src/bin/lttng/commands/stop.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 <assert.h>
  27
  28 #include <common/sessiond-comm/sessiond-comm.h>
  29 #include <common/mi-lttng.h>
  30
  31 #include "../command.h"
  32
  33 static char *opt_session_name;
  34 static int opt_no_wait;
  35 static struct mi_writer *writer;
  36
  37 enum {
  38         OPT_HELP = 1,
  39         OPT_LIST_OPTIONS,
  40 };
  41
  42 static struct poptOption long_options[] = {
  43         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  44         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  45         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  46         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  47         {0, 0, 0, 0, 0, 0, 0}
  48 };
  49
  50 /*
  51  * Mi print of partial session
  52  */
  53 static int mi_print_session(char *session_name, int enabled)
  54 {
  55         int ret;
  56         assert(writer);
  57         assert(session_name);
  58
  59         /* Open session element */
  60         ret = mi_lttng_writer_open_element(writer, config_element_session);
  61         if (ret) {
  62                 goto end;
  63         }
  64
  65         /* Print session name element */
  66         ret = mi_lttng_writer_write_element_string(writer, config_element_name,
  67                         session_name);
  68         if (ret) {
  69                 goto end;
  70         }
  71
  72         /* Is enabled ? */
  73         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
  74                         enabled);
  75         if (ret) {
  76                 goto end;
  77         }
  78
  79         /* Close session element */
  80         ret = mi_lttng_writer_close_element(writer);
  81
  82 end:
  83         return ret;
  84 }
  85
  86 /*
  87  * Start tracing for all trace of the session.
  88  */
  89 static int stop_tracing(void)
  90 {
  91         int ret;
  92         char *session_name;
  93
  94         if (opt_session_name == NULL) {
  95                 session_name = get_session_name();
  96                 if (session_name == NULL) {
  97                         ret = CMD_ERROR;
  98                         goto error;
  99                 }
 100         } else {
 101                 session_name = opt_session_name;
 102         }
 103
 104         ret = lttng_stop_tracing_no_wait(session_name);
 105         if (ret < 0) {
 106                 switch (-ret) {
 107                 case LTTNG_ERR_TRACE_ALREADY_STOPPED:
 108                         WARN("Tracing already stopped for session %s", session_name);
 109                         break;
 110                 default:
 111                         ERR("%s", lttng_strerror(ret));
 112                         break;
 113                 }
 114                 goto free_name;
 115         }
 116
 117         if (!opt_no_wait) {
 118                 _MSG("Waiting for data availability");
 119                 fflush(stdout);
 120                 do {
 121                         ret = lttng_data_pending(session_name);
 122                         if (ret < 0) {
 123                                 /* Return the data available call error. */
 124                                 goto free_name;
 125                         }
 126
 127                         /*
 128                          * Data sleep time before retrying (in usec). Don't sleep if the call
 129                          * returned value indicates availability.
 130                          */
 131                         if (ret) {
 132                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
 133                                 _MSG(".");
 134                                 fflush(stdout);
 135                         }
 136                 } while (ret != 0);
 137                 MSG("");
 138         }
 139
 140         ret = CMD_SUCCESS;
 141
 142         print_session_stats(session_name);
 143         MSG("Tracing stopped for session %s", session_name);
 144         if (lttng_opt_mi) {
 145                 ret = mi_print_session(session_name, 0);
 146                 if (ret) {
 147                         goto free_name;
 148                 }
 149         }
 150
 151 free_name:
 152         if (opt_session_name == NULL) {
 153                 free(session_name);
 154         }
 155
 156 error:
 157         return ret;
 158 }
 159
 160 /*
 161  *  cmd_stop
 162  *
 163  *  The 'stop <options>' first level command
 164  */
 165 int cmd_stop(int argc, const char **argv)
 166 {
 167         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 168         static poptContext pc;
 169         const char *leftover = NULL;
 170
 171         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 172         poptReadDefaultConfig(pc, 0);
 173
 174         while ((opt = poptGetNextOpt(pc)) != -1) {
 175                 switch (opt) {
 176                 case OPT_HELP:
 177                         SHOW_HELP();
 178                         goto end;
 179                 case OPT_LIST_OPTIONS:
 180                         list_cmd_options(stdout, long_options);
 181                         goto end;
 182                 default:
 183                         ret = CMD_UNDEFINED;
 184                         goto end;
 185                 }
 186         }
 187
 188         /* Mi check */
 189         if (lttng_opt_mi) {
 190                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 191                 if (!writer) {
 192                         ret = -LTTNG_ERR_NOMEM;
 193                         goto end;
 194                 }
 195
 196                 /* Open command element */
 197                 ret = mi_lttng_writer_command_open(writer,
 198                                 mi_lttng_element_command_stop);
 199                 if (ret) {
 200                         ret = CMD_ERROR;
 201                         goto end;
 202                 }
 203
 204                 /* Open output element */
 205                 ret = mi_lttng_writer_open_element(writer,
 206                                 mi_lttng_element_command_output);
 207                 if (ret) {
 208                         ret = CMD_ERROR;
 209                         goto end;
 210                 }
 211
 212                 /*
 213                  * Open sessions element
 214                  * For validation
 215                  */
 216                 ret = mi_lttng_writer_open_element(writer,
 217                                 config_element_sessions);
 218                 if (ret) {
 219                         ret = CMD_ERROR;
 220                         goto end;
 221                 }
 222         }
 223
 224         opt_session_name = (char*) poptGetArg(pc);
 225
 226         leftover = poptGetArg(pc);
 227         if (leftover) {
 228                 ERR("Unknown argument: %s", leftover);
 229                 ret = CMD_ERROR;
 230                 goto end;
 231         }
 232
 233         command_ret = stop_tracing();
 234         if (command_ret) {
 235                 success = 0;
 236         }
 237
 238         /* Mi closing */
 239         if (lttng_opt_mi) {
 240                 /* Close sessions and  output element */
 241                 ret = mi_lttng_close_multi_element(writer, 2);
 242                 if (ret) {
 243                         ret = CMD_ERROR;
 244                         goto end;
 245                 }
 246
 247                 /* Success ? */
 248                 ret = mi_lttng_writer_write_element_bool(writer,
 249                                 mi_lttng_element_command_success, success);
 250                 if (ret) {
 251                         ret = CMD_ERROR;
 252                         goto end;
 253                 }
 254
 255                 /* Command element close */
 256                 ret = mi_lttng_writer_command_close(writer);
 257                 if (ret) {
 258                         ret = CMD_ERROR;
 259                         goto end;
 260                 }
 261         }
 262
 263 end:
 264         /* Mi clean-up */
 265         if (writer && mi_lttng_writer_destroy(writer)) {
 266                 /* Preserve original error code */
 267                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 268         }
 269
 270         /* Overwrite ret if an error occurred in stop_tracing() */
 271         ret = command_ret ? command_ret : ret;
 272
 273         poptFreeContext(pc);
 274         return ret;
 275 }