summaryrefslogtreecommitdiffstats
path: root/chromium/base/task/promise/helpers.h
diff options
context:
space:
mode:
Diffstat (limited to 'chromium/base/task/promise/helpers.h')
-rw-r--r--chromium/base/task/promise/helpers.h146
1 files changed, 67 insertions, 79 deletions
diff --git a/chromium/base/task/promise/helpers.h b/chromium/base/task/promise/helpers.h
index 29cb49011ab..87d9ff64bec 100644
--- a/chromium/base/task/promise/helpers.h
+++ b/chromium/base/task/promise/helpers.h
@@ -19,11 +19,6 @@ class DoNothing;
namespace internal {
-// A wrapper around SequencedTaskRunnerHandle::Get(). This file is included by
-// base/task_runner.h which means we can't include anything that depends on
-// that!
-scoped_refptr<TaskRunner> BASE_EXPORT GetCurrentSequence();
-
template <typename T>
using ToNonVoidT = std::conditional_t<std::is_void<T>::value, Void, T>;
@@ -412,9 +407,26 @@ class ArgMoveSemanticsHelper {
}
};
+// Helper for converting a callback to its repeating variant.
+template <typename Cb>
+struct ToRepeatingCallback;
+
+template <typename Cb>
+struct ToRepeatingCallback<OnceCallback<Cb>> {
+ using value = RepeatingCallback<Cb>;
+};
+
+template <typename Cb>
+struct ToRepeatingCallback<RepeatingCallback<Cb>> {
+ using value = RepeatingCallback<Cb>;
+};
+
// Helper for running a promise callback and storing the result if any.
//
-// Callback = signature of the callback to execute,
+// Callback = signature of the callback to execute. Note we use repeating
+// callbacks to avoid the binary size overhead of a once callback which will
+// generate a destructor which is redundant because we overwrite the executor
+// with the promise result which also triggers the destructor.
// ArgStorageType = type of the callback parameter (or void if none)
// ResolveStorage = type to use for resolve, usually Resolved<T>.
// RejectStorage = type to use for reject, usually Rejected<T>.
@@ -431,18 +443,18 @@ template <typename CbResult,
typename ArgStorageType,
typename ResolveStorage,
typename RejectStorage>
-struct RunHelper<OnceCallback<CbResult(CbArg)>,
+struct RunHelper<RepeatingCallback<CbResult(CbArg)>,
ArgStorageType,
ResolveStorage,
RejectStorage> {
- using Callback = OnceCallback<CbResult(CbArg)>;
+ using Callback = RepeatingCallback<CbResult(CbArg)>;
- static void Run(Callback&& executor,
+ static void Run(const Callback& executor,
AbstractPromise* arg,
AbstractPromise* result) {
EmplaceHelper<ResolveStorage, RejectStorage>::Emplace(
- result, std::move(executor).Run(
- ArgMoveSemanticsHelper<CbArg, ArgStorageType>::Get(arg)));
+ result,
+ executor.Run(ArgMoveSemanticsHelper<CbArg, ArgStorageType>::Get(arg)));
}
};
@@ -451,19 +463,18 @@ template <typename CbArg,
typename ArgStorageType,
typename ResolveStorage,
typename RejectStorage>
-struct RunHelper<OnceCallback<void(CbArg)>,
+struct RunHelper<RepeatingCallback<void(CbArg)>,
ArgStorageType,
ResolveStorage,
RejectStorage> {
- using Callback = OnceCallback<void(CbArg)>;
+ using Callback = RepeatingCallback<void(CbArg)>;
- static void Run(Callback&& executor,
+ static void Run(const Callback& executor,
AbstractPromise* arg,
AbstractPromise* result) {
static_assert(std::is_void<typename ResolveStorage::Type>::value, "");
- std::move(executor).Run(
- ArgMoveSemanticsHelper<CbArg, ArgStorageType>::Get(arg));
- result->emplace(Resolved<void>());
+ executor.Run(ArgMoveSemanticsHelper<CbArg, ArgStorageType>::Get(arg));
+ result->EmplaceResolvedVoid();
}
};
@@ -472,17 +483,17 @@ template <typename CbResult,
