iokit/IOKit/IORegistryEntry.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
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  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  24  *
  25  * HISTORY
  26  *
  27  */
  28
  29
  30 #ifndef _IOKIT_IOREGISTRYENTRY_H
  31 #define _IOKIT_IOREGISTRYENTRY_H
  32
  33 #include <IOKit/IOTypes.h>
  34 #include <libkern/c++/OSContainers.h>
  35
  36
  37 extern const OSSymbol * gIONameKey;
  38 extern const OSSymbol * gIOLocationKey;
  39
  40 class IORegistryEntry;
  41 class IORegistryPlane;
  42 class IORegistryIterator;
  43
  44 typedef void (*IORegistryEntryApplierFunction)(IORegistryEntry * entry,
  45                                                void * context);
  46
  47 enum {
  48     kIORegistryIterateRecursively       = 0x00000001,
  49     kIORegistryIterateParents           = 0x00000002
  50 };
  51
  52 /*! @class IORegistryEntry : public OSObject
  53     @abstract The base class for all objects in the registry.
  54     @discussion The IORegistryEntry base class provides functions for describing graphs of connected registry entries, each with a dictionary-based property table. Entries may be connected in different planes, with differing topologies. Access to the registry is protected against multiple threads. Inside the kernel planes are specified with plane objects and are published by the creator - IOService exports the gIOServicePlane plane object for example. Non kernel clients specify planes by their name.
  55 */
  56
  57 class IORegistryEntry : public OSObject
  58 {
  59     friend class IORegistryIterator;
  60
  61     OSDeclareDefaultStructors(IORegistryEntry)
  62
  63 protected:
  64 /*! @struct ExpansionData
  65     @discussion This structure will be used to expand the capablilties of this class in the future.
  66     */
  67     struct ExpansionData { };
  68
  69 /*! @var reserved
  70     Reserved for future use.  (Internal use only)  */
  71     ExpansionData * reserved;
  72
  73 private:
  74
  75     OSDictionary *      fRegistryTable;
  76     OSDictionary *      fPropertyTable;
  77
  78 public:
  79     /* methods available in Mac OS X 10.1 or later */
  80
  81 /*! @function copyProperty
  82     @abstract Synchronized method to obtain a property from a registry entry or one of its parents (or children) in the hierarchy. Available in Mac OS X 10.1 or later.
  83     @discussion This method will search for a property, starting first with this registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will lookup and return the value of the property, using the OSDictionary::getObject semantics. The iteration keeps track of entries that have been recursed into previously to avoid loops. This method is synchronized with other IORegistryEntry accesses to the property table(s).
  84     @param aKey The property's name as a C-string.
  85     @param plane The plane to iterate over, eg. gIOServicePlane.
  86     @param options kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard getProperty() call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.
  87     @result The property value found, or zero. A reference on any found property is returned to caller, which should be released. */
  88
  89     virtual OSObject * copyProperty( const char *           aKey,
  90                                      const IORegistryPlane * plane,
  91                                      IOOptionBits            options =
  92                                         kIORegistryIterateRecursively |
  93                                         kIORegistryIterateParents) const;
  94     OSMetaClassDeclareReservedUsed(IORegistryEntry, 0);
  95
  96 /*! @function copyProperty
  97     @abstract Synchronized method to obtain a property from a registry entry or one of its parents (or children) in the hierarchy. Available in Mac OS X 10.1 or later.
  98     @discussion This method will search for a property, starting first with this registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will lookup and return the value of the property, using the OSDictionary::getObject semantics. The iteration keeps track of entries that have been recursed into previously to avoid loops. This method is synchronized with other IORegistryEntry accesses to the property table(s).
  99     @param aKey The property's name as an OSString.
 100     @param plane The plane to iterate over, eg. gIOServicePlane.
 101     @param options kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard getProperty() call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.
 102     @result The property value found, or zero. A reference on any found property is returned to caller, which should be released. */
 103
 104     virtual OSObject * copyProperty( const OSString *        aKey,
 105                                      const IORegistryPlane * plane,
 106                                      IOOptionBits            options =
 107                                         kIORegistryIterateRecursively |
 108                                         kIORegistryIterateParents) const;
 109     OSMetaClassDeclareReservedUsed(IORegistryEntry, 1);
 110
 111 /*! @function copyProperty
 112     @abstract Synchronized method to obtain a property from a registry entry or one of its parents (or children) in the hierarchy. Available in Mac OS X 10.1 or later.
 113     @discussion This method will search for a property, starting first with this registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will lookup and return the value of the property, using the OSDictionary::getObject semantics. The iteration keeps track of entries that have been recursed into previously to avoid loops. This method is synchronized with other IORegistryEntry accesses to the property table(s).
 114     @param aKey The property's name as an OSSymbol.
 115     @param plane The plane to iterate over, eg. gIOServicePlane.
 116     @param options kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard getProperty() call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.
 117     @result The property value found, or zero. A reference on any found property is returned to caller, which should be released. */
 118
 119     virtual OSObject * copyProperty( const OSSymbol *        aKey,
 120                                      const IORegistryPlane * plane,
 121                                      IOOptionBits            options =
 122                                         kIORegistryIterateRecursively |
 123                                         kIORegistryIterateParents) const;
 124     OSMetaClassDeclareReservedUsed(IORegistryEntry, 2);
 125
 126 /*! @function copyParentEntry
 127     @abstract Returns an registry entry's first parent entry in a plane. Available in Mac OS X 10.1 or later.
 128     @discussion This function will return the parent to which a registry entry was first attached. Since the majority of registry entrys have only one provider, this is a useful simplification.
 129     @param plane The plane object.
