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
33 static std::atomic<kmp_int32> kmp_node_id_seed = ATOMIC_VAR_INIT(0);
34 #endif
35 
36 static 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 }
49 
50 static inline kmp_depnode_t *__kmp_node_ref(kmp_depnode_t *node) {
51  KMP_ATOMIC_INC(&node->dn.nrefs);
52  return node;
53 }
54 
55 enum { KMP_DEPHASH_OTHER_SIZE = 97, KMP_DEPHASH_MASTER_SIZE = 997 };
56 
57 size_t sizes[] = { 997, 2003, 4001, 8191, 16001, 32003, 64007, 131071, 270029 };
58 const size_t MAX_GEN = 8;
59 
60 static inline kmp_int32 __kmp_dephash_hash(kmp_intptr_t addr, size_t hsize) {
61  // TODO alternate to try: set = (((Addr64)(addrUsefulBits * 9.618)) %
62  // m_num_sets );
63  return ((addr >> 6) ^ (addr >> 2)) % hsize;
64 }
65 
66 static kmp_dephash_t *__kmp_dephash_extend(kmp_info_t *thread,
67  kmp_dephash_t *current_dephash) {
68  kmp_dephash_t *h;
69 
70  size_t gen = current_dephash->generation + 1;
71  if (gen >= MAX_GEN)
72  return current_dephash;
73  size_t new_size = sizes[gen];
74 
75  kmp_int32 size_to_allocate =
76  new_size * sizeof(kmp_dephash_entry_t *) + sizeof(kmp_dephash_t);
77 
78 #if USE_FAST_MEMORY
79  h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size_to_allocate);
80 #else
81  h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size_to_allocate);
82 #endif
83 
84  h->size = new_size;
85  h->nelements = current_dephash->nelements;
86  h->buckets = (kmp_dephash_entry **)(h + 1);
87  h->generation = gen;
88  h->nconflicts = 0;
89  // insert existing elements in the new table
90  for (size_t i = 0; i < current_dephash->size; i++) {
91  kmp_dephash_entry_t *next, *entry;
92  for (entry = current_dephash->buckets[i]; entry; entry = next) {
93  next = entry->next_in_bucket;
94  // Compute the new hash using the new size, and insert the entry in
95  // the new bucket.
96  kmp_int32 new_bucket = __kmp_dephash_hash(entry->addr, h->size);
97  entry->next_in_bucket = h->buckets[new_bucket];
98  if (entry->next_in_bucket) {
99  h->nconflicts++;
100  }
101  h->buckets[new_bucket] = entry;
102  }
103  }
104 
105  // Free old hash table
106 #if USE_FAST_MEMORY
107  __kmp_fast_free(thread, current_dephash);
108 #else
109  __kmp_thread_free(thread, current_dephash);
110 #endif
111 
112  return h;
113 }
114 
115 static kmp_dephash_t *__kmp_dephash_create(kmp_info_t *thread,
116  kmp_taskdata_t *current_task) {
117  kmp_dephash_t *h;
118 
119  size_t h_size;
120 
121  if (current_task->td_flags.tasktype == TASK_IMPLICIT)
122  h_size = KMP_DEPHASH_MASTER_SIZE;
123  else
124  h_size = KMP_DEPHASH_OTHER_SIZE;
125 
126  kmp_int32 size =
127  h_size * sizeof(kmp_dephash_entry_t *) + sizeof(kmp_dephash_t);
128 
129 #if USE_FAST_MEMORY
130  h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size);
131 #else
132  h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size);
133 #endif
134  h->size = h_size;
135 
136  h->generation = 0;
137  h->nelements = 0;
138  h->nconflicts = 0;
139  h->buckets = (kmp_dephash_entry **)(h + 1);
140 
141  for (size_t i = 0; i < h_size; i++)
142  h->buckets[i] = 0;
143 
144  return h;
145 }
146 
147 #define ENTRY_LAST_INS 0
148 #define ENTRY_LAST_MTXS 1
149 
150 static kmp_dephash_entry *