typename ArgStorageType,
typename ResolveStorage,
typename RejectStorage>
-struct RunHelper<OnceCallback<CbResult()>,
+struct RunHelper<RepeatingCallback<CbResult()>,
ArgStorageType,
ResolveStorage,
RejectStorage> {
- using Callback = OnceCallback<CbResult()>;
+ using Callback = RepeatingCallback<CbResult()>;
- static void Run(Callback&& executor,
+ static void Run(const Callback& executor,
AbstractPromise* arg,
AbstractPromise* result) {
- EmplaceHelper<ResolveStorage, RejectStorage>::Emplace(
- result, std::move(executor).Run());
+ EmplaceHelper<ResolveStorage, RejectStorage>::Emplace(result,
+ executor.Run());
}
};
@@ -490,16 +501,16 @@ struct RunHelper<OnceCallback<CbResult()>,
template <typename ArgStorageType,
typename ResolveStorage,
typename RejectStorage>
-struct RunHelper<OnceCallback<void()>,
+struct RunHelper<RepeatingCallback<void()>,
ArgStorageType,
ResolveStorage,
RejectStorage> {
- static void Run(OnceCallback<void()>&& executor,
+ static void Run(const RepeatingCallback<void()>& executor,
AbstractPromise* arg,
AbstractPromise* result) {
static_assert(std::is_void<typename ResolveStorage::Type>::value, "");
- std::move(executor).Run();
- result->emplace(Resolved<void>());
+ executor.Run();
+ result->EmplaceResolvedVoid();
}
};
@@ -538,79 +549,51 @@ template <typename CbResult,
typename... CbArgs,
typename ResolveStorage,
typename RejectStorage>
-struct RunHelper<OnceCallback<CbResult(CbArgs...)>,
+struct RunHelper<RepeatingCallback<CbResult(CbArgs...)>,
Resolved<std::tuple<CbArgs...>>,
ResolveStorage,
RejectStorage> {
- using Callback = OnceCallback<CbResult(CbArgs...)>;
+ using Callback = RepeatingCallback<CbResult(CbArgs...)>;
using StorageType = Resolved<std::tuple<CbArgs...>>;
using IndexSequence = std::index_sequence_for<CbArgs...>;
- static void Run(Callback&& executor,
+ static void Run(const Callback& executor,
AbstractPromise* arg,
AbstractPromise* result) {
AbstractPromise::ValueHandle value = arg->TakeValue();
std::tuple<CbArgs...>& tuple = value.value().Get<StorageType>()->value;
- RunInternal(std::move(executor), tuple, result,
+ RunInternal(executor, tuple, result,
std::integral_constant<bool, std::is_void<CbResult>::value>(),
IndexSequence{});
}
private:
template <typename Callback, size_t... Indices>
- static void RunInternal(Callback&& executor,
+ static void RunInternal(const Callback& executor,
std::tuple<CbArgs...>& tuple,
AbstractPromise* result,
std::false_type void_result,
std::index_sequence<Indices...>) {
- EmplaceHelper<ResolveStorage, RejectStorage>::Emplace(
- std::move(executor).Run(
- TupleArgMoveSemanticsHelper<Callback, std::tuple<CbArgs...>,
- Indices>::Get(tuple)...));
+ EmplaceHelper<ResolveStorage, RejectStorage>::Emplace(executor.Run(
+ TupleArgMoveSemanticsHelper<Callback, std::tuple<CbArgs...>,
+ Indices>::Get(tuple)...));
}
template <typename Callback, size_t... Indices>
- static void RunInternal(Callback&& executor,
+ static void RunInternal(const Callback& executor,
std::tuple<CbArgs...>& tuple,
AbstractPromise* result,
std::true_type void_result,
std::index_sequence<Indices...>) {
- std::move(executor).Run(
- TupleArgMoveSemanticsHelper<Callback, std::tuple<CbArgs...>,
- Indices>::Get(tuple)...);
- result->emplace(Resolved<void>());
+ executor.Run(TupleArgMoveSemanticsHelper<Callback, std::tuple<CbArgs...>,
+ Indices>::Get(tuple)...);
+ result->EmplaceResolvedVoid();
}
};
-// For use with base::Bind*. Cancels the promise if the callback was not run by
-// the time the callback is deleted.
