inline
 241 void trace_ust_destroy_event(struct ltt_ust_event *event)
 242 {
 243 }
 244 static inline
 245 struct ltt_ust_context *trace_ust_create_context(
 246                 struct lttng_event_context *ctx)
 247 {
 248         return NULL;
 249 }
 250 static inline struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 251                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 252 {
 253         return NULL;
 254 }
 255 static inline
 256 void trace_ust_delete_channel(struct lttng_ht *ht,
 257                 struct ltt_ust_channel *channel)
 258 {
 259         return;
 260 }
 261
 262 #endif /* HAVE_LIBLTTNG_UST_CTL */
 263
 264 #endif /* _LTT_TRACE_UST_H */