mirror of
https://github.com/geode-sdk/geode.git
synced 2024-11-27 09:55:34 -05:00
ecec11fa93
* Fix spelling mistakes * Fix spelling mistake * Fix spelling mistakes * Fix spelling mistake * Fix spelling mistake
1035 lines
47 KiB
C++
1035 lines
47 KiB
C++
#pragma once
|
|
|
|
#include "general.hpp"
|
|
#include "../loader/Event.hpp"
|
|
#include "../loader/Loader.hpp"
|
|
#include <mutex>
|
|
#include <string_view>
|
|
#include <coroutine>
|
|
|
|
namespace geode {
|
|
namespace geode_internal {
|
|
template <class T, class P>
|
|
struct TaskPromise;
|
|
|
|
template <class T, class P>
|
|
struct TaskAwaiter;
|
|
}
|
|
|
|
/**
|
|
* Tasks represent an asynchronous operation that will be finished at some
|
|
* unknown point in the future. Tasks can report their progress, and will
|
|
* end either through finishing into a value, or due to being cancelled.
|
|
* Tasks are designed to provide a thread-safe general purpose abstraction
|
|
* for dealing with any asynchronous operations.
|
|
* The `Task` class satisfies `EventFilter` and as such is listened
|
|
* to using the Geode events system; tasks may have multiple listeners, and
|
|
* even if a listener is attached after the Task has finished it will
|
|
* receive the finished value.
|
|
* Tasks are a very cheap and tiny struct that just have a reference to
|
|
* a task Handle; as such, Tasks may (and should) be copied around without
|
|
* worry. It should be noted that a Task never owns itself - the listener(s)
|
|
* of a Task are expected to hold an instance of the Task for as long as
|
|
* they intend to listen to it. Usually this is done via just setting
|
|
* the Task as the filter to an `EventListener`, as the `EventListener`
|
|
* manages the lifetime of its filter
|
|
* Task itself does not carry a notion of fallibility aside from
|
|
* cancellation; it is customary to use the `Result` type in Tasks that
|
|
* might finish to a failure value.
|
|
* Once a Task has finished or has been cancelled, it can no longer be
|
|
* revived
|
|
* @tparam T The type the Task will eventually finish to. This type must be
|
|
* move-constructible; though as there is no way to move the value out
|
|
* of the Task (because of potentially multiple listeners), one
|
|
* should ensure they can reasonably copy the value out in some form if they
|
|
* wish to gain ownership of it after the Task is finished
|
|
* @tparam P The type of the progress values the Task (may) post
|
|
*/
|
|
template <std::move_constructible T, std::move_constructible P = std::monostate>
|
|
class [[nodiscard]] Task final {
|
|
public:
|
|
/**
|
|
* A struct used for cancelling Tasks; Tasks may return an instance of
|
|
* this struct to cancel themselves, or to mark they have handled
|
|
* outside cancellation
|
|
*/
|
|
struct [[nodiscard]] Cancel final {};
|
|
|
|
/**
|
|
* A simple holder for the result of this task; holds either the finished
|
|
* value or a mark that the Task was cancelled. The Task body must return
|
|
* this type (though it is implicitly convertible from T and Cancel
|
|
* so the programmer rarely needs to explicitly name it)
|
|
*/
|
|
class Result final {
|
|
private:
|
|
std::variant<T, Cancel> m_value;
|
|
|
|
std::optional<T> getValue() && {
|
|
if (m_value.index() == 0) {
|
|
return std::optional(std::move(std::get<0>(std::move(m_value))));
|
|
}
|
|
return std::nullopt;
|
|
}
|
|
bool isCancelled() const {
|
|
return m_value.index() == 1;
|
|
}
|
|
|
|
template <std::move_constructible T2, std::move_constructible P2>
|
|
friend class Task;
|
|
|
|
public:
|
|
Result(Result&&) = default;
|
|
Result(Result const&) = delete;
|
|
Result(T&& value) : m_value(std::in_place_index<0>, std::forward<T>(value)) {}
|
|
Result(Cancel const&) : m_value(std::in_place_index<1>, Cancel()) {}
|
|
|
|
// Allow constructing Results using anything that can be used to construct T
|
|
template <class V>
|
|
Result(V&& value) requires std::is_constructible_v<T, V&&>
|
|
: m_value(std::in_place_index<0>, std::forward<V>(value))
|
|
{}
|
|
};
|
|
|
|
/// The current status of a Task
|
|
enum class Status {
|
|
/// The task is still running or waiting to start
|
|
Pending,
|
|
/// The task has successfully finished
|
|
Finished,
|
|
/// The task has been cancelled
|
|
Cancelled,
|
|
};
|
|
|
|
/**
|
|
* A handle to a running Task. This is what actually keeps track of
|
|
* the state of the current task; the `Task` class is simply an owning
|
|
* reference & interface to one of these
|
|
*/
|
|
class Handle final {
|
|
private:
|
|
// Handles may contain extra data, for example for holding ownership
|
|
// of other Tasks for `Task::map` and `Task::all`. This struct
|
|
// provides type erasure for that extra data
|
|
struct ExtraData final {