151 __kmp_dephash_find(kmp_info_t *thread, kmp_dephash_t **hash, kmp_intptr_t addr) {
152  kmp_dephash_t *h = *hash;
153  if (h->nelements != 0
154  && h->nconflicts/h->size >= 1) {
155  *hash = __kmp_dephash_extend(thread, h);
156  h = *hash;
157  }
158  kmp_int32 bucket = __kmp_dephash_hash(addr, h->size);
159 
160  kmp_dephash_entry_t *entry;
161  for (entry = h->buckets[bucket]; entry; entry = entry->next_in_bucket)
162  if (entry->addr == addr)
163  break;
164 
165  if (entry == NULL) {
166 // create entry. This is only done by one thread so no locking required
167 #if USE_FAST_MEMORY
168  entry = (kmp_dephash_entry_t *)__kmp_fast_allocate(
169  thread, sizeof(kmp_dephash_entry_t));
170 #else
171  entry = (kmp_dephash_entry_t *)__kmp_thread_malloc(
172  thread, sizeof(kmp_dephash_entry_t));
173 #endif
174  entry->addr = addr;
175  entry->last_out = NULL;
176  entry->last_ins = NULL;
177  entry->last_mtxs = NULL;
178  entry->last_flag = ENTRY_LAST_INS;
179  entry->mtx_lock = NULL;
180  entry->next_in_bucket = h->buckets[bucket];
181  h->buckets[bucket] = entry;
182  h->nelements++;
183  if (entry->next_in_bucket)
184  h->nconflicts++;
185  }
186  return entry;
187 }
188 
189 static kmp_depnode_list_t *__kmp_add_node(kmp_info_t *thread,
190  kmp_depnode_list_t *list,
191  kmp_depnode_t *node) {
192  kmp_depnode_list_t *new_head;
193 
194 #if USE_FAST_MEMORY
195  new_head = (kmp_depnode_list_t *)__kmp_fast_allocate(
196  thread, sizeof(kmp_depnode_list_t));
197 #else
198  new_head = (kmp_depnode_list_t *)__kmp_thread_malloc(
199  thread, sizeof(kmp_depnode_list_t));
200 #endif
201 
202  new_head->node = __kmp_node_ref(node);
203  new_head->next = list;
204 
205  return new_head;
206 }
207 
208 static inline void __kmp_track_dependence(kmp_int32 gtid, kmp_depnode_t *source,
209  kmp_depnode_t *sink,
210  kmp_task_t *sink_task) {
211 #ifdef KMP_SUPPORT_GRAPH_OUTPUT
212  kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
213  // do not use sink->dn.task as that is only filled after the dependencies
214  // are already processed!
215  kmp_taskdata_t *task_sink = KMP_TASK_TO_TASKDATA(sink_task);
216 
217  __kmp_printf("%d(%s) -> %d(%s)\n", source->dn.id,
218  task_source->td_ident->psource, sink->dn.id,
219  task_sink->td_ident->psource);
220 #endif
221 #if OMPT_SUPPORT && OMPT_OPTIONAL
222  /* OMPT tracks dependences between task (a=source, b=sink) in which
223  task a blocks the execution of b through the ompt_new_dependence_callback
224  */
225  if (ompt_enabled.ompt_callback_task_dependence) {
226  kmp_taskdata_t *task_source = KMP_TASK_TO_TASKDATA(source->dn.task);
227  ompt_data_t *sink_data;
228  if (sink_task)
229  sink_data = &(KMP_TASK_TO_TASKDATA(sink_task)->ompt_task_info.task_data);
230  else
231  sink_data = &__kmp_threads[gtid]->th.ompt_thread_info.task_data;
232 
233  ompt_callbacks.ompt_callback(ompt_callback_task_dependence)(
234  &(task_source->ompt_task_info.task_data), sink_data);
235  }
236 #endif /* OMPT_SUPPORT && OMPT_OPTIONAL */
237 }
238 
239 static inline kmp_int32
240 __kmp_depnode_link_successor(kmp_int32 gtid, kmp_info_t *thread,
241  kmp_task_t *task, kmp_depnode_t *node,
242  kmp_depnode_list_t *plist) {
243  if (!plist)
244  return 0;
245  kmp_int32 npredecessors = 0;
246  // link node as successor of list elements
