LLVM OpenMP* Runtime Library
kmp_taskdeps.h
1 /*
2  * kmp_taskdeps.h
3  */
4 
5 
6 //===----------------------------------------------------------------------===//
7 //
8 // The LLVM Compiler Infrastructure
9 //
10 // This file is dual licensed under the MIT and the University of Illinois Open
11 // Source Licenses. See LICENSE.txt for details.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 
16 #ifndef KMP_TASKDEPS_H
17 #define KMP_TASKDEPS_H
18 
19 #include "kmp.h"
20 
21 #if OMP_40_ENABLED
22 
23 #define KMP_ACQUIRE_DEPNODE(gtid, n) __kmp_acquire_lock(&(n)->dn.lock, (gtid))
24 #define KMP_RELEASE_DEPNODE(gtid, n) __kmp_release_lock(&(n)->dn.lock, (gtid))
25 
26 static inline void __kmp_node_deref(kmp_info_t *thread, kmp_depnode_t *node) {
27  if (!node)
28  return;
29 
30  kmp_int32 n = KMP_ATOMIC_DEC(&node->dn.nrefs) - 1;
31  if (n == 0) {
32  KMP_ASSERT(node->dn.nrefs == 0);
33 #if USE_FAST_MEMORY
34  __kmp_fast_free(thread, node);
35 #else
36  __kmp_thread_free(thread, node);
37 #endif
38  }
39 }
40 
41 static inline void __kmp_depnode_list_free(kmp_info_t *thread,
42  kmp_depnode_list *list) {
43  kmp_depnode_list *next;
44 
45  for (; list; list = next) {
46  next = list->next;
47 
48  __kmp_node_deref(thread, list->node);
49 #if USE_FAST_MEMORY
50  __kmp_fast_free(thread, list);
51 #else
52  __kmp_thread_free(thread, list);
53 #endif
54  }
55 }
56 
57 static inline void __kmp_dephash_free_entries(kmp_info_t *thread,
58  kmp_dephash_t *h) {
59  for (size_t i = 0; i < h->size; i++) {
60  if (h->buckets[i]) {
61  kmp_dephash_entry_t *next;
62  for (kmp_dephash_entry_t *entry = h->buckets[i]; entry; entry = next) {
63  next = entry->next_in_bucket;
64  __kmp_depnode_list_free(thread, entry->last_ins);
65  __kmp_depnode_list_free(thread, entry->last_mtxs);
66  __kmp_node_deref(thread, entry->last_out);
67  if (entry->mtx_lock) {
68  __kmp_destroy_lock(entry->mtx_lock);
69  __kmp_free(entry->mtx_lock);
70  }
71 #if USE_FAST_MEMORY
72  __kmp_fast_free(thread, entry);
73 #else
74  __kmp_thread_free(thread, entry);
75 #endif
76  }
77  h->buckets[i] = 0;
78  }
79  }
80 }
81 
82 static inline void __kmp_dephash_free(kmp_info_t *thread, kmp_dephash_t *h) {
83  __kmp_dephash_free_entries(thread, h);
84 #if USE_FAST_MEMORY
85  __kmp_fast_free(thread, h);
86 #else
87  __kmp_thread_free(thread, h);
88 #endif
89 }
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  if (task->td_dephash) {
96  KA_TRACE(
97  40, ("__kmp_release_deps: T#%d freeing dependencies hash of task %p.\n",
98  gtid, task));
99  __kmp_dephash_free(thread, task->td_dephash);
100  task->td_dephash = NULL;
101  }
102 
103  if (!node)
104  return;
105 
106  KA_TRACE(20, ("__kmp_release_deps: T#%d notifying successors of task %p.\n",
107  gtid, task));
108 
109  KMP_ACQUIRE_DEPNODE(gtid, node);
110  node->dn.task =
111  NULL; // mark this task as finished, so no new dependencies are generated
112  KMP_RELEASE_DEPNODE(gtid, node);
113 
114  kmp_depnode_list_t *next;
115  for (kmp_depnode_list_t *p = node->dn.successors; p; p = next) {
116  kmp_depnode_t *successor = p->node;
117  kmp_int32 npredecessors = KMP_ATOMIC_DEC(&successor->dn.npredecessors) - 1;
118 
119  // successor task can be NULL for wait_depends or because deps are still
120  // being processed
121  if (npredecessors == 0) {
122  KMP_MB();
123  if (successor->dn.task) {
124  KA_TRACE(20, ("__kmp_release_deps: T#%d successor %p of %p scheduled "
125  "for execution.\n",
126  gtid, successor->dn.task, task));
127  __kmp_omp_task(gtid, successor->dn.task, false);
128  }
129  }
130 
131  next = p->next;
132  __kmp_node_deref(thread, p->node);
133 #if USE_FAST_MEMORY
134  __kmp_fast_free(thread, p);
135 #else
136  __kmp_thread_free(thread, p);
137 #endif
138  }
139 
140  __kmp_node_deref(thread, node);
141 
142  KA_TRACE(
143  20,
144  ("__kmp_release_deps: T#%d all successors of %p notified of completion\n",
145  gtid, task));
146 }
147 
148 #endif // OMP_40_ENABLED
149 
150 #endif // KMP_TASKDEPS_H