|
|
// Pointer to the owned extra data
|
|
void* ptr;
|
|
// Pointer to a function that deletes that extra data
|
|
// The function MUST have a static lifetime
|
|
void(*onDestroy)(void*);
|
|
// Pointer to a function that handles cancelling any tasks within
|
|
// that extra data when this task is cancelled. Note that the
|
|
// task may not free up the memory associated with itself here
|
|
// and this function may not be called if the user uses
|
|
// `Task::shallowCancel`. However, this pointer *must* always be
|
|
// valid
|
|
// The function MUST have a static lifetime
|
|
void(*onCancelled)(void*);
|
|
|
|
ExtraData(void* ptr, void(*onDestroy)(void*), void(*onCancelled)(void*))
|
|
: ptr(ptr), onDestroy(onDestroy), onCancelled(onCancelled)
|
|
{}
|
|
ExtraData(ExtraData const&) = delete;
|
|
ExtraData(ExtraData&&) = delete;
|
|
|
|
~ExtraData() {
|
|
onDestroy(ptr);
|
|
}
|
|
void cancel() {
|
|
onCancelled(ptr);
|
|
}
|
|
};
|
|
|
|
std::recursive_mutex m_mutex;
|
|
Status m_status = Status::Pending;
|
|
std::optional<T> m_resultValue;
|
|
bool m_finalEventPosted = false;
|
|
std::string m_name;
|
|
std::unique_ptr<ExtraData> m_extraData = nullptr;
|
|
|
|
class PrivateMarker final {};
|
|
|
|
static std::shared_ptr<Handle> create(std::string_view name) {
|
|
return std::make_shared<Handle>(PrivateMarker(), name);
|
|
}
|
|
|
|
bool is(Status status) {
|
|
std::unique_lock<std::recursive_mutex> lock(m_mutex);
|
|
return m_status == status;
|
|
}
|
|
|
|
template <std::move_constructible T2, std::move_constructible P2>
|
|
friend class Task;
|
|
|
|
template <class, class>
|
|
friend struct geode_internal::TaskPromise;
|
|
|
|
template <class, class>
|
|
friend struct geode_internal::TaskAwaiter;
|
|
|
|
public:
|
|
Handle(PrivateMarker, std::string_view name) : m_name(name) {}
|
|
~Handle() {
|
|
// If this Task was still pending when the Handle was destroyed,
|
|
// it can no longer be listened to so just cancel and cleanup
|
|
std::unique_lock<std::recursive_mutex> lock(m_mutex);
|
|
if (m_status == Status::Pending) {
|
|
m_status = Status::Cancelled;
|
|
// If this task carries extra data, call the extra data's
|
|
// handling method
|
|
// Actually: don't do this! This will cancel tasks even if
|
|
// they have other listeners! The extra data's destructor
|
|
// will handle cancellation if it has no other listeners!
|
|
// if (m_extraData) {
|
|
// m_extraData->cancel();
|
|
// }
|
|
// No need to actually post an event because this Task is
|
|
// unlisteanable
|
|
m_finalEventPosted = true;
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* When the Task progresses, finishes, or is cancelled, one of these
|
|
* is posted; the `Task` class itself is used as an event filter to
|
|
* catch the task events for that specific task
|
|
*/
|
|
class Event final : public geode::Event {
|
|
private:
|
|
std::shared_ptr<Handle> m_handle;
|
|
std::variant<T*, P*, Cancel> m_value;
|
|
EventListenerProtocol* m_for = nullptr;
|
|
|
|
Event(std::shared_ptr<Handle> handle, std::variant<T*, P*, Cancel>&& value)
|
|
: m_handle(handle), m_value(std::move(value)) {}
|
|
|
|
static Event createFinished(std::shared_ptr<Handle> handle, T* value) {
|
|
return Event(handle, std::variant<T*, P*, Cancel>(std::in_place_index<0>, value));
|
|
}
|
|
static Event createProgressed(std::shared_ptr<Handle> handle, P* value) {
|
|
return Event(handle, std::variant<T*, P*, Cancel>(std::in_place_index<1>, value));
|
|
}
|
|
static Event createCancelled(std::shared_ptr<Handle> handle) {
|
|
return Event(handle, std::variant<T*, P*, Cancel>(std::in_place_index<2>, Cancel()));
|
|
}
|
|
|
|
template <std::move_constructible T2, std::move_constructible P2>
|
|
friend class Task;
|
|
|
|
public:
|
|
/**
|
|
* Get a reference to the contained finish value, or null if this
|
|
* event holds a progress value or represents cancellation instead
|
|
*/
|
|
T* getValue() {
|
|
return m_value.index() == 0 ? std::get<0>(m_value) : nullptr;
|
|
}
|
|
/**
|
|
* Get a reference to the contained finish value, or null if this
|
|
* event holds a progress value or represents cancellation instead
|
|
*/
|
|
T const* getValue() const {
|
|
return m_value.index() == 0 ? std::get<0>(m_value) : nullptr;
|
|
}
|
|
/**
|
|
* Get a reference to the contained progress value, or null if
|
|
* this event holds a finish value or represents cancellation instead
|
|
*/
|
|
P* getProgress() {
|
|
return m_value.index() == 1 ? std::get<1>(m_value) : nullptr;
|
|
}
|
|
/**
|
|
* Get a reference to the contained progress value, or null if
|
|
* this event holds a finish value or represents cancellation instead
|
|
*/
|
|
P const* getProgress() const {
|
|
return m_value.index() == 1 ? std::get<1>(m_value) : nullptr;
