LLVM OpenMP* Runtime Library
kmp_taskdeps.cpp
1/*
2 * kmp_taskdeps.cpp
3 */
4
5//===----------------------------------------------------------------------===//
6//
7// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
8// See https://llvm.org/LICENSE.txt for license information.
9// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
10//
11//===----------------------------------------------------------------------===//
12
13//#define KMP_SUPPORT_GRAPH_OUTPUT 1
14
15#include "kmp.h"
16#include "kmp_io.h"
17#include "kmp_wait_release.h"
18#include "kmp_taskdeps.h"
19#if OMPT_SUPPORT
20#include "ompt-specific.h"
21#endif
22
23// TODO: Improve memory allocation? keep a list of pre-allocated structures?
24// allocate in blocks? re-use list finished list entries?
25// TODO: don't use atomic ref counters for stack-allocated nodes.
26// TODO: find an alternate to atomic refs for heap-allocated nodes?
27// TODO: Finish graph output support
28// TODO: kmp_lock_t seems a tad to big (and heavy weight) for this. Check other
29// runtime locks
30// TODO: Any ITT support needed?
31
32#ifdef KMP_SUPPORT_GRAPH_OUTPUT
33static std::atomic<kmp_int32> kmp_node_id_seed = 0;
34#endif
35
36static void __kmp_init_node(kmp_depnode_t *node) {
37 node->dn.successors = NULL;
38 node->dn.task = NULL; // will point to the right task
39 // once dependences have been processed
40 for (int i = 0; i < MAX_MTX_DEPS; ++i)
41 node->dn.mtx_locks[i] = NULL;
42 node->dn.mtx_num_locks = 0;
43 __kmp_init_lock(&node->dn.lock);
44 KMP_ATOMIC_ST_RLX(&node->dn.nrefs, 1); // init creates the first reference
45#ifdef KMP_SUPPORT_GRAPH_OUTPUT
46 node->dn.id = KMP_ATOMIC_INC(&kmp_node_id_seed);
47#endif
48#if USE_ITT_BUILD && USE_ITT_NOTIFY
49 __itt_sync_create(node, "OMP task dep node", NULL, 0);
50#endif
51}
52
53static inline kmp_depnode_t *__kmp_node_ref(kmp_depnode_t *node) {
54 KMP_ATOMIC_INC(&node->dn.nrefs);
55 return node;
56}
57
58enum { KMP_DEPHASH_OTHER_SIZE = 97, KMP_DEPHASH_MASTER_SIZE = 997 };
59
60size_t sizes[] = {997, 2003, 4001, 8191, 16001, 32003, 64007, 131071, 270029};
61const size_t MAX_GEN = 8;
62
63static inline size_t __kmp_dephash_hash(kmp_intptr_t addr, size_t hsize) {
64 // TODO alternate to try: set = (((Addr64)(addrUsefulBits * 9.618)) %
65 // m_num_sets );
66 return ((addr >> 6) ^ (addr >> 2)) % hsize;
67}
68
69static kmp_dephash_t *__kmp_dephash_extend(kmp_info_t *thread,
70 kmp_dephash_t *current_dephash) {
71 kmp_dephash_t *h;
72
73 size_t gen = current_dephash->generation + 1;
74 if (gen >= MAX_GEN)
75 return current_dephash;
76 size_t new_size = sizes[gen];
77
78 size_t size_to_allocate =
79 new_size * sizeof(kmp_dephash_entry_t *) + sizeof(kmp_dephash_t);
80
81#if USE_FAST_MEMORY
82 h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size_to_allocate);
83#else
84 h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size_to_allocate);
85#endif
86
87 h->size = new_size;
88 h->nelements = current_dephash->nelements;
89 h->buckets = (kmp_dephash_entry **)(h + 1);
90 h->generation = gen;
91 h->nconflicts = 0;
92 h->last_all = current_dephash->last_all;
93
94 // make sure buckets are properly initialized
95 for (size_t i = 0; i < new_size; i++) {
96 h->buckets[i] = NULL;
97 }
98
99 // insert existing elements in the new table
100 for (size_t i = 0; i < current_dephash->size; i++) {
101 kmp_dephash_entry_t *next, *entry;
102 for (entry = current_dephash->buckets[i]; entry; entry = next) {
103 next = entry->next_in_bucket;
104 // Compute the new hash using the new size, and insert the entry in
105 // the new bucket.
