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         struct lttng_ust_channel_attr attr;
  58         struct lttng_ht *ctx;
  59         struct lttng_ht *events;
  60         struct lttng_ht_node_str node;
  61         uint64_t tracefile_size;
  62         uint64_t tracefile_count;
  63 };
  64
  65 /* UST Metadata */
  66 struct ltt_ust_metadata {
  67         int handle;
  68         struct lttng_ust_object_data *obj;
  69         char pathname[PATH_MAX];              /* Trace file path name */
  70         struct lttng_ust_channel_attr attr;
  71         struct lttng_ust_object_data *stream_obj;
  72 };
  73
  74 /* UST domain global (LTTNG_DOMAIN_UST) */
  75 struct ltt_ust_domain_global {
  76         struct lttng_ht *channels;
  77         struct cds_list_head registry_buffer_uid_list;
  78 };
  79
  80 /* UST session */
  81 struct ltt_ust_session {
  82         uint64_t id;    /* Unique identifier of session */
  83         int start_trace;
  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         /* Tell or not if the session has to output the traces. */
 109         unsigned int output_traces;
 110         unsigned int snapshot_mode;
 111 };
 112
 113 /*
 114  * Validate that the id has reached the maximum allowed or not.
 115  *
 116  * Return 0 if NOT else 1.
 117  */
 118 static inline int trace_ust_is_max_id(uint64_t id)
 119 {
 120         return (id == UINT64_MAX) ? 1 : 0;
 121 }
 122
 123 /*
 124  * Return next available channel id and increment the used counter. The
 125  * trace_ust_is_max_id function MUST be called before in order to validate if
 126  * the maximum number of IDs have been reached. If not, it is safe to call this
 127  * function.
 128  *
 129  * Return a unique channel ID. If max is reached, the used_channel_id counter
 130  * is returned.
 131  */
 132 static inline uint64_t trace_ust_get_next_chan_id(struct ltt_ust_session *s)
 133 {
 134         if (trace_ust_is_max_id(s->used_channel_id)) {
 135                 return s->used_channel_id;
 136         }
 137
 138         s->used_channel_id++;
 139         return s->next_channel_id++;
 140 }
 141
 142 #ifdef HAVE_LIBLTTNG_UST_CTL
 143
 144 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key);
 145 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 146                 const void *_key);
 147
 148 /*
 149  * Lookup functions. NULL is returned if not found.
 150  */
 151 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 152                 char *name, struct lttng_filter_bytecode *filter, int loglevel);
 153 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 154                 char *name);
 155
 156 /*
 157  * Create functions malloc() the data structure.
 158  */
 159 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id);
 160 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *attr);
 161 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 162                 struct lttng_filter_bytecode *filter);
 163 struct ltt_ust_metadata *trace_ust_create_metadata(char *path);
 164 struct ltt_ust_context *trace_ust_create_context(
 165                 struct lttng_event_context *ctx);
 166 void trace_ust_delete_channel(struct lttng_ht *ht,
 167                 struct ltt_ust_channel *channel);
 168
 169 /*
 170  * Destroy functions free() the data structure and remove from linked list if
 171  * it's applies.
 172  */
 173 void trace_ust_destroy_session(struct ltt_ust_session *session);
 174 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata);
 175 void trace_ust_destroy_channel(struct ltt_ust_channel *channel);
 176 void trace_ust_destroy_event(struct ltt_ust_event *event);
 177
 178 #else /* HAVE_LIBLTTNG_UST_CTL */
 179
 180 static inline int trace_ust_ht_match_event(struct cds_lfht_node *node,
 181                 const void *_key)
 182 {
 183         return 0;
 184 }
 185 static inline int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
 186                 const void *_key)
 187 {
 188         return 0;
 189 }
 190 static inline
 191 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 192                 char *name)
 193 {
 194         return NULL;
 195 }
 196
 197 static inline
 198 struct ltt_ust_session *trace_ust_create_session(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 {
 205         return NULL;
 206 }
 207 static inline
 208 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 209                 struct lttng_filter_bytecode *filter)
 210 {
 211         return NULL;
 212 }
 213 static inline
 214 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 215 {
 216         return NULL;
 217 }
 218
 219 static inline
 220 void trace_ust_destroy_session(struct ltt_ust_session *session)
 221 {
 222 }
 223
 224 static inline
 225 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 226 {
 227 }
 228
 229 static inline
 230 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 231 {
 232 }
 233
 234 static inline
 235 void trace_ust_destroy_event(struct ltt_ust_event *event)
 236 {
 237 }
 238 static inline
 239 struct ltt_ust_context *trace_ust_create_context(
 240                 struct lttng_event_context *ctx)
 241 {
 242         return NULL;
 243 }
 244 static inline struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 245                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 246 {
 247         return NULL;
 248 }
 249 static inline
 250 void trace_ust_delete_channel(struct lttng_ht *ht,
 251                 struct ltt_ust_channel *channel)
 252 {
 253         return;
 254 }
 255
 256 #endif /* HAVE_LIBLTTNG_UST_CTL */
 257
 258 #endif /* _LTT_TRACE_UST_H */