|
|
}
|
|
/**
|
|
* Check if the Task was cancelled
|
|
*/
|
|
bool isCancelled() const {
|
|
return m_value.index() == 2;
|
|
}
|
|
/**
|
|
* Cancel the Task that posted this event. If the task has
|
|
* already finished or been cancelled, nothing happens
|
|
*/
|
|
void cancel() {
|
|
Task::cancel(m_handle);
|
|
}
|
|
};
|
|
|
|
using Value = T;
|
|
using Progress = P;
|
|
using PostResult = std::function<void(Result&&)>;
|
|
using PostProgress = std::function<void(P)>;
|
|
using HasBeenCancelled = std::function<bool()>;
|
|
using Run = std::function<Result(PostProgress, HasBeenCancelled)>;
|
|
using RunWithCallback = std::function<void(PostResult, PostProgress, HasBeenCancelled)>;
|
|
|
|
using Callback = void(Event*);
|
|
|
|
private:
|
|
EventListenerProtocol* m_listener = nullptr;
|
|
std::shared_ptr<Handle> m_handle;
|
|
|
|
Task(std::shared_ptr<Handle> handle) : m_handle(handle) {}
|
|
|
|
static void finish(std::shared_ptr<Handle> handle, T&& value) {
|
|
if (!handle) return;
|
|
std::unique_lock<std::recursive_mutex> lock(handle->m_mutex);
|
|
if (handle->m_status == Status::Pending) {
|
|
handle->m_status = Status::Finished;
|
|
handle->m_resultValue.emplace(std::move(value));
|
|
queueInMainThread([handle, value = &*handle->m_resultValue]() mutable {
|
|
// SAFETY: Task::all() depends on the lifetime of the value pointer
|
|
// being as long as the lifetime of the task itself
|
|
Event::createFinished(handle, value).post();
|
|
std::unique_lock<std::recursive_mutex> lock(handle->m_mutex);
|
|
handle->m_finalEventPosted = true;
|
|
});
|
|
}
|
|
}
|
|
static void progress(std::shared_ptr<Handle> handle, P&& value) {
|
|
if (!handle) return;
|
|
std::unique_lock<std::recursive_mutex> lock(handle->m_mutex);
|
|
if (handle->m_status == Status::Pending) {
|
|
queueInMainThread([handle, value = std::move(value)]() mutable {
|
|
Event::createProgressed(handle, &value).post();
|
|
});
|
|
}
|
|
}
|
|
static void cancel(std::shared_ptr<Handle> handle, bool shallow = false) {
|
|
if (!handle) return;
|
|
std::unique_lock<std::recursive_mutex> lock(handle->m_mutex);
|
|
if (handle->m_status == Status::Pending) {
|
|
handle->m_status = Status::Cancelled;
|
|
// If this task carries extra data, call the extra data's handling method
|
|
// (unless shallow cancelling was specifically requested)
|
|
if (!shallow && handle->m_extraData) {
|
|
handle->m_extraData->cancel();
|
|
}
|
|
queueInMainThread([handle]() mutable {
|
|
Event::createCancelled(handle).post();
|
|
std::unique_lock<std::recursive_mutex> lock(handle->m_mutex);
|
|
handle->m_finalEventPosted = true;
|
|
});
|
|
}
|
|
}
|
|
|
|
template <std::move_constructible T2, std::move_constructible P2>
|
|
friend class Task;
|
|
|
|
template <class, class>
|
|
friend struct geode_internal::TaskPromise;
|
|
|
|
template <class, class>
|
|
friend struct geode_internal::TaskAwaiter;
|
|
|
|
public:
|
|
// Allow default-construction
|
|
Task() : m_handle(nullptr) {}
|
|
|
|
Task(Task const& other) : m_handle(other.m_handle) {}
|
|
Task(Task&& other) : m_handle(std::move(other.m_handle)) {}
|
|
Task& operator=(Task const& other) {
|
|
m_handle = other.m_handle;
|
|
return *this;
|
|
}
|
|
Task& operator=(Task&& other) {
|
|
m_handle = std::move(other.m_handle);
|
|
return *this;
|
|
}
|
|
|
|
bool operator==(Task const& other) const {
|
|
return m_handle == other.m_handle;
|
|
}
|
|
bool operator!=(Task const& other) const {
|
|
return m_handle != other.m_handle;
|
|
}
|
|
bool operator<(Task const& other) const {
|
|
return m_handle < other.m_handle;
|
|
}
|
|
bool operator<=(Task const& other) const {
|
|
return m_handle <= other.m_handle;
|
|
}
|
|
bool operator>(Task const& other) const {
|
|
return m_handle > other.m_handle;
|
|
}
|
|
bool operator>=(Task const& other) const {
|
|
return m_handle >= other.m_handle;
|
|
}
|
|
|
|
/**
|
|
* Get the value this Task finished to, if the Task had finished,
|
|
* or null otherwise. Note that this is simply a mutable reference to
|
|
* the value - *you may not move out of it!*
|
|
*/
|
|
T* getFinishedValue() {
|
|
if (m_handle && m_handle->m_resultValue) {
|
|
return &*m_handle->m_resultValue;
|
|
}
|
|
return nullptr;
|
|
}
|
|
/**
|
|
* Cancel this Task. If this is a Task that owns other Task(s) (for example
|
|
* one created through `Task::map`) then that Task is cancelled
|
|
* as well. If this is undesirable, use `shallowCancel()`
|
|
* instead
|
|
*/
|
|
void cancel() {
|
|
Task::cancel(m_handle);
|
|
}
|
|
/**
|
|
* If this is a Task that owns other Task(s) (for example created
|
|
* through `Task::map` or `Task::all`), then this method cancels *only*
|
|
* this Task and *not* any of the Task(s) it is built on top of.
