com.ibm.jusb.os.linux
Class LinuxUsbServices

java.lang.Object
  com.ibm.jusb.os.AbstractUsbServices
      com.ibm.jusb.os.linux.LinuxUsbServices

All Implemented Interfaces:

UsbServices

public class LinuxUsbServices
extends AbstractUsbServices
implements UsbServices

UsbServices implementation for Linux platform.

Author:

Dan Streetman

Field Summary

static int	MAX_FIRST_UPDATE_DELAY
static int	TOPOLOGY_UPDATE_DELAY
static java.lang.String	TOPOLOGY_UPDATE_DELAY_KEY
static int	TOPOLOGY_UPDATE_NEW_DEVICE_DELAY
static java.lang.String	TOPOLOGY_UPDATE_NEW_DEVICE_DELAY_KEY
static boolean	TOPOLOGY_UPDATE_USE_POLLING
static java.lang.String	TOPOLOGY_UPDATE_USE_POLLING_KEY
static java.lang.String	TRACE_DEFAULT
static java.lang.String	TRACE_FILENAME
static java.lang.String	TRACE_HOTPLUG
static java.lang.String	TRACE_LEVEL
static java.lang.String	TRACE_OUTPUT
static java.lang.String	TRACE_URB
static java.lang.String	TRACE_XFER
static java.lang.String	TRACING

Constructor Summary

LinuxUsbServices()

Method Summary

java.lang.String	getApiVersion() Get the (minimum) version number of the javax.usb API that this UsbServices implements.
java.lang.String	getImpDescription() Get a description of this UsbServices implementation.
java.lang.String	getImpVersion() Get the version number of the UsbServices implementation.
UsbHub	getRootUsbHub() Get the virtual UsbHub to which all physical Host Controller UsbHubs are attached.

Methods inherited from class com.ibm.jusb.os.AbstractUsbServices

addUsbServicesListener, getRootUsbHubImp, removeUsbServicesListener

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface javax.usb.UsbServices

addUsbServicesListener, removeUsbServicesListener

Field Detail

MAX_FIRST_UPDATE_DELAY

public static final int MAX_FIRST_UPDATE_DELAY

See Also:

Constant Field Values

TOPOLOGY_UPDATE_DELAY

public static final int TOPOLOGY_UPDATE_DELAY

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Constant Field Values

TOPOLOGY_UPDATE_DELAY_KEY

public static final java.lang.String TOPOLOGY_UPDATE_DELAY_KEY

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Constant Field Values

TOPOLOGY_UPDATE_NEW_DEVICE_DELAY

public static final int TOPOLOGY_UPDATE_NEW_DEVICE_DELAY

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Constant Field Values

TOPOLOGY_UPDATE_NEW_DEVICE_DELAY_KEY

public static final java.lang.String TOPOLOGY_UPDATE_NEW_DEVICE_DELAY_KEY

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Constant Field Values

TOPOLOGY_UPDATE_USE_POLLING

public static final boolean TOPOLOGY_UPDATE_USE_POLLING

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Constant Field Values

TOPOLOGY_UPDATE_USE_POLLING_KEY

public static final java.lang.String TOPOLOGY_UPDATE_USE_POLLING_KEY

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Constant Field Values

TRACING

public static final java.lang.String TRACING

See Also:

Constant Field Values

TRACE_OUTPUT

public static final java.lang.String TRACE_OUTPUT

See Also:

Constant Field Values

TRACE_FILENAME

public static final java.lang.String TRACE_FILENAME

See Also:

Constant Field Values

TRACE_LEVEL

public static final java.lang.String TRACE_LEVEL

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Constant Field Values

TRACE_DEFAULT

public static final java.lang.String TRACE_DEFAULT

See Also:

Constant Field Values

TRACE_HOTPLUG

public static final java.lang.String TRACE_HOTPLUG

See Also:

Constant Field Values

TRACE_XFER

public static final java.lang.String TRACE_XFER

See Also:

Constant Field Values

TRACE_URB

public static final java.lang.String TRACE_URB

See Also:

Constant Field Values

Constructor Detail

LinuxUsbServices

public LinuxUsbServices()
                 throws UsbException

Throws:

UsbException

Method Detail

getRootUsbHub

public UsbHub getRootUsbHub()
                     throws UsbException

Description copied from interface: UsbServices

Get the virtual UsbHub to which all physical Host Controller UsbHubs are attached.

