Files
swift-mirror/stdlib/public/Concurrency/TaskLocal.cpp
2021-04-29 15:48:09 +09:00

291 lines
11 KiB
C++

//===--- TaskLocal.cpp - Task Local Values --------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "../CompatibilityOverride/CompatibilityOverride.h"
#include "swift/ABI/TaskLocal.h"
#include "swift/Runtime/Concurrency.h"
#include "swift/ABI/Task.h"
#include "swift/ABI/Metadata.h"
#include "TaskPrivate.h"
using namespace swift;
// =============================================================================
// ==== ABI --------------------------------------------------------------------
SWIFT_CC(swift)
static void swift_task_localValuePushImpl(AsyncTask *task,
const HeapObject *key,
/* +1 */ OpaqueValue *value,
const Metadata *valueType) {
task->localValuePush(key, value, valueType);
}
SWIFT_CC(swift)
static OpaqueValue* swift_task_localValueGetImpl(AsyncTask *task,
const HeapObject *key,
TaskLocal::TaskLocalInheritance inheritance) {
return task->localValueGet(key, inheritance);
}
SWIFT_CC(swift)
static void swift_task_localValuePopImpl(AsyncTask *task) {
task->localValuePop();
}
SWIFT_CC(swift)
static void destroyTaskLocalHeapItem(SWIFT_CONTEXT HeapObject *obj) {
fprintf(stderr, "[%s:%d] (%s) DESTROY heapItem:%p\n", __FILE__, __LINE__, __FUNCTION__, obj);
// assert(false && "TODO: we got released and should destroy it now");
// TaskLocal::HeapItem *heapItem = static_cast<TaskLocal::HeapItem*>(obj);
}
// =============================================================================
// ==== TaskLocal::HeapItem Metadata -------------------------------------------
/// Heap metadata for an asynchronous task.
FullMetadata<HeapMetadata> swift::taskLocalHeapItemHeapMetadata = {
{
{
&destroyTaskLocalHeapItem
},
{
/*value witness table*/ nullptr
}
},
{
MetadataKind::TaskLocalHeapItem
}
};
// =============================================================================
// ==== Initialization ---------------------------------------------------------
void TaskLocal::Storage::initializeLinkParent(AsyncTask* task,
AsyncTask* parent) {
assert(!head && "initial task local storage was already initialized");
assert(parent && "parent must be provided to link to it");
head = TaskLocal::Item::createParentLink(task, parent);
}
TaskLocal::Item*
TaskLocal::Item::createParentLink(AsyncTask *task, AsyncTask *parent) {
fprintf(stderr, "[%s:%d] (%s) CREATE PARENT LINK\n", __FILE__, __LINE__, __FUNCTION__);
size_t amountToAllocate = Item::itemSize(/*isHeapItem*/false, /*valueType*/nullptr);
// assert(amountToAllocate % MaximumAlignment == 0); // TODO: do we need this?
void *allocation = _swift_task_alloc_specific(task, amountToAllocate);
Item *item = new(allocation) Item();
// FIXME: parent pointer must to be the parent STORAGE not just the next item.
auto parentHead = parent->Local.head;
if (parentHead) {
if (parentHead->isEmpty()) {
switch (parentHead->getNextLinkType()) {
case NextLinkType::IsParent:
// it has no values, and just points to its parent,
// therefore skip also skip pointing to that parent and point
// to whichever parent it was pointing to as well, it may be its
// immediate parent, or some super-parent.
item->next = reinterpret_cast<uintptr_t>(parentHead->getNext()) |
static_cast<uintptr_t>(NextLinkType::IsParent);
break;
case NextLinkType::IsNext:
if (parentHead->getNext()) {
assert(false && "empty taskValue head in parent task, yet parent's 'head' is `IsNext`, "
"this should not happen, as it implies the parent must have stored some value.");
} else {
// is terminal pointer
item->next = reinterpret_cast<uintptr_t>(parentHead->getNext());
}
break;
case NextLinkType::ThisItemIsHeapItem:
assert(false && "ThisItemIsHeapItem?"); // FIXME: what?
}
} else {
item->next = reinterpret_cast<uintptr_t>(parentHead) |
static_cast<uintptr_t>(NextLinkType::IsParent);
}
} else {
item->next = reinterpret_cast<uintptr_t>(parentHead);
}
return item;
}
TaskLocal::Item*
TaskLocal::Item::createLink(AsyncTask *task,
const HeapObject *key,
const Metadata *valueType) {
assert(task);
fprintf(stderr, "[%s:%d] (%s) CREATE LINK, key:%p\n", __FILE__, __LINE__, __FUNCTION__, key);
// If we're executing this inside of a withTaskGroup { ... } we risk the
// following situation:
//
// withTaskGroup(...) { group in // (Parent Task):[,...]
// // the TaskGroupRecord is present throughout the execution of this closure
// Lib.$key.withValue("xoxo") { // (Parent Task)[key="xoxo",...]
// group.spawn {
// <sleep>
// print(Lib.someTaskLocal)
// } //
// }
// return group.next()!
