1069 lines · cpp
1/*2 * kmp_taskdeps.cpp3 */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-exception10//11//===----------------------------------------------------------------------===//12 13//#define KMP_SUPPORT_GRAPH_OUTPUT 114 15#include "kmp.h"16#include "kmp_io.h"17#include "kmp_wait_release.h"18#include "kmp_taskdeps.h"19#if OMPT_SUPPORT20#include "ompt-specific.h"21#endif22 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 support28// TODO: kmp_lock_t seems a tad to big (and heavy weight) for this. Check other29// runtime locks30// TODO: Any ITT support needed?31 32#ifdef KMP_SUPPORT_GRAPH_OUTPUT33static std::atomic<kmp_int32> kmp_node_id_seed = 0;34#endif35 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 task39 // once dependences have been processed40 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 // Init creates the first reference. Bit 0 indicates that this node45 // resides on the stack. The refcount is incremented and decremented in46 // steps of two, maintaining use of even numbers for heap nodes and odd47 // numbers for stack nodes.48 KMP_ATOMIC_ST_RLX(&node->dn.nrefs, on_stack ? 3 : 2);49#ifdef KMP_SUPPORT_GRAPH_OUTPUT50 node->dn.id = KMP_ATOMIC_INC(&kmp_node_id_seed);51#endif52#if USE_ITT_BUILD && USE_ITT_NOTIFY53 __itt_sync_create(node, "OMP task dep node", NULL, 0);54#endif55}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_MEMORY86 h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size_to_allocate);87#else88 h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size_to_allocate);89#endif90 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 initialized99 for (size_t i = 0; i < new_size; i++) {100 h->buckets[i] = NULL;101 }102 103 // insert existing elements in the new table104 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 in109 // the new bucket.110 size_t new_bucket = __kmp_dephash_hash(entry->addr, 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 table120#if USE_FAST_MEMORY121 __kmp_fast_free(thread, current_dephash);122#else123 __kmp_thread_free(thread, current_dephash);124#endif125 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 else138 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_MEMORY143 h = (kmp_dephash_t *)__kmp_fast_allocate(thread, size);144#else145 h = (kmp_dephash_t *)__kmp_thread_malloc(thread, size);146#endif147 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, h);167 h = *hash;168 }169 size_t bucket = __kmp_dephash_hash(addr, 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 required178#if USE_FAST_MEMORY179 entry = (kmp_dephash_entry_t *)__kmp_fast_allocate(180 thread, sizeof(kmp_dephash_entry_t));181#else182 entry = (kmp_dephash_entry_t *)__kmp_thread_malloc(183 thread, sizeof(kmp_dephash_entry_t));184#endif185 entry->addr = addr;186 if (!h->last_all) // no predecessor task with omp_all_memory dependence187 entry->last_out = NULL;188 else // else link the omp_all_memory depnode to the new entry189 entry->last_out = __kmp_node_ref(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_MEMORY209 new_head = (kmp_depnode_list_t *)__kmp_fast_allocate(210 thread, sizeof(kmp_depnode_list_t));211#else212 new_head = (kmp_depnode_list_t *)__kmp_thread_malloc(213 thread, sizeof(kmp_depnode_list_t));214#endif215 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_TASKGRAPH226 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 TDG230 // and the other is not231 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#endif266#ifdef KMP_SUPPORT_GRAPH_OUTPUT267 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 dependences269 // 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#endif276#if OMPT_SUPPORT && OMPT_OPTIONAL277 /* OMPT tracks dependences between task (a=source, b=sink) in which278 task a blocks the execution of b through the ompt_new_dependence_callback279 */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 else286 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_int32305__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 elements312 for (kmp_depnode_list_t *p = plist; p; p = p->next) {313 kmp_depnode_t *dep = p->node;314#if OMPX_TASKGRAPH315 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#endif324 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_TASKGRAPH329 if (!(__kmp_tdg_is_recording(tdg_status)) && task)330#endif331 __kmp_track_dependence(gtid, dep, node, task);332 dep->dn.successors = __kmp_add_node(thread, 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 graph347static 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_TASKGRAPH356 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#endif365 if (sink->dn.task) {366 // synchronously add source to sink' list of successors367 KMP_ACQUIRE_DEPNODE(gtid, sink);368 if (sink->dn.task) {369 if (!sink->dn.successors || sink->dn.successors->node != source) {370#if OMPX_TASKGRAPH371 if (!