mono/utils/mono-counters.c

   1 /**
   2  * \file
   3  * Copyright 2006-2010 Novell
   4  * Copyright 2011 Xamarin Inc
   5  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   6  */
   7
   8 #include <stdlib.h>
   9 #include <glib.h>
  10 #include "config.h"
  11 #include "mono-counters.h"
  12 #include "mono-proclib.h"
  13 #include "mono-os-mutex.h"
  14
  15 #ifdef HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18
  19 struct _MonoCounter {
  20         MonoCounter *next;
  21         const char *name;
  22         void *addr;
  23         int type;
  24         size_t size;
  25 };
  26
  27 static MonoCounter *counters = NULL;
  28 static mono_mutex_t counters_mutex;
  29
  30 static volatile gboolean initialized = FALSE;
  31
  32 static int valid_mask = 0;
  33 static int set_mask = 0;
  34
  35 static GSList *register_callbacks = NULL;
  36
  37 static void initialize_system_counters (void);
  38
  39 /**
  40  * mono_counter_get_variance:
  41  * \param counter counter to get the variance
  42  *
  43  * Variance specifies how the counter value is expected to behave between any two samplings.
  44  *
  45  * \returns the monotonicity of the counter.
  46  */
  47 int
  48 mono_counter_get_variance (MonoCounter *counter)
  49 {
  50         return counter->type & MONO_COUNTER_VARIANCE_MASK;
  51 }
  52
  53 /**
  54  * mono_counter_get_unit:
  55  * \param counter counter to get the unit
  56  *
  57  * The unit gives a high level view of the unit that the counter is measuring.
  58  *
  59  * \returns the unit of the counter.
  60  */
  61 int
  62 mono_counter_get_unit (MonoCounter *counter)
  63 {
  64         return counter->type & MONO_COUNTER_UNIT_MASK;
  65 }
  66
  67 /**
  68  * mono_counter_get_section:
  69  * \param counter counter to get the section
  70  * Sections are the unit of organization between all counters.
  71  * \returns the section of the counter.
  72  */
  73
  74 int
  75 mono_counter_get_section (MonoCounter *counter)
  76 {
  77         return counter->type & MONO_COUNTER_SECTION_MASK;
  78 }
  79
  80 /**
  81  * mono_counter_get_type:
  82  * \param counter counter to get the type
  83  * \returns the type used to store the value of the counter.
  84  */
  85 int
  86 mono_counter_get_type (MonoCounter *counter)
  87 {
  88         return counter->type & MONO_COUNTER_TYPE_MASK;
  89 }
  90
  91 /**
  92  * mono_counter_get_name:
  93  * \param counter counter to get the name
  94  * \returns the counter name. The string should not be freed.
  95  */
  96
  97 const char*
  98 mono_counter_get_name (MonoCounter *counter)
  99 {
 100         return counter->name;
 101 }
 102
 103 /**
 104  * mono_counter_get_size:
 105  * \param counter counter to get the max size of the counter
 106  * Use the returned size to create the buffer used with \c mono_counters_sample
 107  * \returns the max size of the counter data.
 108  */
 109 size_t
 110 mono_counter_get_size (MonoCounter *counter)
 111 {
 112         return counter->size;
 113 }
 114
 115 /**
 116  * mono_counters_enable:
 117  * \param sectionmask a mask listing the sections that will be displayed
 118  * This is used to track which counters will be displayed.
