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, bool on_stack) {
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(lck: &node->dn.lock);
44 // Init creates the first reference. Bit 0 indicates that this node
45 // resides on the stack. The refcount is incremented and decremented in
46 // steps of two, maintaining use of even numbers for heap nodes and odd
47 // numbers for stack nodes.
48 KMP_ATOMIC_ST_RLX(&node->dn.nrefs, on_stack ? 3 : 2);
49#ifdef KMP_SUPPORT_GRAPH_OUTPUT
50 node->dn.id = KMP_ATOMIC_INC(&kmp_node_id_seed);
51#endif
52#if USE_ITT_BUILD && USE_ITT_NOTIFY
53 __itt_sync_create(node, "OMP task dep node", NULL, 0);
54#endif
55}
56
57static inline kmp_depnode_t *__kmp_node_ref(kmp_depnode_t *node) {
58 KMP_ATOMIC_ADD(&node->dn.nrefs, 2);
59 return node;
60}
61
62enum { KMP_DEPHASH_OTHER_SIZE = 97, KMP_DEPHASH_MASTER_SIZE = 997 };
63
64size_t sizes[] = {997, 2003, 4001, 8191, 16001, 32003, 64007, 131071, 270029};
65const size_t MAX_GEN = 8;
66
67static inline size_t __kmp_dephash_hash(kmp_intptr_t addr, size_t hsize) {
68 // TODO alternate to try: set = (((Addr64)(addrUsefulBits * 9.618)) %
69 // m_num_sets );
70 return ((addr >> 6) ^ (addr >> 2)) % hsize;
71}
72
73static kmp_dephash_t *__kmp_dephash_extend(kmp_info_t *thread,
74 kmp_dephash_t *current_dephash) {
75 kmp_dephash_t *h;
76
77 size_t gen = current_dephash->generation + 1;
78 if (gen >= MAX_GEN)
79 return current_dephash;
80 size_t new_size = sizes[gen];
81
82 size_t size_to_allocate =
83 new_size * sizeof(kmp_dephash_entry_t *) + sizeof(kmp_dephash_t);
84
85#if USE_FAST_MEMORY
86 h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size_to_allocate);
87#else
88 h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size_to_allocate);
89#endif
90
91 h->size = new_size;
92 h->nelements = current_dephash->nelements;
93 h->buckets = (kmp_dephash_entry **)(h + 1);
94 h->generation = gen;
95 h->nconflicts = 0;
96 h->last_all = current_dephash->last_all;
97
98 // make sure buckets are properly initialized
99 for (size_t i = 0; i < new_size; i++) {
100 h->buckets[i] = NULL;
101 }
102
103 // insert existing elements in the new table
104 for (size_t i = 0; i < current_dephash->size; i++) {
105 kmp_dephash_entry_t *next, *entry;
106 for (entry = current_dephash->buckets[i]; entry; entry = next) {
107 next = entry->next_in_bucket;
108 // Compute the new hash using the new size, and insert the entry in
109 // the new bucket.
110 size_t new_bucket = __kmp_dephash_hash(addr: entry->addr, hsize: h->size);
111 entry->next_in_bucket = h->buckets[new_bucket];
112 if (entry->next_in_bucket) {
113 h->nconflicts++;
114 }
115 h->buckets[new_bucket] = entry;
116 }
117 }
118
119 // Free old hash table
120#if USE_FAST_MEMORY
121 __kmp_fast_free(thread, current_dephash);
122#else
123 __kmp_thread_free(thread, current_dephash);
124#endif
125
126 return h;
127}
128
129static kmp_dephash_t *__kmp_dephash_create(kmp_info_t *thread,
130 kmp_taskdata_t *current_task) {
131 kmp_dephash_t *h;
132
133 size_t h_size;
134
135 if (current_task->td_flags.tasktype == TASK_IMPLICIT)
136 h_size = KMP_DEPHASH_MASTER_SIZE;
137 else
138 h_size = KMP_DEPHASH_OTHER_SIZE;
139
140 size_t size = h_size * sizeof(kmp_dephash_entry_t *) + sizeof(kmp_dephash_t);
141
142#if USE_FAST_MEMORY
143 h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size);
144#else
145 h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size);
146#endif
147 h->size = h_size;
148
149 h->generation = 0;
150 h->nelements = 0;
151 h->nconflicts = 0;
152 h->buckets = (kmp_dephash_entry **)(h + 1);
153 h->last_all = NULL;
154
155 for (size_t i = 0; i < h_size; i++)
156 h->buckets[i] = 0;
157
158 return h;
159}
160
161static kmp_dephash_entry *__kmp_dephash_find(kmp_info_t *thread,
162 kmp_dephash_t **hash,
163 kmp_intptr_t addr) {
164 kmp_dephash_t *h = *hash;
165 if (h->nelements != 0 && h->nconflicts / h->size >= 1) {
166 *hash = __kmp_dephash_extend(thread, current_dephash: h);
167 h = *hash;
168 }
169 size_t bucket = __kmp_dephash_hash(addr, hsize: h->size);
170
171 kmp_dephash_entry_t *entry;
172 for (entry = h->buckets[bucket]; entry; entry = entry->next_in_bucket)
173 if (entry->addr == addr)
174 break;
175
176 if (entry == NULL) {
177// create entry. This is only done by one thread so no locking required