 130     @result Returns the first parent of the registry entry, or zero if the entry is not attached into the registry in that plane. A reference on the entry is returned to caller, which should be released. */
 131
 132     virtual IORegistryEntry * copyParentEntry( const IORegistryPlane * plane ) const;
 133     OSMetaClassDeclareReservedUsed(IORegistryEntry, 3);
 134
 135 /*! @function copyChildEntry
 136     @abstract Returns an registry entry's first child entry in a plane. Available in Mac OS X 10.1 or later.
 137     @discussion This function will return the child which first attached to a registry entry.
 138     @param plane The plane object.
 139     @result Returns the first child of the registry entry, or zero if the entry is not attached into the registry in that plane. A reference on the entry is returned to caller, which should be released. */
 140
 141     virtual IORegistryEntry * copyChildEntry( const IORegistryPlane * plane ) const;
 142     OSMetaClassDeclareReservedUsed(IORegistryEntry, 4);
 143
 144     /* method available in Mac OS X 10.4 or later */
 145 /*!
 146     @typedef Action
 147     @discussion Type and arguments of callout C function that is used when
 148 a runCommand is executed by a client.  Cast to this type when you want a C++
 149 member function to be used.  Note the arg1 - arg3 parameters are passed straight pass through to the action callout.
 150     @param target
 151         Target of the function, can be used as a refcon.  Note if a C++ function
 152 was specified, this parameter is implicitly the first parameter in the target
 153 member function's parameter list.
 154     @param arg0 Argument to action from run operation.
 155     @param arg1 Argument to action from run operation.
 156     @param arg2 Argument to action from run operation.
 157     @param arg3 Argument to action from run operation.
 158 */
 159     typedef IOReturn (*Action)(OSObject *target,
 160                                void *arg0, void *arg1,
 161                                void *arg2, void *arg3);
 162
 163 /*! @function runPropertyAction
 164     @abstract Single thread a call to an action w.r.t. the property lock
 165     @discussion Client function that causes the given action to be called in a manner that syncrhonises with the registry iterators and serialisers.  This functin can be used to synchronously manipulate the property table of this nub
 166     @param action Pointer to function to be executed in work-loop context.
 167     @param arg0 Parameter for action parameter, defaults to 0.
 168     @param arg1 Parameter for action parameter, defaults to 0.
 169     @param arg2 Parameter for action parameter, defaults to 0.
 170     @param arg3 Parameter for action parameter, defaults to 0.
 171     @result Returns the value of the Action callout.
 172 */
 173     virtual IOReturn runPropertyAction(Action action, OSObject *target,
 174                                void *arg0 = 0, void *arg1 = 0,
 175                                void *arg2 = 0, void *arg3 = 0);
 176     OSMetaClassDeclareReservedUsed(IORegistryEntry, 5);
 177
 178 private:
 179
 180     OSMetaClassDeclareReservedUnused(IORegistryEntry, 6);
 181     OSMetaClassDeclareReservedUnused(IORegistryEntry, 7);
 182     OSMetaClassDeclareReservedUnused(IORegistryEntry, 8);
 183     OSMetaClassDeclareReservedUnused(IORegistryEntry, 9);
 184     OSMetaClassDeclareReservedUnused(IORegistryEntry, 10);
 185     OSMetaClassDeclareReservedUnused(IORegistryEntry, 11);
 186     OSMetaClassDeclareReservedUnused(IORegistryEntry, 12);
 187     OSMetaClassDeclareReservedUnused(IORegistryEntry, 13);
 188     OSMetaClassDeclareReservedUnused(IORegistryEntry, 14);
 189     OSMetaClassDeclareReservedUnused(IORegistryEntry, 15);
 190     OSMetaClassDeclareReservedUnused(IORegistryEntry, 16);
 191     OSMetaClassDeclareReservedUnused(IORegistryEntry, 17);
 192     OSMetaClassDeclareReservedUnused(IORegistryEntry, 18);
 193     OSMetaClassDeclareReservedUnused(IORegistryEntry, 19);
 194     OSMetaClassDeclareReservedUnused(IORegistryEntry, 20);
 195     OSMetaClassDeclareReservedUnused(IORegistryEntry, 21);
 196     OSMetaClassDeclareReservedUnused(IORegistryEntry, 22);
 197     OSMetaClassDeclareReservedUnused(IORegistryEntry, 23);
 198     OSMetaClassDeclareReservedUnused(IORegistryEntry, 24);
 199     OSMetaClassDeclareReservedUnused(IORegistryEntry, 25);
 200     OSMetaClassDeclareReservedUnused(IORegistryEntry, 26);
 201     OSMetaClassDeclareReservedUnused(IORegistryEntry, 27);
 202     OSMetaClassDeclareReservedUnused(IORegistryEntry, 28);
 203     OSMetaClassDeclareReservedUnused(IORegistryEntry, 29);
 204     OSMetaClassDeclareReservedUnused(IORegistryEntry, 30);
 205     OSMetaClassDeclareReservedUnused(IORegistryEntry, 31);
 206
 207 public:
 208
 209     /* Registry accessors */
 210
 211 /*! @function getRegistryRoot
 212     @abstract Returns a pointer to the root instance of the registry.
 213     @discussion This method provides an accessor to the root of the registry for the machine. The root may be passed to a registry iterator when iterating a plane, and contains properties that describe the available planes, and diagnostic information for IOKit. Keys for these properties are in IOKitKeys.h.
 214     @result A pointer to the IORegistryEntry root instance. It should not be released by the caller. */
 215
 216     static IORegistryEntry * getRegistryRoot( void );
 217
 218 /*! @function getGenerationCount
 219     @abstract Returns an generation count for all registry changing operations.
 220     @discussion This method provides an accessor to the current generation count (or seed) of the registry which changes when any topology change occurs in the registry - this does not include property table changes. It may be used to invalidate any caching of the results from IORegistryEntry methods.
 221     @result An integer generation count. */
 222
 223     static SInt32            getGenerationCount( void );
 224
 225 /*! @function getPlane
 226     @abstract Looks up the plane object by a C-string name.
