kern_return_t
IOCreatePlugInInterfaceForService(io_service_t service,
CFUUIDRef pluginType, CFUUIDRef interfaceType,
IOCFPlugInInterface *** theInterface, SInt32 * theScore)
{
CFDictionaryRef plist = 0;
CFArrayRef plists;
CFArrayRef factories;
CFMutableArrayRef candidates;
CFMutableArrayRef scores;
CFIndex index;
CFIndex insert;
CFUUIDRef factoryID;
kern_return_t kr;
SInt32 score;
IOCFPlugInInterface ** interface;
Boolean haveOne;
kr = IOFindPlugIns( service, pluginType,
&factories, &plists );
if( KERN_SUCCESS != kr) {
if (factories) CFRelease(factories);
if (plists) CFRelease(plists);
return( kr );
}
if ((KERN_SUCCESS != kr)
|| (factories == NULL)
|| (0 == CFArrayGetCount(factories))) {
// printf("No factories for type\n");
if (factories) CFRelease(factories);
if (plists) CFRelease(plists);
return( kIOReturnUnsupported );
}
candidates = CFArrayCreateMutable(kCFAllocatorDefault, 0, NULL);
scores = CFArrayCreateMutable(kCFAllocatorDefault, 0, NULL);
// allocate and Probe all
if (candidates && scores) {
CFIndex numfactories = CFArrayGetCount(factories);
for ( index = 0; index < numfactories; index++ ) {
IUnknownVTbl ** iunknown;
factoryID = (CFUUIDRef) CFArrayGetValueAtIndex(factories, index);
iunknown = (IUnknownVTbl **)
CFPlugInInstanceCreate(NULL, factoryID, pluginType);
if (!iunknown) {
// printf("Failed to create instance (link error?)\n");
continue;
}
(*iunknown)->QueryInterface(iunknown, CFUUIDGetUUIDBytes(interfaceType),
(LPVOID *)&interface);
// Now we are done with IUnknown interface
(*iunknown)->Release(iunknown);
if (!interface) {
// printf("Failed to get interface.\n");
continue;
}
if (plists)
plist = (CFDictionaryRef) CFArrayGetValueAtIndex( plists, index );
score = 0; // from property table
kr = (*interface)->Probe(interface, plist, service, &score);
if (kIOReturnSuccess == kr) {
CFIndex numscores = CFArrayGetCount(scores);
for (insert = 0; insert < numscores; insert++) {
if (score > (SInt32) ((intptr_t) CFArrayGetValueAtIndex(scores, insert)))
break;
}
CFArrayInsertValueAtIndex(candidates, insert, (void *) interface);
CFArrayInsertValueAtIndex(scores, insert, (void *) (intptr_t) score);
} else
(*interface)->Release(interface);
}
}
// Start in score order
CFIndex candidatecount = CFArrayGetCount(candidates);
for (haveOne = false, index = 0;
index < candidatecount;
index++) {
Boolean freeIt;
if (plists)
plist = (CFDictionaryRef) CFArrayGetValueAtIndex(plists, index );
interface = (IOCFPlugInInterface **)
CFArrayGetValueAtIndex(candidates, index );
if (!haveOne) {
haveOne = (kIOReturnSuccess == (*interface)->Start(interface, plist, service));
freeIt = !haveOne;
if (haveOne) {
*theInterface = interface;
*theScore = (SInt32) (intptr_t)
CFArrayGetValueAtIndex(scores, index );
}
} else
freeIt = true;
if (freeIt)
(*interface)->Release(interface);
}
if (factories)
CFRelease(factories);
if (plists)
CFRelease(plists);
if (candidates)
CFRelease(candidates);
if (scores)
CFRelease(scores);
// CFRelease(plugin);
return (haveOne ? kIOReturnSuccess : kIOReturnNoResources);
}
static CFPlugInRef MyLoadPlugIn( void )
{
CFPlugInRef newPlugIn;
CFURLRef bundleURL;
CFURLRef plugInURL;
Boolean foundInterface = false;
// Obtain a URL to the PlugIns directory inside our application.
bundleURL = CFBundleCopyBuiltInPlugInsURL( CFBundleGetMainBundle() );
// We just want to load our test plug-in, so append its name to the URL.
plugInURL = CFURLCreateCopyAppendingPathComponent( NULL, bundleURL, CFSTR( kPlugInName ), FALSE );
// Create a CFPlugin using the URL. This step causes the plug-in's types and factories to
// be registered with the system. Note that the plug-in's code is not actually loaded at
// this stage unless the plug-in is using dynamic registration.
newPlugIn = CFPlugInCreate( NULL, plugInURL );
CFRelease( bundleURL );
CFRelease( plugInURL );
// The plug-in was located. Now locate the interface.
if( newPlugIn )
{
CFArrayRef factories;
// See if this plug-in implements the Test type.
factories = CFPlugInFindFactoriesForPlugInTypeInPlugIn( kTestTypeID, newPlugIn );
// If there are factories for the Test type, attempt to get the IUnknown interface.
if ( factories != NULL )
{
CFIndex factoryCount;
CFIndex index;
factoryCount = CFArrayGetCount( factories );
if ( factoryCount > 0 )
{
for ( index = 0 ; (index < factoryCount) && (foundInterface == false) ; index++ )
{
CFUUIDRef factoryID;
// Get the factory ID for the first location in the array of IDs.
factoryID = (CFUUIDRef) CFArrayGetValueAtIndex( factories, index );
if ( factoryID )
{
IUnknownVTbl **iunknown;
// Use the factory ID to get an IUnknown interface. Here the plug-in code is loaded.
iunknown = (IUnknownVTbl **) CFPlugInInstanceCreate( NULL, factoryID, kTestTypeID );
if ( iunknown )
{
// If this is an IUnknown interface, query for the test interface.
(*iunknown)->QueryInterface( iunknown, CFUUIDGetUUIDBytes( kTestInterfaceID ), (LPVOID *)( &gDrawBallInterface ) );
// Now we are done with IUnknown
(*iunknown)->Release( iunknown );
if ( gDrawBallInterface )
{
// We found the interface we need
foundInterface = true;
}
}
}
}
}
}
CFRelease( factories );
}
if ( foundInterface == false )
{
CFRelease( newPlugIn );
newPlugIn = NULL;
}
return( newPlugIn );
}