src/bin/lttng/commands/stop.cpp

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include "../command.hpp"
  10 #include "../utils.hpp"
  11
  12 #include <common/exception.hpp>
  13 #include <common/mi-lttng.hpp>
  14 #include <common/sessiond-comm/sessiond-comm.hpp>
  15
  16 #include <popt.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <sys/stat.h>
  21 #include <sys/types.h>
  22 #include <unistd.h>
  23
  24 enum {
  25         OPT_HELP = 1,
  26         OPT_LIST_OPTIONS,
  27         OPT_ENABLE_GLOB,
  28         OPT_ALL,
  29 };
  30
  31 namespace {
  32 #ifdef LTTNG_EMBED_HELP
  33 static const char help_msg[] =
  34 #include <lttng-stop.1.h>
  35         ;
  36 #endif
  37
  38 int opt_no_wait;
  39 struct mi_writer *writer;
  40
  41 struct poptOption long_options[] = {
  42         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  43         { "help", 'h', POPT_ARG_NONE, nullptr, OPT_HELP, nullptr, nullptr },
  44         { "list-options", 0, POPT_ARG_NONE, nullptr, OPT_LIST_OPTIONS, nullptr, nullptr },
  45         { "no-wait", 'n', POPT_ARG_VAL, &opt_no_wait, 1, nullptr, nullptr },
  46         { "glob", 'g', POPT_ARG_NONE, nullptr, OPT_ENABLE_GLOB, nullptr, nullptr },
  47         { "all", 'a', POPT_ARG_NONE, nullptr, OPT_ALL, nullptr, nullptr },
  48         { nullptr, 0, 0, nullptr, 0, nullptr, nullptr }
  49 };
  50
  51 /*
  52  * Mi print of partial session
  53  */
  54 int mi_print_session(const char *session_name, int enabled)
  55 {
  56         int ret;
  57         LTTNG_ASSERT(writer);
  58         LTTNG_ASSERT(session_name);
  59
  60         /* Open session element */
  61         ret = mi_lttng_writer_open_element(writer, config_element_session);
  62         if (ret) {
  63                 goto end;
  64         }
  65
  66         /* Print session name element */
  67         ret = mi_lttng_writer_write_element_string(writer, config_element_name, 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, enabled);
  74         if (ret) {
  75                 goto end;
  76         }
  77
  78         /* Close session element */
  79         ret = mi_lttng_writer_close_element(writer);
  80
  81 end:
  82         return ret;
  83 }
  84
  85 /*
  86  * Start tracing for all trace of the session.
  87  */
  88 int stop_tracing(const char *session_name)
  89 {
  90         int ret;
  91
  92         ret = lttng_stop_tracing_no_wait(session_name);
  93         if (ret < 0) {
  94                 switch (-ret) {
  95                 case LTTNG_ERR_TRACE_ALREADY_STOPPED:
  96                         WARN("Tracing already stopped for session %s", session_name);
  97                         break;
  98                 default:
  99                         ERR("%s", lttng_strerror(ret));
 100                         break;
 101                 }
 102                 goto error;
 103         }
 104
 105         if (!opt_no_wait) {
 106                 _MSG("Waiting for data availability");
 107                 fflush(stdout);
 108                 do {
 109                         ret = lttng_data_pending(session_name);
 110                         if (ret < 0) {
 111                                 /* Return the data available call error. */
 112                                 goto error;
 113                         }
 114
 115                         /*
 116                          * Data sleep time before retrying (in usec). Don't sleep if the call
 117                          * returned value indicates availability.