247  for (kmp_depnode_list_t *p = plist; p; p = p->next) {
248  kmp_depnode_t *dep = p->node;
249  if (dep->dn.task) {
250  KMP_ACQUIRE_DEPNODE(gtid, dep);
251  if (dep->dn.task) {
252  __kmp_track_dependence(gtid, dep, node, task);
253  dep->dn.successors = __kmp_add_node(thread, dep->dn.successors, node);
254  KA_TRACE(40, ("__kmp_process_deps: T#%d adding dependence from %p to "
255  "%p\n",
256  gtid, KMP_TASK_TO_TASKDATA(dep->dn.task),
257  KMP_TASK_TO_TASKDATA(task)));
258  npredecessors++;
259  }
260  KMP_RELEASE_DEPNODE(gtid, dep);
261  }
262  }
263  return npredecessors;
264 }
265 
266 static inline kmp_int32 __kmp_depnode_link_successor(kmp_int32 gtid,
267  kmp_info_t *thread,
268  kmp_task_t *task,
269  kmp_depnode_t *source,
270  kmp_depnode_t *sink) {
271  if (!sink)
272  return 0;
273  kmp_int32 npredecessors = 0;
274  if (sink->dn.task) {
275  // synchronously add source to sink' list of successors
276  KMP_ACQUIRE_DEPNODE(gtid, sink);
277  if (sink->dn.task) {
278  __kmp_track_dependence(gtid, sink, source, task);
279  sink->dn.successors = __kmp_add_node(thread, sink->dn.successors, source);
280  KA_TRACE(40, ("__kmp_process_deps: T#%d adding dependence from %p to "
281  "%p\n",
282  gtid, KMP_TASK_TO_TASKDATA(sink->dn.task),
283  KMP_TASK_TO_TASKDATA(task)));
284  npredecessors++;
285  }
286  KMP_RELEASE_DEPNODE(gtid, sink);
287  }
288  return npredecessors;
289 }
290 
291 template <bool filter>
292 static inline kmp_int32
293 __kmp_process_deps(kmp_int32 gtid, kmp_depnode_t *node, kmp_dephash_t **hash,
294  bool dep_barrier, kmp_int32 ndeps,
295  kmp_depend_info_t *dep_list, kmp_task_t *task) {
296  KA_TRACE(30, ("__kmp_process_deps<%d>: T#%d processing %d dependencies : "
297  "dep_barrier = %d\n",
298  filter, gtid, ndeps, dep_barrier));
299 
300  kmp_info_t *thread = __kmp_threads[gtid];
301  kmp_int32 npredecessors = 0;
302  for (kmp_int32 i = 0; i < ndeps; i++) {
303  const kmp_depend_info_t *dep = &dep_list[i];
304 
305  if (filter && dep->base_addr == 0)
306  continue; // skip filtered entries
307 
308  kmp_dephash_entry_t *info =
309  __kmp_dephash_find(thread, hash, dep->base_addr);
310  kmp_depnode_t *last_out = info->last_out;
311  kmp_depnode_list_t *last_ins = info->last_ins;
312  kmp_depnode_list_t *last_mtxs = info->last_mtxs;
313 
314  if (dep->flags.out) { // out --> clean lists of ins and mtxs if any
315  if (last_ins || last_mtxs) {
316  if (info->last_flag == ENTRY_LAST_INS) { // INS were last
317  npredecessors +=
318  __kmp_depnode_link_successor(gtid, thread, task, node, last_ins);
319  } else { // MTXS were last
320  npredecessors +=
321  __kmp_depnode_link_successor(gtid, thread, task, node, last_mtxs);
322  }
323  __kmp_depnode_list_free(thread, last_ins);
324  __kmp_depnode_list_free(thread, last_mtxs);
325  info->last_ins = NULL;
326  info->last_mtxs = NULL;
327  } else {
328  npredecessors +=
329  __kmp_depnode_link_successor(gtid, thread, task, node, last_out);
330  }
331  __kmp_node_deref(thread, last_out);
332  if (dep_barrier) {
333  // if this is a sync point in the serial sequence, then the previous
334  // outputs are guaranteed to be completed after the execution of this
335  // task so the previous output nodes can be cleared.
