src/bin/lttng/commands/destroy.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 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 #define _LGPL_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <stdbool.h>
  27
  28 #include "../command.h"
  29
  30 #include <common/mi-lttng.h>
  31 #include <common/sessiond-comm/sessiond-comm.h>
  32 #include <common/utils.h>
  33
  34 static char *opt_session_name;
  35 static int opt_destroy_all;
  36 static int opt_no_wait;
  37
  38 /* Mi writer */
  39 static struct mi_writer *writer;
  40
  41 enum {
  42         OPT_HELP = 1,
  43         OPT_LIST_OPTIONS,
  44 };
  45
  46 static struct poptOption long_options[] = {
  47         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  48         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  49         {"all",       'a', POPT_ARG_VAL, &opt_destroy_all, 1, 0, 0},
  50         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  51         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  52         {0, 0, 0, 0, 0, 0, 0}
  53 };
  54
  55 /*
  56  * destroy_session
  57  *
  58  * Unregister the provided session to the session daemon. On success, removes
  59  * the default configuration.
  60  */
  61 static int destroy_session(struct lttng_session *session)
  62 {
  63         int ret;
  64         char *session_name = NULL;
  65         bool session_was_stopped;
  66
  67         ret = lttng_stop_tracing_no_wait(session->name);
  68         if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
  69                 ERR("%s", lttng_strerror(ret));
  70         }
  71         session_was_stopped = ret == -LTTNG_ERR_TRACE_ALREADY_STOPPED;
  72         if (!opt_no_wait) {
  73                 _MSG("Waiting for data availability");
  74                 fflush(stdout);
  75                 do {
  76                         ret = lttng_data_pending(session->name);
  77                         if (ret < 0) {
  78                                 /* Return the data available call error. */
  79                                 goto error;
  80                         }
  81
  82                         /*
  83                          * Data sleep time before retrying (in usec). Don't sleep if the call
  84                          * returned value indicates availability.
  85                          */
  86                         if (ret) {
  87                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
  88                                 _MSG(".");
  89                                 fflush(stdout);
  90                         }
  91                 } while (ret != 0);
  92                 MSG("");
  93         }
  94         if (!session_was_stopped) {
  95                 /*
  96                  * Don't print the event and packet loss warnings since the user
  97                  * already saw them when stopping the trace.
  98                  */
  99                 print_session_stats(session->name);
 100         }
 101
 102         ret = lttng_destroy_session_no_wait(session->name);
 103         if (ret < 0) {
 104                 goto error;
 105         }
 106
 107         MSG("Session %s destroyed", session->name);
 108
 109         session_name = get_session_name_quiet();
 110         if (session_name && !strncmp(session->name, session_name, NAME_MAX)) {
 111                 config_destroy_default();
 112         }
 113
 114         if (lttng_opt_mi) {
 115                 ret = mi_lttng_session(writer, session, 0);
 116                 if (ret) {
 117                         ret = CMD_ERROR;
 118                         goto error;
 119                 }
 120         }
 121
 122         ret = CMD_SUCCESS;
 123 error:
 124         free(session_name);
 125         return ret;
 126 }
 127
 128 /*
 129  * destroy_all_sessions
 130  *
 131  * Call destroy_sessions for each registered sessions
 132  */
 133 static int destroy_all_sessions(struct lttng_session *sessions, int count)
 134 {
 135         int i, ret = CMD_SUCCESS;
 136
 137         if (count == 0) {
 138                 MSG("No session found, nothing to do.");
 139         } else if (count < 0) {
 140                 ERR("%s", lttng_strerror(ret));
 141                 goto error;
 142         }
 143
 144         for (i = 0; i < count; i++) {
 145                 ret = destroy_session(&sessions[i]);
 146                 if (ret < 0) {
 147                         goto error;
 148                 }
 149         }
 150 error:
 151         return ret;
 152 }
 153
 154 /*
 155  * The 'destroy <options>' first level command
 156  */
 157 int cmd_destroy(int argc, const char **argv)
 158 {
 159         int opt;
 160         int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
 161         static poptContext pc;
 162         char *session_name = NULL;
 163
 164         struct lttng_session *sessions;
 165         int count;
 166         int found;
 167
 168         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 169         poptReadDefaultConfig(pc, 0);
 170
 171         while ((opt = poptGetNextOpt(pc)) != -1) {
 172                 switch (opt) {
 173                 case OPT_HELP:
 174                         SHOW_HELP();
 175                         break;
