libgomp/libgomp.h

   1 /* Copyright (C) 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
   2    Contributed by Richard Henderson <rth@redhat.com>.
   3
   4    This file is part of the GNU OpenMP Library (libgomp).
   5
   6    Libgomp is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU Lesser General Public License as published by
   8    the Free Software Foundation; either version 2.1 of the License, or
   9    (at your option) any later version.
  10
  11    Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
  12    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  13    FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
  14    more details.
  15
  16    You should have received a copy of the GNU Lesser General Public License
  17    along with libgomp; see the file COPYING.LIB.  If not, write to the
  18    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 /* As a special exception, if you link this library with other files, some
  22    of which are compiled with GCC, to produce an executable, this library
  23    does not by itself cause the resulting executable to be covered by the
  24    GNU General Public License.  This exception does not however invalidate
  25    any other reasons why the executable file might be covered by the GNU
  26    General Public License.  */
  27
  28 /* This file contains data types and function declarations that are not
  29    part of the official OpenMP user interface.  There are declarations
  30    in here that are part of the GNU OpenMP ABI, in that the compiler is
  31    required to know about them and use them.
  32
  33    The convention is that the all caps prefix "GOMP" is used group items
  34    that are part of the external ABI, and the lower case prefix "gomp"
  35    is used group items that are completely private to the library.  */
  36
  37 #ifndef LIBGOMP_H
  38 #define LIBGOMP_H 1
  39
  40 #include "config.h"
  41 #include "gstdint.h"
  42
  43 #include <pthread.h>
  44 #include <stdbool.h>
  45
  46 #ifdef HAVE_ATTRIBUTE_VISIBILITY
  47 # pragma GCC visibility push(hidden)
  48 #endif
  49
  50 #include "sem.h"
  51 #include "mutex.h"
  52 #include "bar.h"
  53 #include "ptrlock.h"
  54
  55
  56 /* This structure contains the data to control one work-sharing construct,
  57    either a LOOP (FOR/DO) or a SECTIONS.  */
  58
  59 enum gomp_schedule_type
  60 {
  61   GFS_RUNTIME,
  62   GFS_STATIC,
  63   GFS_DYNAMIC,
  64   GFS_GUIDED,
  65   GFS_AUTO
  66 };
  67
  68 struct gomp_work_share
  69 {
  70   /* This member records the SCHEDULE clause to be used for this construct.
  71      The user specification of "runtime" will already have been resolved.
  72      If this is a SECTIONS construct, this value will always be DYNAMIC.  */
  73   enum gomp_schedule_type sched;
  74
  75   int mode;
  76
  77   union {
  78     struct {
  79       /* This is the chunk_size argument to the SCHEDULE clause.  */
  80       long chunk_size;
  81
  82       /* This is the iteration end point.  If this is a SECTIONS construct,
  83          this is the number of contained sections.  */
  84       long end;
  85
  86       /* This is the iteration step.  If this is a SECTIONS construct, this
  87          is always 1.  */
  88       long incr;
  89     };
  90
  91     struct {
  92       /* The same as above, but for the unsigned long long loop variants.  */
  93       unsigned long long chunk_size_ull;
  94       unsigned long long end_ull;
  95       unsigned long long incr_ull;
  96     };
  97   };
  98
  99   /* This is a circular queue that details which threads will be allowed
 100      into the ordered region and in which order.  When a thread allocates
 101      iterations on which it is going to work, it also registers itself at
 102      the end of the array.  When a thread reaches the ordered region, it