 227     @discussion Planes are usually provided as globals by the creator, eg. gIOServicePlane, gIODeviceTreePlane, or gIOAudioPlane, however they may also be looked up by name with this method.
 228     @result A pointer to the plane object, or zero if no such plane exists. The returned plane should not be released. */
 229
 230     static const IORegistryPlane * getPlane( const char * name );
 231
 232     /* Registry Entry allocation & init */
 233
 234 /*! @function init
 235     @abstract Standard init method for all IORegistryEntry subclasses.
 236     @discussion A registry entry must be initialized with this method before it can be used. A property dictionary may passed and will be retained by this method for use as the registry entry's property table, or an empty one will be created.
 237     @param A dictionary that will become the registry entry's property table (retaining it), or zero which will cause an empty property table to be created.
 238     @result true on success, or false on a resource failure. */
 239
 240     virtual bool init( OSDictionary * dictionary = 0 );
 241
 242 /*! @function free
 243     @abstract Standard free method for all IORegistryEntry subclasses.
 244     @discussion This method will release any resources of the entry, in particular its property table. Note that the registry entry must always be detached from the registry before free may be called, and subclasses (namely IOService) will have additional protocols for removing registry entries. free should never need be called directly. */
 245
 246     virtual void free( void );
 247
 248 /*! @function setPropertyTable
 249     @abstract Replace a registry entry's property table.
 250     @discussion This method will release the current property table of a the entry and replace it with another, retaining the new property table.
 251     @param dict The new dictionary to be used as the entry's property table. */
 252
 253     virtual void setPropertyTable( OSDictionary * dict );
 254
 255     /* Synchronized property accessors; wrappers to OSDictionary
 256      * plus property creation helpers */
 257
 258 /*! @function setProperty
 259     @abstract Synchronized method to add a property to a registry entry's property table.
 260     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 261     @param aKey The properties name as an OSSymbol.
 262     @param anObject The property value.
 263     @result true on success or false on a resource failure. */
 264
 265     virtual bool setProperty(const OSSymbol * aKey, OSObject * anObject);
 266
 267 /*! @function setProperty
 268     @abstract Synchronized method to add a property to a registry entry's property table.
 269     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 270     @param aKey The property's name as an OSString.
 271     @param anObject The property value.
 272     @result true on success or false on a resource failure. */
 273
 274     virtual bool setProperty(const OSString * aKey, OSObject * anObject);
 275
 276 /*! @function setProperty
 277     @abstract Synchronized method to add a property to a registry entry's property table.
 278     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 279     @param aKey The property's name as a C-string.
 280     @param anObject The property value.
 281     @result true on success or false on a resource failure. */
 282
 283     virtual bool setProperty(const char * aKey, OSObject * anObject);
 284
 285 /*! @function setProperty
 286     @abstract Synchronized method to construct and add a OSString property to a registry entry's property table.
 287     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table. The property is created as an OSString from the supplied C-string, set in the property table with the given name, and released.
 288     @param aKey The property's name as a C-string.
 289     @param aString The property value as a C-string.
 290     @result true on success or false on a resource failure. */
 291
 292     virtual bool setProperty(const char * aKey, const char * aString);
 293
 294 /*! @function setProperty
 295     @abstract Synchronized method to construct and add an OSBoolean property to a registry entry's property table.
 296     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table. The property is created as an OSBoolean from the supplied value, set in the property table with the given name, and released.
 297     @param aKey The property's name as a C-string.
 298     @param aBoolean The property's boolean value.
 299     @result true on success or false on a resource failure. */
 300
 301     virtual bool setProperty(const char * aKey, bool aBoolean);
 302
 303 /*! @function setProperty
 304     @abstract Synchronized method to construct and add an OSNumber property to a registry entry's property table.
 305     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table. The property is created as an OSNumber from the supplied value and size, set in the property table with the given name, and released.
 306     @param aKey The property's name as a C-string.
 307     @param aValue The property's numeric value.
 308     @param aNumberOfBits The property's size in bits, for OSNumber.
 309     @result true on success or false on a resource failure. */
 310
 311     virtual bool setProperty( const char *       aKey,
 312                               unsigned long long aValue,
 313                               unsigned int       aNumberOfBits);
 314
 315 /*! @function setProperty
 316     @abstract Synchronized method to construct and add an OSData property to a registry entry's property table.
 317     @discussion This method will add or replace a property in a registry entry's property table, using the OSDictionary::setObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table. The property is created as an OSData copied from the supplied date and length, set in the property table with the given name, and released.
 318     @param aKey The property's name as a C-string.
 319     @param bytes The property's value as a pointer. OSData will copy this data.
 320     @param length The property's size in bytes, for OSData.
 321     @result true on success or false on a resource failure. */
 322
 323     virtual bool setProperty( const char *       aKey,
 324                               void *             bytes,
 325                               unsigned int       length);
 326
 327 /*! @function removeProperty
 328     @abstract Synchronized method to remove a property from a registry entry's property table.
 329     @discussion This method will remove a property from a registry entry's property table, using the OSDictionary::removeObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 330     @param aKey The property's name as an OSSymbol. */
 331
 332     virtual void removeProperty( const OSSymbol * aKey);
 333
 334 /*! @function removeProperty
 335     @abstract Synchronized method to remove a property from a registry entry's property table.
 336     @discussion This method will remove a property from a registry entry's property table, using the OSDictionary::removeObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 337     @param aKey The property's name as an OSString. */
 338
 339     virtual void removeProperty( const OSString * aKey);
 340
 341 /*! @function removeProperty
 342     @abstract Synchronized method to remove a property from a registry entry's property table.
 343     @discussion This method will remove a property from a registry entry's property table, using the OSDictionary::removeObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 344     @param aKey The property's name as a C-string. */
 345
 346     virtual void removeProperty( const char * aKey);
 347
 348 /*! @function getProperty
 349     @abstract Synchronized method to obtain a property from a registry entry's property table.
