l4_msgtag_t Struct Reference

Message tag data structure. More...

#include <types.h>

Collaboration diagram for l4_msgtag_t:

Public Member Functions
long	label () const L4_NOTHROW
	Get the protocol value.
void	label (long v) L4_NOTHROW
	Set the protocol value.
unsigned	words () const L4_NOTHROW
	Get the number of untyped words.
unsigned	items () const L4_NOTHROW
	Get the number of typed items.
unsigned	flags () const L4_NOTHROW
	Get the flags value.
bool	is_page_fault () const L4_NOTHROW
	Test if protocol indicates page-fault protocol.
bool	is_exception () const L4_NOTHROW
	Test if protocol indicates exception protocol.
bool	is_sigma0 () const L4_NOTHROW
	Test if protocol indicates sigma0 protocol.
bool	is_io_page_fault () const L4_NOTHROW
	Test if protocol indicates IO-page-fault protocol.
bool	has_error () const L4_NOTHROW
	Test if flags indicate an error.

Data Fields
l4_mword_t	raw
	raw value

Detailed Description

Message tag data structure.

Include File

#include <l4/sys/types.h> 

Describes the details of an IPC operation, in particular which parts of the UTCB have to be transmitted, and also flags to enable real-time and FPU extensions.

The message tag also contains a user-defined label that could be used to specify a protocol ID. Some negative values are reserved for kernel protocols such as page faults and exceptions.

The type must be treated completely opaque.

Examples

examples/libs/l4re/c++/shared_ds/ds_srv.cc, examples/libs/l4re/streammap/server.cc, examples/sys/aliens/main.c, examples/sys/ipc/ipc_example.c, examples/sys/singlestep/main.c, examples/sys/start-with-exc/main.c, and examples/sys/utcb-ipc/main.c.

Definition at line 152 of file types.h.

Member Function Documentation

flags()

unsigned l4_msgtag_t::flags ( ) const

inline

Get the flags value.

The flags are a combination of the flags defined by L4_msgtag_flags.

Definition at line 177 of file types.h.

References raw.

has_error()

bool l4_msgtag_t::has_error ( ) const

inline

Test if flags indicate an error.

If true, the error code is stored in the UTCB, see l4_utcb_tcr()->error.

Definition at line 190 of file types.h.

References L4_MSGTAG_ERROR, and raw.

Referenced by L4Re::chkipc(), L4Re::chksys(), L4::Server< LOOP_HOOKS >::internal_loop(), L4::Server< LOOP_HOOKS >::reply_n_wait(), and L4::throw_ipc_exception().

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

• l4/sys/types.h