USB: Use BReferenceable for USB objects.

The "busy" counter functionally amounted to a reference count.
So just turn it into a real one, instead.

src/add-ons/kernel/bus_managers/usb/Device.cpp

@@ -334,7 +334,7 @@ Device::~Device()
 	if (fDefaultPipe != NULL) {
 		fDefaultPipe->PutUSBID(false);
 		fDefaultPipe->CancelQueuedTransfers(true);
-		fDefaultPipe->WaitForUnbusy();
+		fDefaultPipe->WaitForIdle();
 	}
 
 	// Destroy open endpoints. Do not send a device request to unconfigure
@@ -365,7 +365,7 @@ Device::~Device()
 				Interface* interfaceObject =
 					(Interface*)GetStack()->GetObject(interface->handle);
 				if (interfaceObject != NULL)
-					interfaceObject->SetBusy(false);
+					interfaceObject->ReleaseReference();
 				delete interfaceObject;
 				interface->handle = 0;
 			}
@@ -648,7 +648,7 @@ Device::ClearEndpoints(int32 interfaceIndex)
 			usb_endpoint_info* endpoint = &interfaceInfo->endpoint[i];
 			Pipe* pipe = (Pipe*)GetStack()->GetObject(endpoint->handle);
 			if (pipe != NULL)
-				pipe->SetBusy(false);
+				pipe->ReleaseReference();
 			delete pipe;
 			endpoint->handle = 0;
 		}

src/add-ons/kernel/bus_managers/usb/Hub.cpp

@@ -76,7 +76,7 @@ Hub::Hub(Object *parent, int8 hubAddress, uint8 hubPort,
 	} else {
 		TRACE_ALWAYS("no interrupt pipe found\n");
 	}
-	object->SetBusy(false);
+	object->ReleaseReference();
 
 	// Wait some time before powering up the ports
 	if (!isRootHub)

src/add-ons/kernel/bus_managers/usb/Object.cpp

@@ -13,8 +13,7 @@ Object::Object(Stack *stack, BusManager *bus)
 	:	fParent(NULL),
 		fBusManager(bus),
 		fStack(stack),
-		fUSBID(fStack->GetUSBID(this)),
-		fBusy(0)
+		fUSBID(fStack->GetUSBID(this))
 {
 }
 
@@ -23,8 +22,7 @@ Object::Object(Object *parent)
 	:	fParent(parent),
 		fBusManager(parent->GetBusManager()),
 		fStack(parent->GetStack()),
-		fUSBID(fStack->GetUSBID(this)),
-		fBusy(0)
+		fUSBID(fStack->GetUSBID(this))
 {
 }
 
@@ -36,26 +34,26 @@ Object::~Object()
 
 
 void
-Object::PutUSBID(bool waitForUnbusy)
+Object::PutUSBID(bool waitForIdle)
 {
 	if (fUSBID != UINT32_MAX) {
 		fStack->PutUSBID(this);
 		fUSBID = UINT32_MAX;
 	}
 
-	if (waitForUnbusy)
-		WaitForUnbusy();
+	if (waitForIdle)
+		WaitForIdle();
 }
 
 
 void
-Object::WaitForUnbusy()
+Object::WaitForIdle()
 {
 	int32 retries = 20;
-	while (atomic_get(&fBusy) != 0 && retries--)
+	while (CountReferences() != 1 && retries--)
 		snooze(100);
 	if (retries <= 0)
-		panic("USB object did not become unbusy!");
+		panic("USB object did not become idle!");
 }
 
 

src/add-ons/kernel/bus_managers/usb/Pipe.cpp

@@ -375,7 +375,7 @@ ControlPipe::~ControlPipe()
 	// We do this here in case a submitted request is still running.
 	PutUSBID(false);
 	ControlPipe::CancelQueuedTransfers(true);
-	WaitForUnbusy();
+	WaitForIdle();
 
 	if (fNotifySem >= 0)
 		delete_sem(fNotifySem);

src/add-ons/kernel/bus_managers/usb/Stack.cpp

@@ -183,7 +183,7 @@ Stack::GetObject(usb_id id)
 	Object *result = fObjectArray[id];
 
 	if (result != NULL)
-		result->SetBusy(true);
+		result->AcquireReference();
 
