blob: 27808ba0eaf735dd4ec2932f78208a4f38d9e44f [file] [log] [blame]
// Copyright 2018 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.
#ifndef SRC_DEVICES_BIN_DRIVER_MANAGER_ASYNC_LOOP_REF_COUNTED_RPC_HANDLER_H_
#define SRC_DEVICES_BIN_DRIVER_MANAGER_ASYNC_LOOP_REF_COUNTED_RPC_HANDLER_H_
#include <lib/async/cpp/wait.h>
#include <lib/zx/channel.h>
#include <utility>
#include <fbl/ref_ptr.h>
// Mixin for representing a type that represents an RPC handler and that has a
// reference owned by an async loop. The loop will own both the wrapped type and the RPC
// connection handle.
//
// Deriving classes should define and implement this function:
// static void HandleRpc(fbl::RefPtr<T>&& conn,
// async_dispatcher_t* dispatcher, async::WaitBase* wait, zx_status_t status,
// const zx_packet_signal_t* signal);
template <typename T>
class AsyncLoopRefCountedRpcHandler {
public:
~AsyncLoopRefCountedRpcHandler() {
zx_status_t status = wait_.Cancel();
ZX_ASSERT(status == ZX_OK || status == ZX_ERR_NOT_FOUND);
zx_handle_close(wait_.object());
}
// Begins waiting in |dispatcher| on |conn->wait|. This transfers ownership
// of a reference to |conn| to the dispatcher. The dispatcher returns ownership when the
// handler is invoked.
static zx_status_t BeginWait(fbl::RefPtr<T> conn, async_dispatcher_t* dispatcher) {
zx_status_t status = conn->wait_.Begin(dispatcher);
if (status == ZX_OK) {
// This reference will be recovered by MakeRefPtrNoAdopt in
// HandleRpcEntry
__UNUSED auto ptr = fbl::ExportToRawPtr(&conn);
}
return status;
}
// Entrypoint for the RPC handler that captures the pointer ownership
// semantics.
void HandleRpcEntry(async_dispatcher_t* dispatcher, async::WaitBase* wait, zx_status_t status,
const zx_packet_signal_t* signal) {
auto self = fbl::ImportFromRawPtr(static_cast<T*>(this));
T::HandleRpc(std::move(self), dispatcher, wait, status, signal);
}
zx::unowned_channel channel() const { return zx::unowned_channel(wait_.object()); }
// Sets the channel to the given handle and returns the old value
zx::channel set_channel(zx::channel h) {
zx::channel old(wait_.object());
wait_.set_object(h.release());
return old;
}
using WaitType = async::WaitMethod<AsyncLoopRefCountedRpcHandler<T>,
&AsyncLoopRefCountedRpcHandler<T>::HandleRpcEntry>;
private:
WaitType wait_{this, ZX_HANDLE_INVALID, ZX_CHANNEL_READABLE | ZX_CHANNEL_PEER_CLOSED};
};
#endif // SRC_DEVICES_BIN_DRIVER_MANAGER_ASYNC_LOOP_REF_COUNTED_RPC_HANDLER_H_