blob: bbbc14efca9a61fd5bbf55ae4d03797706b74b9e [file] [log] [blame]
// Copyright (c) 2012 The Chromium 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 <stddef.h>
#include <stdint.h>
#include <string>
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/pickle.h"
#include "base/trace_event/trace_event.h"
#include "build/build_config.h"
#include "ipc/ipc_buildflags.h"
#include "ipc/ipc_message_support_export.h"
namespace mojo {
namespace internal {
struct UnmappedNativeStructSerializerImpl;
} // namespace mojo
namespace IPC {
namespace internal {
class ChannelReader;
} // namespace internal
struct LogData;
class MessageAttachmentSet;
class IPC_MESSAGE_SUPPORT_EXPORT Message : public base::Pickle {
enum PriorityValue {
// Bit values used in the flags field.
// Upper 24 bits of flags store a reference number, so this enum is limited to
// 8 bits.
enum {
PRIORITY_MASK = 0x03, // Low 2 bits of store the priority value.
SYNC_BIT = 0x04,
REPLY_BIT = 0x08,
~Message() override;
// Initialize a message with a user-defined type, priority value, and
// destination WebView ID.
Message(int32_t routing_id, uint32_t type, PriorityValue priority);
// Initializes a message from a const block of data. The data is not copied;
// instead the data is merely referenced by this message. Only const methods
// should be used on the message when initialized this way.
Message(const char* data, int data_len);
Message(const Message& other);
Message& operator=(const Message& other);
bool IsValid() const { return header_size() == sizeof(Header) && header(); }
PriorityValue priority() const {
return static_cast<PriorityValue>(header()->flags & PRIORITY_MASK);
// True if this is a synchronous message.
void set_sync() {
header()->flags |= SYNC_BIT;
bool is_sync() const {
return (header()->flags & SYNC_BIT) != 0;
// Set this on a reply to a synchronous message.
void set_reply() {
header()->flags |= REPLY_BIT;
bool is_reply() const {
return (header()->flags & REPLY_BIT) != 0;
// Set this on a reply to a synchronous message to indicate that no receiver
// was found.
void set_reply_error() {
header()->flags |= REPLY_ERROR_BIT;
bool is_reply_error() const {
return (header()->flags & REPLY_ERROR_BIT) != 0;
// Normally when a receiver gets a message and they're blocked on a
// synchronous message Send, they buffer a message. Setting this flag causes
// the receiver to be unblocked and the message to be dispatched immediately.
void set_unblock(bool unblock) {
if (unblock) {
header()->flags |= UNBLOCK_BIT;
} else {
header()->flags &= ~UNBLOCK_BIT;
bool should_unblock() const {
return (header()->flags & UNBLOCK_BIT) != 0;
// Tells the receiver that the caller is pumping messages while waiting
// for the result.
bool is_caller_pumping_messages() const {
return (header()->flags & PUMPING_MSGS_BIT) != 0;
void set_dispatch_error() const {
dispatch_error_ = true;
bool dispatch_error() const {
return dispatch_error_;
uint32_t type() const {
return header()->type;
int32_t routing_id() const {
return header()->routing;
void set_routing_id(int32_t new_id) {
header()->routing = new_id;
uint32_t flags() const {
return header()->flags;
// Sets all the given header values. The message should be empty at this
// call.
void SetHeaderValues(int32_t routing, uint32_t type, uint32_t flags);
template<class T, class S, class P>
static bool Dispatch(const Message* msg, T* obj, S* sender, P* parameter,
void (T::*func)()) {
return true;
template<class T, class S, class P>
static bool Dispatch(const Message* msg, T* obj, S* sender, P* parameter,
void (T::*func)(P*)) {
return true;
// Used for async messages with no parameters.
static void Log(std::string* name, const Message* msg, std::string* l) {
// The static method FindNext() returns several pieces of information, which
// are aggregated into an instance of this struct.
// Total message size. Always valid if |message_found| is true.