 	Unlock();
 	return result;

src/add-ons/kernel/bus_managers/usb/usb.cpp

@@ -195,46 +195,6 @@ bus_std_ops(int32 op, ...)
 }
 
 
-// #pragma mark - ObjectBusyReleaser
-
-
-class ObjectBusyReleaser {
-public:
-	ObjectBusyReleaser(Object* object) : fObject(object) {}
-
-	~ObjectBusyReleaser()
-	{
-		Release();
-	}
-
-	void Release()
-	{
-		if (fObject != NULL) {
-			fObject->SetBusy(false);
-			fObject = NULL;
-		}
-	}
-
-	inline bool IsSet() const
-	{
-		return fObject != NULL;
-	}
-
-	inline Object *Get() const
-	{
-		return fObject;
-	}
-
-	inline Object *operator->() const
-	{
-		return fObject;
-	}
-
-private:
-	Object *fObject;
-};
-
-
 // #pragma mark - public methods
 
 
@@ -266,7 +226,7 @@ const usb_device_descriptor *
 get_device_descriptor(usb_device dev)
 {
 	TRACE_MODULE("get_device_descriptor(%" B_PRId32 ")\n", dev);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return NULL;
 	Device *device = (Device *)object.Get();
@@ -280,7 +240,7 @@ get_nth_configuration(usb_device dev, uint32 index)
 {
 	TRACE_MODULE("get_nth_configuration(%" B_PRId32 ", %" B_PRIu32 ")\n",
 		dev, index);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return NULL;
 	Device *device = (Device *)object.Get();
@@ -293,7 +253,7 @@ const usb_configuration_info *
 get_configuration(usb_device dev)
 {
 	TRACE_MODULE("get_configuration(%" B_PRId32 ")\n", dev);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return NULL;
 	Device *device = (Device *)object.Get();
@@ -308,7 +268,7 @@ set_configuration(usb_device dev,
 {
 	TRACE_MODULE("set_configuration(%" B_PRId32 ", %p)\n", dev,
 		configuration);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 	Device *device = (Device *)object.Get();
@@ -321,7 +281,7 @@ status_t
 set_alt_interface(usb_device dev, const usb_interface_info *interface)
 {
 	TRACE_MODULE("set_alt_interface(%" B_PRId32 ", %p)\n", dev, interface);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 	Device *device = (Device *)object.Get();
@@ -334,7 +294,7 @@ status_t
 set_feature(usb_id handle, uint16 selector)
 {
 	TRACE_MODULE("set_feature(%" B_PRId32 ", %d)\n", handle, selector);
-	ObjectBusyReleaser object(gUSBStack->GetObject(handle));
+	BReference<Object> object(gUSBStack->GetObject(handle), true);
 	if (!object.IsSet())
 		return B_DEV_INVALID_PIPE;
 
@@ -346,7 +306,7 @@ status_t
 clear_feature(usb_id handle, uint16 selector)
 {
 	TRACE_MODULE("clear_feature(%" B_PRId32 ", %d)\n", handle, selector);
-	ObjectBusyReleaser object(gUSBStack->GetObject(handle));
+	BReference<Object> object(gUSBStack->GetObject(handle), true);
 	if (!object.IsSet())
 		return B_DEV_INVALID_PIPE;
 
@@ -361,7 +321,7 @@ get_status(usb_id handle, uint16 *status)
 	if (!status)
 		return B_BAD_VALUE;
 
-	ObjectBusyReleaser object(gUSBStack->GetObject(handle));
+	BReference<Object> object(gUSBStack->GetObject(handle), true);
 	if (!object.IsSet())
 		return B_DEV_INVALID_PIPE;
 
