The Tor Browser: ipc/chromium/src/chrome/common/ipc_sync

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.

     2 // Use of this source code is governed by a BSD-style license that can be

     3 // found in the LICENSE file.

     5 #include "build/build_config.h"

     7 #if defined(OS_WIN)

     8 #include <windows.h>

     9 #endif

    10 #include <stack>

    12 #include "base/logging.h"

    13 #include "base/waitable_event.h"

    14 #include "chrome/common/ipc_sync_message.h"

    16 namespace IPC {

    18 uint32_t SyncMessage::next_id_ = 0;

    19 #define kSyncMessageHeaderSize 4

    21 SyncMessage::SyncMessage(

    22     int32_t routing_id,

    23     uint16_t type,

    24     PriorityValue priority,

    25     MessageReplyDeserializer* deserializer)

    26     : Message(routing_id, type, priority),

    27       deserializer_(deserializer),

    28       pump_messages_event_(NULL)

    29       {

    30   set_sync();

    31   set_unblock(true);

    33   // Add synchronous message data before the message payload.

    34   SyncHeader header;

    35   header.message_id = ++next_id_;

    36   WriteSyncHeader(this, header);

    37 }

    39 MessageReplyDeserializer* SyncMessage::GetReplyDeserializer() {

    40   MessageReplyDeserializer* rv = deserializer_;

    41   DCHECK(rv);

    42   deserializer_ = NULL;

    43   return rv;

    44 }

    46 void SyncMessage::EnableMessagePumping() {

    47   static base::WaitableEvent* dummy_event = new base::WaitableEvent(true, true);

    48   DCHECK(!pump_messages_event_);

    49   set_pump_messages_event(dummy_event);

    50 }

    52 bool SyncMessage::IsMessageReplyTo(const Message& msg, int request_id) {

    53   if (!msg.is_reply())

    54     return false;

    56   return GetMessageId(msg) == request_id;

    57 }

    59 void* SyncMessage::GetDataIterator(const Message* msg) {

    60   void* iter = const_cast<char*>(msg->payload());

    61   UpdateIter(&iter, kSyncMessageHeaderSize);

    62   return iter;

    63 }

    65 int SyncMessage::GetMessageId(const Message& msg) {

    66   if (!msg.is_sync() && !msg.is_reply())

    67     return 0;

    69   SyncHeader header;

    70   if (!ReadSyncHeader(msg, &header))

    71     return 0;

    73   return header.message_id;

    74 }

    76 Message* SyncMessage::GenerateReply(const Message* msg) {

    77   DCHECK(msg->is_sync());

    79   Message* reply = new Message(msg->routing_id(), IPC_REPLY_ID,

    80                                msg->priority());

    81   reply->set_reply();

    83   SyncHeader header;

    85   // use the same message id, but this time reply bit is set

    86   header.message_id = GetMessageId(*msg);

    87   WriteSyncHeader(reply, header);

    89   return reply;

    90 }

    92 bool SyncMessage::ReadSyncHeader(const Message& msg, SyncHeader* header) {

    93   DCHECK(msg.is_sync() || msg.is_reply());

    95   void* iter = NULL;

    96   bool result = msg.ReadInt(&iter, &header->message_id);

    97   if (!result) {

    98     NOTREACHED();

    99     return false;

   100   }

   102   return true;

   103 }

   105 bool SyncMessage::WriteSyncHeader(Message* msg, const SyncHeader& header) {

   106   DCHECK(msg->is_sync() || msg->is_reply());

   107   DCHECK(msg->payload_size() == 0);

   108   bool result = msg->WriteInt(header.message_id);

   109   if (!result) {

   110     NOTREACHED();

   111     return false;

   112   }

   114   // Note: if you add anything here, you need to update kSyncMessageHeaderSize.

   115   DCHECK(kSyncMessageHeaderSize == msg->payload_size());

   117   return true;

   118 }

   121 bool MessageReplyDeserializer::SerializeOutputParameters(const Message& msg) {

   122   return SerializeOutputParameters(msg, SyncMessage::GetDataIterator(&msg));

   123 }

   125 }  // namespace IPC

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