106 size_t new_bucket = __kmp_dephash_hash(entry->addr, h->size);
107 entry->next_in_bucket = h->buckets[new_bucket];
108 if (entry->next_in_bucket) {
109 h->nconflicts++;
110 }
111 h->buckets[new_bucket] = entry;
112 }
113 }
114
115 // Free old hash table
116#if USE_FAST_MEMORY
117 __kmp_fast_free(thread, current_dephash);
118#else
119 __kmp_thread_free(thread, current_dephash);
120#endif
121
122 return h;
123}
124
125static kmp_dephash_t *__kmp_dephash_create(kmp_info_t *thread,
126 kmp_taskdata_t *current_task) {
127 kmp_dephash_t *h;
128
129 size_t h_size;
130
131 if (current_task->td_flags.tasktype == TASK_IMPLICIT)
132 h_size = KMP_DEPHASH_MASTER_SIZE;
133 else
134 h_size = KMP_DEPHASH_OTHER_SIZE;
135
136 size_t size = h_size * sizeof(kmp_dephash_entry_t *) + sizeof(kmp_dephash_t);
137
138#if USE_FAST_MEMORY
139 h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size);
140#else
141 h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size);
142#endif
143 h->size = h_size;
144
145 h->generation = 0;
146 h->nelements = 0;
147 h->nconflicts = 0;
148 h->buckets = (kmp_dephash_entry **)(h + 1);
149 h->last_all = NULL;
150
151 for (size_t i = 0; i < h_size; i++)
152 h->buckets[i] = 0;
153
154 return h;
155}
156
157static kmp_dephash_entry *__kmp_dephash_find(kmp_info_t *thread,
158 kmp_dephash_t **hash,
159 kmp_intptr_t addr) {
160 kmp_dephash_t *h = *hash;
161 if (h->nelements != 0 && h->nconflicts / h->size >= 1) {
162 *hash = __kmp_dephash_extend(thread, h);
163 h = *hash;
164 }
165 size_t bucket = __kmp_dephash_hash(addr, h->size);
166
167 kmp_dephash_entry_t *entry;
168 for (entry = h->buckets[bucket]; entry; entry = entry->next_in_bucket)
169 if (entry->addr == addr)
170 break;
171
172 if (entry == NULL) {
173// create entry. This is only done by one thread so no locking required
174#if USE_FAST_MEMORY
175 entry = (kmp_dephash_entry_t *)__kmp_fast_allocate(
176 thread, sizeof(kmp_dephash_entry_t));
177#else
178 entry = (kmp_dephash_entry_t *)__kmp_thread_malloc(
179 thread, sizeof(kmp_dephash_entry_t));
180#endif
181 entry->addr = addr;
182 if (!h->last_all) // no predecessor task with omp_all_memory dependence
183 entry->last_out = NULL;
184 else // else link the omp_all_memory depnode to the new entry
185 entry->last_out = __kmp_node_ref(h->last_all);
186 entry->last_set = NULL;
187 entry->prev_set = NULL;
188 entry->last_flag = 0;
189 entry->mtx_lock = NULL;
190 entry->next_in_bucket = h->buckets[bucket];
191 h->buckets[bucket] = entry;
192 h->nelements++;
193 if (entry->next_in_bucket)
194 h->nconflicts++;
195 }
196 return entry;
197}
198
199static kmp_depnode_list_t *__kmp_add_node(kmp_info_t *thread,
200 kmp_depnode_list_t *list,
201 kmp_depnode_t *node) {
202 kmp_depnode_list_t *new_head;
203
204#if USE_FAST_MEMORY
205 new_head = (kmp_depnode_list_t *)__kmp_fast_allocate(
206 thread, sizeof(kmp_depnode_list_t));
207#else
208 new_head = (kmp_depnode_list_t *)__kmp_thread_malloc(
209 thread, sizeof(kmp_depnode_list_t));
210#endif
211
212 new_head->node = __kmp_node_ref(node);
213 new_head->next = list;
214
215 return new_head;
216}
217
218static inline void __kmp_track_dependence(kmp_int32 gtid, kmp_depnode_t *source,
219 kmp_depnode_t *sink,
220 kmp_task_t *sink_task) {
221#if OMPX_TASKGRAPH
222 kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
223 kmp_taskdata_t *task_sink = KMP_TASK_TO_TASKDATA(sink_task);
224 if (source->dn.task && sink_task) {
225 // Not supporting dependency between two tasks that one is within the TDG
226 // and the other is not
227 KMP_ASSERT(task_source->is_taskgraph == task_sink->is_taskgraph);
228 }
229 if (task_sink->is_taskgraph &&
230 __kmp_tdg_is_recording(task_sink->tdg->tdg_status)) {
231 kmp_node_info_t *source_info =
232 &task_sink->tdg->record_map[task_source->td_task_id];
233 bool exists = false;
234 for (int i = 0; i < source_info->nsuccessors; i++) {
235 if (source_info->successors[i] == task_sink->td_task_id) {
236 exists = true;
237 break;
238 }
239 }
240 if (!exists) {
241 if (source_info->nsuccessors >= source_info->successors_size) {
242 source_info->successors_size = 2 * source_info->successors_size;
243 kmp_int32 *old_succ_ids = source_info->successors;
244 kmp_int32 *new_succ_ids = (kmp_int32 *)__kmp_allocate(
245 source_info->successors_size * sizeof(kmp_int32));
246 source_info->successors = new_succ_ids;
247 __kmp_free(old_succ_ids);
248 }
249
250 source_info->successors[source_info->nsuccessors] = task_sink->td_task_id;
251 source_info->nsuccessors++;
252
253 kmp_node_info_t *sink_info =
254 &(task_sink->tdg->record_map[task_sink->td_task_id]);
255 sink_info->npredecessors++;
256 }
257 }
258#endif
259#ifdef KMP_SUPPORT_GRAPH_OUTPUT
260 kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
261 // do not use sink->dn.task as that is only filled after the dependences
262 // are already processed!
