AppleSCSIEmulatorEventSource.cpp   [plain text]

/*
  File: AppleSCSIEmulatorEventSource.cpp

  Contains:

  Version: 1.0.0

  Copyright: Copyright (c) 2007 by Apple Inc., All Rights Reserved.

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*/


//-----------------------------------------------------------------------------
//	Includes
//-----------------------------------------------------------------------------

#include "DebugSupport.h"
#include "AppleSCSIEmulatorEventSource.h"
#include "AppleSCSIEmulatorAdapter.h"


// Define superclass
#define super IOEventSource
OSDefineMetaClassAndStructors ( AppleSCSIEmulatorEventSource, IOEventSource )


//-----------------------------------------------------------------------------
//	Create
//-----------------------------------------------------------------------------

AppleSCSIEmulatorEventSource *
AppleSCSIEmulatorEventSource::Create ( OSObject * owner, Action action )
{
	
	AppleSCSIEmulatorEventSource *	es		= NULL;
	bool							result	= false;
	
	es = OSTypeAlloc ( AppleSCSIEmulatorEventSource );
	require_nonzero ( es, ErrorExit );
	
	result = es->Init ( owner, action );
	require ( result, ReleaseEventSource );
	
	return es;
	
	
ReleaseEventSource:
	
	
	es->release ( );
	
	
ErrorExit:
	
	
	return NULL;
	
}


//-----------------------------------------------------------------------------
//	Init
//-----------------------------------------------------------------------------

bool
AppleSCSIEmulatorEventSource::Init ( OSObject * owner, Action action )
{
	
	bool	result = false;
	
	// Initialize the queue head.
	queue_init ( &fResponderQueue );
	
	fLock = IOSimpleLockAlloc ( );
	if ( fLock != NULL )
	{
		
		// Call the superclass.
		result = super::init ( owner, ( IOEventSource::Action ) action );
		
	}
	
	return result;
	
}


//-----------------------------------------------------------------------------
//	AddItemToQueue
//-----------------------------------------------------------------------------

void
AppleSCSIEmulatorEventSource::AddItemToQueue ( SCSIEmulatorRequestBlock * srb )
{
	
	// Take the lock to protect the queue.
	IOSimpleLockLock ( fLock );
	
	// Add the item to the queue.
	queue_enter ( &fResponderQueue, srb, SCSIEmulatorRequestBlock *, fQueueChain );
	
	// Drop the lock.
	IOSimpleLockUnlock ( fLock );
	
	// Wakeup the thread since there's work to do...
	signalWorkAvailable ( );
	
}


//-----------------------------------------------------------------------------
//	RemoveItemFromQueue
//-----------------------------------------------------------------------------

SCSIEmulatorRequestBlock *
AppleSCSIEmulatorEventSource::RemoveItemFromQueue ( void )
{
	
	SCSIEmulatorRequestBlock *	srb = NULL;
	
	// Take the lock to protect the queue.
	IOSimpleLockLock ( fLock );
	
	if ( !queue_empty ( &fResponderQueue ) )
	{
		
		// Remove the item to the queue.
		queue_remove_first ( &fResponderQueue, srb, SCSIEmulatorRequestBlock *, fQueueChain );
	
	}
	
	// Drop the lock.
	IOSimpleLockUnlock ( fLock );
	
	return srb;
	
}


//-----------------------------------------------------------------------------
//	checkForWork
//-----------------------------------------------------------------------------

bool
AppleSCSIEmulatorEventSource::checkForWork ( void )
{
	
	SCSIEmulatorRequestBlock *	srb = NULL;
	
	srb = RemoveItemFromQueue ( );
	while ( srb != NULL )
	{
		
		// Complete it if it's non-NULL.
		( *action ) ( owner, srb->fParallelRequest );
		
		srb = RemoveItemFromQueue ( );
		
	}
	
	return false;
	
}