336  info->last_out = NULL;
337  } else {
338  info->last_out = __kmp_node_ref(node);
339  }
340  } else if (dep->flags.in) {
341  // in --> link node to either last_out or last_mtxs, clean earlier deps
342  if (last_mtxs) {
343  npredecessors +=
344  __kmp_depnode_link_successor(gtid, thread, task, node, last_mtxs);
345  __kmp_node_deref(thread, last_out);
346  info->last_out = NULL;
347  if (info->last_flag == ENTRY_LAST_MTXS && last_ins) { // MTXS were last
348  // clean old INS before creating new list
349  __kmp_depnode_list_free(thread, last_ins);
350  info->last_ins = NULL;
351  }
352  } else {
353  // link node as successor of the last_out if any
354  npredecessors +=
355  __kmp_depnode_link_successor(gtid, thread, task, node, last_out);
356  }
357  info->last_flag = ENTRY_LAST_INS;
358  info->last_ins = __kmp_add_node(thread, info->last_ins, node);
359  } else {
360  KMP_DEBUG_ASSERT(dep->flags.mtx == 1);
361  // mtx --> link node to either last_out or last_ins, clean earlier deps
362  if (last_ins) {
363  npredecessors +=
364  __kmp_depnode_link_successor(gtid, thread, task, node, last_ins);
365  __kmp_node_deref(thread, last_out);
366  info->last_out = NULL;
367  if (info->last_flag == ENTRY_LAST_INS && last_mtxs) { // INS were last
368  // clean old MTXS before creating new list
369  __kmp_depnode_list_free(thread, last_mtxs);
370  info->last_mtxs = NULL;
371  }
372  } else {
373  // link node as successor of the last_out if any
374  npredecessors +=
375  __kmp_depnode_link_successor(gtid, thread, task, node, last_out);
376  }
377  info->last_flag = ENTRY_LAST_MTXS;
378  info->last_mtxs = __kmp_add_node(thread, info->last_mtxs, node);
379  if (info->mtx_lock == NULL) {
380  info->mtx_lock = (kmp_lock_t *)__kmp_allocate(sizeof(kmp_lock_t));
381  __kmp_init_lock(info->mtx_lock);
382  }
383  KMP_DEBUG_ASSERT(node->dn.mtx_num_locks < MAX_MTX_DEPS);
384  kmp_int32 m;
385  // Save lock in node's array
386  for (m = 0; m < MAX_MTX_DEPS; ++m) {
387  // sort pointers in decreasing order to avoid potential livelock
388  if (node->dn.mtx_locks[m] < info->mtx_lock) {
389  KMP_DEBUG_ASSERT(node->dn.mtx_locks[node->dn.mtx_num_locks] == NULL);
390  for (int n = node->dn.mtx_num_locks; n > m; --n) {
391  // shift right all lesser non-NULL pointers
392  KMP_DEBUG_ASSERT(node->dn.mtx_locks[n - 1] != NULL);
393  node->dn.mtx_locks[n] = node->dn.mtx_locks[n - 1];
394  }
395  node->dn.mtx_locks[m] = info->mtx_lock;
396  break;
397  }
398  }
399  KMP_DEBUG_ASSERT(m < MAX_MTX_DEPS); // must break from loop
400  node->dn.mtx_num_locks++;
401  }
402  }
403  KA_TRACE(30, ("__kmp_process_deps<%d>: T#%d found %d predecessors\n", filter,
404  gtid, npredecessors));
405  return npredecessors;
406 }
407 
408 #define NO_DEP_BARRIER (false)
409 #define DEP_BARRIER (true)
410 
411 // returns true if the task has any outstanding dependence
412 static bool __kmp_check_deps(kmp_int32 gtid, kmp_depnode_t *node,
413  kmp_task_t *task, kmp_dephash_t **hash,
414  bool dep_barrier, kmp_int32 ndeps,
415  kmp_depend_info_t *dep_list,
416  kmp_int32 ndeps_noalias,
417  kmp_depend_info_t *noalias_dep_list) {
418  int i, n_mtxs = 0;
419 #if KMP_DEBUG
420  kmp_taskdata_t *taskdata = KMP_TASK_TO_TASKDATA(task);
421 #endif
422  KA_TRACE(20, ("__kmp_check_deps: T#%d checking dependencies for task %p : %d "
423  "possibly aliased dependencies, %d non-aliased dependencies : "
424  "dep_barrier=%d .\n",
425  gtid, taskdata, ndeps, ndeps_noalias, dep_barrier));
426 
427  // Filter deps in dep_list