(__kmp_tdg_is_recording(tdg_status)) && task)372#endif373 __kmp_track_dependence(gtid, sink, source, task);374 sink->dn.successors = __kmp_add_node(thread, sink->dn.successors, 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_TASKGRAPH380 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 taskgraph385 // and386 // 1) the task is reset to its initial state (by kmp_free_task) or387 // 2) the task is complete but not yet reset388 npredecessors--;389 }390 }391#endif392 npredecessors++;393 }394 }395 KMP_RELEASE_DEPNODE(gtid, sink);396 }397 return npredecessors;398}399 400static inline kmp_int32401__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 any410 npredecessors +=411 __kmp_depnode_link_successor(gtid, thread, task, node, h->last_all);412 __kmp_node_deref(thread, 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 previous417 // outputs are guaranteed to be completed after the execution of this418 // task so the previous output nodes can be cleared.419 h->last_all = NULL;420 }421 422 // process all regular dependences423 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 dephash426 continue;427 for (; info; info = info->next_in_bucket) {428 // for each entry the omp_all_memory works as OUT dependence429 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, last_set);435 __kmp_depnode_list_free(thread, last_set);436 __kmp_depnode_list_free(thread, prev_set);437 info->last_set = NULL;438 info->prev_set = NULL;439 info->last_flag = 0; // no sets in this dephash entry440 } else {441 npredecessors +=442 __kmp_depnode_link_successor(gtid, thread, task, node, last_out);443 }444 __kmp_node_deref(thread, 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_int32459__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 entries473 474 kmp_dephash_entry_t *info =475 __kmp_dephash_find(thread, hash, 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 any481 if (last_set) {482 npredecessors +=483 __kmp_depnode_link_successor(gtid, thread, task, node, last_set);484 __kmp_depnode_list_free(thread, last_set);485 __kmp_depnode_list_free(thread, prev_set);486 info->last_set = NULL;487 info->prev_set = NULL;488 info->last_flag = 0; // no sets in this dephash entry489 } else {490 npredecessors +=491 __kmp_depnode_link_successor(gtid, thread, task, node, last_out);492 }493 __kmp_node_deref(thread, 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 previous498 // outputs are guaranteed to be completed after the execution of this499 // task so the previous output nodes can be cleared.500 info->last_out = NULL;501 }502 } else { // either IN or MTX or SET503 if (info->last_flag == 0 || info->last_flag == dep->flag) {504 // last_set either didn't exist or of same dep kind505 // link node as successor of the last_out if any506 npredecessors +=507 __kmp_depnode_link_successor(gtid, thread, task, node, last_out);508 // link node as successor of all nodes in the prev_set if any509 npredecessors +=510 __kmp_depnode_link_successor(gtid, thread, task, node, prev_set);511 if (dep_barrier) {512 // clean last_out and prev_set if any; don't touch last_set513 __kmp_node_deref(thread, last_out);514 info->last_out = NULL;515 __kmp_depnode_list_free(thread, prev_set);516 info->prev_set = NULL;517 }518 } else { // last_set is of different dep kind, make it prev_set519 // link node as successor of all nodes in the last_set520 npredecessors +=521 __kmp_depnode_link_successor(gtid, thread, task, node, last_set);522 // clean last_out if any523 __kmp_node_deref(thread, last_out);524 info->last_out = NULL;525 // clean prev_set if any526 __kmp_depnode_list_free(thread, prev_set);527 if (!dep_barrier) {528 // move last_set to prev_set, new last_set will be allocated529 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 otherwise538 if (!dep_barrier) {539 info->last_flag = dep->flag; // store dep kind of the last_set540 info->last_set = __kmp_add_node(thread, info->last_set, node);541 }542 // check if we are processing MTX dependency543 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(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 array551 for (m = 0; m < MAX_MTX_DEPS; ++m) {552 // sort pointers in decreasing order to avoid potential livelock553 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 pointers557 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 loop565 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 dependence578static 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_DEBUG586 kmp_taskdata_t *taskdata = KMP_TASK_TO_TASKDATA(task);587#endif588 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_list594 // 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 OUT606 dep_list[i].flag = KMP_DEP_OUT;607 }608 dep_list[j].base_addr = 0; // Mark j element as void609 }610 }611 if (dep_list[i].flag == KMP_DEP_MTX) {612 // limit number of mtx deps to MAX_MTX_DEPS per node613 if (n_mtxs < MAX_MTX_DEPS && task != NULL) {614 ++n_mtxs;615 } else {616 dep_list[i].flag = KMP_DEP_OUT; // downgrade mutexinoutset to inout617 }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 either622 // (addr=0 && flag=0x80) (flag KMP_DEP_ALL), or (addr=-1).623 // omp_all_memory overrides all other dependences if any624 dep_all = 1;625 break;626 }627 }628 629 // doesn't