|
|
* Ownership of the other Task(s) will be released, so if this is the
|
|
* only Task listening to them, they will still be destroyed due to a
|
|
* lack of listeners
|
|
*/
|
|
void shallowCancel() {
|
|
Task::cancel(m_handle, true);
|
|
}
|
|
bool isPending() const {
|
|
return m_handle && m_handle->is(Status::Pending);
|
|
}
|
|
bool isFinished() const {
|
|
return m_handle && m_handle->is(Status::Finished);
|
|
}
|
|
bool isCancelled() const {
|
|
return m_handle && m_handle->is(Status::Cancelled);
|
|
}
|
|
/**
|
|
* Check if this Task doesn't actually do anything (for instance it
|
|
* was default-constructed)
|
|
*/
|
|
bool isNull() const {
|
|
return m_handle == nullptr;
|
|
}
|
|
|
|
/**
|
|
* Create a new Task that is immediately cancelled
|
|
* @param name The name of the Task; used for debugging
|
|
*/
|
|
static Task cancelled(std::string_view name = "<Cancelled Task>") {
|
|
auto task = Task(Handle::create(name));
|
|
Task::cancel(task.m_handle);
|
|
return task;
|
|
}
|
|
/**
|
|
* Create a new Task that immediately finishes with the given
|
|
* value
|
|
* @param value The value the Task shall be finished with
|
|
* @param name The name of the Task; used for debugging
|
|
*/
|
|
static Task immediate(T value, std::string_view name = "<Immediate Task>") {
|
|
auto task = Task(Handle::create(name));
|
|
Task::finish(task.m_handle, std::move(value));
|
|
return task;
|
|
}
|
|
/**
|
|
* Create a new Task with a function that returns the finished value.
|
|
* See the class description for details about Tasks
|
|
* @param body The body aka actual code of the Task. Note that this
|
|
* function MUST be synchronous - Task creates the thread for you!
|
|
* @param name The name of the Task; used for debugging
|
|
*/
|
|
static Task run(Run&& body, std::string_view name = "<Task>") {
|
|
auto task = Task(Handle::create(name));
|
|
std::thread([handle = std::weak_ptr(task.m_handle), name = std::string(name), body = std::move(body)] {
|
|
utils::thread::setName(fmt::format("Task '{}'", name));
|
|
auto result = body(
|
|
[handle](P progress) {
|
|
Task::progress(handle.lock(), std::move(progress));
|
|
},
|
|
[handle]() -> bool {
|
|
// The task has been cancelled if the user has explicitly cancelled it,
|
|
// or if there is no one listening anymore
|
|
auto lock = handle.lock();
|
|
return !(lock && lock->is(Status::Pending));
|
|
}
|
|
);
|
|
if (result.isCancelled()) {
|
|
Task::cancel(handle.lock());
|
|
}
|
|
else {
|
|
Task::finish(handle.lock(), std::move(*std::move(result).getValue()));
|
|
}
|
|
}).detach();
|
|
return task;
|
|
}
|
|
/**
|
|
* Create a Task using a body that may need to create additional
|
|
* threads within itself; for example due to using an external
|
|
* library that creates its own thread
|
|
* @param body The body aka actual code of the Task. The body may
|
|
* call its provided finish callback *exactly once* - subsequent
|
|
* calls will always be ignored
|
|
* @param name The name of the Task; used for debugging
|
|
*/
|
|
static Task runWithCallback(RunWithCallback&& body, std::string_view name = "<Callback Task>") {
|
|
auto task = Task(Handle::create(name));
|
|
std::thread([handle = std::weak_ptr(task.m_handle), name = std::string(name), body = std::move(body)] {
|
|
utils::thread::setName(fmt::format("Task '{}'", name));
|
|
body(
|
|
[handle](Result result) {
|
|
if (result.isCancelled()) {
|
|
Task::cancel(handle.lock());
|
|
}
|
|
else {
|
|
Task::finish(handle.lock(), std::move(*std::move(result).getValue()));
|
|
}
|
|
},
|
|
[handle](P progress) {
|
|
Task::progress(handle.lock(), std::move(progress));
|
|
},
|
|
[handle]() -> bool {
|
|
// The task has been cancelled if the user has explicitly cancelled it,
|
|
// or if there is no one listening anymore
|
|
auto lock = handle.lock();
|
|
return !lock || lock->is(Status::Cancelled);
|
|
}
|
|
);
|
|
}).detach();
|
|
return task;
|
|
}
|
|
/**
|
|
* Create a Task that waits for a list of other Tasks to finish, and then
|
|
* finishes with a list of their finish values
|
|
* @param tasks The tasks to wait for
|
|
* @param name The name of the Task; used for debugging
|
|
* @warning The result vector may contain nulls if any of the tasks
|
|
* were cancelled!
|
|
*/
|
|
template <std::move_constructible NP>
|
|
static Task<std::vector<T*>, std::monostate> all(std::vector<Task<T, NP>>&& tasks, std::string_view name = "<Multiple Tasks>") {
|
|
using AllTask = Task<std::vector<T*>, std::monostate>;
|
|
|
|
// If there are no tasks, return an immediate task that does nothing
|
|
if (tasks.empty()) {
|
|
return AllTask::immediate({}, name);
|
|
}
|
|
|
|
// Create a new supervising task for all of the provided tasks
|
|
auto task = AllTask(AllTask::Handle::create(name));
|
|
|
|
// Storage for storing the results received so far & keeping
|
|
// ownership of the running tasks
|
|
struct Waiting final {
|
|
std::vector<T*> taskResults;
|
|
std::vector<Task<std::monostate>> taskListeners;
|
|
size_t taskCount;
|
|
};
|
|
task.m_handle->m_extraData = std::make_unique<typename AllTask::Handle::ExtraData>(
|
|
// Create the data
|
|
static_cast<void*>(new Waiting()),
|
|
// When the task is destroyed
|
|
+[](void* ptr) {
|
|
delete static_cast<Waiting*>(ptr);
|
|
},
|
|
// If the task is cancelled
|
|
+[](void* ptr) {
|
|
// The move clears the `taskListeners` vector (important!)
