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