 119  */
 120 void
 121 mono_counters_enable (int section_mask)
 122 {
 123         valid_mask = section_mask & MONO_COUNTER_SECTION_MASK;
 124 }
 125
 126 void
 127 mono_counters_init (void)
 128 {
 129         if (initialized)
 130                 return;
 131
 132         mono_os_mutex_init (&counters_mutex);
 133
 134         initialize_system_counters ();
 135
 136         initialized = TRUE;
 137 }
 138
 139 static void
 140 register_internal (const char *name, int type, void *addr, int size)
 141 {
 142         MonoCounter *counter;
 143         GSList *register_callback;
 144
 145         g_assert (size >= 0);
 146         if ((type & MONO_COUNTER_VARIANCE_MASK) == 0)
 147                 type |= MONO_COUNTER_MONOTONIC;
 148
 149         mono_os_mutex_lock (&counters_mutex);
 150
 151         for (counter = counters; counter; counter = counter->next) {
 152                 if (counter->addr == addr) {
 153                         g_warning ("you are registering the same counter address twice: %s at %p", name, addr);
 154                         mono_os_mutex_unlock (&counters_mutex);
 155                         return;
 156                 }
 157         }
 158
 159         counter = (MonoCounter *) g_malloc (sizeof (MonoCounter));
 160         if (!counter) {
 161                 mono_os_mutex_unlock (&counters_mutex);
 162                 return;
 163         }
 164         counter->name = g_strdup (name);
 165         counter->type = type;
 166         counter->addr = addr;
 167         counter->next = NULL;
 168         counter->size = size;
 169
 170         set_mask |= type;
 171
 172         /* Append */
 173         if (counters) {
 174                 MonoCounter *item = counters;
 175                 while (item->next)
 176                         item = item->next;
 177                 item->next = counter;
 178         } else {
 179                 counters = counter;
 180         }
 181
 182         for (register_callback = register_callbacks; register_callback; register_callback = register_callback->next)
 183                 ((MonoCounterRegisterCallback)register_callback->data) (counter);
 184
 185         mono_os_mutex_unlock (&counters_mutex);
 186 }
 187
 188 /**
 189  * mono_counters_register:
 190  * \param name The name for this counters.
 191  * \param type One of the possible \c MONO_COUNTER types, or \c MONO_COUNTER_CALLBACK for a function pointer.
 192  * \param addr The address to register.
 193  *
 194  * Register \p addr as the address of a counter of type type.
 195  * Note that \p name must be a valid string at all times until
 196  * \c mono_counters_dump() is called.
 197  *
 198  * This function should not be used with counter types that require an explicit size such as string
 199  * as the counter size will be set to zero making them effectively useless.
 200  *
 201  * It may be a function pointer if \c MONO_COUNTER_CALLBACK is specified:
 202  * the function should return the value and take no arguments.
 203  */
 204 void
 205 mono_counters_register (const char* name, int type, void *addr)
 206 {
 207         int size;
 208         switch (type & MONO_COUNTER_TYPE_MASK) {
 209         case MONO_COUNTER_INT:
 210                 size = sizeof (int);
 211                 break;
 212         case MONO_COUNTER_UINT:
 213                 size = sizeof (guint);
 214                 break;
 215         case MONO_COUNTER_LONG:
 216         case MONO_COUNTER_TIME_INTERVAL:
 217                 size = sizeof (gint64);
 218                 break;
 219         case MONO_COUNTER_ULONG:
 220                 size = sizeof (guint64);
 221                 break;
 222         case MONO_COUNTER_WORD:
 223                 size = sizeof (gssize);
 224                 break;
 225         case MONO_COUNTER_DOUBLE:
 226                 size = sizeof (double);
 227                 break;
 228         case MONO_COUNTER_STRING:
 229                 size = 0;
 230                 break;
 231         default:
 232                 g_assert_not_reached ();
 233         }
 234
 235         if (!initialized)
 236                 g_debug ("counters not enabled");
 237         else
 238                 register_internal (name, type, addr, size);
 239 }
 240
 241 /**
 242  * mono_counters_register_with_size:
 243  * \param name The name for this counters.
 244  * \param type One of the possible MONO_COUNTER types, or MONO_COUNTER_CALLBACK for a function pointer.
 245  * \param addr The address to register.
 246  * \param size Max size of the counter data.
 247  *
 248  * Register \p addr as the address of a counter of type \p type.
 249  * Note that \p name must be a valid string at all times until
 250  * \c mono_counters_dump() is called.
 251  *
 252  * It may be a function pointer if \c MONO_COUNTER_CALLBACK is specified:
 253  * the function should return the value and take no arguments.
 254  *
 255  * The value of \p size is ignored for types with fixed size such as int and long.
 256  *
 257  * Use \p size for types that can have dynamic size such as string.
 258  *
 259  * If \p size is negative, it's silently converted to zero.
