src/simdag/sd_workstation.c

   1 /* Copyright (c) 2006-2011. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   4 /* This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the license (GNU LGPL) which comes with this package. */
   6
   7 #include "private.h"
   8 #include "simdag/simdag.h"
   9 #include "xbt/dict.h"
  10 #include "xbt/sysdep.h"
  11 #include "surf/surf.h"
  12 #include "surf/surf_resource.h"
  13
  14
  15
  16 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(sd_workstation, sd,
  17                                 "Logging specific to SimDag (workstation)");
  18
  19 /* Creates a workstation and registers it in SD.
  20  */
  21 SD_workstation_t __SD_workstation_create(void *surf_workstation,
  22                                          void *data)
  23 {
  24
  25   SD_workstation_t workstation;
  26   const char *name;
  27
  28   workstation = xbt_new(s_SD_workstation_t, 1);
  29   workstation->surf_workstation = surf_workstation;
  30   workstation->data = data;     /* user data */
  31   workstation->access_mode = SD_WORKSTATION_SHARED_ACCESS;      /* default mode is shared */
  32   workstation->task_fifo = NULL;
  33   workstation->current_task = NULL;
  34
  35   name = SD_workstation_get_name(workstation);
  36   xbt_lib_set(host_lib,name,SD_HOST_LEVEL,workstation);
  37   return workstation;
  38 }
  39
  40 /**
  41  * \brief Returns a workstation given its name
  42  *
  43  * If there is no such workstation, the function returns \c NULL.
  44  *
  45  * \param name workstation name
  46  * \return the workstation, or \c NULL if there is no such workstation
  47  */
  48 SD_workstation_t SD_workstation_get_by_name(const char *name)
  49 {
  50   return xbt_lib_get_or_null(host_lib, name, SD_HOST_LEVEL);
  51 }
  52
  53 /**
  54  * \brief Returns the workstation list
  55  *
  56  * Use SD_workstation_get_number() to know the array size.
  57  *
  58  * \return an array of \ref SD_workstation_t containing all workstations
  59  * \see SD_workstation_get_number()
  60  */
  61 const SD_workstation_t *SD_workstation_get_list(void)
  62 {
  63
  64   xbt_lib_cursor_t cursor;
  65   char *key;
  66   void **data;
  67   int i;
  68
  69   xbt_assert(SD_workstation_get_number() > 0, "There is no workstation!");
  70
  71   if (sd_global->workstation_list == NULL) {    /* this is the first time the function is called */
  72     sd_global->workstation_list =
  73       xbt_new(SD_workstation_t, xbt_lib_length(host_lib));
  74
  75     i = 0;
  76     xbt_lib_foreach(host_lib, cursor, key, data) {
  77       if(data[SD_HOST_LEVEL])
  78           sd_global->workstation_list[i++] = (SD_workstation_t) data[SD_HOST_LEVEL];
  79     }
  80   }
  81   return sd_global->workstation_list;
  82 }
  83
  84 /**
  85  * \brief Returns the number of workstations
  86  *
  87  * \return the number of existing workstations
  88  * \see SD_workstation_get_list()
  89  */
  90 int SD_workstation_get_number(void)
  91 {
  92   return xbt_lib_length(host_lib);
  93 }
  94
  95 /**
  96  * \brief Returns the user data of a workstation
  97  *
  98  * \param workstation a workstation
  99  * \return the user data associated with this workstation (can be \c NULL)
 100  * \see SD_workstation_set_data()
 101  */
 102 void *SD_workstation_get_data(SD_workstation_t workstation)
 103 {
 104   return workstation->data;
 105 }
 106
 107 /**
 108  * \brief Sets the user data of a workstation
 109  *
 110  * The new data can be \c NULL. The old data should have been freed first
 111  * if it was not \c NULL.