 350     @discussion This method will lookup a property in a registry entry's property table, using the OSDictionary::getObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 351     @param aKey The property's name as an OSSymbol.
 352     @result The property value found, or zero. */
 353
 354     virtual OSObject * getProperty( const OSSymbol * aKey) const;
 355
 356 /*! @function getProperty
 357     @abstract Synchronized method to obtain a property from a registry entry's property table.
 358     @discussion This method will lookup a property in a registry entry's property table, using the OSDictionary::getObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 359     @param aKey The property's name as an OSString.
 360     @result The property value found, or zero. */
 361
 362     virtual OSObject * getProperty( const OSString * aKey) const;
 363
 364 /*! @function getProperty
 365     @abstract Synchronized method to obtain a property from a registry entry's property table.
 366     @discussion This method will lookup a property in a registry entry's property table, using the OSDictionary::getObject semantics. This method is synchronized with other IORegistryEntry accesses to the property table.
 367     @param aKey The property's name as a C-string.
 368     @result The property value found, or zero. */
 369
 370     virtual OSObject * getProperty( const char * aKey) const;
 371
 372 /*! @function getProperty
 373     @abstract Synchronized method to obtain a property from a registry entry or one of its parents (or children) in the hierarchy.
 374     @discussion This method will search for a property, starting first with this registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will lookup and return the value of the property, using the OSDictionary::getObject semantics. The iteration keeps track of entries that have been recursed into previously to avoid loops. This method is synchronized with other IORegistryEntry accesses to the property table(s).
 375     @param aKey The property's name as an OSSymbol.
 376     @param plane The plane to iterate over, eg. gIOServicePlane.
 377     @param options kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard getProperty() call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.
 378     @result The property value found, or zero. */
 379
 380     virtual OSObject * getProperty( const OSSymbol *        aKey,
 381                                     const IORegistryPlane * plane,
 382                                     IOOptionBits            options =
 383                                         kIORegistryIterateRecursively |
 384                                         kIORegistryIterateParents) const;
 385
 386 /*! @function getProperty
 387     @abstract Synchronized method to obtain a property from a registry entry or one of its parents (or children) in the hierarchy.
 388     @discussion This method will search for a property, starting first with this registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will lookup and return the value of the property, using the OSDictionary::getObject semantics. The iteration keeps track of entries that have been recursed into previously to avoid loops. This method is synchronized with other IORegistryEntry accesses to the property table(s).
 389     @param aKey The property's name as an OSString.
 390     @param plane The plane to iterate over, eg. gIOServicePlane.
 391     @param options kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard getProperty() call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.
 392     @result The property value found, or zero. */
 393
 394     virtual OSObject * getProperty( const OSString *        aKey,
 395                                     const IORegistryPlane * plane,
 396                                     IOOptionBits            options =
 397                                         kIORegistryIterateRecursively |
 398                                         kIORegistryIterateParents) const;
 399
 400 /*! @function getProperty
 401     @abstract Synchronized method to obtain a property from a registry entry or one of its parents (or children) in the hierarchy.
 402     @discussion This method will search for a property, starting first with this registry entry's property table, then iterating recusively through either the parent registry entries or the child registry entries of this entry. Once the first occurrence is found, it will lookup and return the value of the property, using the OSDictionary::getObject semantics. The iteration keeps track of entries that have been recursed into previously to avoid loops. This method is synchronized with other IORegistryEntry accesses to the property table(s).
 403     @param aKey The property's name as a C-string.
 404     @param plane The plane to iterate over, eg. gIOServicePlane.
 405     @param options kIORegistryIterateRecursively may be set to recurse automatically into the registry hierarchy. Without this option, this method degenerates into the standard getProperty() call. kIORegistryIterateParents may be set to iterate the parents of the entry, in place of the children.
 406     @result The property value found, or zero. */
 407
 408     virtual OSObject * getProperty( const char *            aKey,
 409                                     const IORegistryPlane * plane,
 410                                     IOOptionBits            options =
 411                                         kIORegistryIterateRecursively |
 412                                         kIORegistryIterateParents) const;
 413
 414 /*! @function copyProperty
 415     @abstract Synchronized method to obtain a property from a registry entry's property table.
 416     @discussion This method will lookup a property in a registry entry's property table, using the OSDictionary::getObject semantics, and return a reference to the caller. This method is synchronized with other IORegistryEntry accesses to the property table.
 417     @param aKey The property's name as an OSSymbol.
 418     @result The property value found, or zero. It should be released by the caller. */
 419
 420     virtual OSObject * copyProperty( const OSSymbol * aKey) const;
 421
 422 /*! @function copyProperty
 423     @abstract Synchronized method to obtain a property from a registry entry's property table.
 424     @discussion This method will lookup a property in a registry entry's property table, using the OSDictionary::getObject semantics, and return a reference to the caller. This method is synchronized with other IORegistryEntry accesses to the property table.
 425     @param aKey The property's name as an OSString.
 426     @result The property value found, or zero. It should be released by the caller. */
 427
 428     virtual OSObject * copyProperty( const OSString * aKey) const;
 429
 430 /*! @function copyProperty
 431     @abstract Synchronized method to obtain a property from a registry entry's property table.
 432     @discussion This method will lookup a property in a registry entry's property table, using the OSDictionary::getObject semantics, and return a reference to the caller. This method is synchronized with other IORegistryEntry accesses to the property table.
 433     @param aKey The property's name as a C-string.
 434     @result The property value found, or zero. It should be released by the caller. */
 435
 436     virtual OSObject * copyProperty( const char * aKey) const;
 437
 438 /*! @function dictionaryWithProperties
 439     @abstract Synchronized method to obtain copy a registry entry's property table.
 440     @discussion This method will copy a registry entry's property table, using the OSDictionary::withDictionary semantics. This method is synchronized with other IORegistryEntry accesses to the property table. Since OSDictionary will only copy property values by reference, synchronization is not guaranteed to any collection values.