 260  */
 261 void
 262 mono_counters_register_with_size (const char *name, int type, void *addr, int size)
 263 {
 264         if (!initialized)
 265                 g_debug ("counters not enabled");
 266         else
 267                 register_internal (name, type, addr, size);
 268 }
 269
 270 /**
 271  * mono_counters_on_register
 272  * \param callback function to callback when a counter is registered
 273  * Add a callback that is going to be called when a counter is registered
 274  */
 275 void
 276 mono_counters_on_register (MonoCounterRegisterCallback callback)
 277 {
 278         if (!initialized) {
 279                 g_debug ("counters not enabled");
 280                 return;
 281         }
 282
 283         mono_os_mutex_lock (&counters_mutex);
 284         register_callbacks = g_slist_append (register_callbacks, (gpointer) callback);
 285         mono_os_mutex_unlock (&counters_mutex);
 286 }
 287
 288 typedef int (*IntFunc) (void);
 289 typedef guint (*UIntFunc) (void);
 290 typedef gint64 (*LongFunc) (void);
 291 typedef guint64 (*ULongFunc) (void);
 292 typedef gssize (*PtrFunc) (void);
 293 typedef double (*DoubleFunc) (void);
 294 typedef char* (*StrFunc) (void);
 295
 296 static gint64
 297 user_time (void)
 298 {
 299         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_USER_TIME);
 300 }
 301
 302 static gint64
 303 system_time (void)
 304 {
 305         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_SYSTEM_TIME);
 306 }
 307
 308 static gint64
 309 total_time (void)
 310 {
 311         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_TOTAL_TIME);
 312 }
 313
 314 static gint64
 315 working_set (void)
 316 {
 317         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_WORKING_SET);
 318 }
 319
 320 static gint64
 321 private_bytes (void)
 322 {
 323         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_PRIVATE_BYTES);
 324 }
 325
 326 static gint64
 327 virtual_bytes (void)
 328 {
 329         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_VIRTUAL_BYTES);
 330 }
 331
 332 static gint64
 333 page_faults (void)
 334 {
 335         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_FAULTS);
 336 }
 337
 338 static gint64
 339 paged_bytes (void)
 340 {
 341         return mono_process_get_data (GINT_TO_POINTER (mono_process_current_pid ()), MONO_PROCESS_PAGED_BYTES);
 342 }
 343
 344
 345 // If cpu_load gets inlined on Windows then cpu_load_1min, cpu_load_5min and cpu_load_15min can be folded into a single function and that will
 346 // cause a failure when registering counters since the same function address will be used by all three functions. Preventing this method from being inlined
 347 // will make sure the registered callback functions remains unique.
 348 #ifdef _MSC_VER
 349 __declspec(noinline)
 350 #endif
 351 static double
 352 cpu_load (int kind)
 353 {
 354 #if defined(TARGET_WIN32)
 355 #elif defined(TARGET_MACH)
 356         double load [3];
 357         if (getloadavg (load, 3) > 0)
 358                 return load [kind];
 359 #else
 360         char buffer[512], *b;
 361         int len, i;
 362         FILE *f = fopen ("/proc/loadavg", "r");
 363         if (f) {
 364                 len = fread (buffer, 1, sizeof (buffer) - 1, f);
 365                 fclose (f);
 366                 if (len > 0) {
 367                         buffer [len < 511 ? len : 511] = 0;
 368                         b = buffer;
 369                         for (i = 0; i < 3; i++) {
 370                                 if (kind == i)
 371                                         return strtod (b, NULL);
 372                                 if (i < 2) {
 373                                         b = strchr (b, ' ');
 374                                         if (!b)
 375                                                 return 0;
 376                                         b += 1;
 377                                 }
 378                         }
 379                 }
 380         }
 381 #endif
 382         return 0;
 383 }
 384
 385 static double
 386 cpu_load_1min (void)
 387 {
 388         return cpu_load (0);
 389 }
 390
 391 static double
 392 cpu_load_5min (void)
 393 {
 394         return cpu_load (1);
 395 }
 396
 397 static double
 398 cpu_load_15min (void)
 399 {
 400         return cpu_load (2);
 401 }
 402