263 kmp_taskdata_t *task_sink = KMP_TASK_TO_TASKDATA(sink_task);
264
265 __kmp_printf("%d(%s) -> %d(%s)\n", source->dn.id,
266 task_source->td_ident->psource, sink->dn.id,
267 task_sink->td_ident->psource);
268#endif
269#if OMPT_SUPPORT && OMPT_OPTIONAL
270 /* OMPT tracks dependences between task (a=source, b=sink) in which
271 task a blocks the execution of b through the ompt_new_dependence_callback
272 */
273 if (ompt_enabled.ompt_callback_task_dependence) {
274 kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
275 ompt_data_t *sink_data;
276 if (sink_task)
277 sink_data = &(KMP_TASK_TO_TASKDATA(sink_task)->ompt_task_info.task_data);
278 else
279 sink_data = &__kmp_threads[gtid]->th.ompt_thread_info.task_data;
280
281 ompt_callbacks.ompt_callback(ompt_callback_task_dependence)(
282 &(task_source->ompt_task_info.task_data), sink_data);
283 }
284#endif /* OMPT_SUPPORT && OMPT_OPTIONAL */
285}
286
287static inline kmp_int32
288__kmp_depnode_link_successor(kmp_int32 gtid, kmp_info_t *thread,
289 kmp_task_t *task, kmp_depnode_t *node,
290 kmp_depnode_list_t *plist) {
291 if (!plist)
292 return 0;
293 kmp_int32 npredecessors = 0;
294 // link node as successor of list elements
295 for (kmp_depnode_list_t *p = plist; p; p = p->next) {
296 kmp_depnode_t *dep = p->node;
297#if OMPX_TASKGRAPH
298 kmp_tdg_status tdg_status = KMP_TDG_NONE;
299 if (task) {
300 kmp_taskdata_t *td = KMP_TASK_TO_TASKDATA(task);
301 if (td->is_taskgraph)
302 tdg_status = KMP_TASK_TO_TASKDATA(task)->tdg->tdg_status;
303 if (__kmp_tdg_is_recording(tdg_status))
304 __kmp_track_dependence(gtid, dep, node, task);
305 }
306#endif
307 if (dep->dn.task) {
308 KMP_ACQUIRE_DEPNODE(gtid, dep);
309 if (dep->dn.task) {
310#if OMPX_TASKGRAPH
311 if (!(__kmp_tdg_is_recording(tdg_status)) && task)
312#endif
313 __kmp_track_dependence(gtid, dep, node, task);
314 dep->dn.successors = __kmp_add_node(thread, dep->dn.successors, node);
315 KA_TRACE(40, ("__kmp_process_deps: T#%d adding dependence from %p to "
316 "%p\n",
317 gtid, KMP_TASK_TO_TASKDATA(dep->dn.task),
318 KMP_TASK_TO_TASKDATA(task)));
319 npredecessors++;
320 }
321 KMP_RELEASE_DEPNODE(gtid, dep);
322 }
323 }
324 return npredecessors;
325}
326
327static inline kmp_int32 __kmp_depnode_link_successor(kmp_int32 gtid,
328 kmp_info_t *thread,
329 kmp_task_t *task,
330 kmp_depnode_t *source,
331 kmp_depnode_t *sink) {
332 if (!sink)
333 return 0;
334 kmp_int32 npredecessors = 0;
335#if OMPX_TASKGRAPH
336 kmp_tdg_status tdg_status = KMP_TDG_NONE;
337 kmp_taskdata_t *td = KMP_TASK_TO_TASKDATA(task);
338 if (task) {
339 if (td->is_taskgraph)
340 tdg_status = KMP_TASK_TO_TASKDATA(task)->tdg->tdg_status;
341 if (__kmp_tdg_is_recording(tdg_status) && sink->dn.task)
342 __kmp_track_dependence(gtid, sink, source, task);
343 }
344#endif
345 if (sink->dn.task) {
346 // synchronously add source to sink' list of successors
347 KMP_ACQUIRE_DEPNODE(gtid, sink);
348 if (sink->dn.task) {
349#if OMPX_TASKGRAPH
350 if (!(__kmp_tdg_is_recording(tdg_status)) && task)
351#endif
352 __kmp_track_dependence(gtid, sink, source, task);
353 sink->dn.successors = __kmp_add_node(thread, sink->dn.successors, source);
354 KA_TRACE(40, ("__kmp_process_deps: T#%d adding dependence from %p to "
355 "%p\n",
356 gtid, KMP_TASK_TO_TASKDATA(sink->dn.task),
357 KMP_TASK_TO_TASKDATA(task)));
358#if OMPX_TASKGRAPH
359 if (__kmp_tdg_is_recording(tdg_status)) {
360 kmp_taskdata_t *tdd = KMP_TASK_TO_TASKDATA(sink->dn.task);
361 if (tdd->is_taskgraph) {
362 if (tdd->td_flags.onced)
363 // decrement npredecessors if sink->dn.task belongs to a taskgraph
364 // and
365 // 1) the task is reset to its initial state (by kmp_free_task) or
366 // 2) the task is complete but not yet reset
367 npredecessors--;
368 }
369 }
370#endif
371 npredecessors++;
372 }
373 KMP_RELEASE_DEPNODE(gtid, sink);
374 }
375 return npredecessors;
376}
377
378static inline kmp_int32
379__kmp_process_dep_all(kmp_int32 gtid, kmp_depnode_t *node, kmp_dephash_t *h,
380 bool dep_barrier, kmp_task_t *task) {
381 KA_TRACE(30, ("__kmp_process_dep_all: T#%d processing dep_all, "
382 "dep_barrier = %d\n",
383 gtid, dep_barrier));
384 kmp_info_t *thread = __kmp_threads[gtid];
385 kmp_int32 npredecessors = 0;
386
387 // process previous omp_all_memory node if any
388 npredecessors +=
389 __kmp_depnode_link_successor(gtid, thread, task, node, h->last_all);
390 __kmp_node_deref(thread, h->last_all);
391 if (!dep_barrier) {
392 h->last_all = __kmp_node_ref(node);
393 } else {
394 // if this is a sync point in the serial sequence, then the previous
395 // outputs are guaranteed to be completed after the execution of this
396 // task so the previous output nodes can be cleared.
