iox::runtime::IpcInterfaceBase

Base-Class should never be used by the end-user. Handles the common properties and methods for the childs. The handling of the IPC channels must be done by the children. More...

#include <ipc_interface_base.hpp>

Inherited by iox::runtime::IpcInterfaceCreator, iox::runtime::IpcInterfaceUser

Public Functions

	Name
bool	receive(IpcMessage & answer) const Receives a message from the IPC channel and stores it in answer.
bool	timedReceive(const units::Duration timeout, IpcMessage & answer) const Tries to receive a message from the IPC channel within a specified timeout. It stores the message in answer.
bool	send(const IpcMessage & msg) const Tries to send the message specified in msg.
bool	timedSend(const IpcMessage & msg, const units::Duration timeout) const Tries to send the message specified in msg to the message queue within a specified timeout.
const RuntimeName_t &	getRuntimeName() const Returns the interface name, the unique char string which explicitly identifies the IPC channel.
bool	isInitialized() const If the IPC channel could not be opened or linked in the constructor it will return false, otherwise true. This is needed since the constructor is not allowed to throw an exception. You should always check a IPC channel with isInitialized before using it, since all other methods will fail and return false if a message could not be successfully initialized.
void	cleanupOutdatedIpcChannel(const RuntimeName_t & name) Since there might be an outdated IPC channel due to an unclean temination this function closes the IPC channel if it's existing.

Protected Functions

	Name
bool	reopen() Closes and opens an existing IPC channel using the same parameters as before. If the queue was not open, it is just openened.
bool	ipcChannelMapsToFile() Checks if the IPC channel has its counterpart in the file system.
	IpcInterfaceBase() The default constructor is explicitly deleted since every IPC channel needs a unique string to be identified with.
	IpcInterfaceBase(const RuntimeName_t & runtimeName, const uint64_t maxMessages, const uint64_t messageSize)
virtual	~IpcInterfaceBase() =default
	IpcInterfaceBase(const IpcInterfaceBase & ) delete copy and move ctor and assignment since they are not needed
	IpcInterfaceBase(IpcInterfaceBase && )
IpcInterfaceBase &	operator=(const IpcInterfaceBase & )
IpcInterfaceBase &	operator=(IpcInterfaceBase && )
bool	openIpcChannel(const posix::IpcChannelSide channelSide) Opens a IPC channel and default permissions stored in m_perms and stores the descriptor.
bool	closeIpcChannel() Closes a IPC channel.
bool	hasClosableIpcChannel() const If a IPC channel was moved then m_runtimeName was cleared and this object gave up the control of that specific IPC channel and therefore shouldnt unlink or close it. Otherwise the object which it was moved to can end up with an invalid IPC channel descriptor.
bool	setMessageFromString(const char * buffer, IpcMessage & answer) Set the content of answer from buffer.

Protected Attributes

	Name
RuntimeName_t	m_runtimeName
uint64_t	m_maxMessageSize
uint64_t	m_maxMessages
iox::posix::IpcChannelSide	m_channelSide
IpcChannelType	m_ipcChannel

Friends

	Name
class	IpcInterfaceUser
class	IpcInterfaceCreator
class	IpcRuntimeInterface

Detailed Description

class iox::runtime::IpcInterfaceBase;

Base-Class should never be used by the end-user. Handles the common properties and methods for the childs. The handling of the IPC channels must be done by the children.

Note: This class won't uniquely identify if another object is using the same IPC channel

Public Functions Documentation

function receive

bool receive(
    IpcMessage & answer
) const

Receives a message from the IPC channel and stores it in answer.

Parameters:

• answer If a message is received it is stored there.

Return: If the call failed or an invalid message was received it returns false, otherwise true.

function timedReceive

bool timedReceive(
    const units::Duration timeout,
    IpcMessage & answer
) const

Tries to receive a message from the IPC channel within a specified timeout. It stores the message in answer.

Parameters:

• timeout for receiving a message.
• answer The answer of the IPC channel. If timedReceive failed the content of answer is undefined.

Return: If a valid message was received before the timeout occures it returns true, otherwise false. It also returns false if clock_gettime() failed

function send

bool send(
    const IpcMessage & msg
) const

Tries to send the message specified in msg.