need to be atomic as no other thread is going to be accessing this630 // node just yet.631 // npredecessors is set -1 to ensure that none of the releasing tasks queues632 // this task before we have finished processing all the dependences633 node->dn.npredecessors = -1;634 635 // used to pack all npredecessors additions into a single atomic operation at636 // the end637 int npredecessors;638 639 if (!dep_all) { // regular dependences640 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_noalias, noalias_dep_list, task);644 } else { // omp_all_memory dependence645 npredecessors = __kmp_process_dep_all(gtid, node, *hash, dep_barrier, task);646 }647 648 node->dn.task = task;649 KMP_MB();650 651 // Account for our initial fake value652 npredecessors++;653 654 // Update predecessors and obtain current value to check if there are still655 // any outstanding dependences (some tasks may have finished while we656 // processed the dependences)657 npredecessors =658 node->dn.npredecessors.fetch_add(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 releasing664 // task...665 return npredecessors > 0 ? true : false;666}667 668/*!669@ingroup TASKING670@param loc_ref location of the original task directive671@param gtid Global Thread ID of encountering thread672@param new_task task thunk allocated by __kmp_omp_task_alloc() for the ''new673task''674@param ndeps Number of depend items with possible aliasing675@param dep_list List of depend items with possible aliasing676@param ndeps_noalias Number of depend items with no aliasing677@param noalias_dep_list List of depend items with no aliasing678 679@return Returns either TASK_CURRENT_NOT_QUEUED if the current task was not680suspended and queued, or TASK_CURRENT_QUEUED if it was suspended and queued681 682Schedule a non-thread-switchable task with dependences for execution683*/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_TASKGRAPH698 // record TDG with deps699 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 needed703 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 other728 // threads use old_record while map_size is already updated729 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#endif739#if OMPT_SUPPORT740 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_OPTIONAL758 /* 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_MEMORY828 kmp_depnode_t *node =829 (kmp_depnode_t *)__kmp_fast_allocate(thread, sizeof(kmp_depnode_t));830#else831 kmp_depnode_t *node =832 (kmp_depnode_t *)__kmp_thread_malloc(thread, sizeof(kmp_depnode_t));833#endif834 835 __kmp_init_node(node, /*on_stack=*/false);836 new_taskdata->td_depnode = node;837 838 if (__kmp_check_deps(gtid, node, new_task, ¤t_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_SUPPORT846 if (ompt_enabled.enabled) {847 current_task->ompt_task_info.frame.enter_frame = ompt_data_none;848 }849#endif850 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, true);864#if OMPT_SUPPORT865 if (ompt_enabled.enabled) {866 current_task->ompt_task_info.frame.enter_frame = ompt_data_none;867 }868#endif869 return ret;870}871 872#if OMPT_SUPPORT873void __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 TASKING886@param loc_ref location of the original task directive887@param gtid Global Thread ID of encountering thread888@param ndeps Number of depend items with possible aliasing889@param dep_list List of depend items with possible aliasing890@param ndeps_noalias Number of depend items with no aliasing891@param noalias_dep_list List of depend items with no aliasing892 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, 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 now905 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_SUPPORT925 // this function represents a taskwait construct with depend clause926 // We signal 4 events:927 // - creation of the taskwait task928 // - dependences of the taskwait task929 // - schedule and finish of the taskwait task930 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_OPTIONAL946 /* 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 for997 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_SUPPORT1011 __ompt_taskwait_dep_finish(current_task, taskwait_task_data);1012#endif /* OMPT_SUPPORT */1013 return;1014 }1015 1016 kmp_depnode_t node = {0};1017 __kmp_init_node(&node, /*on_stack=*/true);1018 1019 if (!__kmp_check_deps(gtid, &node, NULL, ¤t_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_SUPPORT1026 __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(thread, gtid, FALSE,1046 &thread_finished USE_ITT_BUILD_ARG(NULL),1047 __kmp_task_stealing_constraint);1048 }1049 1050 // Wait until the last __kmp_release_deps is finished before we free the1051 // current stack frame holding the "node" variable; once its nrefs count1052 // reaches 3 (meaning 1, since bit zero of the refcount indicates a stack1053 // rather than a heap address), we're sure nobody else can try to reference1054 // 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_SUPPORT1063 __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