xref: /freebsd/contrib/llvm-project/openmp/runtime/src/kmp_taskdeps.h (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c)
1 /*
2  * kmp_taskdeps.h
3  */
4 
5 
6 //===----------------------------------------------------------------------===//
7 //
8 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
9 // See https://llvm.org/LICENSE.txt for license information.
10 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
11 //
12 //===----------------------------------------------------------------------===//
13 
14 
15 #ifndef KMP_TASKDEPS_H
16 #define KMP_TASKDEPS_H
17 
18 #include "kmp.h"
19 
20 #define KMP_ACQUIRE_DEPNODE(gtid, n) __kmp_acquire_lock(&(n)->dn.lock, (gtid))
21 #define KMP_RELEASE_DEPNODE(gtid, n) __kmp_release_lock(&(n)->dn.lock, (gtid))
22 
23 static inline void __kmp_node_deref(kmp_info_t *thread, kmp_depnode_t *node) {
24   if (!node)
25     return;
26 
27   kmp_int32 n = KMP_ATOMIC_DEC(&node->dn.nrefs) - 1;
28   if (n == 0) {
29     KMP_ASSERT(node->dn.nrefs == 0);
30 #if USE_FAST_MEMORY
31     __kmp_fast_free(thread, node);
32 #else
33     __kmp_thread_free(thread, node);
34 #endif
35   }
36 }
37 
38 static inline void __kmp_depnode_list_free(kmp_info_t *thread,
39                                            kmp_depnode_list *list) {
40   kmp_depnode_list *next;
41 
42   for (; list; list = next) {
43     next = list->next;
44 
45     __kmp_node_deref(thread, list->node);
46 #if USE_FAST_MEMORY
47     __kmp_fast_free(thread, list);
48 #else
49     __kmp_thread_free(thread, list);
50 #endif
51   }
52 }
53 
54 static inline void __kmp_dephash_free_entries(kmp_info_t *thread,
55                                               kmp_dephash_t *h) {
56   for (size_t i = 0; i < h->size; i++) {
57     if (h->buckets[i]) {
58       kmp_dephash_entry_t *next;
59       for (kmp_dephash_entry_t *entry = h->buckets[i]; entry; entry = next) {
60         next = entry->next_in_bucket;
61         __kmp_depnode_list_free(thread, entry->last_ins);
62         __kmp_depnode_list_free(thread, entry->last_mtxs);
63         __kmp_node_deref(thread, entry->last_out);
64         if (entry->mtx_lock) {
65           __kmp_destroy_lock(entry->mtx_lock);
66           __kmp_free(entry->mtx_lock);
67         }
68 #if USE_FAST_MEMORY
69         __kmp_fast_free(thread, entry);
70 #else
71         __kmp_thread_free(thread, entry);
72 #endif
73       }
74       h->buckets[i] = 0;
75     }
76   }
77 }
78 
79 static inline void __kmp_dephash_free(kmp_info_t *thread, kmp_dephash_t *h) {
80   __kmp_dephash_free_entries(thread, h);
81 #if USE_FAST_MEMORY
82   __kmp_fast_free(thread, h);
83 #else
84   __kmp_thread_free(thread, h);
85 #endif
86 }
87 
88 static inline void __kmp_release_deps(kmp_int32 gtid, kmp_taskdata_t *task) {
89   kmp_info_t *thread = __kmp_threads[gtid];
90   kmp_depnode_t *node = task->td_depnode;
91 
92   if (task->td_dephash) {
93     KA_TRACE(
94         40, ("__kmp_release_deps: T#%d freeing dependencies hash of task %p.\n",
95              gtid, task));
96     __kmp_dephash_free(thread, task->td_dephash);
97     task->td_dephash = NULL;
98   }
99 
100   if (!node)
101     return;
102 
103   KA_TRACE(20, ("__kmp_release_deps: T#%d notifying successors of task %p.\n",
104                 gtid, task));
105 
106   KMP_ACQUIRE_DEPNODE(gtid, node);
107   node->dn.task =
108       NULL; // mark this task as finished, so no new dependencies are generated
109   KMP_RELEASE_DEPNODE(gtid, node);
110 
111   kmp_depnode_list_t *next;
112   for (kmp_depnode_list_t *p = node->dn.successors; p; p = next) {
113     kmp_depnode_t *successor = p->node;
114     kmp_int32 npredecessors = KMP_ATOMIC_DEC(&successor->dn.npredecessors) - 1;
115 
116     // successor task can be NULL for wait_depends or because deps are still
117     // being processed
118     if (npredecessors == 0) {
119       KMP_MB();
120       if (successor->dn.task) {
121         KA_TRACE(20, ("__kmp_release_deps: T#%d successor %p of %p scheduled "
122                       "for execution.\n",
123                       gtid, successor->dn.task, task));
124         __kmp_omp_task(gtid, successor->dn.task, false);
125       }
126     }
127 
128     next = p->next;
129     __kmp_node_deref(thread, p->node);
130 #if USE_FAST_MEMORY
131     __kmp_fast_free(thread, p);
132 #else
133     __kmp_thread_free(thread, p);
134 #endif
135   }
136 
137   __kmp_node_deref(thread, node);
138 
139   KA_TRACE(
140       20,
141       ("__kmp_release_deps: T#%d all successors of %p notified of completion\n",
142        gtid, task));
143 }
144 
145 #endif // KMP_TASKDEPS_H
146