|
|
for (auto task : std::move(static_cast<Waiting*>(ptr)->taskListeners)) {
|
|
task.cancel();
|
|
}
|
|
}
|
|
);
|
|
|
|
// Store the task count in case some tasks finish immediately during the loop
|
|
static_cast<Waiting*>(task.m_handle->m_extraData->ptr)->taskCount = tasks.size();
|
|
|
|
// Make sure to only give a weak pointer to avoid circular references!
|
|
// (Tasks should NEVER own themselves!!)
|
|
auto markAsDone = [handle = std::weak_ptr(task.m_handle)](T* result) {
|
|
auto lock = handle.lock();
|
|
|
|
// If this task handle has expired, consider the task cancelled
|
|
// (We don't have to do anything because the lack of a handle
|
|
// means all the memory has been freed or is managed by
|
|
// something else)
|
|
if (!lock) return;
|
|
|
|
// Get the waiting handle from the task handle
|
|
auto waiting = static_cast<Waiting*>(lock->m_extraData->ptr);
|
|
|
|
// SAFETY: The lifetime of result pointer is the same as the task that
|
|
// produced that pointer, so as long as we have an owning reference to
|
|
// the tasks through `taskListeners` we can be sure `result` is valid
|
|
waiting->taskResults.push_back(result);
|
|
|
|
// If all tasks are done, finish
|
|
if (waiting->taskResults.size() >= waiting->taskCount) {
|
|
// SAFETY: The task results' lifetimes are tied to the tasks
|
|
// which could have their only owner be `waiting->taskListeners`,
|
|
// but since Waiting is owned by the returned AllTask it should
|
|
// be safe to access as long as it's accessible
|
|
AllTask::finish(lock, std::move(waiting->taskResults));
|
|
}
|
|
};
|
|
|
|
// Iterate the tasks & start listening to them using
|
|
for (auto& taskToWait : tasks) {
|
|
static_cast<Waiting*>(task.m_handle->m_extraData->ptr)->taskListeners.emplace_back(taskToWait.map(
|
|
[markAsDone](auto* result) {
|
|
markAsDone(result);
|
|
return std::monostate();
|
|
},
|
|
[](auto*) { return std::monostate(); },
|
|
[markAsDone]() { markAsDone(nullptr); }
|
|
));
|
|
}
|
|
return task;
|
|
}
|
|
|
|
/**
|
|
* Create a new Task that listens to this Task and maps the values using
|
|
* the provided functions.
|
|
* The new Task takes (shared) ownership of this Task, so the new Task
|
|
* may very well be its only listener
|
|
* @param resultMapper Function that converts the finished values of
|
|
* the mapped Task to a desired type. Note that the function is only
|
|
* given a pointer to the finish value, as `T` is not guaranteed to be
|
|
* copyable - the mapper may NOT move out of the value!
|
|
* @param progressMapper Function that converts the progress values of
|
|
* the mapped Task to a desired type
|
|
* @param onCancelled Function that is called if the mapped Task is
|
|
* cancelled
|
|
* @param name The name of the Task; used for debugging. The name of
|
|
* the mapped task is appended to the end
|
|
*/
|
|
template <class ResultMapper, class ProgressMapper, class OnCancelled>
|
|
auto map(ResultMapper&& resultMapper, ProgressMapper&& progressMapper, OnCancelled&& onCancelled, std::string_view name = "<Mapping Task>") const {
|
|
using T2 = decltype(resultMapper(std::declval<T*>()));
|
|
using P2 = decltype(progressMapper(std::declval<P*>()));
|
|
|
|
static_assert(std::is_move_constructible_v<T2>, "The type being mapped to must be move-constructible!");
|
|
static_assert(std::is_move_constructible_v<P2>, "The type being mapped to must be move-constructible!");
|
|
|
|
Task<T2, P2> task = Task<T2, P2>::Handle::create(fmt::format("{} <= {}", name, m_handle->m_name));
|
|
|
|
// Lock the current task until we have managed to create our new one
|
|
std::unique_lock<std::recursive_mutex> lock(m_handle->m_mutex);
|
|
|
|
// If the current task is cancelled, cancel the new one immediately
|
|
if (m_handle->m_status == Status::Cancelled) {
|
|
onCancelled();
|
|
Task<T2, P2>::cancel(task.m_handle);
|
|
}
|
|
// If the current task is finished, immediately map the value and post that
|
|
else if (m_handle->m_status == Status::Finished) {
|
|
Task<T2, P2>::finish(task.m_handle, std::move(resultMapper(&*m_handle->m_resultValue)));
|
|
}
|
|
// Otherwise start listening and waiting for the current task to finish
|
|
else {
|
|
task.m_handle->m_extraData = std::make_unique<typename Task<T2, P2>::Handle::ExtraData>(
|
|
static_cast<void*>(new EventListener<Task>(
|
|
[
|
|
handle = std::weak_ptr(task.m_handle),
|
|
resultMapper = std::move(resultMapper),
|
|
progressMapper = std::move(progressMapper),
|
|
onCancelled = std::move(onCancelled)
|
|
](Event* event) mutable {
|
|
if (auto v = event->getValue()) {
|
|
Task<T2, P2>::finish(handle.lock(), std::move(resultMapper(v)));
|
|
}
|
|
else if (auto p = event->getProgress()) {
|
|
Task<T2, P2>::progress(handle.lock(), std::move(progressMapper(p)));
|
|
}
|
|
else if (event->isCancelled()) {
|
|
onCancelled();
|
|
Task<T2, P2>::cancel(handle.lock());
|
|
}
|
|
},
|
|
*this
|
|
)),
|
|
+[](void* ptr) {
|
|
delete static_cast<EventListener<Task>*>(ptr);
|
|
},
|
|
+[](void* ptr) {
|
|
// Cancel the mapped task too
|
|
static_cast<EventListener<Task>*>(ptr)->getFilter().cancel();
|
|
}
|
|
);
|
|
}
|
|
return task;
|
|
}
|
|
|
|
/**
|
|
* Create a new Task that listens to this Task and maps the values using
|
|
* the provided functions.