 441     @result The created dictionary, or zero on a resource value. It should be released by the caller. */
 442
 443     virtual OSDictionary * dictionaryWithProperties( void ) const;
 444
 445 /*! @function serializeProperties
 446     @abstract Synchronized method to serialize a registry entry's property table.
 447     @discussion This method will serialize a registry entry's property table, using the OSDictionary::serialize semantics. This method is synchronized with other IORegistryEntry accesses to the property table. Many non-kernel clients of IOKit read information from the registry via properties, and will invoke this method in a registry entry to create a serialization of all the entry's properties, which is then reconstructed in the client's task as a CFDictionary. This method may be intercepted by subclasses to update their properties or implement a different serialization method, though it is usually better to implement such functionality by creating objects in the property table and implementing their serialize methods, avoiding any need to implement serializeProperties.
 448     @param serialize The OSSerialize instance representing the serialization request.
 449     @result True on success, false otherwise. */
 450
 451     virtual bool serializeProperties( OSSerialize * serialize ) const;
 452
 453     /* Unsynchronized(!) property table access */
 454
 455 /*! @function getPropertyTable
 456     @abstract Unsynchronized accessor to a registry entry's property table.
 457     @discussion This method will return a pointer to the live property table as an OSDictionery. Its use is not recommended in most cases, instead use the synchronized accessors and helper functions of IORegistryEntry to access properties. It can only safely be used by one thread, which usually means it can only be used before a registry entry is entered into the registry.
 458     @result A pointer to the property table as an OSDictionary. The pointer is valid while the registry entry is retained, and should not be released by the caller. */
 459
 460     /* inline */ OSDictionary * getPropertyTable( void ) const;
 461             /* { return(fPropertyTable); } */
 462
 463     /* Set properties from user level, to be overridden if supported */
 464
 465 /*! @function setProperties
 466     @abstract Optionally supported external method to set properties in a registry entry.
 467     @discussion This method is not implemented by IORegistryEntry, but is available to kernel and non-kernel clients to set properties in a registry entry. IOUserClient provides connection based, more controlled access to this functionality and may be more appropriate for many uses, since there is no differentiation between clients available to this method.
 468     @param properties Any OSObject subclass, to be interpreted by the implementing method - for example an OSDictionary, OSData etc. may all be appropriate.
 469     @result An IOReturn code to be returned to the caller. */
 470
 471     virtual IOReturn setProperties( OSObject * properties );
 472
 473     /* Topology */
 474
 475 /*! @function getParentIterator
 476     @abstract Returns an iterator over an registry entry's parent entries in a specified plane.
 477     @param plane The plane object.
 478     @result Returns an iterator over the parents of the registry entry, or zero if there is a resource failure. The iterator must be released when the iteration is finished. All objects returned by the iteration are retained while the iterator is valid, though they may no longer be attached during the iteration. */
 479
 480     virtual OSIterator * getParentIterator( const IORegistryPlane * plane )
 481                                                                         const;
 482     virtual void applyToParents( IORegistryEntryApplierFunction applier,
 483                                  void * context,
 484                                  const IORegistryPlane * plane ) const;
 485
 486 /*! @function getParentEntry
 487     @abstract Returns an registry entry's first parent entry in a plane.
 488     @discussion This function will return the parent to which a registry entry was first attached. Since the majority of registry entrys have only one provider, this is a useful simplification.
 489     @param plane The plane object.
 490     @result Returns the first parent of the registry entry, or zero if the entry is not attached into the registry in that plane. The parent is retained while the entry is attached, and should not be released by the caller. */
 491
 492     virtual IORegistryEntry * getParentEntry( const IORegistryPlane * plane ) const;
 493
 494 /*! @function getChildIterator
 495     @abstract Returns an iterator over an registry entry's child entries in a plane.
 496     @discussion This method creates an iterator which will return each of a registry entry's child entries in a specified plane.
 497     @param plane The plane object.
 498     @result Returns an iterator over the children of the entry, or zero if there is a resource failure. The iterator must be released when the iteration is finished. All objects returned by the iteration are retained while the iterator is valid, though they may no longer be attached during the iteration. */
 499
 500     virtual OSIterator * getChildIterator( const IORegistryPlane * plane )
 501                                                                         const;
 502
 503     virtual void applyToChildren( IORegistryEntryApplierFunction applier,
 504                                   void * context,
 505                                   const IORegistryPlane * plane ) const;
 506
 507 /*! @function getChildEntry
 508     @abstract Returns an registry entry's first child entry in a plane.
 509     @discussion This function will return the child which first attached to a registry entry.
 510     @param plane The plane object.
 511     @result Returns the first child of the registry entry, or zero if the entry is not attached into the registry in that plane. The child is retained while the entry is attached, and should not be released by the caller. */
 512
 513     virtual IORegistryEntry * getChildEntry( const IORegistryPlane * plane ) const;
 514
 515 /*! @function isChild
 516     @abstract Determines whether a registry entry is the child of another in a plane.
 517     @discussion This method called in the parent entry determines if the specified entry is a child, in a plane. Additionally, it can check if the child is the only child of the parent entry.
 518     @param child The possible child registry entry.
 519     @param plane The plane object.
 520     @param onlyChild If true, check also if the child is the only child.
 521     @result If the child argument is not a child of the registry entry, false is returned. If onlyChild is true and the child is not the only child of the entry, false is returned, otherwise true is returned. */
 522
 523     virtual bool isChild( IORegistryEntry * child,
 524                                 const IORegistryPlane * plane,
 525                                 bool onlyChild = false ) const;
 526
 527 /*! @function isParent
 528     @abstract Determines whether a registry entry is the parent of another in a plane.
 529     @discussion This method called in the child entry determines if the specified entry is a parent, in a plane. Additionally, it can check if the parent is the only parent of the child entry.
