cosmos::MessageHeaderBase< MSGHDR > Class Template Reference

Base class for SendMessageHeader and ReceiveMessageHeader. More...

#include <message_header.hxx>

Public Member Functions
	MessageHeaderBase ()
	Create a MSGHDR initialized to all zeroes and with default flags applied.
void	clear ()
	Clear the complete system call structure with zeroes.
void	setIOFlags (const MessageFlags flags)
	Set the flags used for sending or receiving data.

Protected Member Functions
void	resetAddress ()
	Reset the address portion of the msghdr struct.
template<typename IOVEC >
void	setIov (IOVEC &iovec)
	Set the msg_iov fields of the msghdr struct based on the given iovector object.
MessageFlags	ioFlags () const
	Returns the currently set MessageFlags for send/receive.

Protected Attributes
MSGHDR	m_header
	The low level struct msghdr
MessageFlags	m_io_flags
	The currently configured send/receive flags.

Detailed Description

template<typename MSGHDR>
class cosmos::MessageHeaderBase< MSGHDR >

Base class for SendMessageHeader and ReceiveMessageHeader.

Since the struct msghdr has quite different uses for sending vs. receiving, we split up the libcosmos wrappers into two different types. This base class shares common semantics between the two.

MSGHDR is the actual struct msghdr to be used, since we remodelled msghdr as msghdr_const for the SendMessageHeader case.

Definition at line 56 of file message_header.hxx.

Constructor & Destructor Documentation

MessageHeaderBase()

template<typename MSGHDR >

cosmos::MessageHeaderBase< MSGHDR >::MessageHeaderBase ( )

inline

Create a MSGHDR initialized to all zeroes and with default flags applied.

Definition at line 60 of file message_header.hxx.

                            {
                clear();
                // by default mark file descriptor received via unix domain
                // sockets CLOEXEC.
                setIOFlags(MessageFlags{MessageFlag::CLOEXEC});
        }

Member Function Documentation

clear()

template<typename MSGHDR >

void cosmos::MessageHeaderBase< MSGHDR >::clear ( )

inline

Clear the complete system call structure with zeroes.

Definition at line 68 of file message_header.hxx.

                     {
                std::memset(&m_header, 0, sizeof(m_header));
        }

ioFlags()

template<typename MSGHDR >

MessageFlags cosmos::MessageHeaderBase< MSGHDR >::ioFlags ( ) const

inlineprotected

Returns the currently set MessageFlags for send/receive.

Definition at line 108 of file message_header.hxx.

                                     {
                return m_io_flags;
        }

resetAddress()

template<typename MSGHDR >

void cosmos::MessageHeaderBase< MSGHDR >::resetAddress ( )

inlineprotected

Reset the address portion of the msghdr struct.

Definition at line 90 of file message_header.hxx.

                            {
                m_header.msg_name = nullptr;
                m_header.msg_namelen = 0;
        }

setIOFlags()

template<typename MSGHDR >

void cosmos::MessageHeaderBase< MSGHDR >::setIOFlags ( const MessageFlags flags )

inline

Set the flags used for sending or receiving data.

This corresponds to the flags argument in sendmsg() and recvmsg(). The msg_flags field in msghdr is actually not used as an input parameter in these system calls, only as an output parameter in recvmsg().

We keep these flags as an extension to struct msghdr in MessageHeaderBase to avoid having to add additional parameters to Socket::sendMessage() and Socket::receiveMessage().

Definition at line 83 of file message_header.hxx.

                                                  {
                m_io_flags = flags;
        }

setIov()

template<typename MSGHDR >

template<typename IOVEC >

void cosmos::MessageHeaderBase< MSGHDR >::setIov ( IOVEC & iovec )

inlineprotected

Set the msg_iov fields of the msghdr struct based on the given iovector object.

Definition at line 97 of file message_header.hxx.

                                  {
                if (iovec.empty()) {
                        m_header.msg_iov = nullptr;
                        m_header.msg_iovlen = 0;
                } else {
                        m_header.msg_iov = iovec.raw();
                        m_header.msg_iovlen = iovec.size();
                }
        }

Member Data Documentation

m_header

template<typename MSGHDR >

MSGHDR cosmos::MessageHeaderBase< MSGHDR >::m_header

protected

The low level struct msghdr

Definition at line 115 of file message_header.hxx.

m_io_flags

template<typename MSGHDR >

MessageFlags cosmos::MessageHeaderBase< MSGHDR >::m_io_flags

protected

The currently configured send/receive flags.

Definition at line 117 of file message_header.hxx.

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The documentation for this class was generated from the following file:

• include/net/message_header.hxx