1 /* 2 * kmp_taskdeps.h 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 #ifndef KMP_TASKDEPS_H 14 #define KMP_TASKDEPS_H 15 16 #include "kmp.h" 17 18 #define KMP_ACQUIRE_DEPNODE(gtid, n) __kmp_acquire_lock(&(n)->dn.lock, (gtid)) 19 #define KMP_RELEASE_DEPNODE(gtid, n) __kmp_release_lock(&(n)->dn.lock, (gtid)) 20 21 static inline void __kmp_node_deref(kmp_info_t *thread, kmp_depnode_t *node) { 22 if (!node) 23 return; 24 25 kmp_int32 n = KMP_ATOMIC_DEC(&node->dn.nrefs) - 1; 26 KMP_DEBUG_ASSERT(n >= 0); 27 if (n == 0) { 28 KMP_ASSERT(node->dn.nrefs == 0); 29 #if USE_FAST_MEMORY 30 __kmp_fast_free(thread, node); 31 #else 32 __kmp_thread_free(thread, node); 33 #endif 34 } 35 } 36 37 static inline void __kmp_depnode_list_free(kmp_info_t *thread, 38 kmp_depnode_list *list) { 39 kmp_depnode_list *next; 40 41 for (; list; list = next) { 42 next = list->next; 43 44 __kmp_node_deref(thread, list->node); 45 #if USE_FAST_MEMORY 46 __kmp_fast_free(thread, list); 47 #else 48 __kmp_thread_free(thread, list); 49 #endif 50 } 51 } 52 53 static inline void __kmp_dephash_free_entries(kmp_info_t *thread, 54 kmp_dephash_t *h) { 55 for (size_t i = 0; i < h->size; i++) { 56 if (h->buckets[i]) { 57 kmp_dephash_entry_t *next; 58 for (kmp_dephash_entry_t *entry = h->buckets[i]; entry; entry = next) { 59 next = entry->next_in_bucket; 60 __kmp_depnode_list_free(thread, entry->last_set); 61 __kmp_depnode_list_free(thread, entry->prev_set); 62 __kmp_node_deref(thread, entry->last_out); 63 if (entry->mtx_lock) { 64 __kmp_destroy_lock(entry->mtx_lock); 65 __kmp_free(entry->mtx_lock); 66 } 67 #if USE_FAST_MEMORY 68 __kmp_fast_free(thread, entry); 69 #else 70 __kmp_thread_free(thread, entry); 71 #endif 72 } 73 h->buckets[i] = 0; 74 } 75 } 76 __kmp_node_deref(thread, h->last_all); 77 h->last_all = NULL; 78 } 79 80 static inline void __kmp_dephash_free(kmp_info_t *thread, kmp_dephash_t *h) { 81 __kmp_dephash_free_entries(thread, h); 82 #if USE_FAST_MEMORY 83 __kmp_fast_free(thread, h); 84 #else 85 __kmp_thread_free(thread, h); 86 #endif 87 } 88 89 extern void __kmpc_give_task(kmp_task_t *ptask, kmp_int32 start); 90 91 static inline void __kmp_release_deps(kmp_int32 gtid, kmp_taskdata_t *task) { 92 kmp_info_t *thread = __kmp_threads[gtid]; 93 kmp_depnode_t *node = task->td_depnode; 94 95 // Check mutexinoutset dependencies, release locks 96 if (UNLIKELY(node && (node->dn.mtx_num_locks < 0))) { 97 // negative num_locks means all locks were acquired 98 node->dn.mtx_num_locks = -node->dn.mtx_num_locks; 99 for (int i = node->dn.mtx_num_locks - 1; i >= 0; --i) { 100 KMP_DEBUG_ASSERT(node->dn.mtx_locks[i] != NULL); 101 __kmp_release_lock(node->dn.mtx_locks[i], gtid); 102 } 103 } 104 105 if (task->td_dephash) { 106 KA_TRACE( 107 40, ("__kmp_release_deps: T#%d freeing dependencies hash of task %p.\n", 108 gtid, task)); 109 __kmp_dephash_free(thread, task->td_dephash); 110 task->td_dephash = NULL; 111 } 112 113 if (!node) 114 return; 115 116 KA_TRACE(20, ("__kmp_release_deps: T#%d notifying successors of task %p.\n", 117 gtid, task)); 118 119 KMP_ACQUIRE_DEPNODE(gtid, node); 120 node->dn.task = 121 NULL; // mark this task as finished, so no new dependencies are generated 122 KMP_RELEASE_DEPNODE(gtid, node); 123 124 kmp_depnode_list_t *next; 125 kmp_taskdata_t *next_taskdata; 126 for (kmp_depnode_list_t *p = node->dn.successors; p; p = next) { 127 kmp_depnode_t *successor = p->node; 128 kmp_int32 npredecessors = KMP_ATOMIC_DEC(&successor->dn.npredecessors) - 1; 129 130 // successor task can be NULL for wait_depends or because deps are still 131 // being processed 132 if (npredecessors == 0) { 133 KMP_MB(); 134 if (successor->dn.task) { 135 KA_TRACE(20, ("__kmp_release_deps: T#%d successor %p of %p scheduled " 136 "for execution.\n", 137 gtid, successor->dn.task, task)); 138 // If a regular task depending on a hidden helper task, when the 139 // hidden helper task is done, the regular task should be executed by 140 // its encountering team. 141 if (KMP_HIDDEN_HELPER_THREAD(gtid)) { 142 // Hidden helper thread can only execute hidden helper tasks 143 KMP_ASSERT(task->td_flags.hidden_helper); 144 next_taskdata = KMP_TASK_TO_TASKDATA(successor->dn.task); 145 // If the dependent task is a regular task, we need to push to its 146 // encountering thread's queue; otherwise, it can be pushed to its own 147 // queue. 148 if (!next_taskdata->td_flags.hidden_helper) { 149 kmp_int32 encountering_gtid = 150 next_taskdata->td_alloc_thread->th.th_info.ds.ds_gtid; 151 kmp_int32 encountering_tid = __kmp_tid_from_gtid(encountering_gtid); 152 __kmpc_give_task(successor->dn.task, encountering_tid); 153 } else { 154 __kmp_omp_task(gtid, successor->dn.task, false); 155 } 156 } else { 157 __kmp_omp_task(gtid, successor->dn.task, false); 158 } 159 } 160 } 161 162 next = p->next; 163 __kmp_node_deref(thread, p->node); 164 #if USE_FAST_MEMORY 165 __kmp_fast_free(thread, p); 166 #else 167 __kmp_thread_free(thread, p); 168 #endif 169 } 170 171 __kmp_node_deref(thread, node); 172 173 KA_TRACE( 174 20, 175 ("__kmp_release_deps: T#%d all successors of %p notified of completion\n", 176 gtid, task)); 177 } 178 179 #endif // KMP_TASKDEPS_H 180