Проект OpenNet: MAN device_is_alive (9) Ядро (FreeBSD и Linux)

Интерактивная система просмотра системных руководств (man-ов)

device_is_alive (9)

>> device_is_alive (9) ( FreeBSD man: Ядро )

BSD mandoc

NAME



device_get_state

 
device_busy

 
device_unbusy

 
device_is_alive

 
device_is_attached

 - manipulate device state

SYNOPSIS

#include <sys/param.h>
#include <sys/bus.h>
device_state_t device_get_state (device_t dev);
void device_busy (device_t dev);
void device_unbusy (device_t dev);
int device_is_alive (device_t dev);
int device_is_attached (device_t dev);

DESCRIPTION

The current state of a device is accessed by calling device_get_state ();
which returns DS_NOTPRESENT DS_ALIVE DS_ATTACHED or DS_BUSY (described in device(9)). To test see if a device was successfully probed, call device_is_alive ();
which simply returns if the state is greater or equal to DS_ALIVE To test see if a device was successfully attached, call device_is_attached ();
which simply returns if the state is greater or equal to DS_ATTACHED

Each device has a busy count which is incremented when device_busy ();
is called and decremented when device_unbusy ();
is called. Both routines return an error if the device state is less than DS_ATTACHED

When device_busy ();
is called on a device in the DS_ATTACHED state, the device changes to the DS_BUSY state. When device_unbusy ();
is called and after decrementing, the busy count for the device is zero, the device changes to the DS_ATTACHED state.

AUTHORS

This manual page was written by An Doug Rabson .

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