 403 #define SYSCOUNTER_TIME (MONO_COUNTER_SYSTEM | MONO_COUNTER_LONG | MONO_COUNTER_TIME | MONO_COUNTER_MONOTONIC | MONO_COUNTER_CALLBACK)
 404 #define SYSCOUNTER_BYTES (MONO_COUNTER_SYSTEM | MONO_COUNTER_LONG | MONO_COUNTER_BYTES | MONO_COUNTER_VARIABLE | MONO_COUNTER_CALLBACK)
 405 #define SYSCOUNTER_COUNT (MONO_COUNTER_SYSTEM | MONO_COUNTER_LONG | MONO_COUNTER_COUNT | MONO_COUNTER_MONOTONIC | MONO_COUNTER_CALLBACK)
 406 #define SYSCOUNTER_LOAD (MONO_COUNTER_SYSTEM | MONO_COUNTER_DOUBLE | MONO_COUNTER_PERCENTAGE | MONO_COUNTER_VARIABLE | MONO_COUNTER_CALLBACK)
 407
 408 static void
 409 initialize_system_counters (void)
 410 {
 411         register_internal ("User Time", SYSCOUNTER_TIME, (gpointer) &user_time, sizeof (gint64));
 412         register_internal ("System Time", SYSCOUNTER_TIME, (gpointer) &system_time, sizeof (gint64));
 413         register_internal ("Total Time", SYSCOUNTER_TIME, (gpointer) &total_time, sizeof (gint64));
 414         register_internal ("Working Set", SYSCOUNTER_BYTES, (gpointer) &working_set, sizeof (gint64));
 415         register_internal ("Private Bytes", SYSCOUNTER_BYTES, (gpointer) &private_bytes, sizeof (gint64));
 416         register_internal ("Virtual Bytes", SYSCOUNTER_BYTES, (gpointer) &virtual_bytes, sizeof (gint64));
 417         register_internal ("Page File Bytes", SYSCOUNTER_BYTES, (gpointer) &paged_bytes, sizeof (gint64));
 418         register_internal ("Page Faults", SYSCOUNTER_COUNT, (gpointer) &page_faults, sizeof (gint64));
 419         register_internal ("CPU Load Average - 1min", SYSCOUNTER_LOAD, (gpointer) &cpu_load_1min, sizeof (double));
 420         register_internal ("CPU Load Average - 5min", SYSCOUNTER_LOAD, (gpointer) &cpu_load_5min, sizeof (double));
 421         register_internal ("CPU Load Average - 15min", SYSCOUNTER_LOAD, (gpointer) &cpu_load_15min, sizeof (double));
 422 }
 423
 424 /**
 425  * mono_counters_foreach:
 426  * \param cb The callback that will be called for each counter.
 427  * \param user_data Value passed as second argument of the callback.
 428  * Iterate over all counters and call \p cb for each one of them. Stop iterating if
 429  * the callback returns FALSE.
 430  */
 431 void
 432 mono_counters_foreach (CountersEnumCallback cb, gpointer user_data)
 433 {
 434         MonoCounter *counter;
 435
 436         if (!initialized) {
 437                 g_debug ("counters not enabled");
 438                 return;
 439         }
 440
 441         mono_os_mutex_lock (&counters_mutex);
 442
 443         for (counter = counters; counter; counter = counter->next) {
 444                 if (!cb (counter, user_data)) {
 445                         mono_os_mutex_unlock (&counters_mutex);
 446                         return;
 447                 }
 448         }
 449
 450         mono_os_mutex_unlock (&counters_mutex);
 451 }
 452
 453 #define COPY_COUNTER(type,functype) do {        \
 454                 size = sizeof (type);   \
 455                 if (buffer_size < size) \
 456                         size = -1;      \
 457                 else                    \
 458                         *(type*)buffer = cb ? ((functype)counter->addr) () : *(type*)counter->addr; \
 459         } while (0);
 460
 461 /* lockless */
 462 static int
 463 sample_internal (MonoCounter *counter, void *buffer, int buffer_size)
 464 {
 465         int cb = counter->type & MONO_COUNTER_CALLBACK;
 466         int size = -1;
 467
 468         char *strval;
 469
 470         switch (mono_counter_get_type (counter)) {
 471         case MONO_COUNTER_INT:
 472                 COPY_COUNTER (int, IntFunc);
 473                 break;
 474         case MONO_COUNTER_UINT:
 475                 COPY_COUNTER (guint, UIntFunc);
 476                 break;
 477         case MONO_COUNTER_LONG:
 478         case MONO_COUNTER_TIME_INTERVAL:
 479                 COPY_COUNTER (gint64, LongFunc);
 480                 break;
 481         case MONO_COUNTER_ULONG:
 482                 COPY_COUNTER (guint64, ULongFunc);
 483                 break;
 484         case MONO_COUNTER_WORD:
 485                 COPY_COUNTER (gssize, PtrFunc);
 486                 break;
 487         case MONO_COUNTER_DOUBLE:
 488                 COPY_COUNTER (double, DoubleFunc);
 489                 break;
 490         case MONO_COUNTER_STRING:
 491                 if (buffer_size < counter->size) {