-class BASE_EXPORT PromiseHolder {
- public:
- explicit PromiseHolder(scoped_refptr<internal::AbstractPromise> promise);
-
- ~PromiseHolder();
-
- PromiseHolder(PromiseHolder&& other);
-
- scoped_refptr<internal::AbstractPromise> Unwrap() const;
-
- private:
- mutable scoped_refptr<internal::AbstractPromise> promise_;
-};
-
-} // namespace internal
-
-template <>
-struct BindUnwrapTraits<internal::PromiseHolder> {
- static scoped_refptr<internal::AbstractPromise> Unwrap(
- const internal::PromiseHolder& o) {
- return o.Unwrap();
- }
-};
-
-namespace internal {
-
-// Used by ManualPromiseResolver<> to generate callbacks.
+// Used by ManualPromiseResolver<> to generate callbacks. Note the use of
+// WrappedPromise, this is necessary because we want to cancel the promise (to
+// release memory) if the callback gets deleted without having being run.
template <typename T, typename... Args>
class PromiseCallbackHelper {
public:
@@ -624,7 +607,7 @@ class PromiseCallbackHelper {
std::forward<Args>(args)...);
promise->OnResolved();
},
- PromiseHolder(promise));
+ promise);
}
static RepeatingCallback GetRepeatingResolveCallback(
@@ -635,7 +618,7 @@ class PromiseCallbackHelper {
std::forward<Args>(args)...);
promise->OnResolved();
},
- PromiseHolder(promise));
+ promise);
}
static Callback GetRejectCallback(scoped_refptr<AbstractPromise>& promise) {
@@ -645,7 +628,7 @@ class PromiseCallbackHelper {
std::forward<Args>(args)...);
promise->OnRejected();
},
- PromiseHolder(promise));
+ promise);
}
static RepeatingCallback GetRepeatingRejectCallback(
@@ -656,7 +639,7 @@ class PromiseCallbackHelper {
std::forward<Args>(args)...);
promise->OnRejected();
},
- PromiseHolder(promise));
+ promise);
}
};
@@ -679,8 +662,7 @@ struct IsValidPromiseArg<PromiseType&, CallbackArgType> {
// rejection storage type.
template <typename RejectT>
struct AllPromiseRejectHelper {
- static void Reject(AbstractPromise* result,
- const scoped_refptr<AbstractPromise>& prerequisite) {
+ static void Reject(AbstractPromise* result, AbstractPromise* prerequisite) {
result->emplace(scoped_refptr<AbstractPromise>(prerequisite));
}
};
@@ -709,14 +691,20 @@ CallbackBase&& ToCallbackBase(const CallbackT&& task) {
// Helps reduce template bloat by moving AbstractPromise construction out of
// line.
-scoped_refptr<AbstractPromise> BASE_EXPORT
-ConstructAbstractPromiseWithSinglePrerequisite(
+PassedPromise BASE_EXPORT ConstructAbstractPromiseWithSinglePrerequisite(
const scoped_refptr<TaskRunner>& task_runner,
const Location& from_here,
AbstractPromise* prerequsite,
- internal::PromiseExecutor::Data&& executor_data) noexcept;
+ PromiseExecutor::Data&& executor_data) noexcept;
+
+// Like ConstructAbstractPromiseWithSinglePrerequisite except tasks are posted
+// onto SequencedTaskRunnerHandle::Get().
+PassedPromise BASE_EXPORT ConstructHereAbstractPromiseWithSinglePrerequisite(
+ const Location& from_here,
+ AbstractPromise* prerequsite,
+ PromiseExecutor::Data&& executor_data) noexcept;
-scoped_refptr<AbstractPromise> BASE_EXPORT
+PassedPromise BASE_EXPORT
ConstructManualPromiseResolverPromise(const Location& from_here,
RejectPolicy reject_policy,
bool can_resolve,
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-16 04:21:45 +0000