| // Copyright 2022 gRPC authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include "src/core/lib/promise/sleep.h" |
| |
| #include <utility> |
| |
| #include <grpc/event_engine/event_engine.h> |
| |
| #include "src/core/lib/event_engine/default_event_engine.h" |
| #include "src/core/lib/gprpp/time.h" |
| #include "src/core/lib/iomgr/exec_ctx.h" |
| #include "src/core/lib/promise/activity.h" |
| #include "src/core/lib/promise/poll.h" |
| |
| namespace grpc_core { |
| |
| using ::grpc_event_engine::experimental::GetDefaultEventEngine; |
| |
| Sleep::Sleep(Timestamp deadline) : deadline_(deadline) {} |
| |
| Sleep::~Sleep() { |
| if (closure_ != nullptr) closure_->Cancel(); |
| } |
| |
| Poll<absl::Status> Sleep::operator()() { |
| // Invalidate now so that we see a fresh version of the time. |
| // TODO(ctiller): the following can be safely removed when we remove ExecCtx. |
| ExecCtx::Get()->InvalidateNow(); |
| // If the deadline is earlier than now we can just return. |
| if (deadline_ <= ExecCtx::Get()->Now()) return absl::OkStatus(); |
| if (closure_ == nullptr) { |
| // TODO(ctiller): it's likely we'll want a pool of closures - probably per |
| // cpu? - to avoid allocating/deallocating on fast paths. |
| closure_ = new ActiveClosure(deadline_); |
| } |
| if (closure_->HasRun()) return absl::OkStatus(); |
| return Pending{}; |
| } |
| |
| Sleep::ActiveClosure::ActiveClosure(Timestamp deadline) |
| : waker_(Activity::current()->MakeOwningWaker()), |
| timer_handle_(GetDefaultEventEngine()->RunAfter( |
| deadline - ExecCtx::Get()->Now(), this)) {} |
| |
| void Sleep::ActiveClosure::Run() { |
| ApplicationCallbackExecCtx callback_exec_ctx; |
| ExecCtx exec_ctx; |
| auto waker = std::move(waker_); |
| if (Unref()) { |
| delete this; |
| } else { |
| waker.Wakeup(); |
| } |
| } |
| |
| void Sleep::ActiveClosure::Cancel() { |
| // If we cancel correctly then we must own both refs still and can simply |
| // delete without unreffing twice, otherwise try unreffing since this may be |
| // the last owned ref. |
| if (GetDefaultEventEngine()->Cancel(timer_handle_) || Unref()) { |
| delete this; |
| } |
| } |
| |
| bool Sleep::ActiveClosure::Unref() { |
| return (refs_.fetch_sub(1, std::memory_order_acq_rel) == 1); |
| } |
| |
| bool Sleep::ActiveClosure::HasRun() const { |
| // If the closure has run (ie woken up the activity) then it will have |
| // decremented this ref count once. |
| return refs_.load(std::memory_order_acquire) == 1; |
| } |
| |
| } // namespace grpc_core |