 112  *
 113  * \param workstation a workstation
 114  * \param data the new data you want to associate with this workstation
 115  * \see SD_workstation_get_data()
 116  */
 117 void SD_workstation_set_data(SD_workstation_t workstation, void *data)
 118 {
 119   workstation->data = data;
 120 }
 121
 122 /**
 123  * \brief Returns the name of a workstation
 124  *
 125  * \param workstation a workstation
 126  * \return the name of this workstation (cannot be \c NULL)
 127  */
 128 const char *SD_workstation_get_name(SD_workstation_t workstation)
 129 {
 130   return surf_resource_name(workstation->surf_workstation);
 131 }
 132
 133 /**
 134  * \brief Returns the value of a given workstation property
 135  *
 136  * \param ws a workstation
 137  * \param name a property name
 138  * \return value of a property (or NULL if property not set)
 139  */
 140 const char *SD_workstation_get_property_value(SD_workstation_t ws,
 141                                               const char *name)
 142 {
 143   return xbt_dict_get_or_null(SD_workstation_get_properties(ws), name);
 144 }
 145
 146
 147 /**
 148  * \brief Returns a #xbt_dict_t consisting of the list of properties assigned to this workstation
 149  *
 150  * \param workstation a workstation
 151  * \return the dictionary containing the properties associated with the workstation
 152  */
 153 xbt_dict_t SD_workstation_get_properties(SD_workstation_t workstation)
 154 {
 155   return surf_workstation_model->extension.
 156       workstation.get_properties(workstation->surf_workstation);
 157
 158 }
 159
 160
 161 /**
 162  * \brief Returns the route between two workstations
 163  *
 164  * Use SD_route_get_size() to know the array size.
 165  *
 166  * \param src a workstation
 167  * \param dst another workstation
 168  * \return a new array of \ref SD_link_t representating the route between these two workstations
 169  * \see SD_route_get_size(), SD_link_t
 170  */
 171 const SD_link_t *SD_route_get_list(SD_workstation_t src,
 172                                    SD_workstation_t dst)
 173 {
 174   void *surf_src;
 175   void *surf_dst;
 176   xbt_dynar_t surf_route;
 177   const char *link_name;
 178   void *surf_link;
 179   unsigned int cpt;
 180
 181   if (sd_global->recyclable_route == NULL) {
 182     /* first run */
 183     sd_global->recyclable_route = xbt_new(SD_link_t, SD_link_get_number());
 184   }
 185
 186   surf_src = src->surf_workstation;
 187   surf_dst = dst->surf_workstation;
 188   surf_route =
 189       surf_workstation_model->extension.workstation.get_route(surf_src,
 190                                                               surf_dst);
 191
 192   xbt_dynar_foreach(surf_route, cpt, surf_link) {
 193     link_name = surf_resource_name(surf_link);
 194     sd_global->recyclable_route[cpt] =
 195         xbt_lib_get_or_null(link_lib, link_name, SD_LINK_LEVEL);
 196   }
 197   return sd_global->recyclable_route;
 198 }
 199
 200 /**
 201  * \brief Returns the number of links on the route between two workstations
 202  *
 203  * \param src a workstation
 204  * \param dst another workstation
 205  * \return the number of links on the route between these two workstations
 206  * \see SD_route_get_list()
 207  */
 208 int SD_route_get_size(SD_workstation_t src, SD_workstation_t dst)
 209 {
 210   return xbt_dynar_length(surf_workstation_model->extension.
 211                           workstation.get_route(src->surf_workstation,
 212                                                 dst->surf_workstation));
 213 }
 214
 215 /**
 216  * \brief Returns the total power of a workstation
 217  *
 218  * \param workstation a workstation
 219  * \return the total power of this workstation
 220  * \see SD_workstation_get_available_power()
 221  */
 222 double SD_workstation_get_power(SD_workstation_t workstation)
 223 {
 224   return surf_workstation_model->extension.workstation.
 225       get_speed(workstation->surf_workstation, 1.0);
 226 }
 227
 228 /**
 229  * \brief Returns the proportion of available power in a workstation
 230  *
 231  * \param workstation a workstation
 232  * \return the proportion of power currently available in this workstation (normally a number between 0 and 1)
 233  * \see SD_workstation_get_power()
 234  */
 235 double SD_workstation_get_available_power(SD_workstation_t workstation)
 236 {
 237   return surf_workstation_model->extension.