178#if USE_FAST_MEMORY
179 entry = (kmp_dephash_entry_t *)__kmp_fast_allocate(
180 thread, sizeof(kmp_dephash_entry_t));
181#else
182 entry = (kmp_dephash_entry_t *)__kmp_thread_malloc(
183 thread, sizeof(kmp_dephash_entry_t));
184#endif
185 entry->addr = addr;
186 if (!h->last_all) // no predecessor task with omp_all_memory dependence
187 entry->last_out = NULL;
188 else // else link the omp_all_memory depnode to the new entry
189 entry->last_out = __kmp_node_ref(node: h->last_all);
190 entry->last_set = NULL;
191 entry->prev_set = NULL;
192 entry->last_flag = 0;
193 entry->mtx_lock = NULL;
194 entry->next_in_bucket = h->buckets[bucket];
195 h->buckets[bucket] = entry;
196 h->nelements++;
197 if (entry->next_in_bucket)
198 h->nconflicts++;
199 }
200 return entry;
201}
202
203static kmp_depnode_list_t *__kmp_add_node(kmp_info_t *thread,
204 kmp_depnode_list_t *list,
205 kmp_depnode_t *node) {
206 kmp_depnode_list_t *new_head;
207
208#if USE_FAST_MEMORY
209 new_head = (kmp_depnode_list_t *)__kmp_fast_allocate(
210 thread, sizeof(kmp_depnode_list_t));
211#else
212 new_head = (kmp_depnode_list_t *)__kmp_thread_malloc(
213 thread, sizeof(kmp_depnode_list_t));
214#endif
215
216 new_head->node = __kmp_node_ref(node);
217 new_head->next = list;
218
219 return new_head;
220}
221
222static inline void __kmp_track_dependence(kmp_int32 gtid, kmp_depnode_t *source,
223 kmp_depnode_t *sink,
224 kmp_task_t *sink_task) {
225#if OMPX_TASKGRAPH
226 kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
227 kmp_taskdata_t *task_sink = KMP_TASK_TO_TASKDATA(sink_task);
228 if (source->dn.task && sink_task) {
229 // Not supporting dependency between two tasks that one is within the TDG
230 // and the other is not
231 KMP_ASSERT(task_source->is_taskgraph == task_sink->is_taskgraph);
232 }
233 if (task_sink->is_taskgraph &&
234 __kmp_tdg_is_recording(task_sink->tdg->tdg_status)) {
235 kmp_node_info_t *source_info =
236 &task_sink->tdg->record_map[task_source->td_tdg_task_id];
237 bool exists = false;
238 for (int i = 0; i < source_info->nsuccessors; i++) {
239 if (source_info->successors[i] == task_sink->td_tdg_task_id) {
240 exists = true;
241 break;
242 }
243 }
244 if (!exists) {
245 if (source_info->nsuccessors >= source_info->successors_size) {
246 kmp_uint old_size = source_info->successors_size;
247 source_info->successors_size = 2 * source_info->successors_size;
248 kmp_int32 *old_succ_ids = source_info->successors;
249 kmp_int32 *new_succ_ids = (kmp_int32 *)__kmp_allocate(
250 source_info->successors_size * sizeof(kmp_int32));
251 KMP_MEMCPY(new_succ_ids, old_succ_ids, old_size * sizeof(kmp_int32));
252 source_info->successors = new_succ_ids;
253 __kmp_free(old_succ_ids);
254 }
255
256 source_info->successors[source_info->nsuccessors] =
257 task_sink->td_tdg_task_id;
258 source_info->nsuccessors++;
259
260 kmp_node_info_t *sink_info =
261 &(task_sink->tdg->record_map[task_sink->td_tdg_task_id]);
262 sink_info->npredecessors++;
263 }
264 }
265#endif
266#ifdef KMP_SUPPORT_GRAPH_OUTPUT
267 kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
268 // do not use sink->dn.task as that is only filled after the dependences
269 // are already processed!
270 kmp_taskdata_t *task_sink = KMP_TASK_TO_TASKDATA(sink_task);
271
272 __kmp_printf("%d(%s) -> %d(%s)\n", source->dn.id,
273 task_source->td_ident->psource, sink->dn.id,
274 task_sink->td_ident->psource);
275#endif
276#if OMPT_SUPPORT && OMPT_OPTIONAL
277 /* OMPT tracks dependences between task (a=source, b=sink) in which
278 task a blocks the execution of b through the ompt_new_dependence_callback
279 */
280 if (ompt_enabled.ompt_callback_task_dependence) {
281 kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
282 ompt_data_t *sink_data;
283 if (sink_task)
284 sink_data = &(KMP_TASK_TO_TASKDATA(sink_task)->ompt_task_info.task_data);
285 else
286 sink_data = &__kmp_threads[gtid]->th.ompt_thread_info.task_data;
287
288 ompt_callbacks.ompt_callback(ompt_callback_task_dependence)(
289 &(task_source->ompt_task_info.task_data), sink_data);
290 }
291#endif /* OMPT_SUPPORT && OMPT_OPTIONAL */
292}
293
294kmp_base_depnode_t *__kmpc_task_get_depnode(kmp_task_t *task) {
295 kmp_taskdata_t *td = KMP_TASK_TO_TASKDATA(task);
296 return td->td_depnode ? &(td->td_depnode->dn) : NULL;
