| // Copyright 2017 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <lib/async/cpp/task.h> |
| |
| #include <lib/async/cpp/time.h> |
| #include <zircon/assert.h> |
| |
| #include <utility> |
| |
| namespace async { |
| namespace internal { |
| |
| struct RetainedTask : public async_task_t { |
| RetainedTask(fit::closure handler, zx::time deadline) |
| : async_task_t{{ASYNC_STATE_INIT}, &RetainedTask::Handler, deadline.get()}, |
| handler(static_cast<fit::closure&&>(handler)) {} |
| |
| fit::closure handler; |
| |
| static void Handler(async_dispatcher_t* dispatcher, async_task_t* task, zx_status_t status) { |
| auto self = static_cast<RetainedTask*>(task); |
| if (status == ZX_OK) |
| self->handler(); |
| delete self; |
| } |
| }; |
| |
| } // namespace internal |
| |
| zx_status_t PostTask(async_dispatcher_t* dispatcher, fit::closure handler) { |
| return PostTaskForTime(dispatcher, static_cast<fit::closure&&>(handler), async::Now(dispatcher)); |
| } |
| |
| zx_status_t PostDelayedTask(async_dispatcher_t* dispatcher, fit::closure handler, |
| zx::duration delay) { |
| return PostTaskForTime(dispatcher, static_cast<fit::closure&&>(handler), |
| async::Now(dispatcher) + delay); |
| } |
| |
| zx_status_t PostTaskForTime(async_dispatcher_t* dispatcher, fit::closure handler, |
| zx::time deadline) { |
| auto* task = new internal::RetainedTask(static_cast<fit::closure&&>(handler), deadline); |
| zx_status_t status = async_post_task(dispatcher, task); |
| if (status != ZX_OK) |
| delete task; |
| return status; |
| } |
| |
| TaskBase::TaskBase(async_task_handler_t* handler) |
| : task_{{ASYNC_STATE_INIT}, handler, ZX_TIME_INFINITE} {} |
| |
| TaskBase::~TaskBase() { |
| if (dispatcher_) { |
| // Failure to cancel here may result in a dangling pointer... |
| zx_status_t status = async_cancel_task(dispatcher_, &task_); |
| ZX_ASSERT_MSG(status == ZX_OK, "status=%d", status); |
| } |
| } |
| |
| zx_status_t TaskBase::Post(async_dispatcher_t* dispatcher) { |
| return PostForTime(dispatcher, async::Now(dispatcher)); |
| } |
| |
| zx_status_t TaskBase::PostDelayed(async_dispatcher_t* dispatcher, zx::duration delay) { |
| return PostForTime(dispatcher, async::Now(dispatcher) + delay); |
| } |
| |
| zx_status_t TaskBase::PostForTime(async_dispatcher_t* dispatcher, zx::time deadline) { |
| if (dispatcher_) |
| return ZX_ERR_ALREADY_EXISTS; |
| |
| dispatcher_ = dispatcher; |
| task_.deadline = deadline.get(); |
| zx_status_t status = async_post_task(dispatcher, &task_); |
| if (status != ZX_OK) { |
| dispatcher_ = nullptr; |
| } |
| return status; |
| } |
| |
| zx_status_t TaskBase::Cancel() { |
| if (!dispatcher_) |
| return ZX_ERR_NOT_FOUND; |
| |
| async_dispatcher_t* dispatcher = dispatcher_; |
| dispatcher_ = nullptr; |
| |
| zx_status_t status = async_cancel_task(dispatcher, &task_); |
| // |dispatcher| is required to be single-threaded, Cancel() is |
| // only supposed to be called on |dispatcher|'s thread, and we |
| // verified that the task was pending before calling |
| // async_cancel_task(). Assuming that |dispatcher| does not yield |
| // between removing the task and invoking the task's handler, |
| // |task_| must have been pending with |dispatcher|. |
| ZX_DEBUG_ASSERT(status != ZX_ERR_NOT_FOUND); |
| return status; |
| } |
| |
| Task::Task(Handler handler) : TaskBase(&Task::CallHandler), handler_(std::move(handler)) {} |
| |
| Task::~Task() = default; |
| |
| void Task::CallHandler(async_dispatcher_t* dispatcher, async_task_t* task, zx_status_t status) { |
| auto self = Dispatch<Task>(task); |
| self->handler_(dispatcher, self, status); |
| } |
| |
| TaskClosure::TaskClosure(fit::closure handler) |
| : TaskBase(&TaskClosure::CallHandler), handler_(std::move(handler)) {} |
| |
| TaskClosure::~TaskClosure() = default; |
| |
| void TaskClosure::CallHandler(async_dispatcher_t* dispatcher, async_task_t* task, |
| zx_status_t status) { |
| auto self = Dispatch<TaskClosure>(task); // must do this if status is not ok |
| if (status == ZX_OK) { |
| self->handler_(); |
| } |
| } |
| |
| } // namespace async |