|
|
* The new Task takes (shared) ownership of this Task, so the new Task
|
|
* may very well be its only listener
|
|
* @param resultMapper Function that converts the finished values of
|
|
* the mapped Task to a desired type. Note that the function is only
|
|
* given a pointer to the finish value, as `T` is not guaranteed to be
|
|
* copyable - the mapper may NOT move out of the value!
|
|
* @param progressMapper Function that converts the progress values of
|
|
* the mapped Task to a desired type
|
|
* @param name The name of the Task; used for debugging. The name of
|
|
* the mapped task is appended to the end
|
|
*/ template <class ResultMapper, class ProgressMapper>
|
|
auto map(ResultMapper&& resultMapper, ProgressMapper&& progressMapper, std::string_view name = "<Mapping Task>") const {
|
|
return this->map(std::move(resultMapper), std::move(progressMapper), +[]() {}, name);
|
|
}
|
|
|
|
/**
|
|
* Create a new Task that listens to this Task and maps the finish value
|
|
* using the provided function. Progress is mapped by copy-constructing
|
|
* the value as-is.
|
|
* The new Task takes (shared) ownership of this Task, so the new Task
|
|
* may very well be its only listener
|
|
* @param resultMapper Function that converts the finished values of
|
|
* the mapped Task to a desired type. Note that the function is only
|
|
* given a pointer to the finish value, as `T` is not guaranteed to be
|
|
* copyable - the mapper may NOT move out of the value!
|
|
* @param name The name of the Task; used for debugging. The name of
|
|
* the mapped task is appended to the end
|
|
*/ template <class ResultMapper>
|
|
requires std::copy_constructible<P>
|
|
auto map(ResultMapper&& resultMapper, std::string_view name = "<Mapping Task>") const {
|
|
return this->map(std::move(resultMapper), +[](P* p) -> P { return *p; }, name);
|
|
}
|
|
|
|
/**
|
|
* Creates an implicit event listener for this Task that will call the
|
|
* provided functions when the Task finishes, progresses, or is cancelled.
|
|
* The listener will automatically be destroyed after the Task has finished.
|
|
* @param onResult Function to call when the Task finishes. The function
|
|
* is given a pointer to the finished value, `T*`.
|
|
* @param onProgress Function to call when the Task progresses. The function
|
|
* is given a pointer to the progress value, `P*`.
|
|
* @param onCancelled Function to call when the Task is cancelled
|
|
*
|
|
* @warning This method should only be used in a global context. If you rely
|
|
* on some node still existing when the task completes, use an event listener instead.
|
|
*/
|
|
template <class OnResult, class OnProgress, class OnCancelled>
|
|
void listen(OnResult&& onResult, OnProgress&& onProgress, OnCancelled&& onCancelled) const {
|
|
// use a raw pointer to avoid cyclic references,
|
|
// we destroy it manually later on
|
|
auto* listener = new EventListener<Task>(*this);
|
|
listener->bind([
|
|
onResult = std::move(onResult),
|
|
onProgress = std::move(onProgress),
|
|
onCancelled = std::move(onCancelled),
|
|
listener
|
|
](Event* event) mutable {
|
|
bool finished = false;
|
|
if (auto v = event->getValue()) {
|
|
finished = true;
|
|
onResult(v);
|
|
}
|
|
else if (auto p = event->getProgress()) {
|
|
onProgress(p);
|
|
}
|
|
else if (event->isCancelled()) {
|
|
finished = true;
|
|
onCancelled();
|
|
}
|
|
if (finished) {
|
|
// delay destroying the listener for a frame
|
|
// to prevent any potential use-after-free
|
|
queueInMainThread([listener] {
|
|
delete listener;
|
|
});
|
|
}
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Creates an implicit event listener for this Task that will call the
|
|
* provided functions when the Task finishes or progresses.
|
|
* The listener will automatically be destroyed after the Task has finished.
|
|
* @param onResult Function to call when the Task finishes. The function
|
|
* is given a pointer to the finished value, `T*`.
|
|
* @param onProgress Function to call when the Task progresses. The function
|
|
* is given a pointer to the progress value, `P*`.
|
|
*
|
|
* @warning This method should only be used in a global context. If you rely
|
|
* on some node still existing when the task completes, use an event listener instead.
|
|
*/
|
|
template <class OnResult, class OnProgress>
|
|
void listen(OnResult&& onResult, OnProgress&& onProgress) const {
|
|
this->listen(std::move(onResult), std::move(onProgress), [] {});
|
|
}
|
|
|
|
/**
|
|
* Creates an implicit event listener for this Task that will call the
|
|
* provided function when the Task finishes.