428  // TODO: Different algorithm for large dep_list ( > 10 ? )
429  for (i = 0; i < ndeps; i++) {
430  if (dep_list[i].base_addr != 0) {
431  for (int j = i + 1; j < ndeps; j++) {
432  if (dep_list[i].base_addr == dep_list[j].base_addr) {
433  dep_list[i].flags.in |= dep_list[j].flags.in;
434  dep_list[i].flags.out |=
435  (dep_list[j].flags.out ||
436  (dep_list[i].flags.in && dep_list[j].flags.mtx) ||
437  (dep_list[i].flags.mtx && dep_list[j].flags.in));
438  dep_list[i].flags.mtx =
439  dep_list[i].flags.mtx | dep_list[j].flags.mtx &&
440  !dep_list[i].flags.out;
441  dep_list[j].base_addr = 0; // Mark j element as void
442  }
443  }
444  if (dep_list[i].flags.mtx) {
445  // limit number of mtx deps to MAX_MTX_DEPS per node
446  if (n_mtxs < MAX_MTX_DEPS && task != NULL) {
447  ++n_mtxs;
448  } else {
449  dep_list[i].flags.in = 1; // downgrade mutexinoutset to inout
450  dep_list[i].flags.out = 1;
451  dep_list[i].flags.mtx = 0;
452  }
453  }
454  }
455  }
456 
457  // doesn't need to be atomic as no other thread is going to be accessing this
458  // node just yet.
459  // npredecessors is set -1 to ensure that none of the releasing tasks queues
460  // this task before we have finished processing all the dependencies
461  node->dn.npredecessors = -1;
462 
463  // used to pack all npredecessors additions into a single atomic operation at
464  // the end
465  int npredecessors;
466 
467  npredecessors = __kmp_process_deps<true>(gtid, node, hash, dep_barrier, ndeps,
468  dep_list, task);
469  npredecessors += __kmp_process_deps<false>(
470  gtid, node, hash, dep_barrier, ndeps_noalias, noalias_dep_list, task);
471 
472  node->dn.task = task;
473  KMP_MB();
474 
475  // Account for our initial fake value
476  npredecessors++;
477 
478  // Update predecessors and obtain current value to check if there are still
479  // any outstanding dependences (some tasks may have finished while we
480  // processed the dependences)
481  npredecessors =
482  node->dn.npredecessors.fetch_add(npredecessors) + npredecessors;
483 
484  KA_TRACE(20, ("__kmp_check_deps: T#%d found %d predecessors for task %p \n",
485  gtid, npredecessors, taskdata));
486 
487  // beyond this point the task could be queued (and executed) by a releasing
488  // task...
489  return npredecessors > 0 ? true : false;
490 }
491 
508 kmp_int32 __kmpc_omp_task_with_deps(ident_t *loc_ref, kmp_int32 gtid,
509  kmp_task_t *new_task, kmp_int32 ndeps,
510  kmp_depend_info_t *dep_list,
511  kmp_int32 ndeps_noalias,
512  kmp_depend_info_t *noalias_dep_list) {
513 
514  kmp_taskdata_t *new_taskdata = KMP_TASK_TO_TASKDATA(new_task);
515  KA_TRACE(10, ("__kmpc_omp_task_with_deps(enter): T#%d loc=%p task=%p\n", gtid,
516  loc_ref, new_taskdata));
517  __kmp_assert_valid_gtid(gtid);
518  kmp_info_t *thread = __kmp_threads[gtid];
519  kmp_taskdata_t *current_task = thread->th.th_current_task;
520 
521 #if OMPT_SUPPORT
522  if (ompt_enabled.enabled) {
523  if (!current_task->ompt_task_info.frame.enter_frame.ptr)
524  current_task->ompt_task_info.frame.enter_frame.ptr =
525  OMPT_GET_FRAME_ADDRESS(0);
526  if (ompt_enabled.ompt_callback_task_create) {
527  ompt_data_t task_data = ompt_data_none;
528  ompt_callbacks.ompt_callback(ompt_callback_task_create)(
529  current_task ? &(current_task->ompt_task_info.task_data) : &task_data,
530  current_task ? &(current_task->ompt_task_info.frame) : NULL,
531  &(new_taskdata->ompt_task_info.task_data),
532  ompt_task_explicit | TASK_TYPE_DETAILS_FORMAT(new_taskdata), 1,
