src/bin/lttng/commands/stop.cpp

   1 /*
   2  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include <popt.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/stat.h>
  14 #include <sys/types.h>
  15 #include <unistd.h>
  16
  17 #include <common/sessiond-comm/sessiond-comm.h>
  18 #include <common/mi-lttng.h>
  19
  20 #include "../command.h"
  21
  22 static char *opt_session_name;
  23 static int opt_no_wait;
  24 static struct mi_writer *writer;
  25
  26 #ifdef LTTNG_EMBED_HELP
  27 static const char help_msg[] =
  28 #include <lttng-stop.1.h>
  29 ;
  30 #endif
  31
  32 enum {
  33         OPT_HELP = 1,
  34         OPT_LIST_OPTIONS,
  35 };
  36
  37 static struct poptOption long_options[] = {
  38         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  39         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  40         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  41         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  42         {0, 0, 0, 0, 0, 0, 0}
  43 };
  44
  45 /*
  46  * Mi print of partial session
  47  */
  48 static int mi_print_session(char *session_name, int enabled)
  49 {
  50         int ret;
  51         LTTNG_ASSERT(writer);
  52         LTTNG_ASSERT(session_name);
  53
  54         /* Open session element */
  55         ret = mi_lttng_writer_open_element(writer, config_element_session);
  56         if (ret) {
  57                 goto end;
  58         }
  59
  60         /* Print session name element */
  61         ret = mi_lttng_writer_write_element_string(writer, config_element_name,
  62                         session_name);
  63         if (ret) {
  64                 goto end;
  65         }
  66
  67         /* Is enabled ? */
  68         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
  69                         enabled);
  70         if (ret) {
  71                 goto end;
  72         }
  73
  74         /* Close session element */
  75         ret = mi_lttng_writer_close_element(writer);
  76
  77 end:
  78         return ret;
  79 }
  80
  81 /*
  82  * Start tracing for all trace of the session.
  83  */
  84 static int stop_tracing(void)
  85 {
  86         int ret;
  87         char *session_name;
  88
  89         if (opt_session_name == NULL) {
  90                 session_name = get_session_name();
  91                 if (session_name == NULL) {
  92                         ret = CMD_ERROR;
  93                         goto error;
  94                 }
  95         } else {
  96                 session_name = opt_session_name;
  97         }
  98
  99         ret = lttng_stop_tracing_no_wait(session_name);
 100         if (ret < 0) {
 101                 switch (-ret) {
 102                 case LTTNG_ERR_TRACE_ALREADY_STOPPED:
 103                         WARN("Tracing already stopped for session %s", session_name);
 104                         break;
 105                 default:
 106                         ERR("%s", lttng_strerror(ret));
 107                         break;
 108                 }
 109                 goto free_name;
 110         }
 111
 112         if (!opt_no_wait) {
 113                 _MSG("Waiting for data availability");
 114                 fflush(stdout);
 115                 do {
 116                         ret = lttng_data_pending(session_name);
 117                         if (ret < 0) {
 118                                 /* Return the data available call error. */
 119                                 goto free_name;
 120                         }
 121
 122                         /*
 123                          * Data sleep time before retrying (in usec). Don't sleep if the call
 124                          * returned value indicates availability.
 125                          */
 126                         if (ret) {
 127                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US);
 128                                 _MSG(".");
 129                                 fflush(stdout);
 130                         }
 131                 } while (ret != 0);
 132                 MSG("");
 133         }
 134
 135         ret = CMD_SUCCESS;
 136
 137         print_session_stats(session_name);
 138         MSG("Tracing stopped for session %s", session_name);
 139         if (lttng_opt_mi) {
 140                 ret = mi_print_session(session_name, 0);
 141                 if (ret) {
 142                         goto free_name;
 143                 }
 144         }
 145
 146 free_name:
 147         if (opt_session_name == NULL) {
 148                 free(session_name);
 149         }
 150
 151 error:
 152         return ret;
 153 }
 154
 155 /*
 156  *  cmd_stop
 157  *
 158  *  The 'stop <options>' first level command
 159  */
 160 int cmd_stop(int argc, const char **argv)
 161 {
 162         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 163         static poptContext pc;
 164         const char *leftover = NULL;
 165
 166         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 167         poptReadDefaultConfig(pc, 0);
 168
 169         while ((opt = poptGetNextOpt(pc)) != -1) {
 170                 switch (opt) {
 171                 case OPT_HELP:
 172                         SHOW_HELP();
 173                         goto end;
 174                 case OPT_LIST_OPTIONS:
 175                         list_cmd_options(stdout, long_options);
 176                         goto end;
 177                 default:
 178                         ret = CMD_UNDEFINED;
 179                         goto end;
 180                 }
 181         }
 182
 183         /* Mi check */
 184         if (lttng_opt_mi) {
 185                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 186                 if (!writer) {
 187                         ret = -LTTNG_ERR_NOMEM;
 188                         goto end;
 189                 }
 190
 191                 /* Open command element */
 192                 ret = mi_lttng_writer_command_open(writer,
 193                                 mi_lttng_element_command_stop);
 194                 if (ret) {
 195                         ret = CMD_ERROR;
 196                         goto end;
 197                 }
 198
 199                 /* Open output element */
 200                 ret = mi_lttng_writer_open_element(writer,
 201                                 mi_lttng_element_command_output);
 202                 if (ret) {
 203                         ret = CMD_ERROR;
 204                         goto end;
 205                 }
 206
 207                 /*
 208                  * Open sessions element
 209                  * For validation
 210                  */
 211                 ret = mi_lttng_writer_open_element(writer,
 212                                 config_element_sessions);
 213                 if (ret) {
 214                         ret = CMD_ERROR;
 215                         goto end;
 216                 }
 217         }
 218
 219         opt_session_name = (char*) poptGetArg(pc);
 220
 221         leftover = poptGetArg(pc);
 222         if (leftover) {
 223                 ERR("Unknown argument: %s", leftover);
 224                 ret = CMD_ERROR;
 225                 goto end;
 226         }
 227
 228         command_ret = stop_tracing();
 229         if (command_ret) {
 230                 success = 0;
 231         }
 232
 233         /* Mi closing */
 234         if (lttng_opt_mi) {
 235                 /* Close sessions and  output element */
 236                 ret = mi_lttng_close_multi_element(writer, 2);
 237                 if (ret) {
 238                         ret = CMD_ERROR;
 239                         goto end;
 240                 }
 241
 242                 /* Success ? */
 243                 ret = mi_lttng_writer_write_element_bool(writer,
 244                                 mi_lttng_element_command_success, success);
 245                 if (ret) {
 246                         ret = CMD_ERROR;
 247                         goto end;
 248                 }
 249
 250                 /* Command element close */
 251                 ret = mi_lttng_writer_command_close(writer);
 252                 if (ret) {
 253                         ret = CMD_ERROR;
 254                         goto end;
 255                 }
 256         }
 257
 258 end:
 259         /* Mi clean-up */
 260         if (writer && mi_lttng_writer_destroy(writer)) {
 261                 /* Preserve original error code */
 262                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 263         }
 264
 265         /* Overwrite ret if an error occurred in stop_tracing() */
 266         ret = command_ret ? command_ret : ret;
 267
 268         poptFreeContext(pc);
 269         return ret;
 270 }