 238       workstation.get_available_speed(workstation->surf_workstation);
 239 }
 240
 241 /**
 242  * \brief Returns an approximative estimated time for the given computation amount on a workstation
 243  *
 244  * \param workstation a workstation
 245  * \param computation_amount the computation amount you want to evaluate (in flops)
 246  * \return an approximative astimated computation time for the given computation amount on this workstation (in seconds)
 247  */
 248 double SD_workstation_get_computation_time(SD_workstation_t workstation,
 249                                            double computation_amount)
 250 {
 251   xbt_assert(computation_amount >= 0,
 252               "computation_amount must be greater than or equal to zero");
 253   return computation_amount / SD_workstation_get_power(workstation);
 254 }
 255
 256 /**
 257  * \brief Returns the latency of the route between two workstations, i.e. the sum of all link latencies
 258  * between the workstations.
 259  *
 260  * \param src the first workstation
 261  * \param dst the second workstation
 262  * \return the latency of the route between the two workstations (in seconds)
 263  * \see SD_route_get_current_bandwidth()
 264  */
 265 double SD_route_get_current_latency(SD_workstation_t src,
 266                                     SD_workstation_t dst)
 267 {
 268
 269   const SD_link_t *links;
 270   int nb_links;
 271   double latency;
 272   int i;
 273
 274   links = SD_route_get_list(src, dst);
 275   nb_links = SD_route_get_size(src, dst);
 276   latency = 0.0;
 277
 278   for (i = 0; i < nb_links; i++) {
 279     latency += SD_link_get_current_latency(links[i]);
 280   }
 281
 282   return latency;
 283 }
 284
 285 /**
 286  * \brief Returns the bandwidth of the route between two workstations, i.e. the minimum link bandwidth of all
 287  * between the workstations.
 288  *
 289  * \param src the first workstation
 290  * \param dst the second workstation
 291  * \return the bandwidth of the route between the two workstations (in bytes/second)
 292  * \see SD_route_get_current_latency()
 293  */
 294 double SD_route_get_current_bandwidth(SD_workstation_t src,
 295                                       SD_workstation_t dst)
 296 {
 297
 298   const SD_link_t *links;
 299   int nb_links;
 300   double bandwidth;
 301   double min_bandwidth;
 302   int i;
 303
 304   links = SD_route_get_list(src, dst);
 305   nb_links = SD_route_get_size(src, dst);
 306   bandwidth = min_bandwidth = -1.0;
 307
 308
 309   for (i = 0; i < nb_links; i++) {
 310     bandwidth = SD_link_get_current_bandwidth(links[i]);
 311     if (bandwidth < min_bandwidth || min_bandwidth == -1.0)
 312       min_bandwidth = bandwidth;
 313   }
 314
 315   return min_bandwidth;
 316 }
 317
 318 /**
 319  * \brief Returns an approximative estimated time for the given
 320  * communication amount between two workstations
 321  *
 322  * \param src the first workstation
 323  * \param dst the second workstation
 324  * \param communication_amount the communication amount you want to evaluate (in bytes)
 325  * \return an approximative astimated computation time for the given communication amount
 326  * between the workstations (in seconds)
 327  */
 328 double SD_route_get_communication_time(SD_workstation_t src,
 329                                        SD_workstation_t dst,
 330                                        double communication_amount)
 331 {
 332
 333
 334   /* total time = latency + transmission time of the slowest link
 335      transmission time of a link = communication amount / link bandwidth */
 336
 337   const SD_link_t *links;
 338   int nb_links;
 339   double bandwidth, min_bandwidth;
 340   double latency;
 341   int i;
 342
 343   xbt_assert(communication_amount >= 0,
 344               "communication_amount must be greater than or equal to zero");
 345
 346
 347
 348   if (communication_amount == 0.0)
 349     return 0.0;
 350
 351   links = SD_route_get_list(src, dst);
 352   nb_links = SD_route_get_size(src, dst);
 353   min_bandwidth = -1.0;
 354   latency = 0;
 355
 356   for (i = 0; i < nb_links; i++) {
 357     latency += SD_link_get_current_latency(links[i]);
 358     bandwidth = SD_link_get_current_bandwidth(links[i]);
 359     if (bandwidth < min_bandwidth || min_bandwidth == -1.0)
 360       min_bandwidth = bandwidth;
 361   }
 362
 363   return latency + (communication_amount / min_bandwidth);
 364 }
 365
 366 /**
 367  * \brief Returns the access mode of this workstation.
