IOHIDEventServiceQueue.cpp [plain text]
#include <IOKit/system.h>
#include <IOKit/IOLib.h>
#include <IOKit/IODataQueueShared.h>
#include <IOKit/IOMemoryDescriptor.h>
#include <libkern/OSAtomic.h>
#undef enqueue
#include "IOHIDEventServiceQueue.h"
#include "IOHIDEventService.h"
#include "IOHIDEvent.h"
#define super IOSharedDataQueue
OSDefineMetaClassAndStructors( IOHIDEventServiceQueue, super )
IOHIDEventServiceQueue *IOHIDEventServiceQueue::withCapacity(UInt32 size)
{
IOHIDEventServiceQueue *dataQueue = new IOHIDEventServiceQueue;
if (dataQueue) {
if (!dataQueue->initWithCapacity(size)) {
dataQueue->release();
dataQueue = 0;
}
}
return dataQueue;
}
void IOHIDEventServiceQueue::free()
{
if ( _descriptor )
{
_descriptor->release();
_descriptor = 0;
}
super::free();
}
Boolean IOHIDEventServiceQueue::enqueueEvent( IOHIDEvent * event )
{
IOByteCount eventSize = event->getLength();
IOByteCount dataSize = ALIGNED_DATA_SIZE (eventSize, sizeof(uint32_t));
UInt32 head;
UInt32 tail;
UInt32 newTail;
const UInt32 entrySize = dataSize + DATA_QUEUE_ENTRY_HEADER_SIZE;
IODataQueueEntry * entry;
bool queueFull = false;
bool result = true;
head = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED);
tail = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->tail, __ATOMIC_RELAXED);
if ( tail > getQueueSize() || head > getQueueSize() || entrySize < dataSize)
{
return false;
}
if ( tail >= head )
{
if ( (getQueueSize() - tail) >= entrySize )
{
entry = (IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail);
entry->size = dataSize;
event->readBytes(&entry->data, eventSize);
newTail = tail + entrySize;
}
else if ( head > entrySize ) {
dataQueue->queue->size = dataSize;
if ( ( getQueueSize() - tail ) >= DATA_QUEUE_ENTRY_HEADER_SIZE )
{
((IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail))->size = dataSize;
}
event->readBytes(&dataQueue->queue->data, eventSize);
newTail = entrySize;
}
else
{
queueFull = true;
result = false; }
}
else
{
if ( (head - tail) > entrySize )
{
entry = (IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail);
entry->size = dataSize;
event->readBytes(&entry->data, eventSize);
newTail = tail + entrySize;
}
else
{
queueFull = true;
result = false; }
}
if (result) {
__c11_atomic_store((_Atomic UInt32 *)&dataQueue->tail, newTail, __ATOMIC_RELEASE);
}
if ( (event->getOptions() & kHIDDispatchOptionDeliveryNotificationSuppress) == 0) {
if ( (event->getOptions() & kHIDDispatchOptionDeliveryNotificationForce) || ( head == tail )
|| ( __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED) == tail ) || queueFull) {
sendDataAvailableNotification();
}
}
return result;
}
void IOHIDEventServiceQueue::setNotificationPort(mach_port_t port) {
super::setNotificationPort(port);
if (dataQueue->head != dataQueue->tail)
sendDataAvailableNotification();
}
IOMemoryDescriptor * IOHIDEventServiceQueue::getMemoryDescriptor()
{
if (!_descriptor)
_descriptor = super::getMemoryDescriptor();
return _descriptor;
}