ltt-sessiond/trace.c

   1 /*
   2  * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <urcu/list.h>
  25
  26 #include "ltt-sessiond.h"
  27 #include "trace.h"
  28
  29 /*
  30  *  trace_create_kernel_session
  31  *
  32  *  Allocate and initialize a kernel session data structure.
  33  *
  34  *  Return pointer to structure or NULL.
  35  */
  36 struct ltt_kernel_session *trace_create_kernel_session(void)
  37 {
  38         struct ltt_kernel_session *lks;
  39
  40         /* Allocate a new ltt kernel session */
  41         lks = malloc(sizeof(struct ltt_kernel_session));
  42         if (lks == NULL) {
  43                 perror("create kernel session malloc");
  44                 goto error;
  45         }
  46
  47         /* Init data structure */
  48         lks->fd = 0;
  49         lks->metadata_stream_fd = 0;
  50         lks->channel_count = 0;
  51         lks->stream_count_global = 0;
  52         lks->metadata = NULL;
  53         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
  54
  55         return lks;
  56
  57 error:
  58         return NULL;
  59 }
  60
  61 /*
  62  *  trace_create_kernel_channel
  63  *
  64  *  Allocate and initialize a kernel channel data structure.
  65  *
  66  *  Return pointer to structure or NULL.
  67  */
  68 struct ltt_kernel_channel *trace_create_kernel_channel(void)
  69 {
  70         int ret;
  71         struct ltt_kernel_channel *lkc;
  72         struct lttng_kernel_channel *chan;
  73
  74         lkc = malloc(sizeof(struct ltt_kernel_channel));
  75         chan = malloc(sizeof(struct lttng_kernel_channel));
  76         if (lkc == NULL || chan == NULL) {
  77                 perror("kernel channel malloc");
  78                 goto error;
  79         }
  80
  81         /* Default value to channel */
  82         chan->overwrite = DEFAULT_KERNEL_OVERWRITE;
  83         chan->subbuf_size = DEFAULT_KERNEL_SUBBUF_SIZE;
  84         chan->num_subbuf = DEFAULT_KERNEL_SUBBUF_NUM;
  85         chan->switch_timer_interval = DEFAULT_KERNEL_SWITCH_TIMER;
  86         chan->read_timer_interval = DEFAULT_KERNEL_READ_TIMER;
  87
  88         lkc->fd = 0;
  89         lkc->stream_count = 0;
  90         lkc->channel = chan;
  91         /* Init linked list */
  92         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
  93         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
  94         /* Set default trace output path */
  95         ret = asprintf(&lkc->pathname, "%s", DEFAULT_TRACE_OUTPUT);
  96         if (ret < 0) {
  97                 perror("asprintf kernel create channel");
  98                 goto error;
  99         }
 100
 101         return lkc;
 102
 103 error:
 104         return NULL;
 105 }
 106
 107 /*
 108  *  trace_create_kernel_event
 109  *
 110  *  Allocate and initialize a kernel event. Set name and event type.
 111  *
 112  *  Return pointer to structure or NULL.
 113  */
 114 struct ltt_kernel_event *trace_create_kernel_event(char *name,
 115                 enum lttng_kernel_instrumentation type)
 116 {
 117         struct ltt_kernel_event *lke;
 118         struct lttng_kernel_event *attr;
 119
 120         lke = malloc(sizeof(struct ltt_kernel_event));
 121         attr = malloc(sizeof(struct lttng_kernel_event));
 122         if (lke == NULL || attr == NULL) {
 123                 perror("kernel event malloc");
 124                 goto error;
 125         }
 126
 127         /* Init event attribute */
 128         attr->instrumentation = type;
 129         strncpy(attr->name, name, LTTNG_SYM_NAME_LEN);
 130         /* Setting up a kernel event */
 131         lke->fd = 0;
 132         lke->event = attr;
 133
 134         return lke;
 135
 136 error:
 137         return NULL;
 138 }
 139
 140 /*
 141  *  trace_create_kernel_metadata
 142  *
 143  *  Allocate and initialize a kernel metadata.
 144  *
 145  *  Return pointer to structure or NULL.