@@ -376,7 +336,7 @@ get_descriptor(usb_device dev, uint8 type, uint8 index, uint16 languageID,
 	TRACE_MODULE("get_descriptor(%" B_PRId32 ", 0x%02x, 0x%02x, 0x%04x, %p, "
 		"%" B_PRIuSIZE ", %p)\n",
 		dev, type, index, languageID, data, dataLength, actualLength);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 	Device *device = (Device *)object.Get();
@@ -393,7 +353,7 @@ send_request(usb_device dev, uint8 requestType, uint8 request,
 	TRACE_MODULE("send_request(%" B_PRId32 ", 0x%02x, 0x%02x, 0x%04x, 0x%04x, "
 		"%d, %p, %p)\n", dev, requestType, request, value, index, length,
 		data, actualLength);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 	Device *device = (Device *)object.Get();
@@ -411,7 +371,7 @@ queue_request(usb_device dev, uint8 requestType, uint8 request,
 	TRACE_MODULE("queue_request(%" B_PRId32 ", 0x%02x, 0x%02x, 0x%04x, 0x%04x,"
 		" %u, %p, %p, %p)\n", dev, requestType, request, value, index,
 		length, data, callback,	callbackCookie);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 	Device *device = (Device *)object.Get();
@@ -427,7 +387,7 @@ queue_interrupt(usb_pipe pipe, void *data, size_t dataLength,
 {
 	TRACE_MODULE("queue_interrupt(%" B_PRId32 ", %p, %ld, %p, %p)\n",
 		pipe, data, dataLength, callback, callbackCookie);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_INTERRUPT_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -442,7 +402,7 @@ queue_bulk(usb_pipe pipe, void *data, size_t dataLength,
 {
 	TRACE_MODULE("queue_bulk(%" B_PRId32 ", %p, %" B_PRIuSIZE ", %p, %p)\n",
 		pipe, data, dataLength, callback, callbackCookie);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_BULK_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -457,7 +417,7 @@ queue_bulk_v(usb_pipe pipe, iovec *vector, size_t vectorCount,
 {
 	TRACE_MODULE("queue_bulk_v(%" B_PRId32 ", %p, %" B_PRIuSIZE " %p, %p)\n",
 		pipe, vector, vectorCount, callback, callbackCookie);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_BULK_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -472,7 +432,7 @@ queue_bulk_v_physical(usb_pipe pipe, physical_entry *vector, size_t vectorCount,
 {
 	TRACE_MODULE("queue_bulk_v_physical(%" B_PRId32 ", %p, %" B_PRIuSIZE
 		", %p, %p)\n", pipe, vector, vectorCount, callback, callbackCookie);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_BULK_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -491,7 +451,7 @@ queue_isochronous(usb_pipe pipe, void *data, size_t dataLength,
 		"%" B_PRId32 ", %p, 0x%08" B_PRIx32 ", %p, %p)\n",
 		pipe, data, dataLength, packetDesc, packetCount, startingFrameNumber,
 		flags, callback, callbackCookie);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_ISO_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -507,7 +467,7 @@ set_pipe_policy(usb_pipe pipe, uint8 maxQueuedPackets,
 {
 	TRACE_MODULE("set_pipe_policy(%" B_PRId32 ", %d, %d, %d)\n", pipe,
 		maxQueuedPackets, maxBufferDurationMS, sampleSize);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_ISO_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -520,7 +480,7 @@ status_t
 cancel_queued_transfers(usb_pipe pipe)
 {
 	TRACE_MODULE("cancel_queued_transfers(%" B_PRId32 ")\n", pipe);
-	ObjectBusyReleaser object(gUSBStack->GetObject(pipe));
+	BReference<Object> object(gUSBStack->GetObject(pipe), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_PIPE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -532,7 +492,7 @@ status_t
 cancel_queued_requests(usb_device dev)
 {
 	TRACE_MODULE("cancel_queued_requests(%" B_PRId32 ")\n", dev);
-	ObjectBusyReleaser object(gUSBStack->GetObject(dev));
+	BReference<Object> object(gUSBStack->GetObject(dev), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 	 Device *device = (Device *)object.Get();
@@ -549,7 +509,7 @@ usb_ioctl(uint32 opcode, void *buffer, size_t bufferSize)
 
