libgomp/libgomp.h

   1 /* Copyright (C) 2005 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
  42 #include <pthread.h>
  43 #include <stdbool.h>
  44
  45 #ifdef HAVE_ATTRIBUTE_VISIBILITY
  46 # pragma GCC visibility push(hidden)
  47 #endif
  48
  49 #include "sem.h"
  50 #include "mutex.h"
  51 #include "bar.h"
  52
  53
  54 /* This structure contains the data to control one work-sharing construct,
  55    either a LOOP (FOR/DO) or a SECTIONS.  */
  56
  57 enum gomp_schedule_type
  58 {
  59   GFS_STATIC,
  60   GFS_DYNAMIC,
  61   GFS_GUIDED,
  62   GFS_RUNTIME
  63 };
  64
  65 struct gomp_work_share
  66 {
  67   /* This member records the SCHEDULE clause to be used for this construct.
  68      The user specification of "runtime" will already have been resolved.
  69      If this is a SECTIONS construct, this value will always be DYNAMIC.  */
  70   enum gomp_schedule_type sched;
  71
  72   /* This is the chunk_size argument to the SCHEDULE clause.  */
  73   long chunk_size;
  74
  75   /* This is the iteration end point.  If this is a SECTIONS construct,
  76      this is the number of contained sections.  */
  77   long end;
  78
  79   /* This is the iteration step.  If this is a SECTIONS construct, this
  80      is always 1.  */
  81   long incr;
  82
  83   /* This lock protects the update of the following members.  */
  84   gomp_mutex_t lock;
  85
  86   union {
  87     /* This is the next iteration value to be allocated.  In the case of
  88        GFS_STATIC loops, this the iteration start point and never changes.  */
  89     long next;
  90
  91     /* This is the returned data structure for SINGLE COPYPRIVATE.  */
  92     void *copyprivate;
  93   };
  94
  95   /* This is the count of the number of threads that have exited the work
  96      share construct.  If the construct was marked nowait, they have moved on
  97      to other work; otherwise they're blocked on a barrier.  The last member
  98      of the team to exit the work share construct must deallocate it.  */
  99   unsigned threads_completed;
 100
 101   /* This is the index into the circular queue ordered_team_ids of the
 102      current thread that's allowed into the ordered reason.  */
 103   unsigned ordered_cur;
 104
 105   /* This is the number of threads that have registered themselves in
 106      the circular queue ordered_team_ids.  */
 107   unsigned ordered_num_used;
 108
 109   /* This is the team_id of the currently acknoledged owner of the ordered
 110      section, or -1u if the ordered section has not been acknowledged by
 111      any thread.  This is distinguished from the thread that is *allowed*
 112      to take the section next.  */
 113   unsigned ordered_owner;
 114
 115   /* This is a circular queue that details which threads will be allowed
 116      into the ordered region and in which order.  When a thread allocates
 117      iterations on which it is going to work, it also registers itself at
 118      the end of the array.  When a thread reaches the ordered region, it
 119      checks to see if it is the one at the head of the queue.  If not, it
 120      blocks on its RELEASE semaphore.  */
 121   unsigned ordered_team_ids[];
 122 };
 123
 124 /* This structure contains all of the thread-local data associated with
 125    a thread team.  This is the data that must be saved when a thread
 126    encounters a nested PARALLEL construct.  */
 127
 128 struct gomp_team_state
 129 {
 130   /* This is the team of which the thread is currently a member.  */
 131   struct gomp_team *team;
 132
 133   /* This is the work share construct which this thread is currently
 134      processing.  Recall that with NOWAIT, not all threads may be
 135      processing the same construct.  This value is NULL when there
 136      is no construct being processed.  */
 137   struct gomp_work_share *work_share;
 138
 139   /* This is the ID of this thread within the team.  This value is
 140      guaranteed to be between 0 and N-1, where N is the number of
 141      threads in the team.  */
 142   unsigned team_id;
 143
 144   /* The work share "generation" is a number that increases by one for
 145      each work share construct encountered in the dynamic flow of the
 146      program.  It is used to find the control data for the work share
 147      when encountering it for the first time.  This particular number
 148      reflects the generation of the work_share member of this struct.  */
 149   unsigned work_share_generation;
 150
 151   /* For GFS_RUNTIME loops that resolved to GFS_STATIC, this is the
 152      trip number through the loop.  So first time a particular loop
 153      is encountered this number is 0, the second time through the loop
 154      is 1, etc.  This is unused when the compiler knows in advance that
 155      the loop is statically scheduled.  */
 156   unsigned long static_trip;
 157 };
 158
 159 /* This structure describes a "team" of threads.  These are the threads
 160    that are spawned by a PARALLEL constructs, as well as the work sharing
 161    constructs that the team encounters.  */
 162
 163 struct gomp_team
 164 {
 165   /* This lock protects access to the following work shares data structures.  */
 166   gomp_mutex_t work_share_lock;
 167
 168   /* This is a dynamically sized array containing pointers to the control
 169      structs for all "live" work share constructs.  Here "live" means that
 170      the construct has been encountered by at least one thread, and not
 171      completed by all threads.  */
 172   struct gomp_work_share **work_shares;
 173
 174   /* The work_shares array is indexed by "generation & generation_mask".