 530     @param parent The possible parent registry entry.
 531     @param plane The plane object.
 532     @param onlyParent If true, check also if the parent is the only parent.
 533     @result If the parent argument is not a parent of the registry entry, false is returned. If onlyParent is true and the parent is not the only parent of the entry, false is returned, otherwise true is returned. */
 534
 535     virtual bool isParent( IORegistryEntry * parent,
 536                                 const IORegistryPlane * plane,
 537                                 bool onlyParent = false ) const;
 538
 539 /*! @function inPlane
 540     @abstract Determines whether a registry entry is attached in a plane.
 541     @discussion This method determines if the entry is attached in a plane to any other entry.  It can also be used to determine if the entry is a member of any plane.
 542     @param plane The plane object, 0 indicates any plane.
 543     @result If the entry has a parent in the given plane or if plane = 0 then if entry has any parent; return true, otherwise false. */
 544
 545     virtual bool inPlane( const IORegistryPlane * plane = 0) const;
 546
 547 /*! @function getDepth
 548     @abstract Counts the maximum number of entries between an entry and the registry root, in a plane.
 549     @discussion This method counts the number of entries between and entry and the registry root, in a plane, for each parent of the entry and returns the maximum value.
 550     @param plane The plane object.
 551     @result The maximum number of entries between the entry and the root. Zero is returned if the entry is not attached in the plane. */
 552
 553     virtual unsigned int getDepth( const IORegistryPlane * plane ) const;
 554
 555     /* Attach / detach */
 556
 557 /*! @function attachToParent
 558     @abstract Attaches a entry to a parent entry in a plane.
 559     @discussion This is the usual method of entering an entry into the registry. It is a no-op and success if the entry is already attached to the parent. Attaching the  entry into the registry retains both the child and parent while they are attached. This method will call attachToChild in the parent entry if it is not being called from attachToChild.
 560     @param parent The registry entry to attach to.
 561     @param plane The plane object.
 562     @result true on success, or false on a resource failure, or if the parent is the same as the child. */
 563
 564     virtual bool attachToParent( IORegistryEntry * parent,
 565                                 const IORegistryPlane * plane );
 566
 567 /*! @function detachFromParent
 568     @abstract Detaches an entry from a parent entry in a plane.
 569     @discussion This is the usual method of removing an entry from the registry. It is a no-op if the entry is not attached to the parent. Detaching the entry will release both the child and parent. This method will call detachFromChild in the parent entry if it is not being called from detachFromChild.
 570     @param parent The registry entry to detach from.
 571     @param plane The plane object. */
 572
 573     virtual void detachFromParent( IORegistryEntry * parent,
 574                                 const IORegistryPlane * plane );
 575
 576 /*! @function attachToChild
 577     @abstract Method called in the parent entry when a child attaches.
 578     @discussion This method is called in the parent entry when a child attaches, to make overrides possible. This method will also call attachToParent in the child entry if it is not being called from attachToParent. It is a no-op and success if the entry is already a child. Attaching the  entry into the registry retains both the child and parent while they are attached.
 579     @param child The registry entry being attached.
 580     @param plane The plane object.
 581     @result true on success, or false on a resource failure, or if the parent is the same as the child. */
 582
 583     virtual bool attachToChild( IORegistryEntry * child,
 584                                 const IORegistryPlane * plane );
 585
 586 /*! @function detachFromChild
 587     @abstract Detaches a child entry from its parent in a plane.
 588     @discussion This method is called in the parent entry when a child detaches, to make overrides possible. It is a no-op if the entry is not a child of the parent. Detaching the entry will release both the child and parent. This method will call detachFromParent in the child entry if it is not being called from detachFromParent.
 589     @param parent The registry entry to detach.
 590     @param plane The plane object. */
 591
 592     virtual void detachFromChild( IORegistryEntry * child,
 593                                 const IORegistryPlane * plane );
 594
 595 /*! @function detachAbove
 596     @abstract Detaches an entry from all its parent entries in a plane.
 597     @discussion This method calls detachFromParent in the entry for each of its parent entries in the plane.
 598     @param plane The plane object. */
 599
 600     virtual void detachAbove( const IORegistryPlane * plane );
 601
 602 /*! @function detachAll
 603     @abstract Detaches an entry and all its children recursively in a plane.
 604     @discussion This method breaks the registry connections for a subtree. detachAbove is called in the entry, and all child entries and their children in the plane.
 605     @param plane The plane object. */
 606
 607     virtual void detachAll( const IORegistryPlane * plane );
 608
 609     /* Name, location and path accessors */
 610
 611 /*! @function getName
 612     @abstract Returns the name assigned to the registry entry as a C-string.
 613     @discussion Entries can be named in a particular plane, or globally. If the entry is named in plane and the plane is specified that name will be returned, otherwise the global name is returned. The global name defaults to the entry's meta class name if it has not been named.
 614     @param plane The plane object, or zero for the global name.
 615     @result A C-string name, valid while the entry is retained. */
 616
 617     virtual const char * getName( const IORegistryPlane * plane = 0 ) const;
 618
 619 /*! @function copyName
 620     @abstract Returns the name assigned to the registry entry as an OSSymbol.
 621     @discussion Entries can be named in a particular plane, or globally. If the entry is named in plane and the plane is specified that name will be returned, otherwise the global name is returned. The global name defaults to the entry's meta class name if it has not been named.
 622     @param plane The plane object, or zero for the global name.
 623     @result A reference to an OSSymbol for the name, which should be released by the caller. */
 624
 625     virtual const OSSymbol * copyName(
 626                                 const IORegistryPlane * plane = 0 ) const;
 627
 628 /*! @function compareNames
 629     @abstract Compares the name of the entry with one or more names, and optionally returns the matching name.
 630     @discussion This method is called during IOService name matching and elsewhere to compare the entry's global name with a list of names, or a single name. A list of names may be passed as any OSCollection of OSStrings, while a single name may be passed an OSString, in the name parameter. compareNames will call the compareName method for each name, for overrides.