297}
298
299kmp_depnode_list_t *__kmpc_task_get_successors(kmp_task_t *task) {
300 kmp_taskdata_t *td = KMP_TASK_TO_TASKDATA(task);
301 return td->td_depnode->dn.successors;
302}
303
304static inline kmp_int32
305__kmp_depnode_link_successor(kmp_int32 gtid, kmp_info_t *thread,
306 kmp_task_t *task, kmp_depnode_t *node,
307 kmp_depnode_list_t *plist) {
308 if (!plist)
309 return 0;
310 kmp_int32 npredecessors = 0;
311 // link node as successor of list elements
312 for (kmp_depnode_list_t *p = plist; p; p = p->next) {
313 kmp_depnode_t *dep = p->node;
314#if OMPX_TASKGRAPH
315 kmp_tdg_status tdg_status = KMP_TDG_NONE;
316 if (task) {
317 kmp_taskdata_t *td = KMP_TASK_TO_TASKDATA(task);
318 if (td->is_taskgraph)
319 tdg_status = KMP_TASK_TO_TASKDATA(task)->tdg->tdg_status;
320 if (__kmp_tdg_is_recording(tdg_status))
321 __kmp_track_dependence(gtid, dep, node, task);
322 }
323#endif
324 if (dep->dn.task) {
325 KMP_ACQUIRE_DEPNODE(gtid, dep);
326 if (dep->dn.task) {
327 if (!dep->dn.successors || dep->dn.successors->node != node) {
328#if OMPX_TASKGRAPH
329 if (!(__kmp_tdg_is_recording(tdg_status)) && task)
330#endif
331 __kmp_track_dependence(gtid, source: dep, sink: node, sink_task: task);
332 dep->dn.successors = __kmp_add_node(thread, list: dep->dn.successors, node);
333 KA_TRACE(40, ("__kmp_process_deps: T#%d adding dependence from %p to "
334 "%p\n",
335 gtid, KMP_TASK_TO_TASKDATA(dep->dn.task),
336 KMP_TASK_TO_TASKDATA(task)));
337 npredecessors++;
338 }
339 }
340 KMP_RELEASE_DEPNODE(gtid, dep);
341 }
342 }
343 return npredecessors;
344}
345
346// Add the edge 'sink' -> 'source' in the task dependency graph
347static inline kmp_int32 __kmp_depnode_link_successor(kmp_int32 gtid,
348 kmp_info_t *thread,
349 kmp_task_t *task,
350 kmp_depnode_t *source,
351 kmp_depnode_t *sink) {
352 if (!sink)
353 return 0;
354 kmp_int32 npredecessors = 0;
355#if OMPX_TASKGRAPH
356 kmp_tdg_status tdg_status = KMP_TDG_NONE;
357 kmp_taskdata_t *td = KMP_TASK_TO_TASKDATA(task);
358 if (task) {
359 if (td->is_taskgraph)
360 tdg_status = KMP_TASK_TO_TASKDATA(task)->tdg->tdg_status;
361 if (__kmp_tdg_is_recording(tdg_status) && sink->dn.task)
362 __kmp_track_dependence(gtid, sink, source, task);
363 }
364#endif
365 if (sink->dn.task) {
366 // synchronously add source to sink' list of successors
367 KMP_ACQUIRE_DEPNODE(gtid, sink);
368 if (sink->dn.task) {
369 if (!sink->dn.successors || sink->dn.successors->node != source) {
370#if OMPX_TASKGRAPH
371 if (!(__kmp_tdg_is_recording(tdg_status)) && task)
372#endif
373 __kmp_track_dependence(gtid, source: sink, sink: source, sink_task: task);
374 sink->dn.successors = __kmp_add_node(thread, list: sink->dn.successors, node: source);
375 KA_TRACE(40, ("__kmp_process_deps: T#%d adding dependence from %p to "
376 "%p\n",
377 gtid, KMP_TASK_TO_TASKDATA(sink->dn.task),
378 KMP_TASK_TO_TASKDATA(task)));
379#if OMPX_TASKGRAPH
380 if (__kmp_tdg_is_recording(tdg_status)) {
381 kmp_taskdata_t *tdd = KMP_TASK_TO_TASKDATA(sink->dn.task);
382 if (tdd->is_taskgraph) {
383 if (tdd->td_flags.onced)
384 // decrement npredecessors if sink->dn.task belongs to a taskgraph
385 // and
386 // 1) the task is reset to its initial state (by kmp_free_task) or
387 // 2) the task is complete but not yet reset
388 npredecessors--;
389 }
390 }
391#endif
392 npredecessors++;
393 }
394 }
395 KMP_RELEASE_DEPNODE(gtid, sink);
396 }
397 return npredecessors;
398}
399
400static inline kmp_int32
401__kmp_process_dep_all(kmp_int32 gtid, kmp_depnode_t *node, kmp_dephash_t *h,
402 bool dep_barrier, kmp_task_t *task) {
403 KA_TRACE(30, ("__kmp_process_dep_all: T#%d processing dep_all, "
404 "dep_barrier = %d\n",
405 gtid, dep_barrier));
406 kmp_info_t *thread = __kmp_threads[gtid];
407 kmp_int32 npredecessors = 0;
408
409 // process previous omp_all_memory node if any
410 npredecessors +=
411 __kmp_depnode_link_successor(gtid, thread, task, source: node, sink: h->last_all);
412 __kmp_node_deref(thread, node: h->last_all);
413 if (!dep_barrier) {
414 h->last_all = __kmp_node_ref(node);
415 } else {
416 // if this is a sync point in the serial sequence, then the previous
417 // outputs are guaranteed to be completed after the execution of this
418 // task so the previous output nodes can be cleared.