397 h->last_all = NULL;
398 }
399
400 // process all regular dependences
401 for (size_t i = 0; i < h->size; i++) {
402 kmp_dephash_entry_t *info = h->buckets[i];
403 if (!info) // skip empty slots in dephash
404 continue;
405 for (; info; info = info->next_in_bucket) {
406 // for each entry the omp_all_memory works as OUT dependence
407 kmp_depnode_t *last_out = info->last_out;
408 kmp_depnode_list_t *last_set = info->last_set;
409 kmp_depnode_list_t *prev_set = info->prev_set;
410 if (last_set) {
411 npredecessors +=
412 __kmp_depnode_link_successor(gtid, thread, task, node, last_set);
413 __kmp_depnode_list_free(thread, last_set);
414 __kmp_depnode_list_free(thread, prev_set);
415 info->last_set = NULL;
416 info->prev_set = NULL;
417 info->last_flag = 0; // no sets in this dephash entry
418 } else {
419 npredecessors +=
420 __kmp_depnode_link_successor(gtid, thread, task, node, last_out);
421 }
422 __kmp_node_deref(thread, last_out);
423 if (!dep_barrier) {
424 info->last_out = __kmp_node_ref(node);
425 } else {
426 info->last_out = NULL;
427 }
428 }
429 }
430 KA_TRACE(30, ("__kmp_process_dep_all: T#%d found %d predecessors\n", gtid,
431 npredecessors));
432 return npredecessors;
433}
434
435template <bool filter>
436static inline kmp_int32
437__kmp_process_deps(kmp_int32 gtid, kmp_depnode_t *node, kmp_dephash_t **hash,
438 bool dep_barrier, kmp_int32 ndeps,
439 kmp_depend_info_t *dep_list, kmp_task_t *task) {
440 KA_TRACE(30, ("__kmp_process_deps<%d>: T#%d processing %d dependences : "
441 "dep_barrier = %d\n",
442 filter, gtid, ndeps, dep_barrier));
443
444 kmp_info_t *thread = __kmp_threads[gtid];
445 kmp_int32 npredecessors = 0;
446 for (kmp_int32 i = 0; i < ndeps; i++) {
447 const kmp_depend_info_t *dep = &dep_list[i];
448
449 if (filter && dep->base_addr == 0)
450 continue; // skip filtered entries
451
452 kmp_dephash_entry_t *info =
453 __kmp_dephash_find(thread, hash, dep->base_addr);
454 kmp_depnode_t *last_out = info->last_out;
455 kmp_depnode_list_t *last_set = info->last_set;
456 kmp_depnode_list_t *prev_set = info->prev_set;
457
458 if (dep->flags.out) { // out or inout --> clean lists if any
459 if (last_set) {
460 npredecessors +=
461 __kmp_depnode_link_successor(gtid, thread, task, node, last_set);
462 __kmp_depnode_list_free(thread, last_set);
463 __kmp_depnode_list_free(thread, prev_set);
464 info->last_set = NULL;
465 info->prev_set = NULL;
466 info->last_flag = 0; // no sets in this dephash entry
467 } else {
468 npredecessors +=
469 __kmp_depnode_link_successor(gtid, thread, task, node, last_out);
470 }
471 __kmp_node_deref(thread, last_out);
472 if (!dep_barrier) {
473 info->last_out = __kmp_node_ref(node);
474 } else {
475 // if this is a sync point in the serial sequence, then the previous
476 // outputs are guaranteed to be completed after the execution of this
477 // task so the previous output nodes can be cleared.
478 info->last_out = NULL;
479 }
480 } else { // either IN or MTX or SET
481 if (info->last_flag == 0 || info->last_flag == dep->flag) {
482 // last_set either didn't exist or of same dep kind
483 // link node as successor of the last_out if any
484 npredecessors +=
485 __kmp_depnode_link_successor(gtid, thread, task, node, last_out);
486 // link node as successor of all nodes in the prev_set if any
487 npredecessors +=
488 __kmp_depnode_link_successor(gtid, thread, task, node, prev_set);
489 if (dep_barrier) {
490 // clean last_out and prev_set if any; don't touch last_set
491 __kmp_node_deref(thread, last_out);
492 info->last_out = NULL;
493 __kmp_depnode_list_free(thread, prev_set);
494 info->prev_set = NULL;
495 }
496 } else { // last_set is of different dep kind, make it prev_set
497 // link node as successor of all nodes in the last_set
498 npredecessors +=
499 __kmp_depnode_link_successor(gtid, thread, task, node, last_set);
500 // clean last_out if any
501 __kmp_node_deref(thread, last_out);
502 info->last_out = NULL;
503 // clean prev_set if any
504 __kmp_depnode_list_free(thread, prev_set);
505 if (!dep_barrier) {
506 // move last_set to prev_set, new last_set will be allocated
507 info->prev_set = last_set;
508 } else {
509 info->prev_set = NULL;
510 info->last_flag = 0;
511 }
512 info->last_set = NULL;
513 }
514 // for dep_barrier last_flag value should remain:
515 // 0 if last_set is empty, unchanged otherwise
516 if (!dep_barrier) {
517 info->last_flag = dep->flag; // store dep kind of the last_set
518 info->last_set = __kmp_add_node(thread, info->last_set, node);
519 }
520 // check if we are processing MTX dependency
521 if (dep->flag == KMP_DEP_MTX) {