 368  *
 369  * \param workstation a workstation
 370  * \return the access mode for the tasks running on this workstation:
 371  * SD_WORKSTATION_SHARED_ACCESS or SD_WORKSTATION_SEQUENTIAL_ACCESS
 372  *
 373  * \see SD_workstation_set_access_mode(), e_SD_workstation_access_mode_t
 374  */
 375 e_SD_workstation_access_mode_t
 376 SD_workstation_get_access_mode(SD_workstation_t workstation)
 377 {
 378   return workstation->access_mode;
 379 }
 380
 381 /**
 382  * \brief Sets the access mode for the tasks that will be executed on a workstation
 383  *
 384  * By default, a workstation model is shared, i.e. several tasks
 385  * can be executed at the same time on a workstation. The CPU power of
 386  * the workstation is shared between the running tasks on the workstation.
 387  * In sequential mode, only one task can use the workstation, and the other
 388  * tasks wait in a FIFO.
 389  *
 390  * \param workstation a workstation
 391  * \param access_mode the access mode you want to set to this workstation:
 392  * SD_WORKSTATION_SHARED_ACCESS or SD_WORKSTATION_SEQUENTIAL_ACCESS
 393  *
 394  * \see SD_workstation_get_access_mode(), e_SD_workstation_access_mode_t
 395  */
 396 void SD_workstation_set_access_mode(SD_workstation_t workstation,
 397                                     e_SD_workstation_access_mode_t
 398                                     access_mode)
 399 {
 400   if (access_mode == workstation->access_mode) {
 401     return;                     // nothing is changed
 402   }
 403
 404   workstation->access_mode = access_mode;
 405
 406   if (access_mode == SD_WORKSTATION_SHARED_ACCESS) {
 407     xbt_fifo_free(workstation->task_fifo);
 408     workstation->task_fifo = NULL;
 409   } else {
 410     workstation->task_fifo = xbt_fifo_new();
 411   }
 412 }
 413
 414 /* Returns whether a task can start now on a workstation.
 415                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               *//*
 416                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    int __SD_workstation_can_start(SD_workstation_t workstation, SD_task_t task) {
 417                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    SD_CHECK_INIT_DONE();
 418                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    xbt_assert(workstation != NULL && task != NULL, "Invalid parameter");
 419
 420                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    return !__SD_workstation_is_busy(workstation) &&
 421                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    (xbt_fifo_size(workstation->task_fifo) == 0) || xbt_fifo_get_first_item(workstation->task_fifo) == task);
 422                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    }
 423                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  */
 424
 425 /* Returns whether a workstation is busy. A workstation is busy is it is
 426  * in sequential mode and a task is running on it or the fifo is not empty.
 427  */
 428 int __SD_workstation_is_busy(SD_workstation_t workstation)
 429 {
 430   XBT_DEBUG
 431       ("Workstation '%s' access mode: '%s', current task: %s, fifo size: %d",
 432        SD_workstation_get_name(workstation),
 433        (workstation->access_mode ==
 434         SD_WORKSTATION_SHARED_ACCESS) ? "SHARED" : "FIFO",
 435        (workstation->current_task ?
 436         SD_task_get_name(workstation->current_task)
 437         : "none"),
 438        (workstation->task_fifo ? xbt_fifo_size(workstation->task_fifo) :
 439         0));
 440
 441   return workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS &&
 442       (workstation->current_task != NULL
 443        || xbt_fifo_size(workstation->task_fifo) > 0);
 444 }
 445
 446 /* Destroys a workstation.
 447  */
 448 void __SD_workstation_destroy(void *workstation)
 449 {
 450
 451   SD_workstation_t w;
 452
 453   /* workstation->surf_workstation is freed by surf_exit and workstation->data is freed by the user */
 454
 455   w = (SD_workstation_t) workstation;
 456
 457   if (w->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 458     xbt_fifo_free(w->task_fifo);
 459   }
 460   xbt_free(w);
 461 }
 462
 463 /**
 464  * \brief Returns the kind of the task currently running on a workstation
 465  * Only call this with sequential access mode set
 466  * \param workstation a workstation */
 467 SD_task_t SD_workstation_get_current_task(SD_workstation_t workstation)
 468 {
 469   xbt_assert(workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS,
 470               "Access mode must be set to SD_WORKSTATION_SEQUENTIAL_ACCESS"
 471               " to use this function");
 472
 473   return (workstation->current_task);
 474 }