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kmp_taskdeps.h
/*
* kmp_taskdeps.h
*/
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef KMP_TASKDEPS_H
#define KMP_TASKDEPS_H
#include "kmp.h"
#define KMP_ACQUIRE_DEPNODE(gtid, n) __kmp_acquire_lock(&(n)->dn.lock, (gtid))
#define KMP_RELEASE_DEPNODE(gtid, n) __kmp_release_lock(&(n)->dn.lock, (gtid))
static inline void __kmp_node_deref(kmp_info_t *thread, kmp_depnode_t *node) {
if (!node)
return;
kmp_int32 n = KMP_ATOMIC_DEC(&node->dn.nrefs) - 1;
KMP_DEBUG_ASSERT(n >= 0);
if (n == 0) {
#if USE_ITT_BUILD && USE_ITT_NOTIFY
__itt_sync_destroy(node);
#endif
KMP_ASSERT(node->dn.nrefs == 0);
#if USE_FAST_MEMORY
__kmp_fast_free(thread, node);
#else
__kmp_thread_free(thread, node);
#endif
}
}
static inline void __kmp_depnode_list_free(kmp_info_t *thread,
kmp_depnode_list *list) {
kmp_depnode_list *next;
for (; list; list = next) {
next = list->next;
__kmp_node_deref(thread, list->node);
#if USE_FAST_MEMORY
__kmp_fast_free(thread, list);
#else
__kmp_thread_free(thread, list);
#endif
}
}
static inline void __kmp_dephash_free_entries(kmp_info_t *thread,
kmp_dephash_t *h) {
for (size_t i = 0; i < h->size; i++) {
if (h->buckets[i]) {
kmp_dephash_entry_t *next;
for (kmp_dephash_entry_t *entry = h->buckets[i]; entry; entry = next) {
next = entry->next_in_bucket;
__kmp_depnode_list_free(thread, entry->last_set);
__kmp_depnode_list_free(thread, entry->prev_set);
__kmp_node_deref(thread, entry->last_out);
if (entry->mtx_lock) {
__kmp_destroy_lock(entry->mtx_lock);
__kmp_free(entry->mtx_lock);
}
#if USE_FAST_MEMORY
__kmp_fast_free(thread, entry);
#else
__kmp_thread_free(thread, entry);
#endif
}
h->buckets[i] = 0;
}
}
__kmp_node_deref(thread, h->last_all);
h->last_all = NULL;
}
static inline void __kmp_dephash_free(kmp_info_t *thread, kmp_dephash_t *h) {
__kmp_dephash_free_entries(thread, h);
#if USE_FAST_MEMORY
__kmp_fast_free(thread, h);
#else
__kmp_thread_free(thread, h);
#endif
}
extern void __kmpc_give_task(kmp_task_t *ptask, kmp_int32 start);
static inline void __kmp_release_deps(kmp_int32 gtid, kmp_taskdata_t *task) {
#if OMPX_TASKGRAPH
if (task->is_taskgraph && !(__kmp_tdg_is_recording(task->tdg->tdg_status))) {
kmp_node_info_t *TaskInfo = &(task->tdg->record_map[task->td_task_id]);
for (int i = 0; i < TaskInfo->nsuccessors; i++) {
kmp_int32 successorNumber = TaskInfo->successors[i];
kmp_node_info_t *successor = &(task->tdg->record_map[successorNumber]);
kmp_int32 npredecessors = KMP_ATOMIC_DEC(&successor->npredecessors_counter) - 1;
if (successor->task != nullptr && npredecessors == 0) {
__kmp_omp_task(gtid, successor->task, false);
}
}
return;
}
#endif
kmp_info_t *thread = __kmp_threads[gtid];
kmp_depnode_t *node = task->td_depnode;
// Check mutexinoutset dependencies, release locks
if (UNLIKELY(node && (node->dn.mtx_num_locks < 0))) {
// negative num_locks means all locks were acquired
node->dn.mtx_num_locks = -node->dn.mtx_num_locks;
for (int i = node->dn.mtx_num_locks - 1; i >= 0; --i) {
KMP_DEBUG_ASSERT(node->dn.mtx_locks[i] != NULL);
__kmp_release_lock(node->dn.mtx_locks[i], gtid);
}
}
if (task->td_dephash) {
KA_TRACE(
40, ("__kmp_release_deps: T#%d freeing dependencies hash of task %p.\n",
gtid, task));
__kmp_dephash_free(thread, task->td_dephash);
task->td_dephash = NULL;
}
if (!node)
return;
KA_TRACE(20, ("__kmp_release_deps: T#%d notifying successors of task %p.\n",
gtid, task));
KMP_ACQUIRE_DEPNODE(gtid, node);
#if OMPX_TASKGRAPH
if (!task->is_taskgraph ||
(task->is_taskgraph && !__kmp_tdg_is_recording(task->tdg->tdg_status)))
#endif
node->dn.task =
NULL; // mark this task as finished, so no new dependencies are generated
KMP_RELEASE_DEPNODE(gtid, node);
kmp_depnode_list_t *next;
kmp_taskdata_t *next_taskdata;
for (kmp_depnode_list_t *p = node->dn.successors; p; p = next) {
kmp_depnode_t *successor = p->node;
#if USE_ITT_BUILD && USE_ITT_NOTIFY
__itt_sync_releasing(successor);
#endif
kmp_int32 npredecessors = KMP_ATOMIC_DEC(&successor->dn.npredecessors) - 1;
// successor task can be NULL for wait_depends or because deps are still
// being processed
if (npredecessors == 0) {
#if USE_ITT_BUILD && USE_ITT_NOTIFY
__itt_sync_acquired(successor);
#endif
KMP_MB();
if (successor->dn.task) {
KA_TRACE(20, ("__kmp_release_deps: T#%d successor %p of %p scheduled "
"for execution.\n",
gtid, successor->dn.task, task));
// If a regular task depending on a hidden helper task, when the
// hidden helper task is done, the regular task should be executed by
// its encountering team.
if (KMP_HIDDEN_HELPER_THREAD(gtid)) {
// Hidden helper thread can only execute hidden helper tasks
KMP_ASSERT(task->td_flags.hidden_helper);
next_taskdata = KMP_TASK_TO_TASKDATA(successor->dn.task);
// If the dependent task is a regular task, we need to push to its
// encountering thread's queue; otherwise, it can be pushed to its own
// queue.
if (!next_taskdata->td_flags.hidden_helper) {
kmp_int32 encountering_gtid =
next_taskdata->td_alloc_thread->th.th_info.ds.ds_gtid;
kmp_int32 encountering_tid = __kmp_tid_from_gtid(encountering_gtid);
__kmpc_give_task(successor->dn.task, encountering_tid);
} else {
__kmp_omp_task(gtid, successor->dn.task, false);
}
} else {
__kmp_omp_task(gtid, successor->dn.task, false);
}
}
}
next = p->next;
__kmp_node_deref(thread, p->node);
#if USE_FAST_MEMORY
__kmp_fast_free(thread, p);
#else
__kmp_thread_free(thread, p);
#endif
}
__kmp_node_deref(thread, node);
KA_TRACE(
20,
("__kmp_release_deps: T#%d all successors of %p notified of completion\n",
gtid, task));
}
#endif // KMP_TASKDEPS_H