 631     @param name The name or names to compare with as any OSCollection (eg. OSArray, OSSet, OSDictionary) of OSStrings, or a single name may be passed an OSString.
 632     @param matched If the caller wants the successfully matched name returned, pass a non-zero pointer for the matched parameter and an OSString will be returned here. It should be released by the caller.
 633     @result True if one of the names compared true with the entry's global name. */
 634
 635     virtual bool compareNames( OSObject * name, OSString ** matched = 0 ) const;
 636
 637 /*! @function compareName
 638     @abstract Compares the name of the entry with one name, and optionally returns the matching name.
 639     @discussion This method is called during IOService name matching and elsewhere from the compareNames method. It should be overridden to provide non-standard name matching.
 640     @param name The name to compare with as an OSString.
 641     @param matched If the caller wants the successfully matched name returned, pass a non-zero pointer for the matched parameter and an OSString will be returned here. It should be released by the caller. Generally, this will be the same as the name parameter, but may not be if wildcards are used.
 642     @result True if the name compared true with the entry's global name. */
 643
 644     virtual bool compareName( OSString * name, OSString ** matched = 0 ) const;
 645
 646 /*! @function setName
 647     @abstract Sets a name for the registry entry, in a particular plane, or globally.
 648     @discussion Entries can be named in a particular plane, or globally. If the plane is specified the name applies only to that plane, otherwise the global name is set. The global name defaults to the entry's meta class name if it has not been named.
 649     @param name An OSSymbol which will be retained.
 650     @param plane The plane object, or zero to set the global name. */
 651
 652     virtual void setName( const OSSymbol * name,
 653                                 const IORegistryPlane * plane = 0 );
 654
 655 /*! @function setName
 656     @abstract Sets a name for the registry entry, in a particular plane, or globally.
 657     @discussion Entries can be named in a particular plane, or globally. If the plane is specified the name applies only to that plane, otherwise the global name is set. The global name defaults to the entry's meta class name if it has not been named.
 658     @param name A const C-string name which will be copied.
 659     @param plane The plane object, or zero to set the global name. */
 660
 661     virtual void setName( const char * name,
 662                                 const IORegistryPlane * plane = 0 );
 663
 664 /*! @function getLocation
 665     @abstract Returns the location string assigned to the registry entry as a C-string.
 666     @discussion Entries can given a location string in a particular plane, or globally. If the entry has had a location set in a plane and the plane is specified that location string will be returned, otherwise the global location string is returned. If no global location string has been set, zero is returned.
 667     @param plane The plane object, or zero for the global name.
 668     @result A C-string location string, valid while the entry is retained, or zero. */
 669
 670     virtual const char * getLocation( const IORegistryPlane * plane = 0 ) const;
 671
 672 /*! @function copyLocation
 673     @abstract Returns the location string assigned to the registry entry as an OSSymbol.
 674     @discussion Entries can given a location string in a particular plane, or globally. If the entry has had a location set in a plane and the plane is specified that location string will be returned, otherwise the global location string is returned. If no global location string has been set, zero is returned.
 675     @param plane The plane object, or zero for the global name.
 676     @result A reference to an OSSymbol for the location if one exists, which should be released by the caller, or zero. */
 677
 678     virtual const OSSymbol * copyLocation(
 679                                 const IORegistryPlane * plane = 0 ) const;
 680
 681 /*! @function setLocation
 682     @abstract Sets a location string for the registry entry, in a particular plane, or globally.
 683     @discussion Entries can be given a location string in a particular plane, or globally. If the plane is specified the location applies only to that plane, otherwise the global location is set. The location string may be used during path lookups of registry entries, to distinguish between sibling entries with the same name. The default IORegistryEntry parsing of location strings expects a list of hex numbers separated by commas, though subclasses of IORegistryEntry might do their own parsing.
 684     @param location A C-string location string which will be copied, or an OSSymbol which will be retained.
 685     @param plane The plane object, or zero to set the global location string. */
 686
 687     virtual void setLocation( const OSSymbol * location,
 688                                 const IORegistryPlane * plane = 0 );
 689     virtual void setLocation( const char * location,
 690                                 const IORegistryPlane * plane = 0 );
 691
 692 /*! @function getPath
 693     @abstract Create a path for a registry entry.
 694     @discussion The path for a registry entry is copied to the caller's buffer. The path describes the entry's attachment in a particular plane, which must be specified. The path begins with the plane name followed by a colon, and then followed by '/' separated path components for each of the entries between the root and the registry entry. Each component is constructed with the getPathComponent method called in each entry. An alias may also exist for the entry, which are described as properties in a registry entry found at /aliases in the plane. If a property value interpreted as a path in a call to IORegistryEntry::fromPath yields the entry, then the property name is used as the entry's path.
 695     @param path A char buffer allocated by the caller.
 696     @param length An in/out parameter - the caller sets the length of the buffer available, and getPath returns the total length of the path copied to the buffer.
 697     @param plane The plane object.
 698     @result getPath will fail if the entry is not attached in the plane, or if the buffer is not large enough to contain the path. */
 699
 700     virtual bool getPath( char * path, int * length,
 701                             const IORegistryPlane * plane) const;
 702
 703 /*! @function getPathComponent
 704     @abstract Create a path component for a registry entry.
 705     @discussion Each component of a path created with getPath is created with getPathComponent. The default implementation concatenates the entry's name in the the plane, with the "at" symbol and the location string of the entry in the plane if it has been set.
 706     @param path A char buffer allocated by the caller.
 707     @param length An in/out parameter - the caller sets the length of the buffer available, and getPathComponent returns the total length of the path component copied to the buffer.
 708     @param plane The plane object.