419 h->last_all = NULL;
420 }
421
422 // process all regular dependences
423 for (size_t i = 0; i < h->size; i++) {
424 kmp_dephash_entry_t *info = h->buckets[i];
425 if (!info) // skip empty slots in dephash
426 continue;
427 for (; info; info = info->next_in_bucket) {
428 // for each entry the omp_all_memory works as OUT dependence
429 kmp_depnode_t *last_out = info->last_out;
430 kmp_depnode_list_t *last_set = info->last_set;
431 kmp_depnode_list_t *prev_set = info->prev_set;
432 if (last_set) {
433 npredecessors +=
434 __kmp_depnode_link_successor(gtid, thread, task, node, plist: last_set);
435 __kmp_depnode_list_free(thread, list: last_set);
436 __kmp_depnode_list_free(thread, list: prev_set);
437 info->last_set = NULL;
438 info->prev_set = NULL;
439 info->last_flag = 0; // no sets in this dephash entry
440 } else {
441 npredecessors +=
442 __kmp_depnode_link_successor(gtid, thread, task, source: node, sink: last_out);
443 }
444 __kmp_node_deref(thread, node: last_out);
445 if (!dep_barrier) {
446 info->last_out = __kmp_node_ref(node);
447 } else {
448 info->last_out = NULL;
449 }
450 }
451 }
452 KA_TRACE(30, ("__kmp_process_dep_all: T#%d found %d predecessors\n", gtid,
453 npredecessors));
454 return npredecessors;
455}
456
457template <bool filter>
458static inline kmp_int32
459__kmp_process_deps(kmp_int32 gtid, kmp_depnode_t *node, kmp_dephash_t **hash,
460 bool dep_barrier, kmp_int32 ndeps,
461 kmp_depend_info_t *dep_list, kmp_task_t *task) {
462 KA_TRACE(30, ("__kmp_process_deps<%d>: T#%d processing %d dependences : "
463 "dep_barrier = %d\n",
464 filter, gtid, ndeps, dep_barrier));
465
466 kmp_info_t *thread = __kmp_threads[gtid];
467 kmp_int32 npredecessors = 0;
468 for (kmp_int32 i = 0; i < ndeps; i++) {
469 const kmp_depend_info_t *dep = &dep_list[i];
470
471 if (filter && dep->base_addr == 0)
472 continue; // skip filtered entries
473
474 kmp_dephash_entry_t *info =
475 __kmp_dephash_find(thread, hash, addr: dep->base_addr);
476 kmp_depnode_t *last_out = info->last_out;
477 kmp_depnode_list_t *last_set = info->last_set;
478 kmp_depnode_list_t *prev_set = info->prev_set;
479
480 if (dep->flags.out) { // out or inout --> clean lists if any
481 if (last_set) {
482 npredecessors +=
483 __kmp_depnode_link_successor(gtid, thread, task, node, plist: last_set);
484 __kmp_depnode_list_free(thread, list: last_set);
485 __kmp_depnode_list_free(thread, list: prev_set);
486 info->last_set = NULL;
487 info->prev_set = NULL;
488 info->last_flag = 0; // no sets in this dephash entry
489 } else {
490 npredecessors +=
491 __kmp_depnode_link_successor(gtid, thread, task, source: node, sink: last_out);
492 }
493 __kmp_node_deref(thread, node: last_out);
494 if (!dep_barrier) {
495 info->last_out = __kmp_node_ref(node);
496 } else {
497 // if this is a sync point in the serial sequence, then the previous
498 // outputs are guaranteed to be completed after the execution of this
499 // task so the previous output nodes can be cleared.
500 info->last_out = NULL;
501 }
502 } else { // either IN or MTX or SET
503 if (info->last_flag == 0 || info->last_flag == dep->flag) {
504 // last_set either didn't exist or of same dep kind
505 // link node as successor of the last_out if any
506 npredecessors +=
507 __kmp_depnode_link_successor(gtid, thread, task, source: node, sink: last_out);
508 // link node as successor of all nodes in the prev_set if any
509 npredecessors +=
510 __kmp_depnode_link_successor(gtid, thread, task, node, plist: prev_set);
511 if (dep_barrier) {
512 // clean last_out and prev_set if any; don't touch last_set
513 __kmp_node_deref(thread, node: last_out);
514 info->last_out = NULL;
515 __kmp_depnode_list_free(thread, list: prev_set);
516 info->prev_set = NULL;
517 }
518 } else { // last_set is of different dep kind, make it prev_set
519 // link node as successor of all nodes in the last_set
520 npredecessors +=
521 __kmp_depnode_link_successor(gtid, thread, task, node, plist: last_set);
522 // clean last_out if any
523 __kmp_node_deref(thread, node: last_out);
524 info->last_out = NULL;
525 // clean prev_set if any
526 __kmp_depnode_list_free(thread, list: prev_set);
527 if (!dep_barrier) {
528 // move last_set to prev_set, new last_set will be allocated
529 info->prev_set = last_set;
530 } else {
531 info->prev_set = NULL;
532 info->last_flag = 0;
533 }
534 info->last_set = NULL;
535 }
536 // for dep_barrier last_flag value should remain:
537 // 0 if last_set is empty, unchanged otherwise
538 if (!dep_barrier) {
539 info->last_flag = dep->flag; // store dep kind of the last_set
540 info->last_set = __kmp_add_node(thread, list: info->last_set, node);
541 }
542 // check if we are processing MTX dependency
543 if (dep->flag == KMP_DEP_MTX) {
544 if (info->mtx_lock == NULL) {
545 info->mtx_lock = (kmp_lock_t *)__kmp_allocate(sizeof(kmp_lock_t));
546 __kmp_init_lock(lck: info->mtx_lock);
547 }
548 KMP_DEBUG_ASSERT(node->dn.mtx_num_locks < MAX_MTX_DEPS);
549 kmp_int32 m;
550 // Save lock in node's array
551 for (m = 0; m < MAX_MTX_DEPS; ++m) {
552 // sort pointers in decreasing order to avoid potential livelock
553 if (node->dn.mtx_locks[m] < info->mtx_lock) {
