-/* Copyright (c) 2016. The SimGrid Team.
+/* Copyright (c) 2016-2019. The SimGrid Team.
* All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
FutureStateBase(FutureStateBase const&) = delete;
FutureStateBase& operator=(FutureStateBase const&) = delete;
- XBT_PUBLIC(void) schedule(simgrid::xbt::Task<void()>&& job);
+ XBT_PUBLIC void schedule(simgrid::xbt::Task<void()>&& job);
void set_exception(std::exception_ptr exception)
{
schedule(std::move(continuation));
break;
case FutureStatus::not_ready:
- // The future is not ready so we mast keep the continuation for
+ // The future is not ready so we must keep the continuation for
// executing it later:
continuation_ = std::move(continuation);
break;
status_ = FutureStatus::ready;
if (continuation_) {
// We unregister the continuation before executing it.
- // We need to do this becase the current implementation of the
+ // We need to do this because the current implementation of the
// continuation has a shared_ptr to the FutureState.
auto continuation = std::move(continuation_);
this->schedule(std::move(continuation));
/** Shared state for future and promises
*
* You are not expected to use them directly but to create them
- * implicitely through a @ref simgrid::kernel::Promise.
+ * implicitly through a @ref simgrid::kernel::Promise.
* Alternatively kernel operations could inherit or contain FutureState
- * if they are managed with @ref std::shared_ptr.
+ * if they are managed with std::shared_ptr.
**/
template<class T>
class FutureState : public FutureStateBase {
public:
-
void set_value(T value)
{
if (this->get_status() != FutureStatus::not_ready)
xbt_assert(this->value_);
auto result = std::move(this->value_.get());
this->value_ = boost::optional<T>();
- return std::move(result);
+ return result;
}
private:
xbt_assert(this->value_);
T* result = value_;
value_ = nullptr;
- return *value_;
+ return *result;
}
private:
}
};
-template<class T>
-void bindPromise(Promise<T> promise, Future<T> future)
+template <class T> void bind_promise(Promise<T>&& promise, Future<T> future)
{
- struct PromiseBinder {
+ class PromiseBinder {
public:
- explicit PromiseBinder(Promise<T> promise) : promise_(std::move(promise)) {}
- void operator()(Future<T> future)
- {
- simgrid::xbt::setPromise(promise_, future);
- }
+ explicit PromiseBinder(Promise<T>&& promise) : promise_(std::move(promise)) {}
+ void operator()(Future<T> future) { simgrid::xbt::set_promise(promise_, future); }
+
private:
Promise<T> promise_;
};
future.then_(PromiseBinder(std::move(promise)));
}
-template<class T> Future<T> unwrapFuture(Future<Future<T>> future);
+template <class T> Future<T> unwrap_future(Future<Future<T>> future);
/** Result of some (probably) asynchronous operation in the SimGrid kernel
*
* @ref simgrid::simix::Future and @ref simgrid::simix::Future provide an
- * abstration for asynchronous stuff happening in the SimGrid kernel. They
+ * abstraction for asynchronous stuff happening in the SimGrid kernel. They
* are based on C++1z futures.
*
* The future represents a value which will be available at some point when this
- * asynchronous operaiont is finished. Alternatively, if this operations fails,
+ * asynchronous operation is finished. Alternatively, if this operations fails,
* the result of the operation might be an exception.
*
* As the operation is possibly no terminated yet, we cannot get the result
* // available:
* try {
* // Try to get value, this might throw an exception if the operation
- * // failed (such as an exception throwed by the worker process):
+ * // failed (such as an exception thrown by the worker process):
* std::string value = result.get();
* XBT_INFO("Value: %s", value.c_str());
* }
* );
* </pre>
*
- * This is based on C++1z @ref std::future but with some differences:
+ * This is based on C++1z std::future but with some differences:
*
* * there is no thread synchronization (atomic, mutex, condition variable,
* etc.) because everything happens in the SimGrid event loop;
* * inside the `.then()`, `.get()` can be used;
*
* * `.get()` can only be used when `.is_ready()` (as everything happens in
- * a single-thread, the future would be guaranted to deadlock if `.get()`
+ * a single-thread, the future would be guaranteed to deadlock if `.get()`
* is called when the future is not ready);
*
* * there is no future chaining support for now (`.then().then()`);
public:
Future() = default;
explicit Future(std::shared_ptr<FutureState<T>> state) : state_(std::move(state)) {}
+ ~Future() = default;
// Move type:
Future(Future&) = delete;
throw std::future_error(std::future_errc::no_state);
// Give shared-ownership to the continuation:
auto state = std::move(state_);
- state->set_continuation(simgrid::xbt::makeTask(
- std::move(continuation), state));
+ state->set_continuation(simgrid::xbt::make_task(std::move(continuation), state));
}
/** Attach a continuation to this future
*
* This version never does future unwrapping.
*/
- template<class F>
- auto thenNoUnwrap(F continuation)
- -> Future<decltype(continuation(std::move(*this)))>
+ template <class F> auto then_no_unwrap(F continuation) -> Future<decltype(continuation(std::move(*this)))>
{
typedef decltype(continuation(std::move(*this))) R;
if (state_ == nullptr)
Promise<R> promise;
Future<R> future = promise.get_future();
// ...and when the current future is ready...