The USB root hub is a special hub at the top of the topology tree. The USB 1.1 specification mentions root hubs in sec 5.2.3, where it states that 'the host includes an embedded hub called the root hub'. The implication of this seems to be that the (hardware) Host Controller device is the root hub, since the Host Controller device 'emulates' a USB hub, and in systems with only one physical Host Controller device, its emulated hub is in effect the root hub. However when multiple Host Controller devices are considered, there are two (2) options that were considered:

1. Have an array or list of the available topology trees, with each physical Host Controller's emulated root hub as the root UsbHub of that particular topology tree. This configuration could be compared to the MS-DOS/Windows decision to assign drive letters to different physical drives (partitions).
2. Have a 'virtual' root hub, which is completely virtual (not associated with any physical device) and is created and managed solely by the javax.usb implementation. This configuration could be compared to the UNIX descision to put all physical drives on 'mount points' under a single 'root' (/) directory filesystem.

The first configuration results in having to maintain a list of different and completely unconnected device topologies. This means a search for a particular device must be performed on all the device topologies. Since a UsbHub already has a list of UsbDevices, and a UsbHub is a UsbDevice, introducing a new, different list is not a desirable action, since it introduces extra unnecessary steps in performing actions, like searching.

As an example, a recursive search for a certain device in the first configuration involves getting the first root UsbHub, getting all its attached UsbDevices, and checking each device; any of those devices which are UsbHubs can be also searched recursively. Then, the entire operation must be performed on the next root UsbHub, and this is repeated for all the root UsbHubs in the array/list. In the second configuration, the virtual root UsbHub is recursively searched in a single operation.

The second configuration is what is used in this API. The implementation is responsible for creating a single root UsbHub which is completely virtual (and available through the UsbServices object). Every UsbHub attached to this virtual root UsbHub corresponds to a physical Host Controller's emulated hub. I.e., the first level of UsbDevices under the virtual root UsbHub are all UsbHubs corresponding to a particular Host Controller on the system. Note that since the root UsbHub is a virtual hub, the number of ports is not posible to specify; so all that is guaranteed is the number of ports is at least equal to the number of UsbHubs attached to the root UsbHub. The number of ports on the virtual root UsbHub may change if UsbHubs are attached or detached (e.g., if a Host Controller is physically hot-removed from the system or hot-plugged, or if its driver is dynamically loaded, or for any other reason a top-level Host Controller's hub is attached/detached). This API specification suggests that the number of ports for the root UsbHub equal the number of directly attached UsbHubs.

Specified by:

getRootUsbHub in interface UsbServices

Overrides:

getRootUsbHub in class AbstractUsbServices

Returns:

The virtual USB root hub

Throws:

UsbException - If there is an error accessing javax.usb.

getApiVersion

public java.lang.String getApiVersion()

Description copied from interface: UsbServices

Get the (minimum) version number of the javax.usb API that this UsbServices implements.

This should correspond to the output of (some version of) the javax.usb.Version.

Specified by:

getApiVersion in interface UsbServices

Returns:

The minimum API version this supports.

getImpVersion

public java.lang.String getImpVersion()

Description copied from interface: UsbServices

Get the version number of the UsbServices implementation.

The format should be ..

Specified by:

getImpVersion in interface UsbServices

Returns:

The version number of this implementation.

getImpDescription

public java.lang.String getImpDescription()

Description copied from interface: UsbServices

Get a description of this UsbServices implementation.

The format is implementation-specific, but should include at least the following:

• The company or individual author(s).
• The license, or license header.
• Contact information.
• The minimum or expected version of Java.
• The Operating System(s) supported (usually one per implementation).
• Any other useful information.

Specified by:

getImpDescription in interface UsbServices

Returns:

Get a description of this UsbServices implementation.