554 KMP_DEBUG_ASSERT(!node->dn.mtx_locks[node->dn.mtx_num_locks]);
555 for (int n = node->dn.mtx_num_locks; n > m; --n) {
556 // shift right all lesser non-NULL pointers
557 KMP_DEBUG_ASSERT(node->dn.mtx_locks[n - 1] != NULL);
558 node->dn.mtx_locks[n] = node->dn.mtx_locks[n - 1];
559 }
560 node->dn.mtx_locks[m] = info->mtx_lock;
561 break;
562 }
563 }
564 KMP_DEBUG_ASSERT(m < MAX_MTX_DEPS); // must break from loop
565 node->dn.mtx_num_locks++;
566 }
567 }
568 }
569 KA_TRACE(30, ("__kmp_process_deps<%d>: T#%d found %d predecessors\n", filter,
570 gtid, npredecessors));
571 return npredecessors;
572}
573
574#define NO_DEP_BARRIER (false)
575#define DEP_BARRIER (true)
576
577// returns true if the task has any outstanding dependence
578static bool __kmp_check_deps(kmp_int32 gtid, kmp_depnode_t *node,
579 kmp_task_t *task, kmp_dephash_t **hash,
580 bool dep_barrier, kmp_int32 ndeps,
581 kmp_depend_info_t *dep_list,
582 kmp_int32 ndeps_noalias,
583 kmp_depend_info_t *noalias_dep_list) {
584 int i, n_mtxs = 0, dep_all = 0;
585#if KMP_DEBUG
586 kmp_taskdata_t *taskdata = KMP_TASK_TO_TASKDATA(task);
587#endif
588 KA_TRACE(20, ("__kmp_check_deps: T#%d checking dependences for task %p : %d "
589 "possibly aliased dependences, %d non-aliased dependences : "
590 "dep_barrier=%d .\n",
591 gtid, taskdata, ndeps, ndeps_noalias, dep_barrier));
592
593 // Filter deps in dep_list
594 // TODO: Different algorithm for large dep_list ( > 10 ? )
595 for (i = 0; i < ndeps; i++) {
596 if (dep_list[i].base_addr != 0 &&
597 dep_list[i].base_addr != (kmp_intptr_t)KMP_SIZE_T_MAX) {
598 KMP_DEBUG_ASSERT(
599 dep_list[i].flag == KMP_DEP_IN || dep_list[i].flag == KMP_DEP_OUT ||
600 dep_list[i].flag == KMP_DEP_INOUT ||
601 dep_list[i].flag == KMP_DEP_MTX || dep_list[i].flag == KMP_DEP_SET);
602 for (int j = i + 1; j < ndeps; j++) {
603 if (dep_list[i].base_addr == dep_list[j].base_addr) {
604 if (dep_list[i].flag != dep_list[j].flag) {
605 // two different dependences on same address work identical to OUT
606 dep_list[i].flag = KMP_DEP_OUT;
607 }
608 dep_list[j].base_addr = 0; // Mark j element as void
609 }
610 }
611 if (dep_list[i].flag == KMP_DEP_MTX) {
612 // limit number of mtx deps to MAX_MTX_DEPS per node
613 if (n_mtxs < MAX_MTX_DEPS && task != NULL) {
614 ++n_mtxs;
615 } else {
616 dep_list[i].flag = KMP_DEP_OUT; // downgrade mutexinoutset to inout
617 }
618 }
619 } else if (dep_list[i].flag == KMP_DEP_ALL ||
620 dep_list[i].base_addr == (kmp_intptr_t)KMP_SIZE_T_MAX) {
621 // omp_all_memory dependence can be marked by compiler by either
622 // (addr=0 && flag=0x80) (flag KMP_DEP_ALL), or (addr=-1).
623 // omp_all_memory overrides all other dependences if any
624 dep_all = 1;
625 break;
626 }
627 }
628
629 // doesn't need to be atomic as no other thread is going to be accessing this
630 // node just yet.
631 // npredecessors is set -1 to ensure that none of the releasing tasks queues
632 // this task before we have finished processing all the dependences
633 node->dn.npredecessors = -1;
634
635 // used to pack all npredecessors additions into a single atomic operation at
636 // the end
637 int npredecessors;
638
639 if (!dep_all) { // regular dependences
640 npredecessors = __kmp_process_deps<true>(gtid, node, hash, dep_barrier,
641 ndeps, dep_list, task);
642 npredecessors += __kmp_process_deps<false>(
643 gtid, node, hash, dep_barrier, ndeps: ndeps_noalias, dep_list: noalias_dep_list, task);
644 } else { // omp_all_memory dependence
645 npredecessors = __kmp_process_dep_all(gtid, node, h: *hash, dep_barrier, task);
646 }
647
648 node->dn.task = task;
649 KMP_MB();
650
651 // Account for our initial fake value
652 npredecessors++;
653
654 // Update predecessors and obtain current value to check if there are still
655 // any outstanding dependences (some tasks may have finished while we
656 // processed the dependences)
657 npredecessors =
658 node->dn.npredecessors.fetch_add(i: npredecessors) + npredecessors;
659
660 KA_TRACE(20, ("__kmp_check_deps: T#%d found %d predecessors for task %p \n",
661 gtid, npredecessors, taskdata));
662
663 // beyond this point the task could be queued (and executed) by a releasing
664 // task...
665 return npredecessors > 0 ? true : false;
666}
667
668/*!
669@ingroup TASKING
670@param loc_ref location of the original task directive
671@param gtid Global Thread ID of encountering thread
672@param new_task task thunk allocated by __kmp_omp_task_alloc() for the ''new
673task''
674@param ndeps Number of depend items with possible aliasing
675@param dep_list List of depend items with possible aliasing
676@param ndeps_noalias Number of depend items with no aliasing
677@param noalias_dep_list List of depend items with no aliasing
678
679@return Returns either TASK_CURRENT_NOT_QUEUED if the current task was not
680suspended and queued, or TASK_CURRENT_QUEUED if it was suspended and queued
681
682Schedule a non-thread-switchable task with dependences for execution
683*/
684kmp_int32 __kmpc_omp_task_with_deps(ident_t *loc_ref, kmp_int32 gtid,
685 kmp_task_t *new_task, kmp_int32 ndeps,
686 kmp_depend_info_t *dep_list,
687 kmp_int32 ndeps_noalias,