 118                          */
 119                         if (ret) {
 120                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US);
 121                                 _MSG(".");
 122                                 fflush(stdout);
 123                         }
 124                 } while (ret != 0);
 125                 MSG("");
 126         }
 127
 128         ret = CMD_SUCCESS;
 129
 130         print_session_stats(session_name);
 131         MSG("Tracing stopped for session %s", session_name);
 132         if (lttng_opt_mi) {
 133                 ret = mi_print_session(session_name, 0);
 134         }
 135 error:
 136         return ret;
 137 }
 138
 139 int stop_tracing(const struct session_spec& spec)
 140 {
 141         int ret = CMD_SUCCESS;
 142
 143         try {
 144                 for (const auto& session : list_sessions(spec)) {
 145                         int const sub_ret = stop_tracing(session.name);
 146
 147                         if (sub_ret != CMD_SUCCESS) {
 148                                 ret = sub_ret;
 149                         }
 150                 }
 151         } catch (lttng::ctl::error& error) {
 152                 ret = error.code();
 153         }
 154
 155         return ret;
 156 }
 157 } /* namespace */
 158
 159 /*
 160  *  cmd_stop
 161  *
 162  *  The 'stop <options>' first level command
 163  */
 164 int cmd_stop(int argc, const char **argv)
 165 {
 166         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 167         static poptContext pc;
 168         const char *leftover = nullptr;
 169         struct session_spec session_spec = {
 170                 .type = session_spec::NAME,
 171                 .value = nullptr,
 172         };
 173
 174         pc = poptGetContext(nullptr, argc, argv, long_options, 0);
 175         poptReadDefaultConfig(pc, 0);
 176
 177         while ((opt = poptGetNextOpt(pc)) != -1) {
 178                 switch (opt) {
 179                 case OPT_HELP:
 180                         SHOW_HELP();
 181                         goto end;
 182                 case OPT_LIST_OPTIONS:
 183                         list_cmd_options(stdout, long_options);
 184                         goto end;
 185                 case OPT_ENABLE_GLOB:
 186                         session_spec.type = session_spec::GLOB_PATTERN;
 187                         break;
 188                 case OPT_ALL:
 189                         session_spec.type = session_spec::ALL;
 190                         break;
 191                 default:
 192                         ret = CMD_UNDEFINED;
 193                         goto end;
 194                 }
 195         }
 196
 197         /* Mi check */
 198         if (lttng_opt_mi) {
 199                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 200                 if (!writer) {
 201                         ret = -LTTNG_ERR_NOMEM;
 202                         goto end;
 203                 }
 204
 205                 /* Open command element */
 206                 ret = mi_lttng_writer_command_open(writer, mi_lttng_element_command_stop);
 207                 if (ret) {
 208                         ret = CMD_ERROR;
 209                         goto end;
 210                 }
 211
 212                 /* Open output element */
 213                 ret = mi_lttng_writer_open_element(writer, mi_lttng_element_command_output);
 214                 if (ret) {
 215                         ret = CMD_ERROR;
 216                         goto end;
 217                 }
 218
 219                 /*
 220                  * Open sessions element
 221                  * For validation
 222                  */
 223                 ret = mi_lttng_writer_open_element(writer, config_element_sessions);
 224                 if (ret) {
 225                         ret = CMD_ERROR;
 226                         goto end;
 227                 }
 228         }
 229
 230         session_spec.value = poptGetArg(pc);
 231
 232         leftover = poptGetArg(pc);
 233         if (leftover) {
 234                 ERR("Unknown argument: %s", leftover);
 235                 ret = CMD_ERROR;
 236                 goto end;
 237         }
 238
 239         command_ret = stop_tracing(session_spec);
 240         if (command_ret) {
 241                 success = 0;
 242         }
 243
 244         /* Mi closing */
 245         if (lttng_opt_mi) {
 246                 /* Close sessions and  output element */
 247                 ret = mi_lttng_close_multi_element(writer, 2);
 248                 if (ret) {
 249                         ret = CMD_ERROR;
 250                         goto end;
 251                 }
 252
 253                 /* Success ? */
 254                 ret = mi_lttng_writer_write_element_bool(
 255                         writer, mi_lttng_element_command_success, success);
 256                 if (ret) {
 257                         ret = CMD_ERROR;
 258                         goto end;
 259                 }
 260
 261                 /* Command element close */
 262                 ret = mi_lttng_writer_command_close(writer);
 263                 if (ret) {
 264                         ret = CMD_ERROR;
 265                         goto end;
 266                 }
 267         }
 268
 269 end:
 270         /* Mi clean-up */
 271         if (writer && mi_lttng_writer_destroy(writer)) {
 272                 /* Preserve original error code */
 273                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 274         }
 275
 276         /* Overwrite ret if an error occurred in stop_tracing() */
 277         ret = command_ret ? command_ret : ret;
 278
 279         poptFreeContext(pc);
 280         return ret;
 281 }