 103      checks to see if it is the one at the head of the queue.  If not, it
 104      blocks on its RELEASE semaphore.  */
 105   unsigned *ordered_team_ids;
 106
 107   /* This is the number of threads that have registered themselves in
 108      the circular queue ordered_team_ids.  */
 109   unsigned ordered_num_used;
 110
 111   /* This is the team_id of the currently acknowledged owner of the ordered
 112      section, or -1u if the ordered section has not been acknowledged by
 113      any thread.  This is distinguished from the thread that is *allowed*
 114      to take the section next.  */
 115   unsigned ordered_owner;
 116
 117   /* This is the index into the circular queue ordered_team_ids of the
 118      current thread that's allowed into the ordered reason.  */
 119   unsigned ordered_cur;
 120
 121   /* This is a chain of allocated gomp_work_share blocks, valid only
 122      in the first gomp_work_share struct in the block.  */
 123   struct gomp_work_share *next_alloc;
 124
 125   /* The above fields are written once during workshare initialization,
 126      or related to ordered worksharing.  Make sure the following fields
 127      are in a different cache line.  */
 128
 129   /* This lock protects the update of the following members.  */
 130   gomp_mutex_t lock __attribute__((aligned (64)));
 131
 132   /* This is the count of the number of threads that have exited the work
 133      share construct.  If the construct was marked nowait, they have moved on
 134      to other work; otherwise they're blocked on a barrier.  The last member
 135      of the team to exit the work share construct must deallocate it.  */
 136   unsigned threads_completed;
 137
 138   union {
 139     /* This is the next iteration value to be allocated.  In the case of
 140        GFS_STATIC loops, this the iteration start point and never changes.  */
 141     long next;
 142
 143     /* The same, but with unsigned long long type.  */
 144     unsigned long long next_ull;
 145
 146     /* This is the returned data structure for SINGLE COPYPRIVATE.  */
 147     void *copyprivate;
 148   };
 149
 150   union {
 151     /* Link to gomp_work_share struct for next work sharing construct
 152        encountered after this one.  */
 153     gomp_ptrlock_t next_ws;
 154
 155     /* gomp_work_share structs are chained in the free work share cache
 156        through this.  */
 157     struct gomp_work_share *next_free;
 158   };
 159
 160   /* If only few threads are in the team, ordered_team_ids can point
 161      to this array which fills the padding at the end of this struct.  */
 162   unsigned inline_ordered_team_ids[0];
 163 };
 164
 165 /* This structure contains all of the thread-local data associated with
 166    a thread team.  This is the data that must be saved when a thread
 167    encounters a nested PARALLEL construct.  */
 168
 169 struct gomp_team_state
 170 {
 171   /* This is the team of which the thread is currently a member.  */
 172   struct gomp_team *team;
 173
 174   /* This is the work share construct which this thread is currently
 175      processing.  Recall that with NOWAIT, not all threads may be
 176      processing the same construct.  */
 177   struct gomp_work_share *work_share;
 178
 179   /* This is the previous work share construct or NULL if there wasn't any.
 180      When all threads are done with the current work sharing construct,
 181      the previous one can be freed.  The current one can't, as its
 182      next_ws field is used.  */
 183   struct gomp_work_share *last_work_share;
 184
 185   /* This is the ID of this thread within the team.  This value is
 186      guaranteed to be between 0 and N-1, where N is the number of
 187      threads in the team.  */
 188   unsigned team_id;
 189
 190   /* Nesting level.  */
 191   unsigned level;
 192
 193   /* Active nesting level.  Only active parallel regions are counted.  */