|
|
* The listener will automatically be destroyed after the Task has finished.
|
|
* @param onResult Function to call when the Task finishes. The function
|
|
* is given a pointer to the finished value, `T*`.
|
|
*
|
|
* @warning This method should only be used in a global context. If you rely
|
|
* on some node still existing when the task completes, use an event listener instead.
|
|
*/
|
|
template <class OnResult>
|
|
void listen(OnResult&& onResult) const {
|
|
this->listen(std::move(onResult), [](auto const&) {}, [] {});
|
|
}
|
|
|
|
/**
|
|
* Create a new Task that listens to this Task and maps the values using
|
|
* the provided function. The new Task will only start when this Task finishes.
|
|
* @param mapper Function that makes a new task given the finished value of this task.
|
|
* The function signature should be `Task<NewType, NewProgress>(T*)`, and it will be executed
|
|
* on the main thread.
|
|
* @param name The name of the Task; used for debugging.
|
|
* @return The new Task that will run when this Task finishes.
|
|
* @note Progress from this task is not sent through, only progress from the new task is.
|
|
*/
|
|
template <std::invocable<T*> Mapper>
|
|
auto chain(Mapper mapper, std::string_view name = "<Chained Task>") const -> decltype(mapper(std::declval<T*>())) {
|
|
using NewTask = decltype(mapper(std::declval<T*>()));
|
|
using NewType = typename NewTask::Value;
|
|
using NewProgress = typename NewTask::Progress;
|
|
|
|
std::unique_lock<std::recursive_mutex> lock(m_handle->m_mutex);
|
|
|
|
if (m_handle->m_status == Status::Cancelled) {
|
|
// if the current task has been cancelled already, make an immediate cancelled task
|
|
return NewTask::cancelled();
|
|
}
|
|
else if (m_handle->m_status == Status::Finished) {
|
|
// if the current task is already done, we can just call the mapper directly
|
|
return mapper(&*m_handle->m_resultValue);
|
|
}
|
|
|
|
// otherwise, make a wrapper task that waits for the current task to finish,
|
|
// and then runs the mapper on the result. this new task will also wait for the task
|
|
// created by the mapper to finish, and will just forward the values through.
|
|
// do this because we cant really change the handle of the task we already returned
|
|
|
|
NewTask task = NewTask::Handle::create(fmt::format("{} <- {}", name, m_handle->m_name));
|
|
|
|
task.m_handle->m_extraData = std::make_unique<typename NewTask::Handle::ExtraData>(
|
|
// make the first event listener that waits for the current task
|
|
static_cast<void*>(new EventListener<Task>(
|
|
[handle = std::weak_ptr(task.m_handle), mapper = std::move(mapper)](Event* event) mutable {
|
|
if (auto v = event->getValue()) {
|
|
auto newInnerTask = mapper(v);
|
|
// this is scary.. but it doesn't seem to crash lol
|
|
handle.lock()->m_extraData = std::make_unique<typename NewTask::Handle::ExtraData>(
|
|
// make the second event listener that waits for the mapper's task
|
|
// and just forwards everything through
|
|
static_cast<void*>(new EventListener<NewTask>(
|
|
[handle](typename NewTask::Event* event) mutable {
|
|
if (auto v = event->getValue()) {
|
|
NewTask::finish(handle.lock(), std::move(*v));
|
|
}
|
|
else if (auto p = event->getProgress()) {
|
|
NewTask::progress(handle.lock(), std::move(*p));
|
|
}
|
|
else if (event->isCancelled()) {
|
|
NewTask::cancel(handle.lock());
|
|
}
|
|
},
|
|
std::move(newInnerTask)
|
|
)),
|
|
+[](void* ptr) {
|
|
delete static_cast<EventListener<NewTask>*>(ptr);
|
|
},
|
|
+[](void* ptr) {
|
|
static_cast<EventListener<NewTask>*>(ptr)->getFilter().cancel();
|
|
}
|
|
);
|
|
}
|
|
else if (auto p = event->getProgress()) {
|
|
// no guarantee P and NewProgress are compatible
|
|
// nor does it seem like the intended behavior?
|
|
// TODO: maybe add a mapper for progress?