533  OMPT_LOAD_OR_GET_RETURN_ADDRESS(gtid));
534  }
535 
536  new_taskdata->ompt_task_info.frame.enter_frame.ptr = OMPT_GET_FRAME_ADDRESS(0);
537  }
538 
539 #if OMPT_OPTIONAL
540  /* OMPT grab all dependences if requested by the tool */
541  if (ndeps + ndeps_noalias > 0 &&
542  ompt_enabled.ompt_callback_dependences) {
543  kmp_int32 i;
544 
545  int ompt_ndeps = ndeps + ndeps_noalias;
546  ompt_dependence_t *ompt_deps = (ompt_dependence_t *)KMP_OMPT_DEPS_ALLOC(
547  thread, (ndeps + ndeps_noalias) * sizeof(ompt_dependence_t));
548 
549  KMP_ASSERT(ompt_deps != NULL);
550 
551  for (i = 0; i < ndeps; i++) {
552  ompt_deps[i].variable.ptr = (void *)dep_list[i].base_addr;
553  if (dep_list[i].flags.in && dep_list[i].flags.out)
554  ompt_deps[i].dependence_type = ompt_dependence_type_inout;
555  else if (dep_list[i].flags.out)
556  ompt_deps[i].dependence_type = ompt_dependence_type_out;
557  else if (dep_list[i].flags.in)
558  ompt_deps[i].dependence_type = ompt_dependence_type_in;
559  else if (dep_list[i].flags.mtx)
560  ompt_deps[i].dependence_type = ompt_dependence_type_mutexinoutset;
561  }
562  for (i = 0; i < ndeps_noalias; i++) {
563  ompt_deps[ndeps + i].variable.ptr = (void *)noalias_dep_list[i].base_addr;
564  if (noalias_dep_list[i].flags.in && noalias_dep_list[i].flags.out)
565  ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inout;
566  else if (noalias_dep_list[i].flags.out)
567  ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_out;
568  else if (noalias_dep_list[i].flags.in)
569  ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_in;
570  else if (noalias_dep_list[i].flags.mtx)
571  ompt_deps[ndeps + i].dependence_type =
572  ompt_dependence_type_mutexinoutset;
573  }
574  ompt_callbacks.ompt_callback(ompt_callback_dependences)(
575  &(new_taskdata->ompt_task_info.task_data), ompt_deps, ompt_ndeps);
576  /* We can now free the allocated memory for the dependencies */
577  /* For OMPD we might want to delay the free until end of this function */
578  KMP_OMPT_DEPS_FREE(thread, ompt_deps);
579  }
580 #endif /* OMPT_OPTIONAL */
581 #endif /* OMPT_SUPPORT */
582 
583  bool serial = current_task->td_flags.team_serial ||
584  current_task->td_flags.tasking_ser ||
585  current_task->td_flags.final;
586  kmp_task_team_t *task_team = thread->th.th_task_team;
587  serial = serial && !(task_team && task_team->tt.tt_found_proxy_tasks);
588 
589  if (!serial && (ndeps > 0 || ndeps_noalias > 0)) {
590  /* if no dependencies have been tracked yet, create the dependence hash */
591  if (current_task->td_dephash == NULL)
592  current_task->td_dephash = __kmp_dephash_create(thread, current_task);
593 
594 #if USE_FAST_MEMORY
595  kmp_depnode_t *node =
596  (kmp_depnode_t *)__kmp_fast_allocate(thread, sizeof(kmp_depnode_t));
597 #else
598  kmp_depnode_t *node =
599  (kmp_depnode_t *)__kmp_thread_malloc(thread, sizeof(kmp_depnode_t));
600 #endif
601 
602  __kmp_init_node(node);
603  new_taskdata->td_depnode = node;
604 
605  if (__kmp_check_deps(gtid, node, new_task, &current_task->td_dephash,
606  NO_DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
607  noalias_dep_list)) {
608  KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had blocking "
609  "dependencies: "
610  "loc=%p task=%p, return: TASK_CURRENT_NOT_QUEUED\n",
611  gtid, loc_ref, new_taskdata));
612 #if OMPT_SUPPORT
613  if (ompt_enabled.enabled) {
614  current_task->ompt_task_info.frame.enter_frame = ompt_data_none;
615  }
616 #endif
617  return TASK_CURRENT_NOT_QUEUED;