 	switch (opcode) {
 		case 'DNAM': {
-			ObjectBusyReleaser object(gUSBStack->GetObject(*(usb_id *)buffer));
+			BReference<Object> object(gUSBStack->GetObject(*(usb_id *)buffer), true);
 			if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 				return B_BAD_VALUE;
 			Device *device = (Device *)object.Get();
@@ -589,7 +549,7 @@ get_nth_child(usb_device _hub, uint8 index, usb_device *childDevice)
 	if (!childDevice)
 		return B_BAD_VALUE;
 
-	ObjectBusyReleaser object(gUSBStack->GetObject(_hub));
+	BReference<Object> object(gUSBStack->GetObject(_hub), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_HUB) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -615,7 +575,7 @@ get_device_parent(usb_device _device, usb_device *parentHub, uint8 *portIndex)
 	if (!parentHub || !portIndex)
 		return B_BAD_VALUE;
 
-	ObjectBusyReleaser object(gUSBStack->GetObject(_device));
+	BReference<Object> object(gUSBStack->GetObject(_device), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_DEVICE) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -639,7 +599,7 @@ get_device_parent(usb_device _device, usb_device *parentHub, uint8 *portIndex)
 status_t
 reset_port(usb_device _hub, uint8 portIndex)
 {
-	ObjectBusyReleaser object(gUSBStack->GetObject(_hub));
+	BReference<Object> object(gUSBStack->GetObject(_hub), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_HUB) == 0)
 		return B_DEV_INVALID_PIPE;
 
@@ -651,7 +611,7 @@ reset_port(usb_device _hub, uint8 portIndex)
 status_t
 disable_port(usb_device _hub, uint8 portIndex)
 {
-	ObjectBusyReleaser object(gUSBStack->GetObject(_hub));
+	BReference<Object> object(gUSBStack->GetObject(_hub), true);
 	if (!object.IsSet() || (object->Type() & USB_OBJECT_HUB) == 0)
 		return B_DEV_INVALID_PIPE;
 

src/add-ons/kernel/bus_managers/usb/usb_private.h

@@ -137,10 +137,10 @@ public:
 		usb_id							GetUSBID(Object *object);
 		void							PutUSBID(Object *object);
 
-		// This sets the object as busy; the caller must set it un-busy.
+		// Acquires a reference to the object.
 		Object *						GetObject(usb_id id);
 
-		// only for the kernel debugger
+		// only for the kernel debugger (and doesn't acquire a reference)
 		Object *						GetObjectNoLock(usb_id id) const;
 
 		void							AddBusManager(BusManager *bus);
@@ -270,7 +270,7 @@ private:
 };
 
 
-class Object {
+class Object : public BReferenceable {
 public:
 										Object(Stack *stack, BusManager *bus);
 										Object(Object *parent);
@@ -283,8 +283,6 @@ virtual									~Object();
 		Stack *							GetStack() const { return fStack; }
 
 		usb_id							USBID() const { return fUSBID; }
-		void							SetBusy(bool busy)
-											{ atomic_add(&fBusy, busy ? 1 : -1); }
 
 virtual	uint32							Type() const { return USB_OBJECT_NONE; }
 virtual	const char *					TypeName() const { return "object"; }
@@ -295,15 +293,14 @@ virtual	status_t						ClearFeature(uint16 selector);
 virtual	status_t						GetStatus(uint16 *status);
 
 protected:
-		void							PutUSBID(bool waitForUnbusy = true);
-		void							WaitForUnbusy();
+		void							PutUSBID(bool waitForIdle = true);
+		void							WaitForIdle();
 
 private:
 		Object *						fParent;
 		BusManager *					fBusManager;
 		Stack *							fStack;
 		usb_id							fUSBID;
-		int32							fBusy;
 };