 492                         size = -1;
 493                 } else if (counter->size == 0) {
 494                         size = 0;
 495                 } else {
 496                         strval = cb ? ((StrFunc)counter->addr) () : (char*)counter->addr;
 497                         if (!strval) {
 498                                 size = 0;
 499                         } else {
 500                                 size = counter->size;
 501                                 memcpy ((char *) buffer, strval, size - 1);
 502                                 ((char*)buffer)[size - 1] = '\0';
 503                         }
 504                 }
 505         }
 506
 507         return size;
 508 }
 509
 510 int
 511 mono_counters_sample (MonoCounter *counter, void *buffer, int buffer_size)
 512 {
 513         if (!initialized) {
 514                 g_debug ("counters not enabled");
 515                 return -1;
 516         }
 517
 518         return sample_internal (counter, buffer, buffer_size);
 519 }
 520
 521 #define ENTRY_FMT "%-36s: "
 522 static void
 523 dump_counter (MonoCounter *counter, FILE *outfile) {
 524         void *buffer = g_malloc0 (counter->size);
 525         int size = sample_internal (counter, buffer, counter->size);
 526
 527         switch (counter->type & MONO_COUNTER_TYPE_MASK) {
 528         case MONO_COUNTER_INT:
 529                 fprintf (outfile, ENTRY_FMT "%d\n", counter->name, *(int*)buffer);
 530                 break;
 531         case MONO_COUNTER_UINT:
 532                 fprintf (outfile, ENTRY_FMT "%u\n", counter->name, *(guint*)buffer);
 533                 break;
 534         case MONO_COUNTER_LONG:
 535                 if ((counter->type & MONO_COUNTER_UNIT_MASK) == MONO_COUNTER_TIME)
 536                         fprintf (outfile, ENTRY_FMT "%.2f ms\n", counter->name, (double)(*(gint64*)buffer) / 10000.0);
 537                 else
 538                         fprintf (outfile, ENTRY_FMT "%lld\n", counter->name, *(long long *)buffer);
 539                 break;
 540         case MONO_COUNTER_ULONG:
 541                 if ((counter->type & MONO_COUNTER_UNIT_MASK) == MONO_COUNTER_TIME)
 542                         fprintf (outfile, ENTRY_FMT "%.2f ms\n", counter->name, (double)(*(guint64*)buffer) / 10000.0);
 543                 else
 544                         fprintf (outfile, ENTRY_FMT "%llu\n", counter->name, *(unsigned long long *)buffer);
 545                 break;
 546         case MONO_COUNTER_WORD:
 547                 fprintf (outfile, ENTRY_FMT "%lld\n", counter->name, (long long)*(gssize*)buffer);
 548                 break;
 549         case MONO_COUNTER_DOUBLE:
 550                 fprintf (outfile, ENTRY_FMT "%.4f\n", counter->name, *(double*)buffer);
 551                 break;
 552         case MONO_COUNTER_STRING:
 553                 fprintf (outfile, ENTRY_FMT "%s\n", counter->name, (size == 0) ? "(null)" : (char*)buffer);
 554                 break;
 555         case MONO_COUNTER_TIME_INTERVAL:
 556                 fprintf (outfile, ENTRY_FMT "%.2f ms\n", counter->name, (double)(*(gint64*)buffer) / 1000.0);
 557                 break;
 558         }
 559
 560         g_free (buffer);
 561 }
 562
 563 static const char
 564 section_names [][12] = {
 565         "JIT",
 566         "GC",
 567         "Metadata",
 568         "Generics",
 569         "Security",
 570         "Runtime",
 571         "System",
 572         "", // MONO_COUNTER_PERFCOUNTERS - not used.
 573         "Profiler",
 574         "Interp",
 575 };
 576
 577 static void
 578 mono_counters_dump_section (int section, int variance, FILE *outfile)
 579 {
 580         MonoCounter *counter = counters;
 581         while (counter) {
 582                 if ((counter->type & section) && (mono_counter_get_variance (counter) & variance))
 583                         dump_counter (counter, outfile);
 584                 counter = counter->next;
 585         }
 586 }
 587
 588 /**
 589  * mono_counters_dump:
 590  * \param section_mask The sections to dump counters for
 591  * \param outfile a FILE to dump the results to
 592  * Displays the counts of all the enabled counters registered.
 593  * To filter by variance, you can OR one or more variance with the specific section you want.
 594  * Use \c MONO_COUNTER_SECTION_MASK to dump all categories of a specific variance.