 194   unsigned active_level;
 195
 196 #ifdef HAVE_SYNC_BUILTINS
 197   /* Number of single stmts encountered.  */
 198   unsigned long single_count;
 199 #endif
 200
 201   /* For GFS_RUNTIME loops that resolved to GFS_STATIC, this is the
 202      trip number through the loop.  So first time a particular loop
 203      is encountered this number is 0, the second time through the loop
 204      is 1, etc.  This is unused when the compiler knows in advance that
 205      the loop is statically scheduled.  */
 206   unsigned long static_trip;
 207 };
 208
 209 /* These are the OpenMP 3.0 Internal Control Variables described in
 210    section 2.3.1.  Those described as having one copy per task are
 211    stored within the structure; those described as having one copy
 212    for the whole program are (naturally) global variables.  */
 213
 214 struct gomp_task_icv
 215 {
 216   unsigned long nthreads_var;
 217   enum gomp_schedule_type run_sched_var;
 218   int run_sched_modifier;
 219   bool dyn_var;
 220   bool nest_var;
 221 };
 222
 223 extern struct gomp_task_icv gomp_global_icv;
 224 extern unsigned long gomp_thread_limit_var;
 225 extern unsigned long gomp_remaining_threads_count;
 226 #ifndef HAVE_SYNC_BUILTINS
 227 extern gomp_mutex_t gomp_remaining_threads_lock;
 228 #endif
 229 extern unsigned long gomp_max_active_levels_var;
 230 extern unsigned long long gomp_spin_count_var, gomp_throttled_spin_count_var;
 231 extern unsigned long gomp_available_cpus, gomp_managed_threads;
 232
 233 enum gomp_task_kind
 234 {
 235   GOMP_TASK_IMPLICIT,
 236   GOMP_TASK_IFFALSE,
 237   GOMP_TASK_WAITING,
 238   GOMP_TASK_TIED
 239 };
 240
 241 /* This structure describes a "task" to be run by a thread.  */
 242
 243 struct gomp_task
 244 {
 245   struct gomp_task *parent;
 246   struct gomp_task *children;
 247   struct gomp_task *next_child;
 248   struct gomp_task *prev_child;
 249   struct gomp_task *next_queue;
 250   struct gomp_task *prev_queue;
 251   struct gomp_task_icv icv;
 252   void (*fn) (void *);
 253   void *fn_data;
 254   enum gomp_task_kind kind;
 255   bool in_taskwait;
 256   bool in_tied_task;
 257   gomp_sem_t taskwait_sem;
 258 };
 259
 260 /* This structure describes a "team" of threads.  These are the threads
 261    that are spawned by a PARALLEL constructs, as well as the work sharing
 262    constructs that the team encounters.  */
 263
 264 struct gomp_team
 265 {
 266   /* This is the number of threads in the current team.  */
 267   unsigned nthreads;
 268
 269   /* This is number of gomp_work_share structs that have been allocated
 270      as a block last time.  */
 271   unsigned work_share_chunk;
 272
 273   /* This is the saved team state that applied to a master thread before
 274      the current thread was created.  */
 275   struct gomp_team_state prev_ts;
 276
 277   /* This semaphore should be used by the master thread instead of its
 278      "native" semaphore in the thread structure.  Required for nested
 279      parallels, as the master is a member of two teams.  */
 280   gomp_sem_t master_release;
 281
 282   /* This points to an array with pointers to the release semaphore
 283      of the threads in the team.  */
 284   gomp_sem_t **ordered_release;
 285
 286   /* List of gomp_work_share structs chained through next_free fields.
 287      This is populated and taken off only by the first thread in the
 288      team encountering a new work sharing construct, in a critical
 289      section.  */
 290   struct gomp_work_share *work_share_list_alloc;
 291
 292   /* List of gomp_work_share structs freed by free_work_share.  New
 293      entries are atomically added to the start of the list, and
 294      alloc_work_share can safely only move all but the first entry
 295      to work_share_list alloc, as free_work_share can happen concurrently
 296      with alloc_work_share.  */