|
|
}
|
|
else if (event->isCancelled()) {
|
|
NewTask::cancel(handle.lock());
|
|
}
|
|
},
|
|
*this
|
|
)),
|
|
+[](void* ptr) {
|
|
delete static_cast<EventListener<Task>*>(ptr);
|
|
},
|
|
+[](void* ptr) {
|
|
static_cast<EventListener<Task>*>(ptr)->getFilter().cancel();
|
|
}
|
|
);
|
|
return task;
|
|
}
|
|
|
|
ListenerResult handle(std::function<Callback> fn, Event* e) {
|
|
if (e->m_handle == m_handle && (!e->m_for || e->m_for == m_listener)) {
|
|
fn(e);
|
|
}
|
|
return ListenerResult::Propagate;
|
|
}
|
|
|
|
// todo: i believe alk wanted tasks to be in their own pool
|
|
EventListenerPool* getPool() const {
|
|
return DefaultEventListenerPool::get();
|
|
}
|
|
|
|
void setListener(EventListenerProtocol* listener) {
|
|
m_listener = listener;
|
|
|
|
if (!m_handle) return;
|
|
|
|
// If this task has already been finished and the finish event
|
|
// isn't pending in the event queue, immediately queue up a
|
|
// finish event for this listener
|
|
std::unique_lock<std::recursive_mutex> lock(m_handle->m_mutex);
|
|
if (m_handle->m_finalEventPosted) {
|
|
if (m_handle->m_status == Status::Finished) {
|
|
queueInMainThread([handle = m_handle, listener = m_listener, value = &*m_handle->m_resultValue]() {
|
|
auto ev = Event::createFinished(handle, value);
|
|
ev.m_for = listener;
|
|
ev.post();
|
|
});
|
|
}
|
|
else {
|
|
queueInMainThread([handle = m_handle, listener = m_listener]() {
|
|
auto ev = Event::createCancelled(handle);
|
|
ev.m_for = listener;
|
|
ev.post();
|
|
});
|
|
}
|
|
}
|
|
}
|
|
EventListenerProtocol* getListener() const {
|
|
return m_listener;
|
|
}
|
|
};
|
|
|
|
static_assert(is_filter<Task<int>>, "The Task class must be a valid event filter!");
|
|
}
|
|
|
|
// - C++20 coroutine support for Task - //
|
|
|
|
// Example usage (function must return a Task):
|
|
// ```
|
|
// Task<int> someTask() {
|
|
// auto response = co_await web::WebRequest().get("https://example.com");
|
|
// co_return response.code();
|
|
// }
|
|
// ```
|
|
// This will create a Task that will finish with the response code of the
|
|
// web request.
|
|
//
|
|
// Note: If the Task the coroutine is waiting on is cancelled, the coroutine
|
|
// will be destroyed and the Task will be cancelled as well. If the Task returned
|
|
// by the coroutine is cancelled, the coroutine will be destroyed as well and execution
|
|
// stops as soon as possible.
|
|
//
|
|
// The body of the coroutine is ran in whatever thread it got called in.
|
|
// TODO: maybe guarantee main thread?
|
|
//
|
|
// The coroutine can also yield progress values using `co_yield`:
|
|
// ```
|
|
// Task<std::string, int> someTask() {
|
|
// for (int i = 0; i < 10; i++) {
|
|
// co_yield i;
|
|
// }
|
|
// co_return "done!";
|
|
// }
|
|
// ```
|
|
|
|
namespace geode {
|
|
namespace geode_internal {
|
|
template <class T, class P>
|
|
struct TaskPromise {
|
|
using MyTask = Task<T, P>;
|
|
std::weak_ptr<typename MyTask::Handle> m_handle;
|
|
|
|
~TaskPromise() {
|
|
// does nothing if its not pending
|
|
MyTask::cancel(m_handle.lock());
|
|
}
|
|
|
|
std::suspend_never initial_suspend() noexcept { return {}; }
|
|
std::suspend_never final_suspend() noexcept { return {}; }
|
|
// TODO: do something here?
|
|
void unhandled_exception() {}
|
|
|
|
MyTask get_return_object() {
|
|
auto handle = MyTask::Handle::create("<Coroutine Task>");
|
|
m_handle = handle;
|
|
return handle;
|
|
}
|
|
|
|
void return_value(T x) {
|
|
MyTask::finish(m_handle.lock(), std::move(x));
|
|
}
|
|
|
|
std::suspend_never yield_value(P value) {
|
|
MyTask::progress(m_handle.lock(), std::move(value));
|
|
return {};
|
|
}
|
|
|
|
bool isCancelled() {
|
|
if (auto p = m_handle.lock()) {
|
|
return p->is(MyTask::Status::Cancelled);
|
|
}
|
|
return true;
|
|
}
|
|
};
|
|
|
|
template <class T, class P>
|
|
struct TaskAwaiter {
|
|
Task<T, P> task;
|
|
|
|
bool await_ready() {
|
|
return task.isFinished();
|
|
}
|
|
|
|
template <class U, class V>
|
|
void await_suspend(std::coroutine_handle<TaskPromise<U, V>> handle) {
|
|
if (handle.promise().isCancelled()) {
|
|
handle.destroy();
|
|
return;
|
|
}
|
|
// this should be fine because the parent task can only have
|
|
// one pending task at a time
|
|
auto parentHandle = handle.promise().m_handle.lock();
|
|
if (!parentHandle) {
|
|
handle.destroy();
|
|
return;
|
|
}
|
|
parentHandle->m_extraData = std::make_unique<typename Task<U, V>::Handle::ExtraData>(
|
|
static_cast<void*>(new EventListener<Task<T, P>>(
|
|
[handle](auto* event) {
|
|
if (event->getValue()) {
|
|
handle.resume();
|
|
}
|
|
if (event->isCancelled()) {
|
|
handle.destroy();
|
|
}
|
|
},
|
|
task
|
|
)),
|
|
+[](void* ptr) {
|
|
delete static_cast<EventListener<Task<T, P>>*>(ptr);
|
|
},
|
|
+[](void* ptr) {
|
|
static_cast<EventListener<Task<T, P>>*>(ptr)->getFilter().cancel();
|
|
}
|
|
);
|
|
}
|
|
|
|
T await_resume() {
|
|
return std::move(*task.getFinishedValue());
|
|
}
|
|
};
|
|
}
|
|
}
|
|
|
|
template <class T, class P>
|
|
auto operator co_await(geode::Task<T, P> task) {
|
|
return geode::geode_internal::TaskAwaiter<T, P>{task};
|
|
}
|
|
|
|
template <class T, class P, class... Args>
|
|
struct std::coroutine_traits<geode::Task<T, P>, Args...> {
|
|
using promise_type = geode::geode_internal::TaskPromise<T, P>;
|
|
};
|