Input stream for IPC unmarshalling. More...

#include <ipc_stream>

Inheritance diagram for L4::Ipc::Istream:

Collaboration diagram for L4::Ipc::Istream:

Public Member Functions
	Istream (l4_utcb_t *utcb)
	Create an input stream for the given message buffer.

void	reset ()
	Reset the stream to empty, and ready for receive()/wait().

template<typename T >
bool	has_more (unsigned long count=1)
	Check whether a value of type T can be obtained from the stream.

l4_utcb_t *	utcb () const
	Return utcb pointer.

Get/Put Functions.
template<typename T >
unsigned long	get (T *buf, unsigned long elems)
	Copy out an array of type `T` with `size` elements.

template<typename T >
void	skip (unsigned long elems)
	Skip size elements of type T in the stream.

template<typename T >
unsigned long	get (Msg_ptr< T > const &buf, unsigned long elems=1)
	Read one size elements of type T from the stream and return a pointer.

template<typename T >
bool	get (T &v)
	Extract a single element of type T from the stream.

l4_msgtag_t	tag () const
	Get the message tag of a received IPC.

l4_msgtag_t &	tag ()
	Get the message tag of a received IPC.

IPC operations.
l4_msgtag_t	wait (l4_umword_t *src)
	Wait for an incoming message from any sender.

l4_msgtag_t	wait (l4_umword_t *src, l4_timeout_t timeout)
	Wait for an incoming message from any sender.

l4_msgtag_t	receive (l4_cap_idx_t src)
	Wait for a message from the specified sender.

Detailed Description

Input stream for IPC unmarshalling.

Ipc::Istream is part of the dynamic IPC marshalling infrastructure, as well as Ipc::Ostream and Ipc::Iostream.

Ipc::Istream is an input stream supporting extraction of values from an IPC message buffer. A received IPC message can be unmarshalled using the usual extraction operator (>>).

There exist some special wrapper classes to extract arrays (see Ipc_buf_cp_in and Ipc_buf_in) and indirect strings (see Msg_in_buffer and Msg_io_buffer).

Definition at line 345 of file ipc_stream.

Constructor & Destructor Documentation

◆ Istream()

L4::Ipc::Istream::Istream ( l4_utcb_t * utcb )

inline

Create an input stream for the given message buffer.

The given message buffer is used for IPC operations wait()/receive() and received data can be extracted using the >> operator afterwards. In the case of indirect message parts a buffer of type Msg_in_buffer must be inserted into the stream before the IPC operation and contains received data afterwards.

Parameters

utcb	The message buffer to receive IPC messages.

Definition at line 359 of file ipc_stream.

Member Function Documentation

◆ get() [1/3]

template<typename T >

unsigned long L4::Ipc::Istream::get	(	Msg_ptr< T > const &	buf,
		unsigned long	elems = `1`
	)

inline

Read one size elements of type T from the stream and return a pointer.

Parameters

buf	A Msg_ptr that is actually set to point to the element in the stream.
elems	Number of elements to extract (default is 1).

Returns: The number of elements extracted.

In contrast to a normal get, this version does actually not copy the data but returns a pointer to the data.

See Istream::operator>>()

Definition at line 450 of file ipc_stream.

References L4_UNLIKELY.

◆ get() [2/3]

template<typename T >

bool L4::Ipc::Istream::get ( T & v )

inline

Extract a single element of type T from the stream.

Parameters

[out] v The element.

Return values

true	An element was successfully extracted.
false	An element could not be extracted.

See Istream::operator>>()

Definition at line 475 of file ipc_stream.

References L4_UNLIKELY.

◆ get() [3/3]

template<typename T >

unsigned long L4::Ipc::Istream::get	(	T *	buf,
		unsigned long	elems
	)

inline

Copy out an array of type T with size elements.

Parameters

buf	Pointer to a buffer for size elements of type T.
elems	Number of elements of type T to copy out.

Returns: The number of elements copied out.

See Istream::operator>>()

Definition at line 405 of file ipc_stream.

References L4_UNLIKELY.

Referenced by operator>>(), operator>>(), operator>>(), operator>>(), and operator>>().

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◆ receive()

l4_msgtag_t L4::Ipc::Istream::receive ( l4_cap_idx_t src )

inline

Wait for a message from the specified sender.

Parameters

src	The sender id to receive from.

Returns: The IPC result tag (l4_msgtag_t).

This is commonly known as 'closed wait'.

Definition at line 583 of file ipc_stream.

References L4_IPC_NEVER, and receive().

Referenced by receive().

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◆ reset()

void L4::Ipc::Istream::reset ( )

inline

Reset the stream to empty, and ready for receive()/wait().

The stream is reset to the same state as on its creation.

Definition at line 369 of file ipc_stream.

References l4_msg_regs_t::mr.

Referenced by L4::Ipc::Iostream::reset().

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◆ skip()

template<typename T >

void L4::Ipc::Istream::skip ( unsigned long elems )

inline

Skip size elements of type T in the stream.

Parameters

elems Number of elements to skip.

Definition at line 425 of file ipc_stream.

References L4_UNLIKELY.

◆ tag() [1/2]

l4_msgtag_t & L4::Ipc::Istream::tag ( )

inline

Get the message tag of a received IPC.

Returns: A reference to the L4 message tag for the received IPC.

This is in particular useful for handling page faults or exceptions.

See Istream::operator>>()

Definition at line 528 of file ipc_stream.

◆ tag() [2/2]

l4_msgtag_t L4::Ipc::Istream::tag ( ) const

inline

Get the message tag of a received IPC.

Returns: The L4 message tag for the received IPC.

This is in particular useful for handling page faults or exceptions.

See Istream::operator>>()

Definition at line 516 of file ipc_stream.

Referenced by L4::Ipc::Iostream::call(), operator>>(), L4::Ipc::Iostream::reply_and_wait(), and wait().

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◆ wait() [1/2]

l4_msgtag_t L4::Ipc::Istream::wait ( l4_umword_t * src )

inline

Wait for an incoming message from any sender.

Parameters

[out] src Contains the sender after a successful IPC operation.

Returns: Syscall return tag.

This wait is actually known as 'open wait'.

Definition at line 559 of file ipc_stream.

References L4_IPC_NEVER, and wait().

Referenced by wait().

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◆ wait() [2/2]

l4_msgtag_t L4::Ipc::Istream::wait	(	l4_umword_t *	src,
		l4_timeout_t	timeout
	)

inline

Wait for an incoming message from any sender.

Parameters

[out]	src	Contains the sender after a successful IPC operation.
	timeout	Timeout used for IPC.

Returns: The IPC result tag (l4_msgtag_t).

This wait is actually known as 'open wait'.

Definition at line 1018 of file ipc_stream.

References l4_ipc_wait(), and tag().

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

l4/cxx/ipc_stream

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Istream()

Member Function Documentation

◆ get() [1/3]

◆ get() [2/3]

◆ get() [3/3]

◆ receive()

◆ reset()

◆ skip()

◆ tag() [1/2]

◆ tag() [2/2]

◆ wait() [1/2]

◆ wait() [2/2]