 297   struct gomp_work_share *work_share_list_free;
 298
 299 #ifdef HAVE_SYNC_BUILTINS
 300   /* Number of simple single regions encountered by threads in this
 301      team.  */
 302   unsigned long single_count;
 303 #else
 304   /* Mutex protecting addition of workshares to work_share_list_free.  */
 305   gomp_mutex_t work_share_list_free_lock;
 306 #endif
 307
 308   /* This barrier is used for most synchronization of the team.  */
 309   gomp_barrier_t barrier;
 310
 311   /* Initial work shares, to avoid allocating any gomp_work_share
 312      structs in the common case.  */
 313   struct gomp_work_share work_shares[8];
 314
 315   gomp_mutex_t task_lock;
 316   struct gomp_task *task_queue;
 317   int task_count;
 318   int task_running_count;
 319
 320   /* This array contains structures for implicit tasks.  */
 321   struct gomp_task implicit_task[];
 322 };
 323
 324 /* This structure contains all data that is private to libgomp and is
 325    allocated per thread.  */
 326
 327 struct gomp_thread
 328 {
 329   /* This is the function that the thread should run upon launch.  */
 330   void (*fn) (void *data);
 331   void *data;
 332
 333   /* This is the current team state for this thread.  The ts.team member
 334      is NULL only if the thread is idle.  */
 335   struct gomp_team_state ts;
 336
 337   /* This is the task that the thread is currently executing.  */
 338   struct gomp_task *task;
 339
 340   /* This semaphore is used for ordered loops.  */
 341   gomp_sem_t release;
 342
 343   /* user pthread thread pool */
 344   struct gomp_thread_pool *thread_pool;
 345 };
 346
 347
 348 struct gomp_thread_pool
 349 {
 350   /* This array manages threads spawned from the top level, which will
 351      return to the idle loop once the current PARALLEL construct ends.  */
 352   struct gomp_thread **threads;
 353   unsigned threads_size;
 354   unsigned threads_used;
 355   struct gomp_team *last_team;
 356
 357   /* This barrier holds and releases threads waiting in threads.  */
 358   gomp_barrier_t threads_dock;
 359 };
 360
 361 /* ... and here is that TLS data.  */
 362
 363 #ifdef HAVE_TLS
 364 extern __thread struct gomp_thread gomp_tls_data;
 365 static inline struct gomp_thread *gomp_thread (void)
 366 {
 367   return &gomp_tls_data;
 368 }
 369 #else
 370 extern pthread_key_t gomp_tls_key;
 371 static inline struct gomp_thread *gomp_thread (void)
 372 {
 373   return pthread_getspecific (gomp_tls_key);
 374 }
 375 #endif
 376
 377 extern struct gomp_task_icv *gomp_new_icv (void);
 378
 379 /* Here's how to access the current copy of the ICVs.  */
 380
 381 static inline struct gomp_task_icv *gomp_icv (bool write)
 382 {
 383   struct gomp_task *task = gomp_thread ()->task;
 384   if (task)
 385     return &task->icv;
 386   else if (write)
 387     return gomp_new_icv ();
 388   else
 389     return &gomp_global_icv;
 390 }
 391
 392 /* The attributes to be used during thread creation.  */
 393 extern pthread_attr_t gomp_thread_attr;
 394
 395 /* Other variables.  */
 396
 397 extern unsigned short *gomp_cpu_affinity;
 398 extern size_t gomp_cpu_affinity_len;
 399
 400 /* Function prototypes.  */
 401
 402 /* affinity.c */
 403
 404 extern void gomp_init_affinity (void);
 405 extern void gomp_init_thread_affinity (pthread_attr_t *);
 406
 407 /* alloc.c */
 408
 409 extern void *gomp_malloc (size_t) __attribute__((malloc));
 410 extern void *gomp_malloc_cleared (size_t) __attribute__((malloc));
 411 extern void *gomp_realloc (void *, size_t);
 412
 413 /* Avoid conflicting prototypes of alloca() in system headers by using
 414    GCC's builtin alloca().  */
 415 #define gomp_alloca(x)  __builtin_alloca(x)
 416
 417 /* error.c */
 418
 419 extern void gomp_error (const char *, ...)
 420         __attribute__((format (printf, 1, 2)));
 421 extern void gomp_fatal (const char *, ...)