522 if (info->mtx_lock == NULL) {
523 info->mtx_lock = (kmp_lock_t *)__kmp_allocate(sizeof(kmp_lock_t));
524 __kmp_init_lock(info->mtx_lock);
525 }
526 KMP_DEBUG_ASSERT(node->dn.mtx_num_locks < MAX_MTX_DEPS);
527 kmp_int32 m;
528 // Save lock in node's array
529 for (m = 0; m < MAX_MTX_DEPS; ++m) {
530 // sort pointers in decreasing order to avoid potential livelock
531 if (node->dn.mtx_locks[m] < info->mtx_lock) {
532 KMP_DEBUG_ASSERT(!node->dn.mtx_locks[node->dn.mtx_num_locks]);
533 for (int n = node->dn.mtx_num_locks; n > m; --n) {
534 // shift right all lesser non-NULL pointers
535 KMP_DEBUG_ASSERT(node->dn.mtx_locks[n - 1] != NULL);
536 node->dn.mtx_locks[n] = node->dn.mtx_locks[n - 1];
537 }
538 node->dn.mtx_locks[m] = info->mtx_lock;
539 break;
540 }
541 }
542 KMP_DEBUG_ASSERT(m < MAX_MTX_DEPS); // must break from loop
543 node->dn.mtx_num_locks++;
544 }
545 }
546 }
547 KA_TRACE(30, ("__kmp_process_deps<%d>: T#%d found %d predecessors\n", filter,
548 gtid, npredecessors));
549 return npredecessors;
550}
551
552#define NO_DEP_BARRIER (false)
553#define DEP_BARRIER (true)
554
555// returns true if the task has any outstanding dependence
556static bool __kmp_check_deps(kmp_int32 gtid, kmp_depnode_t *node,
557 kmp_task_t *task, kmp_dephash_t **hash,
558 bool dep_barrier, kmp_int32 ndeps,
559 kmp_depend_info_t *dep_list,
560 kmp_int32 ndeps_noalias,
561 kmp_depend_info_t *noalias_dep_list) {
562 int i, n_mtxs = 0, dep_all = 0;
563#if KMP_DEBUG
564 kmp_taskdata_t *taskdata = KMP_TASK_TO_TASKDATA(task);
565#endif
566 KA_TRACE(20, ("__kmp_check_deps: T#%d checking dependences for task %p : %d "
567 "possibly aliased dependences, %d non-aliased dependences : "
568 "dep_barrier=%d .\n",
569 gtid, taskdata, ndeps, ndeps_noalias, dep_barrier));
570
571 // Filter deps in dep_list
572 // TODO: Different algorithm for large dep_list ( > 10 ? )
573 for (i = 0; i < ndeps; i++) {
574 if (dep_list[i].base_addr != 0 &&
575 dep_list[i].base_addr != (kmp_intptr_t)KMP_SIZE_T_MAX) {
576 KMP_DEBUG_ASSERT(
577 dep_list[i].flag == KMP_DEP_IN || dep_list[i].flag == KMP_DEP_OUT ||
578 dep_list[i].flag == KMP_DEP_INOUT ||
579 dep_list[i].flag == KMP_DEP_MTX || dep_list[i].flag == KMP_DEP_SET);
580 for (int j = i + 1; j < ndeps; j++) {
581 if (dep_list[i].base_addr == dep_list[j].base_addr) {
582 if (dep_list[i].flag != dep_list[j].flag) {
583 // two different dependences on same address work identical to OUT
584 dep_list[i].flag = KMP_DEP_OUT;
585 }
586 dep_list[j].base_addr = 0; // Mark j element as void
587 }
588 }
589 if (dep_list[i].flag == KMP_DEP_MTX) {
590 // limit number of mtx deps to MAX_MTX_DEPS per node
591 if (n_mtxs < MAX_MTX_DEPS && task != NULL) {
592 ++n_mtxs;
593 } else {
594 dep_list[i].flag = KMP_DEP_OUT; // downgrade mutexinoutset to inout
595 }
596 }
597 } else if (dep_list[i].flag == KMP_DEP_ALL ||
598 dep_list[i].base_addr == (kmp_intptr_t)KMP_SIZE_T_MAX) {
599 // omp_all_memory dependence can be marked by compiler by either
600 // (addr=0 && flag=0x80) (flag KMP_DEP_ALL), or (addr=-1).
601 // omp_all_memory overrides all other dependences if any
602 dep_all = 1;
603 break;
604 }
605 }
606
607 // doesn't need to be atomic as no other thread is going to be accessing this
608 // node just yet.
609 // npredecessors is set -1 to ensure that none of the releasing tasks queues
610 // this task before we have finished processing all the dependences
611 node->dn.npredecessors = -1;
612
613 // used to pack all npredecessors additions into a single atomic operation at
614 // the end
615 int npredecessors;
616
617 if (!dep_all) { // regular dependences
618 npredecessors = __kmp_process_deps<true>(gtid, node, hash, dep_barrier,
619 ndeps, dep_list, task);
620 npredecessors += __kmp_process_deps<false>(
621 gtid, node, hash, dep_barrier, ndeps_noalias, noalias_dep_list, task);
622 } else { // omp_all_memory dependence
623 npredecessors = __kmp_process_dep_all(gtid, node, *hash, dep_barrier, task);
624 }
625
626 node->dn.task = task;
627 KMP_MB();
628
629 // Account for our initial fake value
630 npredecessors++;
631
632 // Update predecessors and obtain current value to check if there are still
633 // any outstanding dependences (some tasks may have finished while we
634 // processed the dependences)
635 npredecessors =
636 node->dn.npredecessors.fetch_add(npredecessors) + npredecessors;
637
638 KA_TRACE(20, ("__kmp_check_deps: T#%d found %d predecessors for task %p \n",
639 gtid, npredecessors, taskdata));
640
641 // beyond this point the task could be queued (and executed) by a releasing
642 // task...