 175      The mask will be 2**N - 1, where 2**N is the size of the array.  */
 176   unsigned generation_mask;
 177
 178   /* These two values define the bounds of the elements of the work_shares
 179      array that are currently in use.  */
 180   unsigned oldest_live_gen;
 181   unsigned num_live_gen;
 182
 183   /* This is the number of threads in the current team.  */
 184   unsigned nthreads;
 185
 186   /* This is the saved team state that applied to a master thread before
 187      the current thread was created.  */
 188   struct gomp_team_state prev_ts;
 189
 190   /* This barrier is used for most synchronization of the team.  */
 191   gomp_barrier_t barrier;
 192
 193   /* This semaphore should be used by the master thread instead of its
 194      "native" semaphore in the thread structure.  Required for nested
 195      parallels, as the master is a member of two teams.  */
 196   gomp_sem_t master_release;
 197
 198   /* This array contains pointers to the release semaphore of the threads
 199      in the team.  */
 200   gomp_sem_t *ordered_release[];
 201 };
 202
 203 /* This structure contains all data that is private to libgomp and is
 204    allocated per thread.  */
 205
 206 struct gomp_thread
 207 {
 208   /* This is the function that the thread should run upon launch.  */
 209   void (*fn) (void *data);
 210   void *data;
 211
 212   /* This is the current team state for this thread.  The ts.team member
 213      is NULL only if the thread is idle.  */
 214   struct gomp_team_state ts;
 215
 216   /* This semaphore is used for ordered loops.  */
 217   gomp_sem_t release;
 218 };
 219
 220 /* ... and here is that TLS data.  */
 221
 222 #ifdef HAVE_TLS
 223 extern __thread struct gomp_thread gomp_tls_data;
 224 static inline struct gomp_thread *gomp_thread (void)
 225 {
 226   return &gomp_tls_data;
 227 }
 228 #else
 229 extern pthread_key_t gomp_tls_key;
 230 static inline struct gomp_thread *gomp_thread (void)
 231 {
 232   return pthread_getspecific (gomp_tls_key);
 233 }
 234 #endif
 235
 236 /* These are the OpenMP 2.5 internal control variables described in
 237    section 2.3.  At least those that correspond to environment variables.  */
 238
 239 extern unsigned gomp_nthreads_var;
 240 extern bool gomp_dyn_var;
 241 extern bool gomp_nest_var;
 242 extern enum gomp_schedule_type gomp_run_sched_var;
 243 extern unsigned gomp_run_sched_chunk;
 244
 245 /* Function prototypes.  */
 246
 247 /* alloc.c */
 248
 249 extern void *gomp_malloc (size_t) __attribute__((malloc));
 250 extern void *gomp_malloc_cleared (size_t) __attribute__((malloc));
 251 extern void *gomp_realloc (void *, size_t);
 252
 253 /* error.c */
 254
 255 extern void gomp_error (const char *, ...)
 256         __attribute__((format (printf, 1, 2)));
 257 extern void gomp_fatal (const char *, ...)
 258         __attribute__((noreturn, format (printf, 1, 2)));
 259
 260 /* iter.c */
 261
 262 extern int gomp_iter_static_next (long *, long *);
 263 extern bool gomp_iter_dynamic_next_locked (long *, long *);
 264 extern bool gomp_iter_guided_next_locked (long *, long *);
 265
 266 #ifdef HAVE_SYNC_BUILTINS
 267 extern bool gomp_iter_dynamic_next (long *, long *);
 268 extern bool gomp_iter_guided_next (long *, long *);
 269 #endif
 270
 271 /* ordered.c */
 272
 273 extern void gomp_ordered_first (void);
 274 extern void gomp_ordered_last (void);
 275 extern void gomp_ordered_next (void);
 276 extern void gomp_ordered_static_init (void);
 277 extern void gomp_ordered_static_next (void);
 278 extern void gomp_ordered_sync (void);
 279
 280 /* parallel.c */
 281
 282 extern unsigned gomp_resolve_num_threads (unsigned);
 283
 284 /* proc.c (in config/) */
 285
 286 extern void gomp_init_num_threads (void);
 287 extern unsigned gomp_dynamic_max_threads (void);
 288
 289 /* team.c */
 290
 291 extern void gomp_team_start (void (*) (void *), void *, unsigned,
 292                              struct gomp_work_share *);
 293 extern void gomp_team_end (void);
 294
 295 /* work.c */
 296
 297 extern struct gomp_work_share * gomp_new_work_share (bool, unsigned);
 298 extern bool gomp_work_share_start (bool);
 299 extern void gomp_work_share_end (void);
 300 extern void gomp_work_share_end_nowait (void);
 301
 302 #ifdef HAVE_ATTRIBUTE_VISIBILITY
 303 # pragma GCC visibility pop
 304 #endif
 305
 306 /* Now that we're back to default visibility, include the globals.  */
 307 #include "libgomp_g.h"
 308
 309 /* Include omp.h by parts.  */
 310 #include "omp-lock.h"
 311 #define _LIBGOMP_OMP_LOCK_DEFINED 1
 312 #include "omp.h.in"
 313
 314 #ifdef HAVE_ATTRIBUTE_VISIBILITY
 315 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 316 #else
 317 # define attribute_hidden
 318 #endif
 319
 320 #ifdef HAVE_ATTRIBUTE_ALIAS
 321 # define ialias(fn) \
 322   extern __typeof (fn) gomp_ialias_##fn \
 323     __attribute__ ((alias (#fn))) attribute_hidden;
 324 #else
 325 # define ialias(fn)
 326 #endif
 327
 328 #endif /* LIBGOMP_H */