688 kmp_depend_info_t *noalias_dep_list) {
689
690 kmp_taskdata_t *new_taskdata = KMP_TASK_TO_TASKDATA(new_task);
691 KA_TRACE(10, ("__kmpc_omp_task_with_deps(enter): T#%d loc=%p task=%p\n", gtid,
692 loc_ref, new_taskdata));
693 __kmp_assert_valid_gtid(gtid);
694 kmp_info_t *thread = __kmp_threads[gtid];
695 kmp_taskdata_t *current_task = thread->th.th_current_task;
696
697#if OMPX_TASKGRAPH
698 // record TDG with deps
699 if (new_taskdata->is_taskgraph &&
700 __kmp_tdg_is_recording(new_taskdata->tdg->tdg_status)) {
701 kmp_tdg_info_t *tdg = new_taskdata->tdg;
702 // extend record_map if needed
703 if (new_taskdata->td_tdg_task_id >= tdg->map_size) {
704 __kmp_acquire_bootstrap_lock(&tdg->graph_lock);
705 if (new_taskdata->td_tdg_task_id >= tdg->map_size) {
706 kmp_uint old_size = tdg->map_size;
707 kmp_uint new_size = old_size * 2;
708 kmp_node_info_t *old_record = tdg->record_map;
709 kmp_node_info_t *new_record = (kmp_node_info_t *)__kmp_allocate(
710 new_size * sizeof(kmp_node_info_t));
711 KMP_MEMCPY(new_record, tdg->record_map,
712 old_size * sizeof(kmp_node_info_t));
713 tdg->record_map = new_record;
714
715 __kmp_free(old_record);
716
717 for (kmp_int i = old_size; i < new_size; i++) {
718 kmp_int32 *successorsList = (kmp_int32 *)__kmp_allocate(
719 __kmp_successors_size * sizeof(kmp_int32));
720 new_record[i].task = nullptr;
721 new_record[i].successors = successorsList;
722 new_record[i].nsuccessors = 0;
723 new_record[i].npredecessors = 0;
724 new_record[i].successors_size = __kmp_successors_size;
725 KMP_ATOMIC_ST_REL(&new_record[i].npredecessors_counter, 0);
726 }
727 // update the size at the end, so that we avoid other
728 // threads use old_record while map_size is already updated
729 tdg->map_size = new_size;
730 }
731 __kmp_release_bootstrap_lock(&tdg->graph_lock);
732 }
733 tdg->record_map[new_taskdata->td_tdg_task_id].task = new_task;
734 tdg->record_map[new_taskdata->td_tdg_task_id].parent_task =
735 new_taskdata->td_parent;
736 KMP_ATOMIC_INC(&tdg->num_tasks);
737 }
738#endif
739#if OMPT_SUPPORT
740 if (ompt_enabled.enabled) {
741 if (!current_task->ompt_task_info.frame.enter_frame.ptr)
742 current_task->ompt_task_info.frame.enter_frame.ptr =
743 OMPT_GET_FRAME_ADDRESS(0);
744 if (ompt_enabled.ompt_callback_task_create) {
745 ompt_callbacks.ompt_callback(ompt_callback_task_create)(
746 &(current_task->ompt_task_info.task_data),
747 &(current_task->ompt_task_info.frame),
748 &(new_taskdata->ompt_task_info.task_data),
749 TASK_TYPE_DETAILS_FORMAT(new_taskdata), 1,
750 OMPT_LOAD_OR_GET_RETURN_ADDRESS(gtid));
751 }
752
753 new_taskdata->ompt_task_info.frame.enter_frame.ptr =
754 OMPT_GET_FRAME_ADDRESS(0);
755 }
756
757#if OMPT_OPTIONAL
758 /* OMPT grab all dependences if requested by the tool */
759 if (ndeps + ndeps_noalias > 0 && ompt_enabled.ompt_callback_dependences) {
760 kmp_int32 i;
761
762 int ompt_ndeps = ndeps + ndeps_noalias;
763 ompt_dependence_t *ompt_deps = (ompt_dependence_t *)KMP_OMPT_DEPS_ALLOC(
764 thread, (ndeps + ndeps_noalias) * sizeof(ompt_dependence_t));
765
766 KMP_ASSERT(ompt_deps != NULL);
767
768 for (i = 0; i < ndeps; i++) {
769 ompt_deps[i].variable.ptr = (void *)dep_list[i].base_addr;
770 if (dep_list[i].base_addr == (kmp_intptr_t)KMP_SIZE_T_MAX)
771 ompt_deps[i].dependence_type = ompt_dependence_type_out_all_memory;
772 else if (dep_list[i].flags.in && dep_list[i].flags.out)
773 ompt_deps[i].dependence_type = ompt_dependence_type_inout;
774 else if (dep_list[i].flags.out)
775 ompt_deps[i].dependence_type = ompt_dependence_type_out;
776 else if (dep_list[i].flags.in)
777 ompt_deps[i].dependence_type = ompt_dependence_type_in;
778 else if (dep_list[i].flags.mtx)
779 ompt_deps[i].dependence_type = ompt_dependence_type_mutexinoutset;
780 else if (dep_list[i].flags.set)
781 ompt_deps[i].dependence_type = ompt_dependence_type_inoutset;
782 else if (dep_list[i].flags.all)
783 ompt_deps[i].dependence_type = ompt_dependence_type_out_all_memory;
784 }
785 for (i = 0; i < ndeps_noalias; i++) {
786 ompt_deps[ndeps + i].variable.ptr = (void *)noalias_dep_list[i].base_addr;
787 if (noalias_dep_list[i].base_addr == (kmp_intptr_t)KMP_SIZE_T_MAX)
788 ompt_deps[ndeps + i].dependence_type =
789 ompt_dependence_type_out_all_memory;
790 else if (noalias_dep_list[i].flags.in && noalias_dep_list[i].flags.out)
791 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inout;
792 else if (noalias_dep_list[i].flags.out)
793 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_out;
794 else if (noalias_dep_list[i].flags.in)
795 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_in;
796 else if (noalias_dep_list[i].flags.mtx)
797 ompt_deps[ndeps + i].dependence_type =
798 ompt_dependence_type_mutexinoutset;
799 else if (noalias_dep_list[i].flags.set)
800 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inoutset;
801 else if (noalias_dep_list[i].flags.all)
802 ompt_deps[ndeps + i].dependence_type =
803 ompt_dependence_type_out_all_memory;
804 }
805 ompt_callbacks.ompt_callback(ompt_callback_dependences)(
806 &(new_taskdata->ompt_task_info.task_data), ompt_deps, ompt_ndeps);
807 /* We can now free the allocated memory for the dependences */