618  }
619  } else {
620  KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d ignored dependencies "
621  "for task (serialized)"
622  "loc=%p task=%p\n",
623  gtid, loc_ref, new_taskdata));
624  }
625 
626  KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had no blocking "
627  "dependencies : "
628  "loc=%p task=%p, transferring to __kmp_omp_task\n",
629  gtid, loc_ref, new_taskdata));
630 
631  kmp_int32 ret = __kmp_omp_task(gtid, new_task, true);
632 #if OMPT_SUPPORT
633  if (ompt_enabled.enabled) {
634  current_task->ompt_task_info.frame.enter_frame = ompt_data_none;
635  }
636 #endif
637  return ret;
638 }
639 
640 #if OMPT_SUPPORT
641 void __ompt_taskwait_dep_finish(kmp_taskdata_t *current_task,
642  ompt_data_t *taskwait_task_data) {
643  if (ompt_enabled.ompt_callback_task_schedule) {
644  ompt_data_t task_data = ompt_data_none;
645  ompt_callbacks.ompt_callback(ompt_callback_task_schedule)(
646  current_task ? &(current_task->ompt_task_info.task_data) : &task_data,
647  ompt_task_switch, taskwait_task_data);
648  ompt_callbacks.ompt_callback(ompt_callback_task_schedule)(
649  taskwait_task_data, ompt_task_complete,
650  current_task ? &(current_task->ompt_task_info.task_data) : &task_data);
651  }
652  current_task->ompt_task_info.frame.enter_frame.ptr = NULL;
653  *taskwait_task_data = ompt_data_none;
654 }
655 #endif /* OMPT_SUPPORT */
656 
668 void __kmpc_omp_wait_deps(ident_t *loc_ref, kmp_int32 gtid, kmp_int32 ndeps,
669  kmp_depend_info_t *dep_list, kmp_int32 ndeps_noalias,
670  kmp_depend_info_t *noalias_dep_list) {
671  KA_TRACE(10, ("__kmpc_omp_wait_deps(enter): T#%d loc=%p\n", gtid, loc_ref));
672 
673  if (ndeps == 0 && ndeps_noalias == 0) {
674  KA_TRACE(10, ("__kmpc_omp_wait_deps(exit): T#%d has no dependencies to "
675  "wait upon : loc=%p\n",
676  gtid, loc_ref));
677  return;
678  }
679  __kmp_assert_valid_gtid(gtid);
680  kmp_info_t *thread = __kmp_threads[gtid];
681  kmp_taskdata_t *current_task = thread->th.th_current_task;
682 
683 #if OMPT_SUPPORT
684  // this function represents a taskwait construct with depend clause
685  // We signal 4 events:
686  // - creation of the taskwait task
687  // - dependences of the taskwait task
688  // - schedule and finish of the taskwait task
689  ompt_data_t *taskwait_task_data = &thread->th.ompt_thread_info.task_data;
690  KMP_ASSERT(taskwait_task_data->ptr == NULL);
691  if (ompt_enabled.enabled) {
692  if (!current_task->ompt_task_info.frame.enter_frame.ptr)
693  current_task->ompt_task_info.frame.enter_frame.ptr =
694  OMPT_GET_FRAME_ADDRESS(0);
695  if (ompt_enabled.ompt_callback_task_create) {
696  ompt_data_t task_data = ompt_data_none;
697  ompt_callbacks.ompt_callback(ompt_callback_task_create)(
698  current_task ? &(current_task->ompt_task_info.task_data) : &task_data,
699  current_task ? &(current_task->ompt_task_info.frame) : NULL,
700  taskwait_task_data,
701  ompt_task_explicit | ompt_task_undeferred | ompt_task_mergeable, 1,
702  OMPT_LOAD_OR_GET_RETURN_ADDRESS(gtid));
703  }
704  }
705 
706 #if OMPT_OPTIONAL
707  /* OMPT grab all dependences if requested by the tool */
708  if (ndeps + ndeps_noalias > 0 && ompt_enabled.ompt_callback_dependences) {
709  kmp_int32 i;
710 
711  int ompt_ndeps = ndeps + ndeps_noalias;
712  ompt_dependence_t *ompt_deps = (ompt_dependence_t *)KMP_OMPT_DEPS_ALLOC(
713  thread, (ndeps + ndeps_noalias) * sizeof(ompt_dependence_t));
714 
715  KMP_ASSERT(ompt_deps != NULL);
716 
717  for (i = 0; i < ndeps; i++) {
