src/bin/lttng/commands/stop.c

   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 #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 char *opt_session_name;
  24 static int opt_no_wait;
  25 static struct mi_writer *writer;
  26
  27 #ifdef LTTNG_EMBED_HELP
  28 static const char help_msg[] =
  29 #include <lttng-stop.1.h>
  30 ;
  31 #endif
  32
  33 enum {
  34         OPT_HELP = 1,
  35         OPT_LIST_OPTIONS,
  36 };
  37
  38 static struct poptOption long_options[] = {
  39         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  40         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  41         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  42         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  43         {0, 0, 0, 0, 0, 0, 0}
  44 };
  45
  46 /*
  47  * Mi print of partial session
  48  */
  49 static int mi_print_session(char *session_name, int enabled)
  50 {
  51         int ret;
  52         assert(writer);
  53         assert(session_name);
  54
  55         /* Open session element */
  56         ret = mi_lttng_writer_open_element(writer, config_element_session);
  57         if (ret) {
  58                 goto end;
  59         }
  60
  61         /* Print session name element */
  62         ret = mi_lttng_writer_write_element_string(writer, config_element_name,
  63                         session_name);
  64         if (ret) {
  65                 goto end;
  66         }
  67
  68         /* Is enabled ? */
  69         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
  70                         enabled);
  71         if (ret) {
  72                 goto end;
  73         }
  74
  75         /* Close session element */
  76         ret = mi_lttng_writer_close_element(writer);
  77
  78 end:
  79         return ret;
  80 }
  81
  82 /*
  83  * Start tracing for all trace of the session.
  84  */
  85 static int stop_tracing(void)
  86 {
  87         int ret;
  88         char *session_name;
  89
  90         if (opt_session_name == NULL) {
  91                 session_name = get_session_name();
  92                 if (session_name == NULL) {
  93                         ret = CMD_ERROR;
  94                         goto error;
  95                 }
  96         } else {
  97                 session_name = opt_session_name;
  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         if (opt_session_name == NULL) {
 149                 free(session_name);
 150         }
 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 *leftover = NULL;
 166
 167         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 168         poptReadDefaultConfig(pc, 0);
 169
 170         while ((opt = poptGetNextOpt(pc)) != -1) {
 171                 switch (opt) {
 172                 case OPT_HELP:
 173                         SHOW_HELP();
 174                         goto end;
 175                 case OPT_LIST_OPTIONS:
 176                         list_cmd_options(stdout, long_options);
 177                         goto end;
 178                 default:
 179                         ret = CMD_UNDEFINED;
 180                         goto end;
 181                 }
 182         }
 183
 184         /* Mi check */
 185         if (lttng_opt_mi) {
 186                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 187                 if (!writer) {
 188                         ret = -LTTNG_ERR_NOMEM;
 189                         goto end;
 190                 }
 191
 192                 /* Open command element */
 193                 ret = mi_lttng_writer_command_open(writer,
 194                                 mi_lttng_element_command_stop);
 195                 if (ret) {
 196                         ret = CMD_ERROR;
 197                         goto end;
 198                 }
 199
 200                 /* Open output element */
 201                 ret = mi_lttng_writer_open_element(writer,
 202                                 mi_lttng_element_command_output);
 203                 if (ret) {
 204                         ret = CMD_ERROR;
 205                         goto end;
 206                 }
 207
 208                 /*
 209                  * Open sessions element
 210                  * For validation
 211                  */
 212                 ret = mi_lttng_writer_open_element(writer,
 213                                 config_element_sessions);
 214                 if (ret) {
 215                         ret = CMD_ERROR;
 216                         goto end;
 217                 }
 218         }
 219
 220         opt_session_name = (char*) poptGetArg(pc);
 221
 222         leftover = poptGetArg(pc);
 223         if (leftover) {
 224                 ERR("Unknown argument: %s", leftover);
 225                 ret = CMD_ERROR;
 226                 goto end;
 227         }
 228
 229         command_ret = stop_tracing();
 230         if (command_ret) {
 231                 success = 0;
 232         }
 233
 234         /* Mi closing */
 235         if (lttng_opt_mi) {
 236                 /* Close sessions and  output element */
 237                 ret = mi_lttng_close_multi_element(writer, 2);
 238                 if (ret) {
 239                         ret = CMD_ERROR;
 240                         goto end;
 241                 }
 242
 243                 /* Success ? */
 244                 ret = mi_lttng_writer_write_element_bool(writer,
 245                                 mi_lttng_element_command_success, success);
 246                 if (ret) {
 247                         ret = CMD_ERROR;
 248                         goto end;
 249                 }
 250
 251                 /* Command element close */
 252                 ret = mi_lttng_writer_command_close(writer);
 253                 if (ret) {
 254                         ret = CMD_ERROR;
 255                         goto end;
 256                 }
 257         }
 258
 259 end:
 260         /* Mi clean-up */
 261         if (writer && mi_lttng_writer_destroy(writer)) {
 262                 /* Preserve original error code */
 263                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 264         }
 265
 266         /* Overwrite ret if an error occurred in stop_tracing() */
 267         ret = command_ret ? command_ret : ret;
 268
 269         poptFreeContext(pc);
 270         return ret;
 271 }