643 return npredecessors > 0 ? true : false;
644}
645
662kmp_int32 __kmpc_omp_task_with_deps(ident_t *loc_ref, kmp_int32 gtid,
663 kmp_task_t *new_task, kmp_int32 ndeps,
664 kmp_depend_info_t *dep_list,
665 kmp_int32 ndeps_noalias,
666 kmp_depend_info_t *noalias_dep_list) {
667
668 kmp_taskdata_t *new_taskdata = KMP_TASK_TO_TASKDATA(new_task);
669 KA_TRACE(10, ("__kmpc_omp_task_with_deps(enter): T#%d loc=%p task=%p\n", gtid,
670 loc_ref, new_taskdata));
671 __kmp_assert_valid_gtid(gtid);
672 kmp_info_t *thread = __kmp_threads[gtid];
673 kmp_taskdata_t *current_task = thread->th.th_current_task;
674
675#if OMPX_TASKGRAPH
676 // record TDG with deps
677 if (new_taskdata->is_taskgraph &&
678 __kmp_tdg_is_recording(new_taskdata->tdg->tdg_status)) {
679 kmp_tdg_info_t *tdg = new_taskdata->tdg;
680 // extend record_map if needed
681 if (new_taskdata->td_task_id >= tdg->map_size) {
682 __kmp_acquire_bootstrap_lock(&tdg->graph_lock);
683 if (new_taskdata->td_task_id >= tdg->map_size) {
684 kmp_uint old_size = tdg->map_size;
685 kmp_uint new_size = old_size * 2;
686 kmp_node_info_t *old_record = tdg->record_map;
687 kmp_node_info_t *new_record = (kmp_node_info_t *)__kmp_allocate(
688 new_size * sizeof(kmp_node_info_t));
689 KMP_MEMCPY(new_record, tdg->record_map,
690 old_size * sizeof(kmp_node_info_t));
691 tdg->record_map = new_record;
692
693 __kmp_free(old_record);
694
695 for (kmp_int i = old_size; i < new_size; i++) {
696 kmp_int32 *successorsList = (kmp_int32 *)__kmp_allocate(
697 __kmp_successors_size * sizeof(kmp_int32));
698 new_record[i].task = nullptr;
699 new_record[i].successors = successorsList;
700 new_record[i].nsuccessors = 0;
701 new_record[i].npredecessors = 0;
702 new_record[i].successors_size = __kmp_successors_size;
703 KMP_ATOMIC_ST_REL(&new_record[i].npredecessors_counter, 0);
704 }
705 // update the size at the end, so that we avoid other
706 // threads use old_record while map_size is already updated
707 tdg->map_size = new_size;
708 }
709 __kmp_release_bootstrap_lock(&tdg->graph_lock);
710 }
711 tdg->record_map[new_taskdata->td_task_id].task = new_task;
712 tdg->record_map[new_taskdata->td_task_id].parent_task =
713 new_taskdata->td_parent;
714 KMP_ATOMIC_INC(&tdg->num_tasks);
715 }
716#endif
717#if OMPT_SUPPORT
718 if (ompt_enabled.enabled) {
719 if (!current_task->ompt_task_info.frame.enter_frame.ptr)
720 current_task->ompt_task_info.frame.enter_frame.ptr =
721 OMPT_GET_FRAME_ADDRESS(0);
722 if (ompt_enabled.ompt_callback_task_create) {
723 ompt_callbacks.ompt_callback(ompt_callback_task_create)(
724 &(current_task->ompt_task_info.task_data),
725 &(current_task->ompt_task_info.frame),
726 &(new_taskdata->ompt_task_info.task_data),
727 ompt_task_explicit | TASK_TYPE_DETAILS_FORMAT(new_taskdata), 1,
728 OMPT_LOAD_OR_GET_RETURN_ADDRESS(gtid));
729 }
730
731 new_taskdata->ompt_task_info.frame.enter_frame.ptr =
732 OMPT_GET_FRAME_ADDRESS(0);
733 }
734
735#if OMPT_OPTIONAL
736 /* OMPT grab all dependences if requested by the tool */
737 if (ndeps + ndeps_noalias > 0 && ompt_enabled.ompt_callback_dependences) {
738 kmp_int32 i;
739
740 int ompt_ndeps = ndeps + ndeps_noalias;
741 ompt_dependence_t *ompt_deps = (ompt_dependence_t *)KMP_OMPT_DEPS_ALLOC(
742 thread, (ndeps + ndeps_noalias) * sizeof(ompt_dependence_t));
743
744 KMP_ASSERT(ompt_deps != NULL);
745
746 for (i = 0; i < ndeps; i++) {
747 ompt_deps[i].variable.ptr = (void *)dep_list[i].base_addr;
748 if (dep_list[i].base_addr == KMP_SIZE_T_MAX)
749 ompt_deps[i].dependence_type = ompt_dependence_type_out_all_memory;
750 else if (dep_list[i].flags.in && dep_list[i].flags.out)
751 ompt_deps[i].dependence_type = ompt_dependence_type_inout;
752 else if (dep_list[i].flags.out)
753 ompt_deps[i].dependence_type = ompt_dependence_type_out;
754 else if (dep_list[i].flags.in)
755 ompt_deps[i].dependence_type = ompt_dependence_type_in;
756 else if (dep_list[i].flags.mtx)
757 ompt_deps[i].dependence_type = ompt_dependence_type_mutexinoutset;
758 else if (dep_list[i].flags.set)
759 ompt_deps[i].dependence_type = ompt_dependence_type_inoutset;
760 else if (dep_list[i].flags.all)
761 ompt_deps[i].dependence_type = ompt_dependence_type_out_all_memory;
762 }
763 for (i = 0; i < ndeps_noalias; i++) {