 146  */
 147 struct ltt_kernel_metadata *trace_create_kernel_metadata(void)
 148 {
 149         int ret;
 150         struct ltt_kernel_metadata *lkm;
 151         struct lttng_kernel_channel *attr;
 152
 153         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 154         attr = malloc(sizeof(struct lttng_kernel_channel));
 155         if (lkm == NULL || attr == NULL) {
 156                 perror("kernel metadata malloc");
 157                 goto error;
 158         }
 159
 160         /* Set default attributes */
 161         attr->overwrite = DEFAULT_KERNEL_OVERWRITE;
 162         attr->subbuf_size = DEFAULT_KERNEL_SUBBUF_SIZE;
 163         attr->num_subbuf = DEFAULT_KERNEL_SUBBUF_NUM;
 164         attr->switch_timer_interval = DEFAULT_KERNEL_SWITCH_TIMER;
 165         attr->read_timer_interval = DEFAULT_KERNEL_READ_TIMER;
 166
 167         /* Init metadata */
 168         lkm->fd = 0;
 169         lkm->conf = attr;
 170         /* Set default metadata path */
 171         ret = asprintf(&lkm->pathname, "%s/metadata", DEFAULT_TRACE_OUTPUT);
 172         if (ret < 0) {
 173                 perror("asprintf kernel metadata");
 174                 goto error;
 175         }
 176
 177         return lkm;
 178
 179 error:
 180         return NULL;
 181 }
 182
 183 /*
 184  *  trace_create_kernel_stream
 185  *
 186  *  Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 187  *  default.
 188  *
 189  *  Return pointer to structure or NULL.
 190  */
 191 struct ltt_kernel_stream *trace_create_kernel_stream(void)
 192 {
 193         struct ltt_kernel_stream *lks;
 194
 195         lks = malloc(sizeof(struct ltt_kernel_stream));
 196         if (lks == NULL) {
 197                 perror("kernel stream malloc");
 198                 goto error;
 199         }
 200
 201         /* Init stream */
 202         lks->fd = 0;
 203         lks->pathname = NULL;
 204         lks->state = 0;
 205
 206         return lks;
 207
 208 error:
 209         return NULL;
 210 }
 211
 212 void trace_destroy_kernel_stream(struct ltt_kernel_stream *stream)
 213 {
 214         /* Close kernel fd */
 215         close(stream->fd);
 216         free(stream->pathname);
 217
 218         /* Remove from stream list */
 219         cds_list_del(&stream->list);
 220         free(stream);
 221 }
 222
 223 void trace_destroy_kernel_event(struct ltt_kernel_event *event)
 224 {
 225         /* Close kernel fd */
 226         close(event->fd);
 227         /* Free attributes */
 228         free(event->event);
 229
 230         /* Remove from event list */
 231         cds_list_del(&event->list);
 232         free(event);
 233 }
 234
 235 void trace_destroy_kernel_channel(struct ltt_kernel_channel *channel)
 236 {
 237         struct ltt_kernel_stream *stream;
 238         struct ltt_kernel_event *event;
 239
 240         /* Close kernel fd */
 241         close(channel->fd);
 242         free(channel->pathname);
 243         /* Free attributes structure */
 244         free(channel->channel);
 245
 246         /* For each stream in the channel list */
 247         cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
 248                 trace_destroy_kernel_stream(stream);
 249         }
 250
 251         /* For each event in the channel list */
 252         cds_list_for_each_entry(event, &channel->events_list.head, list) {
 253                 trace_destroy_kernel_event(event);
 254         }
 255
 256         /* Remove from channel list */
 257         cds_list_del(&channel->list);
 258         free(channel);
 259 }
 260
 261 void trace_destroy_kernel_metadata(struct ltt_kernel_metadata *metadata)
 262 {
 263         /* Close kernel fd */
 264         close(metadata->fd);
 265         /* Free attributes */
 266         free(metadata->conf);
 267
 268         free(metadata);
 269 }
 270
 271 void trace_destroy_kernel_session(struct ltt_kernel_session *session)
 272 {
 273         struct ltt_kernel_channel *channel;
 274
 275         /* Close kernel fds */
 276         close(session->fd);
 277         close(session->metadata_stream_fd);
 278
 279         trace_destroy_kernel_metadata(session->metadata);
 280
 281         cds_list_for_each_entry(channel, &session->channel_list.head, list) {
 282                 trace_destroy_kernel_channel(channel);
 283         }
 284
 285         free(session);
 286 }