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 #ifdef LTTNG_EMBED_HELP
  39 static const char help_msg[] =
  40 #include <lttng-destroy.1.h>
  41 ;
  42 #endif
  43
  44 /* Mi writer */
  45 static struct mi_writer *writer;
  46
  47 enum {
  48         OPT_HELP = 1,
  49         OPT_LIST_OPTIONS,
  50 };
  51
  52 static struct poptOption long_options[] = {
  53         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  54         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  55         {"all",       'a', POPT_ARG_VAL, &opt_destroy_all, 1, 0, 0},
  56         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  57         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  58         {0, 0, 0, 0, 0, 0, 0}
  59 };
  60
  61 /*
  62  * destroy_session
  63  *
  64  * Unregister the provided session to the session daemon. On success, removes
  65  * the default configuration.
  66  */
  67 static int destroy_session(struct lttng_session *session)
  68 {
  69         int ret;
  70         char *session_name = NULL;
  71         bool session_was_stopped;
  72
  73         ret = lttng_stop_tracing_no_wait(session->name);
  74         if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
  75                 ERR("%s", lttng_strerror(ret));
  76         }
  77         session_was_stopped = ret == -LTTNG_ERR_TRACE_ALREADY_STOPPED;
  78         if (!opt_no_wait) {
  79                 bool printed_wait_msg = false;
  80
  81                 do {
  82                         ret = lttng_data_pending(session->name);
  83                         if (ret < 0) {
  84                                 /* Return the data available call error. */
  85                                 goto error;
  86                         }
  87
  88                         /*
  89                          * Data sleep time before retrying (in usec). Don't sleep if the call
  90                          * returned value indicates availability.
  91                          */
  92                         if (ret) {
  93                                 if (!printed_wait_msg) {
  94                                         _MSG("Waiting for data availability");
  95                                         fflush(stdout);
  96                                 }
  97
  98                                 printed_wait_msg = true;
  99                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
 100                                 _MSG(".");
 101                                 fflush(stdout);
 102                         }
 103                 } while (ret != 0);
 104                 if (printed_wait_msg) {
 105                         MSG("");
 106                 }
 107         }
 108         if (!session_was_stopped) {
 109                 /*
 110                  * Don't print the event and packet loss warnings since the user
 111                  * already saw them when stopping the trace.
 112                  */
 113                 print_session_stats(session->name);
 114         }
 115
 116         ret = lttng_destroy_session(session->name);
 117         if (ret < 0) {
 118                 goto error;
 119         }
 120
 121         MSG("Session %s destroyed", session->name);
 122
 123         session_name = get_session_name_quiet();
 124         if (session_name && !strncmp(session->name, session_name, NAME_MAX)) {
 125                 config_destroy_default();
 126         }
 127
 128         if (lttng_opt_mi) {
 129                 ret = mi_lttng_session(writer, session, 0);
 130                 if (ret) {
 131                         ret = CMD_ERROR;
 132                         goto error;
 133                 }
 134         }
 135
 136         ret = CMD_SUCCESS;
 137 error:
 138         free(session_name);
 139         return ret;
 140 }
 141
 142 /*
 143  * destroy_all_sessions
 144  *
 145  * Call destroy_sessions for each registered sessions
 146  */
 147 static int destroy_all_sessions(struct lttng_session *sessions, int count)
 148 {
 149         int i, ret = CMD_SUCCESS;
 150
 151         if (count == 0) {
 152                 MSG("No session found, nothing to do.");
 153         } else if (count < 0) {
 154                 ERR("%s", lttng_strerror(ret));
 155                 goto error;
 156         }
 157
 158         for (i = 0; i < count; i++) {
 159                 ret = destroy_session(&sessions[i]);
 160                 if (ret < 0) {
 161                         goto error;
 162                 }
 163         }
 164 error:
 165         return ret;
 166 }
 167
 168 /*
 169  * The 'destroy <options>' first level command
 170  */
 171 int cmd_destroy(int argc, const char **argv)
 172 {
 173         int opt;
 174         int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
 175         static poptContext pc;
 176         char *session_name = NULL;
 177         const char *leftover = NULL;
 178
 179         struct lttng_session *sessions;
 180         int count;
 181         int found;
 182
 183         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 184         poptReadDefaultConfig(pc, 0);
 185
 186         while ((opt = poptGetNextOpt(pc)) != -1) {
 187                 switch (opt) {
 188                 case OPT_HELP:
 189                         SHOW_HELP();
 190                         break;
 191                 case OPT_LIST_OPTIONS:
 192                         list_cmd_options(stdout, long_options);
