| // 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. |
| |
| #pragma once |
| |
| #include <lib/zx/channel.h> |
| #include <zircon/fidl.h> |
| |
| namespace devmgr { |
| |
| // Manages state of a FIDL transaction so we can reply to the correct message. |
| // FidlTxn must not outlive the channel it is given |
| class FidlTxn { |
| public: |
| FidlTxn(zx::unowned_channel channel, uint32_t txid) : channel_(channel), txid_(txid) {} |
| FidlTxn(const zx::channel& channel, uint32_t txid) : channel_(channel), txid_(txid) {} |
| |
| FidlTxn& operator=(const FidlTxn&) = delete; |
| FidlTxn(const FidlTxn&) = delete; |
| |
| FidlTxn& operator=(FidlTxn&&) = delete; |
| FidlTxn(FidlTxn&&) = delete; |
| |
| zx_status_t Reply(const fidl_msg_t* msg) { |
| auto hdr = static_cast<fidl_message_header_t*>(msg->bytes); |
| hdr->txid = txid_; |
| return channel_->write(0, msg->bytes, msg->num_bytes, msg->handles, msg->num_handles); |
| } |
| |
| static zx_status_t FidlReply(fidl_txn_t* reply, const fidl_msg_t* msg) { |
| static_assert(offsetof(FidlTxn, txn_) == 0); |
| return reinterpret_cast<FidlTxn*>(reply)->Reply(msg); |
| } |
| |
| fidl_txn_t* fidl_txn() { return &txn_; } |
| |
| private: |
| // Due to the implementation of FidlReply, it is important that this be the |
| // first member variable. |
| fidl_txn_t txn_ = {.reply = FidlTxn::FidlReply}; |
| |
| // Reply channel |
| const zx::unowned_channel channel_; |
| |
| // Transaction id of the message we're replying to |
| const uint32_t txid_; |
| }; |
| |
| } // namespace devmgr |