- state->set_continuation(simgrid::xbt::makeTask(
- [](Promise<R> promise, std::shared_ptr<FutureState<T>> state, F continuation) {
- // ...set the new future value by running the continuation.
- Future<T> future(std::move(state));
- simgrid::xbt::fulfillPromise(promise,[&]{
- return continuation(std::move(future));
- });
- },
- std::move(promise), state, std::move(continuation)));
- return std::move(future);
+ state->set_continuation(simgrid::xbt::make_task(
+ [](Promise<R> promise, std::shared_ptr<FutureState<T>> state, F continuation) {
+ // ...set the new future value by running the continuation.
+ Future<T> future(std::move(state));
+ simgrid::xbt::fulfill_promise(promise, [&continuation, &future] { return continuation(std::move(future)); });
+ },
+ std::move(promise), state, std::move(continuation)));
+ return future;
}
/** Attach a continuation to this future
auto then(F continuation) -> typename std::enable_if<not is_future<decltype(continuation(std::move(*this)))>::value,
Future<decltype(continuation(std::move(*this)))>>::type
{
- return this->thenNoUnwrap(std::move(continuation));
+ return this->then_no_unwrap(std::move(continuation));
}
/** Attach a continuation to this future (future chaining) */
decltype(continuation(std::move(*this)))
>::type
{
- return unwrapFuture(this->thenNoUnwap(std::move(continuation)));
+ return unwrap_future(this->then_no_unwrap(std::move(continuation)));
}
/** Get the value from the future
*
* The future must be valid and ready in order to make this call.
- * @ref std::future blocks when the future is not ready but we are
+ * std::future blocks when the future is not ready but we are
* completely single-threaded so blocking would be a deadlock.
* After the call, the future becomes invalid.
*
std::shared_ptr<FutureState<T>> state_;
};
-template<class T>
-Future<T> unwrapFuture(Future<Future<T>> future)
+template <class T> Future<T> unwrap_future(Future<Future<T>> future)
{
Promise<T> promise;
Future<T> result = promise.get_future();
- bindPromise(std::move(promise), std::move(future));
- return std::move(result);
+ bind_promise(std::move(promise), std::move(future));
+ return result;
}
/** Producer side of a @ref simgrid::kernel::Future
* A @ref Promise is connected to some `Future` and can be used to
* set its result.
*
- * Similar to @ref std::promise
+ * Similar to std::promise
*
* <code>
* // Create a promise and a future:
* auto promise = std::make_shared<simgrid::kernel::Promise<T>>();
* auto future = promise->get_future();
*
- * SIMIX_timer_set(date, [promise] {
+ * simgrid::simix::Timer::set(date, [promise] {
* try {
* int value = compute_the_value();
* if (value < 0)
* promise.set_value(value);
* }
* catch (...) {
- * // If an error occured, we can set an exception which
- * // will be throwed buy future.get():
+ * // If an error occurred, we can set an exception which
+ * // will be thrown by future.get():
* promise.set_exception(std::current_exception());
* }
* });
template<class T>
class Promise {
public:
- explicit Promise() : state_(std::make_shared<FutureState<T>>()) {}
+ Promise() = default;
explicit Promise(std::shared_ptr<FutureState<T>> state) : state_(std::move(state)) {}
// Move type
Promise(Promise const&) = delete;
Promise& operator=(Promise const&) = delete;
- Promise(Promise&& that) :
- state_(std::move(that.state_)), future_get_(that.future_get_)
- {
- that.future_get_ = false;
- }
+ Promise(Promise&& that) : state_(std::move(that.state_)) { std::swap(future_get_, that.future_get_); }
Promise& operator=(Promise&& that)
{
}
private:
- std::shared_ptr<FutureState<T>> state_;
+ std::shared_ptr<FutureState<T>> state_{new FutureState<T>()};
bool future_get_ = false;
};
template<>
class Promise<void> {
public:
- Promise() : state_(std::make_shared<FutureState<void>>()) {}
- Promise(std::shared_ptr<FutureState<void>> state) : state_(std::move(state)) {}
+ Promise() = default;
+ explicit Promise(std::shared_ptr<FutureState<void>> state) : state_(std::move(state)) {}
~Promise()
{
if (state_ && state_->get_status() == FutureStatus::not_ready)
// Move type
Promise(Promise const&) = delete;
Promise& operator=(Promise const&) = delete;
- Promise(Promise&& that) :
- state_(std::move(that.state_)), future_get_(that.future_get_)
- {
- that.future_get_ = false;
- }
+ Promise(Promise&& that) : state_(std::move(that.state_)) { std::swap(future_get_, that.future_get_); }
Promise& operator=(Promise&& that)
{
this->state_ = std::move(that.state_);
}
private:
- std::shared_ptr<FutureState<void>> state_;
+ std::shared_ptr<FutureState<void>> state_{new FutureState<void>()};
bool future_get_ = false;
};