808 /* For OMPD we might want to delay the free until end of this function */
809 KMP_OMPT_DEPS_FREE(thread, ompt_deps);
810 }
811#endif /* OMPT_OPTIONAL */
812#endif /* OMPT_SUPPORT */
813
814 bool serial = current_task->td_flags.team_serial ||
815 current_task->td_flags.tasking_ser ||
816 current_task->td_flags.final;
817 kmp_task_team_t *task_team = thread->th.th_task_team;
818 serial = serial &&
819 !(task_team && (task_team->tt.tt_found_proxy_tasks ||
820 task_team->tt.tt_hidden_helper_task_encountered));
821
822 if (!serial && (ndeps > 0 || ndeps_noalias > 0)) {
823 /* if no dependences have been tracked yet, create the dependence hash */
824 if (current_task->td_dephash == NULL)
825 current_task->td_dephash = __kmp_dephash_create(thread, current_task);
826
827#if USE_FAST_MEMORY
828 kmp_depnode_t *node =
829 (kmp_depnode_t *)__kmp_fast_allocate(thread, sizeof(kmp_depnode_t));
830#else
831 kmp_depnode_t *node =
832 (kmp_depnode_t *)__kmp_thread_malloc(thread, sizeof(kmp_depnode_t));
833#endif
834
835 __kmp_init_node(node, /*on_stack=*/false);
836 new_taskdata->td_depnode = node;
837
838 if (__kmp_check_deps(gtid, node, task: new_task, hash: &current_task->td_dephash,
839 NO_DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
840 noalias_dep_list)) {
841 KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had blocking "
842 "dependences: "
843 "loc=%p task=%p, return: TASK_CURRENT_NOT_QUEUED\n",
844 gtid, loc_ref, new_taskdata));
845#if OMPT_SUPPORT
846 if (ompt_enabled.enabled) {
847 current_task->ompt_task_info.frame.enter_frame = ompt_data_none;
848 }
849#endif
850 return TASK_CURRENT_NOT_QUEUED;
851 }
852 } else {
853 KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d ignored dependences "
854 "for task (serialized) loc=%p task=%p\n",
855 gtid, loc_ref, new_taskdata));
856 }
857
858 KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had no blocking "
859 "dependences : "
860 "loc=%p task=%p, transferring to __kmp_omp_task\n",
861 gtid, loc_ref, new_taskdata));
862
863 kmp_int32 ret = __kmp_omp_task(gtid, new_task, serialize_immediate: true);
864#if OMPT_SUPPORT
865 if (ompt_enabled.enabled) {
866 current_task->ompt_task_info.frame.enter_frame = ompt_data_none;
867 }
868#endif
869 return ret;
870}
871
872#if OMPT_SUPPORT
873void __ompt_taskwait_dep_finish(kmp_taskdata_t *current_task,
874 ompt_data_t *taskwait_task_data) {
875 if (ompt_enabled.ompt_callback_task_schedule) {
876 ompt_callbacks.ompt_callback(ompt_callback_task_schedule)(
877 taskwait_task_data, ompt_taskwait_complete, NULL);
878 }
879 current_task->ompt_task_info.frame.enter_frame.ptr = NULL;
880 *taskwait_task_data = ompt_data_none;
881}
882#endif /* OMPT_SUPPORT */
883
884/*!
885@ingroup TASKING
886@param loc_ref location of the original task directive
887@param gtid Global Thread ID of encountering thread
888@param ndeps Number of depend items with possible aliasing
889@param dep_list List of depend items with possible aliasing
890@param ndeps_noalias Number of depend items with no aliasing
891@param noalias_dep_list List of depend items with no aliasing
892
893Blocks the current task until all specifies dependences have been fulfilled.
894*/
895void __kmpc_omp_wait_deps(ident_t *loc_ref, kmp_int32 gtid, kmp_int32 ndeps,
896 kmp_depend_info_t *dep_list, kmp_int32 ndeps_noalias,
897 kmp_depend_info_t *noalias_dep_list) {
898 __kmpc_omp_taskwait_deps_51(loc_ref, gtid, ndeps, dep_list, ndeps_noalias,
899 noalias_dep_list, has_no_wait: false);
900}
901
902/* __kmpc_omp_taskwait_deps_51 : Function for OpenMP 5.1 nowait clause.
903 Placeholder for taskwait with nowait clause.
904 Earlier code of __kmpc_omp_wait_deps() is now
905 in this function.
906*/
907void __kmpc_omp_taskwait_deps_51(ident_t *loc_ref, kmp_int32 gtid,
908 kmp_int32 ndeps, kmp_depend_info_t *dep_list,
909 kmp_int32 ndeps_noalias,
910 kmp_depend_info_t *noalias_dep_list,
911 kmp_int32 has_no_wait) {
912 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(enter): T#%d loc=%p nowait#%d\n",
913 gtid, loc_ref, has_no_wait));
914 if (ndeps == 0 && ndeps_noalias == 0) {
915 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d has no dependences to "
916 "wait upon : loc=%p\n",
917 gtid, loc_ref));
918 return;
919 }
920 __kmp_assert_valid_gtid(gtid);
921 kmp_info_t *thread = __kmp_threads[gtid];
922 kmp_taskdata_t *current_task = thread->th.th_current_task;
923
924#if OMPT_SUPPORT
925 // this function represents a taskwait construct with depend clause
926 // We signal 4 events:
927 // - creation of the taskwait task
928 // - dependences of the taskwait task
929 // - schedule and finish of the taskwait task
930 ompt_data_t *taskwait_task_data = &thread->th.ompt_thread_info.task_data;
931 KMP_ASSERT(taskwait_task_data->ptr == NULL);
932 if (ompt_enabled.enabled) {
933 if (!current_task->ompt_task_info.frame.enter_frame.ptr)
934 current_task->ompt_task_info.frame.enter_frame.ptr =
935 OMPT_GET_FRAME_ADDRESS(0);
936 if (ompt_enabled.ompt_callback_task_create) {
937 ompt_callbacks.ompt_callback(ompt_callback_task_create)(
938 &(current_task->ompt_task_info.task_data),
939 &(current_task->ompt_task_info.frame), taskwait_task_data,
