L4Re - L4 Runtime Environment
l4_msgtag_t Struct Reference

Message tag data structure. More...

#include <types.h>

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Public Member Functions

long label () const throw ()
 Get the protocol value.
 
void label (long v) throw ()
 Set the protocol value.
 
unsigned words () const throw ()
 Get the number of untyped words.
 
unsigned items () const throw ()
 Get the number of typed items.
 
unsigned flags () const throw ()
 Get the flags value. More...
 
bool is_page_fault () const throw ()
 Test if protocol indicates page-fault protocol.
 
bool is_preemption () const throw ()
 Test if protocol indicates preemption protocol.
 
bool is_sys_exception () const throw ()
 Test if protocol indicates system-exception protocol.
 
bool is_exception () const throw ()
 Test if protocol indicates exception protocol.
 
bool is_sigma0 () const throw ()
 Test if protocol indicates sigma0 protocol.
 
bool is_io_page_fault () const throw ()
 Test if protocol indicates IO-page-fault protocol.
 
unsigned has_error () const throw ()
 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/isr/main.c, examples/sys/singlestep/main.c, examples/sys/start-with-exc/main.c, and examples/sys/utcb-ipc/main.c.

Definition at line 159 of file types.h.

Member Function Documentation

◆ flags()

unsigned l4_msgtag_t::flags ( ) const
throw (
)
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.

Referenced by has_error().

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