 193                         break;
 194                 default:
 195                         ret = CMD_UNDEFINED;
 196                         break;
 197                 }
 198                 goto end;
 199         }
 200
 201         /* Mi preparation */
 202         if (lttng_opt_mi) {
 203                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 204                 if (!writer) {
 205                         ret = -LTTNG_ERR_NOMEM;
 206                         goto end;
 207                 }
 208
 209                 /* Open command element */
 210                 ret = mi_lttng_writer_command_open(writer,
 211                                 mi_lttng_element_command_destroy);
 212                 if (ret) {
 213                         ret = CMD_ERROR;
 214                         goto end;
 215                 }
 216
 217                 /* Open output element */
 218                 ret = mi_lttng_writer_open_element(writer,
 219                                 mi_lttng_element_command_output);
 220                 if (ret) {
 221                         ret = CMD_ERROR;
 222                         goto end;
 223                 }
 224
 225                 /* For validation and semantic purpose we open a sessions element */
 226                 ret = mi_lttng_sessions_open(writer);
 227                 if (ret) {
 228                         ret = CMD_ERROR;
 229                         goto end;
 230                 }
 231         }
 232
 233         /* Recuperate all sessions for further operation */
 234         count = lttng_list_sessions(&sessions);
 235         if (count < 0) {
 236                 ERR("%s", lttng_strerror(count));
 237                 command_ret = CMD_ERROR;
 238                 success = 0;
 239                 goto mi_closing;
 240         }
 241
 242         /* Ignore session name in case all sessions are to be destroyed */
 243         if (opt_destroy_all) {
 244                 command_ret = destroy_all_sessions(sessions, count);
 245                 if (command_ret) {
 246                         success = 0;
 247                 }
 248         } else {
 249                 opt_session_name = (char *) poptGetArg(pc);
 250
 251                 if (!opt_session_name) {
 252                         /* No session name specified, lookup default */
 253                         session_name = get_session_name();
 254                         if (session_name == NULL) {
 255                                 command_ret = CMD_ERROR;
 256                                 success = 0;
 257                                 goto mi_closing;
 258                         }
 259                 } else {
 260                         session_name = opt_session_name;
 261                 }
 262
 263                 /* Find the corresponding lttng_session struct */
 264                 found = 0;
 265                 for (i = 0; i < count; i++) {
 266                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 267                                 found = 1;
 268                                 command_ret = destroy_session(&sessions[i]);
 269                                 if (command_ret) {
 270                                         success = 0;
 271                                 }
 272
 273                         }
 274                 }
 275
 276                 if (!found) {
 277                         ERR("Session name %s not found", session_name);
 278                         command_ret = LTTNG_ERR_SESS_NOT_FOUND;
 279                         success = 0;
 280                         goto mi_closing;
 281                 }
 282         }
 283
 284         leftover = poptGetArg(pc);
 285         if (leftover) {
 286                 ERR("Unknown argument: %s", leftover);
 287                 ret = CMD_ERROR;
 288                 success = 0;
 289                 goto mi_closing;
 290         }
 291
 292 mi_closing:
 293         /* Mi closing */
 294         if (lttng_opt_mi) {
 295                 /* Close sessions and output element element */
 296                 ret = mi_lttng_close_multi_element(writer, 2);
 297                 if (ret) {
 298                         ret = CMD_ERROR;
 299                         goto end;
 300                 }
 301
 302                 /* Success ? */
 303                 ret = mi_lttng_writer_write_element_bool(writer,
 304                                 mi_lttng_element_command_success, success);
 305                 if (ret) {
 306                         ret = CMD_ERROR;
 307                         goto end;
 308                 }
 309
 310                 /* Command element close */
 311                 ret = mi_lttng_writer_command_close(writer);
 312                 if (ret) {
 313                         ret = CMD_ERROR;
 314                         goto end;
 315                 }
 316         }
 317 end:
 318         /* Mi clean-up */
 319         if (writer && mi_lttng_writer_destroy(writer)) {
 320                 /* Preserve original error code */
 321                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 322         }
 323
 324         if (opt_session_name == NULL) {
 325                 free(session_name);
 326         }
 327
 328         /* Overwrite ret if an error occurred during destroy_session/all */
 329         ret = command_ret ? command_ret : ret;
 330
 331         poptFreeContext(pc);
 332         return ret;
 333 }