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