718  ompt_deps[i].variable.ptr = (void *)dep_list[i].base_addr;
719  if (dep_list[i].flags.in && dep_list[i].flags.out)
720  ompt_deps[i].dependence_type = ompt_dependence_type_inout;
721  else if (dep_list[i].flags.out)
722  ompt_deps[i].dependence_type = ompt_dependence_type_out;
723  else if (dep_list[i].flags.in)
724  ompt_deps[i].dependence_type = ompt_dependence_type_in;
725  else if (dep_list[i].flags.mtx)
726  ompt_deps[ndeps + i].dependence_type =
727  ompt_dependence_type_mutexinoutset;
728  }
729  for (i = 0; i < ndeps_noalias; i++) {
730  ompt_deps[ndeps + i].variable.ptr = (void *)noalias_dep_list[i].base_addr;
731  if (noalias_dep_list[i].flags.in && noalias_dep_list[i].flags.out)
732  ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_inout;
733  else if (noalias_dep_list[i].flags.out)
734  ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_out;
735  else if (noalias_dep_list[i].flags.in)
736  ompt_deps[ndeps + i].dependence_type = ompt_dependence_type_in;
737  else if (noalias_dep_list[i].flags.mtx)
738  ompt_deps[ndeps + i].dependence_type =
739  ompt_dependence_type_mutexinoutset;
740  }
741  ompt_callbacks.ompt_callback(ompt_callback_dependences)(
742  taskwait_task_data, ompt_deps, ompt_ndeps);
743  /* We can now free the allocated memory for the dependencies */
744  /* For OMPD we might want to delay the free until end of this function */
745  KMP_OMPT_DEPS_FREE(thread, ompt_deps);
746  ompt_deps = NULL;
747  }
748 #endif /* OMPT_OPTIONAL */
749 #endif /* OMPT_SUPPORT */
750 
751  // We can return immediately as:
752  // - dependences are not computed in serial teams (except with proxy tasks)
753  // - if the dephash is not yet created it means we have nothing to wait for
754  bool ignore = current_task->td_flags.team_serial ||
755  current_task->td_flags.tasking_ser ||
756  current_task->td_flags.final;
757  ignore = ignore && thread->th.th_task_team != NULL &&
758  thread->th.th_task_team->tt.tt_found_proxy_tasks == FALSE;
759  ignore = ignore || current_task->td_dephash == NULL;
760 
761  if (ignore) {
762  KA_TRACE(10, ("__kmpc_omp_wait_deps(exit): T#%d has no blocking "
763  "dependencies : loc=%p\n",
764  gtid, loc_ref));
765 #if OMPT_SUPPORT
766  __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
767 #endif /* OMPT_SUPPORT */
768  return;
769  }
770 
771  kmp_depnode_t node = {0};
772  __kmp_init_node(&node);
773  // the stack owns the node
774  __kmp_node_ref(&node);
775 
776  if (!__kmp_check_deps(gtid, &node, NULL, &current_task->td_dephash,
777  DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
778  noalias_dep_list)) {
779  KA_TRACE(10, ("__kmpc_omp_wait_deps(exit): T#%d has no blocking "
780  "dependencies : loc=%p\n",
781  gtid, loc_ref));
782 #if OMPT_SUPPORT
783  __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
784 #endif /* OMPT_SUPPORT */
785  return;
786  }
787 
788  int thread_finished = FALSE;
789  kmp_flag_32 flag((std::atomic<kmp_uint32> *)&node.dn.npredecessors, 0U);
790  while (node.dn.npredecessors > 0) {
791  flag.execute_tasks(thread, gtid, FALSE,
792  &thread_finished USE_ITT_BUILD_ARG(NULL),
793  __kmp_task_stealing_constraint);
794  }
795 
796 #if OMPT_SUPPORT
797  __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
798 #endif /* OMPT_SUPPORT */
799  KA_TRACE(10, ("__kmpc_omp_wait_deps(exit): T#%d finished waiting : loc=%p\n",
800  gtid, loc_ref));
801 }
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)
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)
Definition: kmp.h:226