// 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.
#ifndef IPC_IPC_MESSAGE_H_
#define IPC_IPC_MESSAGE_H_
#include <string>
#include "base/basictypes.h"
#include "base/debug/trace_event.h"
#include "base/files/file.h"
#include "base/pickle.h"
#include "ipc/ipc_export.h"
#if !defined(NDEBUG)
#define IPC_MESSAGE_LOG_ENABLED
#endif
#if defined(OS_POSIX)
#include "base/memory/ref_counted.h"
#endif
class FileDescriptorSet;
namespace IPC {
//------------------------------------------------------------------------------
struct LogData;
class IPC_EXPORT Message : public Pickle {
public:
enum PriorityValue {
PRIORITY_LOW = 1,
PRIORITY_NORMAL,
PRIORITY_HIGH
};
// 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,
REPLY_ERROR_BIT = 0x10,
UNBLOCK_BIT = 0x20,
PUMPING_MSGS_BIT = 0x40,
HAS_SENT_TIME_BIT = 0x80,
};
virtual ~Message();
Message();
// Initialize a message with a user-defined type, priority value, and
// destination WebView ID.
Message(int32 routing_id, uint32 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);
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 type() const {
return header()->type;
}
int32 routing_id() const {
return header()->routing;
}
void set_routing_id(int32 new_id) {
header()->routing = new_id;
}
uint32 flags() const {
return header()->flags;
}
// Sets all the given header values. The message should be empty at this
// call.
void SetHeaderValues(int32 routing, uint32 type, uint32 flags);
template<class T, class S, class P>
static bool Dispatch(const Message* msg, T* obj, S* sender, P* parameter,
void (T::*func)()) {
(obj->*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*)) {
(obj->*func)(parameter);
return true;
}
// Used for async messages with no parameters.
static void Log(std::string* name, const Message* msg, std::string* l) {
}
// Find the end of the message data that starts at range_start. Returns NULL
// if the entire message is not found in the given data range.
static const char* FindNext(const char* range_start, const char* range_end) {
return Pickle::FindNext(sizeof(Header), range_start, range_end);
}
#if defined(OS_POSIX)
// On POSIX, a message supports reading / writing FileDescriptor objects.
// This is used to pass a file descriptor to the peer of an IPC channel.
// Add a descriptor to the end of the set. Returns false if the set is full.
bool WriteFile(base::ScopedFD descriptor);
bool WriteBorrowingFile(const base::PlatformFile& descriptor);
// Get a file descriptor from the message. Returns false on error.
// iter: a Pickle iterator to the current location in the message.
bool ReadFile(PickleIterator* iter, base::ScopedFD* file) const;
// Returns true if there are any file descriptors in this message.
bool HasFileDescriptors() const;
#endif
#ifdef IPC_MESSAGE_LOG_ENABLED
// 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 time);
int64 sent_time() const;
void set_received_time(int64 time) const;
int64 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_; }
#endif
// Called to trace when message is sent.
void TraceMessageBegin() {
TRACE_EVENT_FLOW_BEGIN0(TRACE_DISABLED_BY_DEFAULT("ipc.flow"), "IPC",
header()->flags);
}
// Called to trace when message is received.
void TraceMessageEnd() {
TRACE_EVENT_FLOW_END0(TRACE_DISABLED_BY_DEFAULT("ipc.flow"), "IPC",
header()->flags);
}
protected:
friend class Channel;
friend class ChannelMojo;
friend class ChannelNacl;
friend class ChannelPosix;
friend class ChannelWin;
friend class MessageReplyDeserializer;
friend class SyncMessage;
#pragma pack(push, 4)
struct Header : Pickle::Header {
int32 routing; // ID of the view that this message is destined for
uint32 type; // specifies the user-defined message type
uint32 flags; // specifies control flags for the message
#if defined(OS_POSIX)
uint16 num_fds; // the number of descriptors included with this message
uint16 pad; // explicitly initialize this to appease valgrind
#endif
};
#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_;
#if defined(OS_POSIX)
// The set of file descriptors associated with this message.
scoped_refptr<FileDescriptorSet> file_descriptor_set_;
// Ensure that a FileDescriptorSet is allocated
void EnsureFileDescriptorSet();
FileDescriptorSet* file_descriptor_set() {
EnsureFileDescriptorSet();
return file_descriptor_set_.get();
}
const FileDescriptorSet* file_descriptor_set() const {
return file_descriptor_set_.get();
}
#endif
#ifdef IPC_MESSAGE_LOG_ENABLED
// Used for logging.
mutable int64 received_time_;
mutable std::string output_params_;
mutable LogData* log_data_;
mutable bool dont_log_;
#endif
};
//------------------------------------------------------------------------------
} // namespace IPC
enum SpecialRoutingIDs {
// indicates that we don't have a routing ID yet.
MSG_ROUTING_NONE = -2,
// indicates a general message not sent to a particular tab.
MSG_ROUTING_CONTROL = kint32max,
};
#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_