 595  */
 596 void
 597 mono_counters_dump (int section_mask, FILE *outfile)
 598 {
 599         int i, j;
 600         int variance;
 601         section_mask &= valid_mask;
 602
 603         if (!initialized)
 604                 return;
 605
 606         mono_os_mutex_lock (&counters_mutex);
 607
 608         if (!counters) {
 609                 mono_os_mutex_unlock (&counters_mutex);
 610                 return;
 611         }
 612
 613         variance = section_mask & MONO_COUNTER_VARIANCE_MASK;
 614
 615         /* If no variance mask is supplied, we default to all kinds. */
 616         if (!variance)
 617                 variance = MONO_COUNTER_VARIANCE_MASK;
 618         section_mask &= ~MONO_COUNTER_VARIANCE_MASK;
 619
 620         for (j = 0, i = MONO_COUNTER_JIT; i < MONO_COUNTER_LAST_SECTION; j++, i <<= 1) {
 621                 if ((section_mask & i) && (set_mask & i)) {
 622                         fprintf (outfile, "\n%s statistics\n", section_names [j]);
 623                         mono_counters_dump_section (i, variance, outfile);
 624                 }
 625         }
 626
 627         fflush (outfile);
 628         mono_os_mutex_unlock (&counters_mutex);
 629 }
 630
 631 /**
 632  * mono_counters_cleanup:
 633  *
 634  * Perform any needed cleanup at process exit.
 635  */
 636 void
 637 mono_counters_cleanup (void)
 638 {
 639         MonoCounter *counter;
 640
 641         if (!initialized)
 642                 return;
 643
 644         mono_os_mutex_lock (&counters_mutex);
 645
 646         counter = counters;
 647         counters = NULL;
 648         while (counter) {
 649                 MonoCounter *tmp = counter;
 650                 counter = counter->next;
 651                 g_free ((void*)tmp->name);
 652                 g_free (tmp);
 653         }
 654
 655         mono_os_mutex_unlock (&counters_mutex);
 656 }
 657
 658 static MonoResourceCallback limit_reached = NULL;
 659 static uintptr_t resource_limits [MONO_RESOURCE_COUNT * 2];
 660
 661 /**
 662  * mono_runtime_resource_check_limit:
 663  * \param resource_type one of the \c MonoResourceType enum values
 664  * \param value the current value of the resource usage
 665  * Check if a runtime resource limit has been reached. This function
 666  * is intended to be used by the runtime only.
 667  */
 668 void
 669 mono_runtime_resource_check_limit (int resource_type, uintptr_t value)
 670 {
 671         if (!limit_reached)
 672                 return;
 673         /* check the hard limit first */
 674         if (value > resource_limits [resource_type * 2 + 1]) {
 675                 limit_reached (resource_type, value, 0);
 676                 return;
 677         }
 678         if (value > resource_limits [resource_type * 2])
 679                 limit_reached (resource_type, value, 1);
 680 }
 681
 682 /**
 683  * mono_runtime_resource_limit:
 684  * \param resource_type one of the \c MonoResourceType enum values
 685  * \param soft_limit the soft limit value
 686  * \param hard_limit the hard limit value
 687  * This function sets the soft and hard limit for runtime resources. When the limit
 688  * is reached, a user-specified callback is called. The callback runs in a restricted
 689  * environment, in which the world coult be stopped, so it can't take locks, perform
 690  * allocations etc. The callback may be called multiple times once a limit has been reached
 691  * if action is not taken to decrease the resource use.
 692  * \returns 0 on error or a positive integer otherwise.
 693  */
 694 int
 695 mono_runtime_resource_limit (int resource_type, uintptr_t soft_limit, uintptr_t hard_limit)
 696 {
 697         if (resource_type >= MONO_RESOURCE_COUNT || resource_type < 0)
 698                 return 0;
 699         if (soft_limit > hard_limit)
 700                 return 0;
 701         resource_limits [resource_type * 2] = soft_limit;
 702         resource_limits [resource_type * 2 + 1] = hard_limit;
 703         return 1;
 704 }
 705
 706 /**
 707  * mono_runtime_resource_set_callback:
 708  * \param callback a function pointer
 709  * Set the callback to be invoked when a resource limit is reached.
 710  * The callback will receive the resource type, the resource amount in resource-specific
 711  * units and a flag indicating whether the soft or hard limit was reached.
 712  */
 713 void
 714 mono_runtime_resource_set_callback (MonoResourceCallback callback)
 715 {
 716         limit_reached = callback;
 717 }
 718
 719