764 ompt_deps[ndeps + i].variable.ptr = (void *)noalias_dep_list[i].base_addr;
765 if (noalias_dep_list[i].base_addr == KMP_SIZE_T_MAX)
766 ompt_deps[ndeps + i].dependence_type =
767 ompt_dependence_type_out_all_memory;
768 else if (noalias_dep_list[i].flags.in && noalias_dep_list[i].flags.out)
769 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inout;
770 else if (noalias_dep_list[i].flags.out)
771 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_out;
772 else if (noalias_dep_list[i].flags.in)
773 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_in;
774 else if (noalias_dep_list[i].flags.mtx)
775 ompt_deps[ndeps + i].dependence_type =
776 ompt_dependence_type_mutexinoutset;
777 else if (noalias_dep_list[i].flags.set)
778 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inoutset;
779 else if (noalias_dep_list[i].flags.all)
780 ompt_deps[ndeps + i].dependence_type =
781 ompt_dependence_type_out_all_memory;
782 }
783 ompt_callbacks.ompt_callback(ompt_callback_dependences)(
784 &(new_taskdata->ompt_task_info.task_data), ompt_deps, ompt_ndeps);
785 /* We can now free the allocated memory for the dependences */
786 /* For OMPD we might want to delay the free until end of this function */
787 KMP_OMPT_DEPS_FREE(thread, ompt_deps);
788 }
789#endif /* OMPT_OPTIONAL */
790#endif /* OMPT_SUPPORT */
791
792 bool serial = current_task->td_flags.team_serial ||
793 current_task->td_flags.tasking_ser ||
794 current_task->td_flags.final;
795 kmp_task_team_t *task_team = thread->th.th_task_team;
796 serial = serial &&
797 !(task_team && (task_team->tt.tt_found_proxy_tasks ||
798 task_team->tt.tt_hidden_helper_task_encountered));
799
800 if (!serial && (ndeps > 0 || ndeps_noalias > 0)) {
801 /* if no dependences have been tracked yet, create the dependence hash */
802 if (current_task->td_dephash == NULL)
803 current_task->td_dephash = __kmp_dephash_create(thread, current_task);
804
805#if USE_FAST_MEMORY
806 kmp_depnode_t *node =
807 (kmp_depnode_t *)__kmp_fast_allocate(thread, sizeof(kmp_depnode_t));
808#else
809 kmp_depnode_t *node =
810 (kmp_depnode_t *)__kmp_thread_malloc(thread, sizeof(kmp_depnode_t));
811#endif
812
813 __kmp_init_node(node);
814 new_taskdata->td_depnode = node;
815
816 if (__kmp_check_deps(gtid, node, new_task, &current_task->td_dephash,
817 NO_DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
818 noalias_dep_list)) {
819 KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had blocking "
820 "dependences: "
821 "loc=%p task=%p, return: TASK_CURRENT_NOT_QUEUED\n",
822 gtid, loc_ref, new_taskdata));
823#if OMPT_SUPPORT
824 if (ompt_enabled.enabled) {
825 current_task->ompt_task_info.frame.enter_frame = ompt_data_none;
826 }
827#endif
828 return TASK_CURRENT_NOT_QUEUED;
829 }
830 } else {
831 KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d ignored dependences "
832 "for task (serialized) loc=%p task=%p\n",
833 gtid, loc_ref, new_taskdata));
834 }
835
836 KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had no blocking "
837 "dependences : "
838 "loc=%p task=%p, transferring to __kmp_omp_task\n",
839 gtid, loc_ref, new_taskdata));
840
841 kmp_int32 ret = __kmp_omp_task(gtid, new_task, true);
842#if OMPT_SUPPORT
843 if (ompt_enabled.enabled) {
844 current_task->ompt_task_info.frame.enter_frame = ompt_data_none;
845 }
846#endif
847 return ret;
848}
849
850#if OMPT_SUPPORT
851void __ompt_taskwait_dep_finish(kmp_taskdata_t *current_task,
852 ompt_data_t *taskwait_task_data) {
853 if (ompt_enabled.ompt_callback_task_schedule) {
854 ompt_callbacks.ompt_callback(ompt_callback_task_schedule)(
855 taskwait_task_data, ompt_taskwait_complete, NULL);
856 }
857 current_task->ompt_task_info.frame.enter_frame.ptr = NULL;
858 *taskwait_task_data = ompt_data_none;
859}
860#endif /* OMPT_SUPPORT */
861
873void __kmpc_omp_wait_deps(ident_t *loc_ref, kmp_int32 gtid, kmp_int32 ndeps,
874 kmp_depend_info_t *dep_list, kmp_int32 ndeps_noalias,
875 kmp_depend_info_t *noalias_dep_list) {
876 __kmpc_omp_taskwait_deps_51(loc_ref, gtid, ndeps, dep_list, ndeps_noalias,
877 noalias_dep_list, false);
878}
879
880/* __kmpc_omp_taskwait_deps_51 : Function for OpenMP 5.1 nowait clause.
881 Placeholder for taskwait with nowait clause.
882 Earlier code of __kmpc_omp_wait_deps() is now
883 in this function.