 176                 case OPT_LIST_OPTIONS:
 177                         list_cmd_options(stdout, long_options);
 178                         break;
 179                 default:
 180                         ret = CMD_UNDEFINED;
 181                         break;
 182                 }
 183                 goto end;
 184         }
 185
 186         /* Mi preparation */
 187         if (lttng_opt_mi) {
 188                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 189                 if (!writer) {
 190                         ret = -LTTNG_ERR_NOMEM;
 191                         goto end;
 192                 }
 193
 194                 /* Open command element */
 195                 ret = mi_lttng_writer_command_open(writer,
 196                                 mi_lttng_element_command_destroy);
 197                 if (ret) {
 198                         ret = CMD_ERROR;
 199                         goto end;
 200                 }
 201
 202                 /* Open output element */
 203                 ret = mi_lttng_writer_open_element(writer,
 204                                 mi_lttng_element_command_output);
 205                 if (ret) {
 206                         ret = CMD_ERROR;
 207                         goto end;
 208                 }
 209
 210                 /* For validation and semantic purpose we open a sessions element */
 211                 ret = mi_lttng_sessions_open(writer);
 212                 if (ret) {
 213                         ret = CMD_ERROR;
 214                         goto end;
 215                 }
 216         }
 217
 218         /* Recuperate all sessions for further operation */
 219         count = lttng_list_sessions(&sessions);
 220         if (count < 0) {
 221                 command_ret = count;
 222                 success = 0;
 223                 goto mi_closing;
 224         }
 225
 226         /* Ignore session name in case all sessions are to be destroyed */
 227         if (opt_destroy_all) {
 228                 command_ret = destroy_all_sessions(sessions, count);
 229                 if (command_ret) {
 230                         success = 0;
 231                 }
 232         } else {
 233                 opt_session_name = (char *) poptGetArg(pc);
 234
 235                 if (!opt_session_name) {
 236                         /* No session name specified, lookup default */
 237                         session_name = get_session_name();
 238                         if (session_name == NULL) {
 239                                 command_ret = CMD_ERROR;
 240                                 success = 0;
 241                                 goto mi_closing;
 242                         }
 243                 } else {
 244                         session_name = opt_session_name;
 245                 }
 246
 247                 /* Find the corresponding lttng_session struct */
 248                 found = 0;
 249                 for (i = 0; i < count; i++) {
 250                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 251                                 found = 1;
 252                                 command_ret = destroy_session(&sessions[i]);
 253                                 if (command_ret) {
 254                                         success = 0;
 255                                 }
 256
 257                         }
 258                 }
 259
 260                 if (!found) {
 261                         ERR("Session name %s not found", session_name);
 262                         command_ret = LTTNG_ERR_SESS_NOT_FOUND;
 263                         success = 0;
 264                         goto mi_closing;
 265                 }
 266         }
 267
 268 mi_closing:
 269         /* Mi closing */
 270         if (lttng_opt_mi) {
 271                 /* Close sessions and output element element */
 272                 ret = mi_lttng_close_multi_element(writer, 2);
 273                 if (ret) {
 274                         ret = CMD_ERROR;
 275                         goto end;
 276                 }
 277
 278                 /* Success ? */
 279                 ret = mi_lttng_writer_write_element_bool(writer,
 280                                 mi_lttng_element_command_success, success);
 281                 if (ret) {
 282                         ret = CMD_ERROR;
 283                         goto end;
 284                 }
 285
 286                 /* Command element close */
 287                 ret = mi_lttng_writer_command_close(writer);
 288                 if (ret) {
 289                         ret = CMD_ERROR;
 290                         goto end;
 291                 }
 292         }
 293 end:
 294         /* Mi clean-up */
 295         if (writer && mi_lttng_writer_destroy(writer)) {
 296                 /* Preserve original error code */
 297                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 298         }
 299
 300         if (opt_session_name == NULL) {
 301                 free(session_name);
 302         }
 303
 304         /* Overwrite ret if an error occurred during destroy_session/all */
 305         ret = command_ret ? command_ret : ret;
 306
 307         poptFreeContext(pc);
 308         return ret;
 309 }