Parameters:

• msg Must be a valid message, if its an invalid message send will return false

Return: If a valid message was send it returns true, otherwise if the message was invalid it will return false.

function timedSend

bool timedSend(
    const IpcMessage & msg,
    const units::Duration timeout
) const

Tries to send the message specified in msg to the message queue within a specified timeout.

Parameters:

• msg Must be a valid message, if its an invalid message send will return false
• timeout specifies the duration to wait for sending.

Return: If a valid message was send it returns true, otherwise if the message was invalid it will return false.

function getRuntimeName

const RuntimeName_t & getRuntimeName() const

Returns the interface name, the unique char string which explicitly identifies the IPC channel.

Return: name of the IPC channel

function isInitialized

bool isInitialized() const

If the IPC channel could not be opened or linked in the constructor it will return false, otherwise true. This is needed since the constructor is not allowed to throw an exception. You should always check a IPC channel with isInitialized before using it, since all other methods will fail and return false if a message could not be successfully initialized.

Return: initialization state

function cleanupOutdatedIpcChannel

static void cleanupOutdatedIpcChannel(
    const RuntimeName_t & name
)

Since there might be an outdated IPC channel due to an unclean temination this function closes the IPC channel if it's existing.

Parameters:

• name of the IPC channel to clean up

Protected Functions Documentation

function reopen

bool reopen()

Closes and opens an existing IPC channel using the same parameters as before. If the queue was not open, it is just openened.

Return: true if successfully reopened, false if not

function ipcChannelMapsToFile

bool ipcChannelMapsToFile()

Checks if the IPC channel has its counterpart in the file system.

Return: If the IPC channel, which corresponds to a descriptor, is still availabe in the file system it returns true, otherwise it was deleted or the IPC channel was not open and returns false

function IpcInterfaceBase

IpcInterfaceBase()

The default constructor is explicitly deleted since every IPC channel needs a unique string to be identified with.

function IpcInterfaceBase

IpcInterfaceBase(
    const RuntimeName_t & runtimeName,
    const uint64_t maxMessages,
    const uint64_t messageSize
)

function ~IpcInterfaceBase

virtual ~IpcInterfaceBase() =default

function IpcInterfaceBase

IpcInterfaceBase(
    const IpcInterfaceBase & 
)

delete copy and move ctor and assignment since they are not needed

function IpcInterfaceBase

IpcInterfaceBase(
    IpcInterfaceBase && 
)

function operator=

IpcInterfaceBase & operator=(
    const IpcInterfaceBase & 
)

function operator=

IpcInterfaceBase & operator=(
    IpcInterfaceBase && 
)

function openIpcChannel

bool openIpcChannel(
    const posix::IpcChannelSide channelSide
)

Opens a IPC channel and default permissions stored in m_perms and stores the descriptor.

Parameters:

• channelSide of the queue. SERVER will also destroy the IPC channel in the dTor, while CLIENT keeps the IPC channel in the file system after the dTor is called

Return: Returns true if a IPC channel could be opened, otherwise false.

function closeIpcChannel

bool closeIpcChannel()

Closes a IPC channel.

Return: Returns true if the IPC channel could be closed, otherwise false.

function hasClosableIpcChannel

bool hasClosableIpcChannel() const

If a IPC channel was moved then m_runtimeName was cleared and this object gave up the control of that specific IPC channel and therefore shouldnt unlink or close it. Otherwise the object which it was moved to can end up with an invalid IPC channel descriptor.

Return: Returns true if the IPC channel is closable, otherwise false.

function setMessageFromString

static bool setMessageFromString(
    const char * buffer,
    IpcMessage & answer
)

Set the content of answer from buffer.

Parameters:

• buffer Raw message as char pointer
• answer Raw message is setting this IpcMessage

Return: answer.isValid()

Protected Attributes Documentation

variable m_runtimeName

RuntimeName_t m_runtimeName;

variable m_maxMessageSize

uint64_t m_maxMessageSize {0U};

variable m_maxMessages

uint64_t m_maxMessages {0U};

variable m_channelSide

iox::posix::IpcChannelSide m_channelSide {posix::IpcChannelSide::CLIENT};

variable m_ipcChannel

IpcChannelType m_ipcChannel;

Friends

friend IpcInterfaceUser

friend class IpcInterfaceUser;

friend IpcInterfaceCreator

friend class IpcInterfaceCreator;

friend IpcRuntimeInterface

friend class IpcRuntimeInterface;

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Updated on 31 May 2022 at 15:29:16 CEST