884*/
885void __kmpc_omp_taskwait_deps_51(ident_t *loc_ref, kmp_int32 gtid,
886 kmp_int32 ndeps, kmp_depend_info_t *dep_list,
887 kmp_int32 ndeps_noalias,
888 kmp_depend_info_t *noalias_dep_list,
889 kmp_int32 has_no_wait) {
890 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(enter): T#%d loc=%p nowait#%d\n",
891 gtid, loc_ref, has_no_wait));
892 if (ndeps == 0 && ndeps_noalias == 0) {
893 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d has no dependences to "
894 "wait upon : loc=%p\n",
895 gtid, loc_ref));
896 return;
897 }
898 __kmp_assert_valid_gtid(gtid);
899 kmp_info_t *thread = __kmp_threads[gtid];
900 kmp_taskdata_t *current_task = thread->th.th_current_task;
901
902#if OMPT_SUPPORT
903 // this function represents a taskwait construct with depend clause
904 // We signal 4 events:
905 // - creation of the taskwait task
906 // - dependences of the taskwait task
907 // - schedule and finish of the taskwait task
908 ompt_data_t *taskwait_task_data = &thread->th.ompt_thread_info.task_data;
909 KMP_ASSERT(taskwait_task_data->ptr == NULL);
910 if (ompt_enabled.enabled) {
911 if (!current_task->ompt_task_info.frame.enter_frame.ptr)
912 current_task->ompt_task_info.frame.enter_frame.ptr =
913 OMPT_GET_FRAME_ADDRESS(0);
914 if (ompt_enabled.ompt_callback_task_create) {
915 ompt_callbacks.ompt_callback(ompt_callback_task_create)(
916 &(current_task->ompt_task_info.task_data),
917 &(current_task->ompt_task_info.frame), taskwait_task_data,
918 ompt_task_taskwait | ompt_task_undeferred | ompt_task_mergeable, 1,
919 OMPT_LOAD_OR_GET_RETURN_ADDRESS(gtid));
920 }
921 }
922
923#if OMPT_OPTIONAL
924 /* OMPT grab all dependences if requested by the tool */
925 if (ndeps + ndeps_noalias > 0 && ompt_enabled.ompt_callback_dependences) {
926 kmp_int32 i;
927
928 int ompt_ndeps = ndeps + ndeps_noalias;
929 ompt_dependence_t *ompt_deps = (ompt_dependence_t *)KMP_OMPT_DEPS_ALLOC(
930 thread, (ndeps + ndeps_noalias) * sizeof(ompt_dependence_t));
931
932 KMP_ASSERT(ompt_deps != NULL);
933
934 for (i = 0; i < ndeps; i++) {
935 ompt_deps[i].variable.ptr = (void *)dep_list[i].base_addr;
936 if (dep_list[i].flags.in && dep_list[i].flags.out)
937 ompt_deps[i].dependence_type = ompt_dependence_type_inout;
938 else if (dep_list[i].flags.out)
939 ompt_deps[i].dependence_type = ompt_dependence_type_out;
940 else if (dep_list[i].flags.in)
941 ompt_deps[i].dependence_type = ompt_dependence_type_in;
942 else if (dep_list[i].flags.mtx)
943 ompt_deps[ndeps + i].dependence_type =
944 ompt_dependence_type_mutexinoutset;
945 else if (dep_list[i].flags.set)
946 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inoutset;
947 }
948 for (i = 0; i < ndeps_noalias; i++) {
949 ompt_deps[ndeps + i].variable.ptr = (void *)noalias_dep_list[i].base_addr;
950 if (noalias_dep_list[i].flags.in && noalias_dep_list[i].flags.out)
951 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inout;
952 else if (noalias_dep_list[i].flags.out)
953 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_out;
954 else if (noalias_dep_list[i].flags.in)
955 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_in;
956 else if (noalias_dep_list[i].flags.mtx)
957 ompt_deps[ndeps + i].dependence_type =
958 ompt_dependence_type_mutexinoutset;
959 else if (noalias_dep_list[i].flags.set)
960 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inoutset;
961 }
962 ompt_callbacks.ompt_callback(ompt_callback_dependences)(
963 taskwait_task_data, ompt_deps, ompt_ndeps);
964 /* We can now free the allocated memory for the dependences */
965 /* For OMPD we might want to delay the free until end of this function */
966 KMP_OMPT_DEPS_FREE(thread, ompt_deps);
967 ompt_deps = NULL;
968 }
969#endif /* OMPT_OPTIONAL */
970#endif /* OMPT_SUPPORT */
971
972 // We can return immediately as:
973 // - dependences are not computed in serial teams (except with proxy tasks)
974 // - if the dephash is not yet created it means we have nothing to wait for
975 bool ignore = current_task->td_flags.team_serial ||
976 current_task->td_flags.tasking_ser ||
977 current_task->td_flags.final;
978 ignore =
979 ignore && thread->th.th_task_team != NULL &&
980 thread->th.th_task_team->tt.tt_found_proxy_tasks == FALSE &&
981 thread->th.th_task_team->tt.tt_hidden_helper_task_encountered == FALSE;
982 ignore = ignore || current_task->td_dephash == NULL;
983
984 if (ignore) {
985 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d has no blocking "
986 "dependences : loc=%p\n",
987 gtid, loc_ref));
988#if OMPT_SUPPORT
989 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
990#endif /* OMPT_SUPPORT */
991 return;
992 }
993
994 kmp_depnode_t node = {0};
995 __kmp_init_node(&node);
996
997 if (!__kmp_check_deps(gtid, &node, NULL, &current_task->td_dephash,
998 DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
999 noalias_dep_list)) {
1000 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d has no blocking "
1001 "dependences : loc=%p\n",
1002 gtid, loc_ref));
1003#if OMPT_SUPPORT
1004 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
1005#endif /* OMPT_SUPPORT */
1006 return;
1007 }
1008
1009 int thread_finished = FALSE;
1010 kmp_flag_32<false, false> flag(
1011 (std::atomic<kmp_uint32> *)&node.dn.npredecessors, 0U);
1012 while (node.dn.npredecessors > 0) {
1013 flag.execute_tasks(thread, gtid, FALSE,
1014 &thread_finished USE_ITT_BUILD_ARG(NULL),
1015 __kmp_task_stealing_constraint);
1016 }
1017
1018#if OMPT_SUPPORT
1019 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
1020#endif /* OMPT_SUPPORT */
1021 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d finished waiting : loc=%p\
1022 \n",
1023 gtid, loc_ref));
1024}
kmp_int32 __kmpc_omp_task_with_deps(ident_t *loc_ref, kmp_int32 gtid, kmp_task_t *new_task, kmp_int32 ndeps, kmp_depend_info_t *dep_list, kmp_int32 ndeps_noalias, kmp_depend_info_t *noalias_dep_list)
void __kmpc_omp_wait_deps(ident_t *loc_ref, kmp_int32 gtid, kmp_int32 ndeps, kmp_depend_info_t *dep_list, kmp_int32 ndeps_noalias, kmp_depend_info_t *noalias_dep_list)
Definition: kmp.h:234