// If |message_found| is false but we could determine message size
// from the header, this field is non-zero. Otherwise it's zero.
size_t message_size;
// Whether an entire message was found in the given memory range.
bool message_found;
// Only filled in if |message_found| is true.
// The start address is passed into FindNext() by the caller, so isn't
// repeated in this struct. The end address of the pickle should be used to
// construct a base::Pickle.
const char* pickle_end;
// Only filled in if |message_found| is true.
// The end address of the message should be used to determine the start
// address of the next message.
const char* message_end;
// |info| is an output parameter and must not be nullptr.
static void FindNext(const char* range_start,
const char* range_end,
NextMessageInfo* info);
// WriteAttachment appends |attachment| to the end of the set. It returns
// false iff the set is full.
bool WriteAttachment(
scoped_refptr<base::Pickle::Attachment> attachment) override;
// ReadAttachment parses an attachment given the parsing state |iter| and
// writes it to |*attachment|. It returns true on success.
bool ReadAttachment(
base::PickleIterator* iter,
scoped_refptr<base::Pickle::Attachment>* attachment) const override;
// Returns true if there are any attachment in this message.
bool HasAttachments() const override;
// Adds the outgoing time from Time::Now() at the end of the message and sets
// a bit to indicate that it's been added.
void set_sent_time(int64_t time);
int64_t sent_time() const;
void set_received_time(int64_t time) const;
int64_t received_time() const { return received_time_; }
void set_output_params(const std::string& op) const { output_params_ = op; }
const std::string& output_params() const { return output_params_; }
// The following four functions are needed so we can log sync messages with
// delayed replies. We stick the log data from the sent message into the
// reply message, so that when it's sent and we have the output parameters
// we can log it. As such, we set a flag on the sent message to not log it.
void set_sync_log_data(LogData* data) const { log_data_ = data; }
LogData* sync_log_data() const { return log_data_; }
void set_dont_log() const { dont_log_ = true; }
bool dont_log() const { return dont_log_; }
friend class Channel;
friend class ChannelMojo;
friend class ChannelNacl;
friend class ChannelPosix;
friend class ChannelWin;
friend class internal::ChannelReader;
friend class MessageReplyDeserializer;
friend class SyncMessage;
friend struct mojo::internal::UnmappedNativeStructSerializerImpl;
#pragma pack(push, 4)
struct Header : base::Pickle::Header {
int32_t routing; // ID of the view that this message is destined for
uint32_t type; // specifies the user-defined message type
uint32_t flags; // specifies control flags for the message
#if defined(OS_POSIX) || defined(OS_FUCHSIA)
uint16_t num_fds; // the number of descriptors included with this message
uint16_t pad; // explicitly initialize this to appease valgrind
#pragma pack(pop)
Header* header() {
return headerT<Header>();
const Header* header() const {
return headerT<Header>();
void Init();
// Used internally to support IPC::Listener::OnBadMessageReceived.
mutable bool dispatch_error_;
// The set of file descriptors associated with this message.
scoped_refptr<MessageAttachmentSet> attachment_set_;
// Ensure that a MessageAttachmentSet is allocated
void EnsureMessageAttachmentSet();
MessageAttachmentSet* attachment_set() {
return attachment_set_.get();
const MessageAttachmentSet* attachment_set() const {
return attachment_set_.get();
// Used for logging.
mutable int64_t received_time_;
mutable std::string output_params_;
mutable LogData* log_data_;
mutable bool dont_log_;
FRIEND_TEST_ALL_PREFIXES(IPCMessageTest, FindNextOverflow);
} // namespace IPC
enum SpecialRoutingIDs {
// indicates that we don't have a routing ID yet.
// indicates a general message not sent to a particular tab.
#define IPC_REPLY_ID 0xFFFFFFF0 // Special message id for replies
#define IPC_LOGGING_ID 0xFFFFFFF1 // Special message id for logging
#endif // IPC_IPC_MESSAGE_H_