src/bin/lttng/commands/stop.c

   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 <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 #include <assert.h>
  17
  18 #include <common/sessiond-comm/sessiond-comm.h>
  19 #include <common/mi-lttng.h>
  20
  21 #include "../command.h"
  22
  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         assert(writer);
  52         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(const char *arg_session_name)
  85 {
  86         int ret;
  87         char *session_name;
  88
  89         if (arg_session_name == NULL) {
  90                 session_name = get_session_name();
  91         } else {
  92                 session_name = strdup(arg_session_name);
  93                 if (session_name == NULL) {
  94                         PERROR("Failed to copy session name");
  95                 }
  96         }
  97
  98         if (session_name == NULL) {
  99                 ret = CMD_ERROR;
 100                 goto error;
 101         }
 102
 103         ret = lttng_stop_tracing_no_wait(session_name);
 104         if (ret < 0) {
 105                 switch (-ret) {
 106                 case LTTNG_ERR_TRACE_ALREADY_STOPPED:
 107                         WARN("Tracing already stopped for session %s", session_name);
 108                         break;
 109                 default:
 110                         ERR("%s", lttng_strerror(ret));
 111                         break;
 112                 }
 113                 goto free_name;
 114         }
 115
 116         if (!opt_no_wait) {
 117                 _MSG("Waiting for data availability");
 118                 fflush(stdout);
 119                 do {
 120                         ret = lttng_data_pending(session_name);
 121                         if (ret < 0) {
 122                                 /* Return the data available call error. */
 123                                 goto free_name;
 124                         }
 125
 126                         /*
 127                          * Data sleep time before retrying (in usec). Don't sleep if the call
 128                          * returned value indicates availability.
 129                          */
 130                         if (ret) {
 131                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US);
 132                                 _MSG(".");
 133                                 fflush(stdout);
 134                         }
 135                 } while (ret != 0);
 136                 MSG("");
 137         }
 138
 139         ret = CMD_SUCCESS;
 140
 141         print_session_stats(session_name);
 142         MSG("Tracing stopped for session %s", session_name);
 143         if (lttng_opt_mi) {
 144                 ret = mi_print_session(session_name, 0);
 145                 if (ret) {
 146                         goto free_name;
 147                 }
 148         }
 149
 150 free_name:
 151         free(session_name);
 152
 153 error:
 154         return ret;
 155 }
 156
 157 /*
 158  *  cmd_stop
 159  *
 160  *  The 'stop <options>' first level command
 161  */
 162 int cmd_stop(int argc, const char **argv)
 163 {
 164         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 165         static poptContext pc;
 166         const char *arg_session_name = NULL;
 167         const char *leftover = NULL;
 168
 169         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 170         poptReadDefaultConfig(pc, 0);
 171
 172         while ((opt = poptGetNextOpt(pc)) != -1) {
 173                 switch (opt) {
 174                 case OPT_HELP:
 175                         SHOW_HELP();
 176                         goto end;
 177                 case OPT_LIST_OPTIONS:
 178                         list_cmd_options(stdout, long_options);
 179                         goto end;
 180                 default:
 181                         ret = CMD_UNDEFINED;
 182                         goto end;
 183                 }
 184         }
 185
 186         /* Mi check */
 187         if (lttng_opt_mi) {
 188                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 189                 if (!writer) {
 190                         ret = -LTTNG_ERR_NOMEM;
 191                         goto end;
 192                 }
 193
 194                 /* Open command element */
 195                 ret = mi_lttng_writer_command_open(writer,
 196                                 mi_lttng_element_command_stop);
 197                 if (ret) {
 198                         ret = CMD_ERROR;
 199                         goto end;
 200                 }
 201
 202                 /* Open output element */
 203                 ret = mi_lttng_writer_open_element(writer,
 204                                 mi_lttng_element_command_output);
 205                 if (ret) {
 206                         ret = CMD_ERROR;
 207                         goto end;
 208                 }
 209
 210                 /*
 211                  * Open sessions element
 212                  * For validation
 213                  */
 214                 ret = mi_lttng_writer_open_element(writer,
 215                                 config_element_sessions);
 216                 if (ret) {
 217                         ret = CMD_ERROR;
 218                         goto end;
 219                 }
 220         }
 221
 222         arg_session_name = poptGetArg(pc);
 223
 224         leftover = poptGetArg(pc);
 225         if (leftover) {
 226                 ERR("Unknown argument: %s", leftover);
 227                 ret = CMD_ERROR;
 228                 goto end;
 229         }
 230
 231         command_ret = stop_tracing(arg_session_name);
 232         if (command_ret) {
 233                 success = 0;
 234         }
 235
 236         /* Mi closing */
 237         if (lttng_opt_mi) {
 238                 /* Close sessions and  output element */
 239                 ret = mi_lttng_close_multi_element(writer, 2);
 240                 if (ret) {
 241                         ret = CMD_ERROR;
 242                         goto end;
 243                 }
 244
 245                 /* Success ? */
 246                 ret = mi_lttng_writer_write_element_bool(writer,
 247                                 mi_lttng_element_command_success, success);
 248                 if (ret) {
 249                         ret = CMD_ERROR;
 250                         goto end;
 251                 }
 252
 253                 /* Command element close */
 254                 ret = mi_lttng_writer_command_close(writer);
 255                 if (ret) {
 256                         ret = CMD_ERROR;
 257                         goto end;
 258                 }
 259         }
 260
 261 end:
 262         /* Mi clean-up */
 263         if (writer && mi_lttng_writer_destroy(writer)) {
 264                 /* Preserve original error code */
 265                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 266         }
 267
 268         /* Overwrite ret if an error occurred in stop_tracing() */
 269         ret = command_ret ? command_ret : ret;
 270
 271         poptFreeContext(pc);
 272         return ret;
 273 }