940 ompt_task_taskwait | ompt_task_undeferred | ompt_task_mergeable, 1,
941 OMPT_LOAD_OR_GET_RETURN_ADDRESS(gtid));
942 }
943 }
944
945#if OMPT_OPTIONAL
946 /* OMPT grab all dependences if requested by the tool */
947 if (ndeps + ndeps_noalias > 0 && ompt_enabled.ompt_callback_dependences) {
948 kmp_int32 i;
949
950 int ompt_ndeps = ndeps + ndeps_noalias;
951 ompt_dependence_t *ompt_deps = (ompt_dependence_t *)KMP_OMPT_DEPS_ALLOC(
952 thread, (ndeps + ndeps_noalias) * sizeof(ompt_dependence_t));
953
954 KMP_ASSERT(ompt_deps != NULL);
955
956 for (i = 0; i < ndeps; i++) {
957 ompt_deps[i].variable.ptr = (void *)dep_list[i].base_addr;
958 if (dep_list[i].flags.in && dep_list[i].flags.out)
959 ompt_deps[i].dependence_type = ompt_dependence_type_inout;
960 else if (dep_list[i].flags.out)
961 ompt_deps[i].dependence_type = ompt_dependence_type_out;
962 else if (dep_list[i].flags.in)
963 ompt_deps[i].dependence_type = ompt_dependence_type_in;
964 else if (dep_list[i].flags.mtx)
965 ompt_deps[ndeps + i].dependence_type =
966 ompt_dependence_type_mutexinoutset;
967 else if (dep_list[i].flags.set)
968 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inoutset;
969 }
970 for (i = 0; i < ndeps_noalias; i++) {
971 ompt_deps[ndeps + i].variable.ptr = (void *)noalias_dep_list[i].base_addr;
972 if (noalias_dep_list[i].flags.in && noalias_dep_list[i].flags.out)
973 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inout;
974 else if (noalias_dep_list[i].flags.out)
975 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_out;
976 else if (noalias_dep_list[i].flags.in)
977 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_in;
978 else if (noalias_dep_list[i].flags.mtx)
979 ompt_deps[ndeps + i].dependence_type =
980 ompt_dependence_type_mutexinoutset;
981 else if (noalias_dep_list[i].flags.set)
982 ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inoutset;
983 }
984 ompt_callbacks.ompt_callback(ompt_callback_dependences)(
985 taskwait_task_data, ompt_deps, ompt_ndeps);
986 /* We can now free the allocated memory for the dependences */
987 /* For OMPD we might want to delay the free until end of this function */
988 KMP_OMPT_DEPS_FREE(thread, ompt_deps);
989 ompt_deps = NULL;
990 }
991#endif /* OMPT_OPTIONAL */
992#endif /* OMPT_SUPPORT */
993
994 // We can return immediately as:
995 // - dependences are not computed in serial teams (except with proxy tasks)
996 // - if the dephash is not yet created it means we have nothing to wait for
997 bool ignore = current_task->td_flags.team_serial ||
998 current_task->td_flags.tasking_ser ||
999 current_task->td_flags.final;
1000 ignore =
1001 ignore && thread->th.th_task_team != NULL &&
1002 thread->th.th_task_team->tt.tt_found_proxy_tasks == FALSE &&
1003 thread->th.th_task_team->tt.tt_hidden_helper_task_encountered == FALSE;
1004 ignore = ignore || current_task->td_dephash == NULL;
1005
1006 if (ignore) {
1007 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d has no blocking "
1008 "dependences : loc=%p\n",
1009 gtid, loc_ref));
1010#if OMPT_SUPPORT
1011 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
1012#endif /* OMPT_SUPPORT */
1013 return;
1014 }
1015
1016 kmp_depnode_t node = {.dn_align: 0};
1017 __kmp_init_node(node: &node, /*on_stack=*/true);
1018
1019 if (!__kmp_check_deps(gtid, node: &node, NULL, hash: &current_task->td_dephash,
1020 DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
1021 noalias_dep_list)) {
1022 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d has no blocking "
1023 "dependences : loc=%p\n",
1024 gtid, loc_ref));
1025#if OMPT_SUPPORT
1026 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
1027#endif /* OMPT_SUPPORT */
1028
1029 // There may still be references to this node here, due to task stealing.
1030 // Wait for them to be released.
1031 kmp_int32 nrefs;
1032 while ((nrefs = node.dn.nrefs) > 3) {
1033 KMP_DEBUG_ASSERT((nrefs & 1) == 1);
1034 KMP_YIELD(TRUE);
1035 }
1036 KMP_DEBUG_ASSERT(nrefs == 3);
1037
1038 return;
1039 }
1040
1041 int thread_finished = FALSE;
1042 kmp_flag_32<false, false> flag(
1043 (std::atomic<kmp_uint32> *)&node.dn.npredecessors, 0U);
1044 while (node.dn.npredecessors > 0) {
1045 flag.execute_tasks(this_thr: thread, gtid, FALSE,
1046 thread_finished: &thread_finished USE_ITT_BUILD_ARG(NULL),
1047 is_constrained: __kmp_task_stealing_constraint);
1048 }
1049
1050 // Wait until the last __kmp_release_deps is finished before we free the
1051 // current stack frame holding the "node" variable; once its nrefs count
1052 // reaches 3 (meaning 1, since bit zero of the refcount indicates a stack
1053 // rather than a heap address), we're sure nobody else can try to reference
1054 // it again.
1055 kmp_int32 nrefs;
1056 while ((nrefs = node.dn.nrefs) > 3) {
1057 KMP_DEBUG_ASSERT((nrefs & 1) == 1);
1058 KMP_YIELD(TRUE);
1059 }
1060 KMP_DEBUG_ASSERT(nrefs == 3);
1061
1062#if OMPT_SUPPORT
1063 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
1064#endif /* OMPT_SUPPORT */
1065 KA_TRACE(10, ("__kmpc_omp_taskwait_deps(exit): T#%d finished waiting : loc=%p\
1066 \n",
1067 gtid, loc_ref));
1068}
1069

source code of openmp/runtime/src/kmp_taskdeps.cpp