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116 lines
2.8 KiB
116 lines
2.8 KiB
// Copyright (c) 2012 The Chromium Authors. All rights reserved. |
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// Use of this source code is governed by a BSD-style license that can be |
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// found in the LICENSE file. |
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#include "ipc/ipc_sync_message.h" |
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#include <stdint.h> |
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#include "base/atomic_sequence_num.h" |
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#include "base/logging.h" |
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#include "build/build_config.h" |
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namespace { |
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base::AtomicSequenceNumber g_next_id; |
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} // namespace |
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namespace IPC { |
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#define kSyncMessageHeaderSize 4 |
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SyncMessage::SyncMessage(int32_t routing_id, |
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uint32_t type, |
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PriorityValue priority, |
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MessageReplyDeserializer* deserializer) |
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: Message(routing_id, type, priority), |
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deserializer_(deserializer) { |
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set_sync(); |
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set_unblock(true); |
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// Add synchronous message data before the message payload. |
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SyncHeader header; |
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header.message_id = g_next_id.GetNext(); |
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WriteSyncHeader(this, header); |
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} |
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SyncMessage::~SyncMessage() = default; |
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MessageReplyDeserializer* SyncMessage::GetReplyDeserializer() { |
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DCHECK(deserializer_.get()); |
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return deserializer_.release(); |
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} |
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bool SyncMessage::IsMessageReplyTo(const Message& msg, int request_id) { |
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if (!msg.is_reply()) |
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return false; |
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return GetMessageId(msg) == request_id; |
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} |
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base::PickleIterator SyncMessage::GetDataIterator(const Message* msg) { |
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base::PickleIterator iter(*msg); |
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if (!iter.SkipBytes(kSyncMessageHeaderSize)) |
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return base::PickleIterator(); |
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else |
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return iter; |
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} |
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int SyncMessage::GetMessageId(const Message& msg) { |
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if (!msg.is_sync() && !msg.is_reply()) |
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return 0; |
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SyncHeader header; |
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if (!ReadSyncHeader(msg, &header)) |
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return 0; |
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return header.message_id; |
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} |
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Message* SyncMessage::GenerateReply(const Message* msg) { |
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DCHECK(msg->is_sync()); |
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Message* reply = new Message(msg->routing_id(), IPC_REPLY_ID, |
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msg->priority()); |
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reply->set_reply(); |
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SyncHeader header; |
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// use the same message id, but this time reply bit is set |
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header.message_id = GetMessageId(*msg); |
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WriteSyncHeader(reply, header); |
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return reply; |
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} |
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bool SyncMessage::ReadSyncHeader(const Message& msg, SyncHeader* header) { |
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DCHECK(msg.is_sync() || msg.is_reply()); |
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base::PickleIterator iter(msg); |
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bool result = iter.ReadInt(&header->message_id); |
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if (!result) { |
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NOTREACHED(); |
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return false; |
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} |
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return true; |
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} |
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bool SyncMessage::WriteSyncHeader(Message* msg, const SyncHeader& header) { |
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DCHECK(msg->is_sync() || msg->is_reply()); |
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DCHECK(msg->payload_size() == 0); |
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msg->WriteInt(header.message_id); |
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// Note: if you add anything here, you need to update kSyncMessageHeaderSize. |
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DCHECK(kSyncMessageHeaderSize == msg->payload_size()); |
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return true; |
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} |
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bool MessageReplyDeserializer::SerializeOutputParameters(const Message& msg) { |
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return SerializeOutputParameters(msg, SyncMessage::GetDataIterator(&msg)); |
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} |
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} // namespace IPC
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