 422         __attribute__((noreturn, format (printf, 1, 2)));
 423
 424 /* iter.c */
 425
 426 extern int gomp_iter_static_next (long *, long *);
 427 extern bool gomp_iter_dynamic_next_locked (long *, long *);
 428 extern bool gomp_iter_guided_next_locked (long *, long *);
 429
 430 #ifdef HAVE_SYNC_BUILTINS
 431 extern bool gomp_iter_dynamic_next (long *, long *);
 432 extern bool gomp_iter_guided_next (long *, long *);
 433 #endif
 434
 435 /* iter_ull.c */
 436
 437 extern int gomp_iter_ull_static_next (unsigned long long *,
 438                                       unsigned long long *);
 439 extern bool gomp_iter_ull_dynamic_next_locked (unsigned long long *,
 440                                                unsigned long long *);
 441 extern bool gomp_iter_ull_guided_next_locked (unsigned long long *,
 442                                               unsigned long long *);
 443
 444 #if defined HAVE_SYNC_BUILTINS && defined __LP64__
 445 extern bool gomp_iter_ull_dynamic_next (unsigned long long *,
 446                                         unsigned long long *);
 447 extern bool gomp_iter_ull_guided_next (unsigned long long *,
 448                                        unsigned long long *);
 449 #endif
 450
 451 /* ordered.c */
 452
 453 extern void gomp_ordered_first (void);
 454 extern void gomp_ordered_last (void);
 455 extern void gomp_ordered_next (void);
 456 extern void gomp_ordered_static_init (void);
 457 extern void gomp_ordered_static_next (void);
 458 extern void gomp_ordered_sync (void);
 459
 460 /* parallel.c */
 461
 462 extern unsigned gomp_resolve_num_threads (unsigned, unsigned);
 463
 464 /* proc.c (in config/) */
 465
 466 extern void gomp_init_num_threads (void);
 467 extern unsigned gomp_dynamic_max_threads (void);
 468
 469 /* task.c */
 470
 471 extern void gomp_init_task (struct gomp_task *, struct gomp_task *,
 472                             struct gomp_task_icv *);
 473 extern void gomp_end_task (void);
 474 extern void gomp_barrier_handle_tasks (gomp_barrier_state_t);
 475
 476 static void inline
 477 gomp_finish_task (struct gomp_task *task)
 478 {
 479   gomp_sem_destroy (&task->taskwait_sem);
 480 }
 481
 482 /* team.c */
 483
 484 extern struct gomp_team *gomp_new_team (unsigned);
 485 extern void gomp_team_start (void (*) (void *), void *, unsigned,
 486                              struct gomp_team *);
 487 extern void gomp_team_end (void);
 488
 489 /* work.c */
 490
 491 extern void gomp_init_work_share (struct gomp_work_share *, bool, unsigned);
 492 extern void gomp_fini_work_share (struct gomp_work_share *);
 493 extern bool gomp_work_share_start (bool);
 494 extern void gomp_work_share_end (void);
 495 extern void gomp_work_share_end_nowait (void);
 496
 497 static inline void
 498 gomp_work_share_init_done (void)
 499 {
 500   struct gomp_thread *thr = gomp_thread ();
 501   if (__builtin_expect (thr->ts.last_work_share != NULL, 1))
 502     gomp_ptrlock_set (&thr->ts.last_work_share->next_ws, thr->ts.work_share);
 503 }
 504
 505 #ifdef HAVE_ATTRIBUTE_VISIBILITY
 506 # pragma GCC visibility pop
 507 #endif
 508
