@abstract Create a matching dictionary that specifies an IOService class match.
@discussion A very common matching criteria for IOService is based on its class. IOServiceMatching will create a matching dictionary that specifies any IOService of a class, or its subclasses. The class is specified by C-string name.
@param name The class name, as a const C-string. Class matching is successful on IOService's of this class or any subclass.
@result The matching dictionary created, is returned on success, or zero on failure. The dictionary is commonly passed to IOServiceGetMatchingServices or IOServiceAddNotification which will consume a reference, otherwise it should be released with CFRelease by the caller. */
// Serial devices are instances of class IOSerialBSDClient
printf("IOServiceMatching returned a NULL dictionary.\n");
}else{
/*!
@function CFDictionarySetValue
Sets the value of the key in the dictionary.
@param theDict The dictionary to which the value is to be set. If this
parameter is not a valid mutable CFDictionary, the behavior is
undefined. If the dictionary is a fixed-capacity dictionary and
it is full before this operation, and the key does not exist in
the dictionary, the behavior is undefined.
@param key The key of the value to set into the dictionary. If a key
which matches this key is already present in the dictionary, only
the value is changed ("add if absent, replace if present"). If
no key matches the given key, the key-value pair is added to the
dictionary. If added, the key is retained by the dictionary,
using the retain callback provided
when the dictionary was created. If the key is not of the sort
expected by the key retain callback, the behavior is undefined.
@param value The value to add to or replace into the dictionary. The value
is retained by the dictionary using the retain callback provided
when the dictionary was created, and the previous value if any is
released. If the value is not of the sort expected by the
retain or release callbacks, the behavior is undefined.
*/
CFDictionarySetValue(classesToMatch,
CFSTR(kIOSerialBSDTypeKey),
CFSTR(kIOSerialBSDModemType));
// Each serial device object has a property with key
// kIOSerialBSDTypeKey and a value that is one of kIOSerialBSDAllTypes,
// kIOSerialBSDModemType, or kIOSerialBSDRS232Type. You can experiment with the
// matching by changing the last parameter in the above call to CFDictionarySetValue.
// As shipped, this sample is only interested in modems,
// so add this property to the CFDictionary we're matching on.
// This will find devices that advertise themselves as modems,
// such as built-in and USB modems. However, this match won't find serial modems.
}
/*! @function IOServiceGetMatchingServices
@abstract Look up registered IOService objects that match a matching dictionary.
@discussion This is the preferred method of finding IOService objects currently registered by IOKit. IOServiceAddNotification can also supply this information and install a notification of new IOServices. The matching information used in the matching dictionary may vary depending on the class of service being looked up.
@param masterPort The master port obtained from IOMasterPort().
@param matching A CF dictionary containing matching information, of which one reference is consumed by this function. IOKitLib can contruct matching dictionaries for common criteria with helper functions such as IOServiceMatching, IOOpenFirmwarePathMatching.
@param existing An iterator handle is returned on success, and should be released by the caller when the iteration is finished.