// }
bool isStructured = !swift_task_hasTaskGroupStatusRecord();
bool isHeapItem = !isStructured;
size_t amountToAllocate = Item::itemSize(isHeapItem, valueType);
// assert(amountToAllocate % MaximumAlignment == 0); // TODO: do we need this?
void *allocation;
Item *item = nullptr;
HeapItem *heapItem = nullptr;
if (isStructured) {
allocation = _swift_task_alloc_specific(task, amountToAllocate);
fprintf(stderr, "[%s:%d] (%s) fast-path, TASK_ALLOC, key:%p, ptr:%p\n",
__FILE__, __LINE__, __FUNCTION__, key, allocation);
item = new(allocation) Item(key, valueType);
} else {
allocation = malloc(amountToAllocate);
fprintf(stderr, "[%s:%d] (%s) slow-path, unstructured, MALLOC, key:%p, ptr:%p\n", __FILE__, __LINE__, __FUNCTION__, key, allocation);
heapItem = new(allocation) HeapItem(key, valueType);
fprintf(stderr, "[%s:%d] (%s) slow-path, unstructured; heapItem:%p\n", __FILE__, __LINE__, __FUNCTION__, heapItem);
item = heapItem->getItem();
fprintf(stderr, "[%s:%d] (%s) slow-path, unstructured; item:%p\n", __FILE__, __LINE__, __FUNCTION__, item);
fprintf(stderr, "[%s:%d] (%s) BEFORE heapItem:%p, ref-count:%d\n", __FILE__, __LINE__, __FUNCTION__, heapItem, swift_retainCount(heapItem));
swift_retain(heapItem);
fprintf(stderr, "[%s:%d] (%s) AFTER heapItem:%p, ref-count:%d\n", __FILE__, __LINE__, __FUNCTION__, heapItem, swift_retainCount(heapItem));
}
auto next = task->Local.head;
auto nextLinkType = isStructured ? NextLinkType::IsNext // FIXME: don't really need the isNext, only is parent and heap item need markers
: NextLinkType::ThisItemIsHeapItem;
item->next = reinterpret_cast<uintptr_t>(next) |
static_cast<uintptr_t>(nextLinkType);
return item;
//
// Item *item = new(allocation) Item(key, valueType);
//
// auto next = task->Local.head;
//// auto nextLinkType = next ? NextLinkType::IsNext
//// : NextLinkType::IsTerminal;
// auto nextLinkType = isStructured ? NextLinkType::IsNext
// : NextLinkType::ThisItemIsHeapItem;
// item->next = reinterpret_cast<uintptr_t>(next) |
// static_cast<uintptr_t>(nextLinkType);
//
// return item;
}
// =============================================================================
// ==== destroy ----------------------------------------------------------------
void TaskLocal::Item::destroy(AsyncTask *task) {
auto linkType = getNextLinkType();
// if it was unstructured, we cannot delete it until all references are gone
if (linkType == TaskLocal::NextLinkType::ThisItemIsHeapItem) {
fprintf(stderr, "[%s:%d] (%s) destroy item:%p\n", __FILE__, __LINE__, __FUNCTION__, this);
assert(false && "implement releasing the heap item");
return;
}
// otherwise it was task-local allocated, so we can safely destroy it right away
if (valueType) {
valueType->vw_destroy(getStoragePtr());
}
_swift_task_dealloc_specific(task, this);
}
void TaskLocal::Storage::destroy(AsyncTask *task) {
auto item = head;
head = nullptr;
TaskLocal::Item *next;
while (item) {
auto linkType = item->getNextLinkType();
switch (linkType) {
case TaskLocal::NextLinkType::ThisItemIsHeapItem: {
fprintf(stderr, "[%s:%d] (%s) destroy UNSTRUCTURED\n", __FILE__, __LINE__, __FUNCTION__);
LLVM_FALLTHROUGH;
}
case TaskLocal::NextLinkType::IsNext:
next = item->getNext();
item->destroy(task);
item = next;
break;
case TaskLocal::NextLinkType::IsParent:
// we're done here; as we must not proceed into the parent owned values.
// we do have to destroy the item pointing at the parent/edge itself though.
item->destroy(task);
return;
}
}
}
// =============================================================================
// ==== push / pop / get -------------------------------------------------------
void TaskLocal::Storage::pushValue(AsyncTask *task,
const HeapObject *key,
/* +1 */ OpaqueValue *value,
const Metadata *valueType) {
assert(value && "Task local value must not be nil");
auto item = Item::createLink(task, key, valueType);
fprintf(stderr, "[%s:%d] (%s) here\n", __FILE__, __LINE__, __FUNCTION__);
valueType->vw_initializeWithTake(item->getStoragePtr(), value);
head = item;
}
void TaskLocal::Storage::popValue(AsyncTask *task) {
assert(head && "attempted to pop value off empty task-local stack");
auto old = head;
head = head->getNext();
old->destroy(task);
}
OpaqueValue* TaskLocal::Storage::getValue(AsyncTask *task,
const HeapObject *key,
const TaskLocalInheritance inherit) {
assert(key && "TaskLocal key must not be null.");
auto item = head;
while (item) {
if (item->key == key) {
return item->getStoragePtr();
}
// if the key is an `inherit = .never` type, we stop our search the first
// time we would be jumping to a parent task to continue the search.
if (item->getNextLinkType() == NextLinkType::IsParent &&
inherit == TaskLocalInheritance::Never)
return nullptr;
item = item->getNext();
}
return nullptr;
}
#define OVERRIDE_TASK_LOCAL COMPATIBILITY_OVERRIDE
#include COMPATIBILITY_OVERRIDE_INCLUDE_PATH