 509 /* Now that we're back to default visibility, include the globals.  */
 510 #include "libgomp_g.h"
 511
 512 /* Include omp.h by parts.  */
 513 #include "omp-lock.h"
 514 #define _LIBGOMP_OMP_LOCK_DEFINED 1
 515 #include "omp.h.in"
 516
 517 #if !defined (HAVE_ATTRIBUTE_VISIBILITY) \
 518     || !defined (HAVE_ATTRIBUTE_ALIAS) \
 519     || !defined (HAVE_AS_SYMVER_DIRECTIVE) \
 520     || !defined (PIC)
 521 # undef LIBGOMP_GNU_SYMBOL_VERSIONING
 522 #endif
 523
 524 #ifdef LIBGOMP_GNU_SYMBOL_VERSIONING
 525 extern void gomp_init_lock_30 (omp_lock_t *) __GOMP_NOTHROW;
 526 extern void gomp_destroy_lock_30 (omp_lock_t *) __GOMP_NOTHROW;
 527 extern void gomp_set_lock_30 (omp_lock_t *) __GOMP_NOTHROW;
 528 extern void gomp_unset_lock_30 (omp_lock_t *) __GOMP_NOTHROW;
 529 extern int gomp_test_lock_30 (omp_lock_t *) __GOMP_NOTHROW;
 530 extern void gomp_init_nest_lock_30 (omp_nest_lock_t *) __GOMP_NOTHROW;
 531 extern void gomp_destroy_nest_lock_30 (omp_nest_lock_t *) __GOMP_NOTHROW;
 532 extern void gomp_set_nest_lock_30 (omp_nest_lock_t *) __GOMP_NOTHROW;
 533 extern void gomp_unset_nest_lock_30 (omp_nest_lock_t *) __GOMP_NOTHROW;
 534 extern int gomp_test_nest_lock_30 (omp_nest_lock_t *) __GOMP_NOTHROW;
 535
 536 extern void gomp_init_lock_25 (omp_lock_25_t *) __GOMP_NOTHROW;
 537 extern void gomp_destroy_lock_25 (omp_lock_25_t *) __GOMP_NOTHROW;
 538 extern void gomp_set_lock_25 (omp_lock_25_t *) __GOMP_NOTHROW;
 539 extern void gomp_unset_lock_25 (omp_lock_25_t *) __GOMP_NOTHROW;
 540 extern int gomp_test_lock_25 (omp_lock_25_t *) __GOMP_NOTHROW;
 541 extern void gomp_init_nest_lock_25 (omp_nest_lock_25_t *) __GOMP_NOTHROW;
 542 extern void gomp_destroy_nest_lock_25 (omp_nest_lock_25_t *) __GOMP_NOTHROW;
 543 extern void gomp_set_nest_lock_25 (omp_nest_lock_25_t *) __GOMP_NOTHROW;
 544 extern void gomp_unset_nest_lock_25 (omp_nest_lock_25_t *) __GOMP_NOTHROW;
 545 extern int gomp_test_nest_lock_25 (omp_nest_lock_25_t *) __GOMP_NOTHROW;
 546
 547 # define strong_alias(fn, al) \
 548   extern __typeof (fn) al __attribute__ ((alias (#fn)));
 549 # define omp_lock_symver(fn) \
 550   __asm (".symver g" #fn "_30, " #fn "@@OMP_3.0"); \
 551   __asm (".symver g" #fn "_25, " #fn "@OMP_1.0");
 552 #else
 553 # define gomp_init_lock_30 omp_init_lock
 554 # define gomp_destroy_lock_30 omp_destroy_lock
 555 # define gomp_set_lock_30 omp_set_lock
 556 # define gomp_unset_lock_30 omp_unset_lock
 557 # define gomp_test_lock_30 omp_test_lock
 558 # define gomp_init_nest_lock_30 omp_init_nest_lock
 559 # define gomp_destroy_nest_lock_30 omp_destroy_nest_lock
 560 # define gomp_set_nest_lock_30 omp_set_nest_lock
 561 # define gomp_unset_nest_lock_30 omp_unset_nest_lock
 562 # define gomp_test_nest_lock_30 omp_test_nest_lock
 563 #endif
 564
 565 #ifdef HAVE_ATTRIBUTE_VISIBILITY
 566 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 567 #else
 568 # define attribute_hidden
 569 #endif
 570
 571 #ifdef HAVE_ATTRIBUTE_ALIAS
 572 # define ialias(fn) \
 573   extern __typeof (fn) gomp_ialias_##fn \
 574     __attribute__ ((alias (#fn))) attribute_hidden;
 575 #else
 576 # define ialias(fn)
 577 #endif
 578
 579 #endif /* LIBGOMP_H */