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 <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.hpp>
  18 #include <common/mi-lttng.hpp>
  19
  20 #include "../command.hpp"
  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, 0, OPT_HELP, 0, 0},
  39         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  40         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  41         {0, 0, 0, 0, 0, 0, 0}
  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,
  61                         session_name);
  62         if (ret) {
  63                 goto end;
  64         }
  65
  66         /* Is enabled ? */
  67         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
  68                         enabled);
  69         if (ret) {
  70                 goto end;
  71         }
  72
  73         /* Close session element */
  74         ret = mi_lttng_writer_close_element(writer);
  75
  76 end:
  77         return ret;
  78 }
  79
  80 /*
  81  * Start tracing for all trace of the session.
  82  */
  83 static int stop_tracing(const char *arg_session_name)
  84 {
  85         int ret;
  86         char *session_name;
  87
  88         if (arg_session_name == NULL) {
  89                 session_name = get_session_name();
  90         } else {
  91                 session_name = strdup(arg_session_name);
  92                 if (session_name == NULL) {
  93                         PERROR("Failed to copy session name");
  94                 }
  95         }
  96
  97         if (session_name == NULL) {
  98                 ret = CMD_ERROR;
  99                 goto error;
 100         }
 101
 102         ret = lttng_stop_tracing_no_wait(session_name);
 103         if (ret < 0) {
 104                 switch (-ret) {
 105                 case LTTNG_ERR_TRACE_ALREADY_STOPPED:
 106                         WARN("Tracing already stopped for session %s", session_name);
 107                         break;
 108                 default:
 109                         ERR("%s", lttng_strerror(ret));
 110                         break;
 111                 }
 112                 goto free_name;
 113         }
 114
 115         if (!opt_no_wait) {
 116                 _MSG("Waiting for data availability");
 117                 fflush(stdout);
 118                 do {
 119                         ret = lttng_data_pending(session_name);
 120                         if (ret < 0) {
 121                                 /* Return the data available call error. */
 122                                 goto free_name;
 123                         }
 124
 125                         /*
 126                          * Data sleep time before retrying (in usec). Don't sleep if the call
 127                          * returned value indicates availability.
 128                          */
 129                         if (ret) {
 130                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US);
 131                                 _MSG(".");
 132                                 fflush(stdout);
 133                         }
 134                 } while (ret != 0);
 135                 MSG("");
 136         }
 137
 138         ret = CMD_SUCCESS;
 139
 140         print_session_stats(session_name);
 141         MSG("Tracing stopped for session %s", session_name);
 142         if (lttng_opt_mi) {
 143                 ret = mi_print_session(session_name, 0);
 144                 if (ret) {
 145                         goto free_name;
 146                 }
 147         }
 148
 149 free_name:
 150         free(session_name);
 151
 152 error:
 153         return ret;
 154 }
 155
 156 /*
 157  *  cmd_stop
 158  *
 159  *  The 'stop <options>' first level command
 160  */
 161 int cmd_stop(int argc, const char **argv)
 162 {
 163         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 164         static poptContext pc;
 165         const char *arg_session_name = NULL;
 166         const char *leftover = NULL;
 167
 168         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 169         poptReadDefaultConfig(pc, 0);
 170
 171         while ((opt = poptGetNextOpt(pc)) != -1) {
 172                 switch (opt) {
 173                 case OPT_HELP:
 174                         SHOW_HELP();
 175                         goto end;
 176                 case OPT_LIST_OPTIONS:
 177                         list_cmd_options(stdout, long_options);
 178                         goto end;
 179                 default:
 180                         ret = CMD_UNDEFINED;
 181                         goto end;
 182                 }
 183         }
 184
 185         /* Mi check */
 186         if (lttng_opt_mi) {
 187                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 188                 if (!writer) {
 189                         ret = -LTTNG_ERR_NOMEM;
 190                         goto end;
 191                 }
 192
 193                 /* Open command element */
 194                 ret = mi_lttng_writer_command_open(writer,
 195                                 mi_lttng_element_command_stop);
 196                 if (ret) {
 197                         ret = CMD_ERROR;
 198                         goto end;
 199                 }
 200
 201                 /* Open output element */
 202                 ret = mi_lttng_writer_open_element(writer,
 203                                 mi_lttng_element_command_output);
 204                 if (ret) {
 205                         ret = CMD_ERROR;
 206                         goto end;
 207                 }
 208
 209                 /*
 210                  * Open sessions element
 211                  * For validation
 212                  */
 213                 ret = mi_lttng_writer_open_element(writer,
 214                                 config_element_sessions);
 215                 if (ret) {
 216                         ret = CMD_ERROR;
 217                         goto end;
 218                 }
 219         }
 220
 221         arg_session_name = poptGetArg(pc);
 222
 223         leftover = poptGetArg(pc);
 224         if (leftover) {
 225                 ERR("Unknown argument: %s", leftover);
 226                 ret = CMD_ERROR;
 227                 goto end;
 228         }
 229
 230         command_ret = stop_tracing(arg_session_name);
 231         if (command_ret) {
 232                 success = 0;
 233         }
 234
 235         /* Mi closing */
 236         if (lttng_opt_mi) {
 237                 /* Close sessions and  output element */
 238                 ret = mi_lttng_close_multi_element(writer, 2);
 239                 if (ret) {
 240                         ret = CMD_ERROR;
 241                         goto end;
 242                 }
 243
 244                 /* Success ? */
 245                 ret = mi_lttng_writer_write_element_bool(writer,
 246                                 mi_lttng_element_command_success, success);
 247                 if (ret) {
 248                         ret = CMD_ERROR;
 249                         goto end;
 250                 }
 251
 252                 /* Command element close */
 253                 ret = mi_lttng_writer_command_close(writer);
 254                 if (ret) {
 255                         ret = CMD_ERROR;
 256                         goto end;
 257                 }
 258         }
 259
 260 end:
 261         /* Mi clean-up */
 262         if (writer && mi_lttng_writer_destroy(writer)) {
 263                 /* Preserve original error code */
 264                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 265         }
 266
 267         /* Overwrite ret if an error occurred in stop_tracing() */
 268         ret = command_ret ? command_ret : ret;
 269
 270         poptFreeContext(pc);
 271         return ret;
 272 }