 709     @result true if the path fits into the supplied buffer or false on a overflow. */
 710
 711     virtual bool getPathComponent( char * path, int * length,
 712                                     const IORegistryPlane * plane ) const;
 713
 714 /*! @function fromPath
 715     @abstract Looks up a registry entry by path.
 716     @discussion This function parses paths to lookup registry entries. The path may begin with the <plane name>: created by getPath, or the plane may be set by the caller. If there are characters remaining unparsed after an entry has been looked up, this may be considered an invalid lookup, or those characters may be passed back to the caller and the lookup successful.
 717     @param path A C-string path.
 718     @param plane The plane to lookup up the path, or zero, in which case the path must begin with the plane name.
 719     @param residualPath If the path may contain residual characters after the last path component, the residual will be copied back to the caller's residualPath buffer. If there are residual characters and no residual buffer is specified, fromPath will fail.
 720     @param residualLength An in/out parameter - the caller sets the length of the residual buffer available, and fromPath returns the total length of the residual path copied to the buffer. If there is no residualBuffer (residualPath = 0) then residualLength may be zero also.
 721     @param fromEntry The lookup will proceed rooted at this entry if non-zero, otherwise it proceeds from the root of the plane.
 722     @result A retained registry entry is returned on success, or zero on failure. The caller should release the entry. */
 723
 724     static IORegistryEntry * fromPath(  const char * path,
 725                                         const IORegistryPlane * plane = 0,
 726                                         char * residualPath = 0,
 727                                         int * residualLength = 0,
 728                                         IORegistryEntry * fromEntry = 0 );
 729
 730 /*! @function fromPath
 731     @abstract Looks up a registry entry by relative path.
 732     @discussion This function looks up a entry below the called entry by a relative path. It is just a convenience that calls IORegistryEntry::fromPath with this as the fromEntry parameter.
 733     @param path See IORegistryEntry::fromPath.
 734     @param plane See IORegistryEntry::fromPath.
 735     @param residualPath See IORegistryEntry::fromPath.
 736     @param residualLength See IORegistryEntry::fromPath.
 737     @result See IORegistryEntry::fromPath. */
 738
 739     virtual IORegistryEntry * childFromPath( const char * path,
 740                                              const IORegistryPlane * plane = 0,
 741                                              char * residualPath = 0,
 742                                              int * residualLength = 0 );
 743
 744 /*! @function dealiasPath
 745     @abstract Strips any aliases from the head of path and returns the full path.
 746     @discussion If the path specified begins with an alias found in the /aliases entry, the value of the alias is returned, and a pointer into the passed in path after the alias is passed back to the caller. If an alias is not found, zero is returned and the path parameter is unchanged.
 747     @param opath An in/out paramter - the caller passes in a pointer to a C-string pointer to a path. If an alias is found, dealiasPath returns a pointer into the path just beyond the end of the alias.
 748     @param plane A plane object must be specified.
 749     @result A C-string pointer to the value of the alias if one is found, or zero if not. */
 750
 751     static const char * dealiasPath( const char ** opath,
 752                                     const IORegistryPlane * plane );
 753
 754     /* * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 755     /* * * * * * * * * * * * internals * * * * * * * * * * * */
 756     /* * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 757
 758 public:
 759     static IORegistryEntry * initialize( void );
 760     static const IORegistryPlane * makePlane( const char * name );
 761     // don't even think about using this
 762     virtual bool init( IORegistryEntry * from,
 763                                 const IORegistryPlane * inPlane );
 764 private:
 765     inline bool arrayMember( OSArray * set,
 766                             const IORegistryEntry * member,
 767                             unsigned int * index = 0 ) const;
 768
 769     bool makeLink( IORegistryEntry * to,
 770                     unsigned int relation,
 771                     const IORegistryPlane * plane ) const;
 772     void breakLink( IORegistryEntry * to,
 773                     unsigned int relation,
 774                     const IORegistryPlane * plane ) const;
 775
 776     virtual OSArray * getParentSetReference( const IORegistryPlane * plane )
 777                                                                         const;
 778     virtual OSArray * getChildSetReference( const IORegistryPlane * plane )
 779                                                                         const;
 780     virtual IORegistryEntry * getChildFromComponent( const char ** path,
 781                                 const IORegistryPlane * plane );
 782
 783     virtual const OSSymbol * hasAlias(  const IORegistryPlane * plane,
 784                                     char * opath = 0, int * length = 0 ) const;
 785     virtual const char * matchPathLocation( const char * cmp,
 786                                 const IORegistryPlane * plane );
 787
 788 };
 789
 790 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 791
 792 /*! @class IORegistryIterator : public OSIterator
 793     @abstract An iterator over the registry.
 794     @discussion An iterator that can traverse the children or parents of a registry entry in a plane, and recurse. Access to the registry is protected against multiple threads, but an IORegistryIterator instance is for use by one thread only. */
 795
 796 class IORegistryIterator : public OSIterator
 797 {
 798     OSDeclareAbstractStructors(IORegistryIterator)
 799
 800 private:
 801     struct IORegCursor {
 802         IORegCursor          *  next;
 803         IORegistryEntry      *  current;
 804         OSIterator           *  iter;
 805     };
 806     IORegCursor                 start;
 807     IORegCursor           *     where;
 808     IORegistryEntry       *     root;
 809     OSOrderedSet          *     done;
 810     const IORegistryPlane *     plane;
 811     IOOptionBits                options;
 812
 813     virtual void free( void );
 814
 815 public:
 816 /*! @function iterateOver
 817     @abstract Create an iterator rooted at a given registry entry.
 818     @discussion This method creates an IORegistryIterator that is set up with options to iterate children or parents of a root entry, and to recurse automatically into entries as they are returned, or only when instructed. The iterator object keeps track of entries that have been recursed into previously to avoid loops.
 819     @param start The root entry to begin the iteration at.
 820     @param plane A plane object must be specified.
 821     @param options kIORegistryIterateRecursively may be set to recurse automatically into each entry as it is returned. This option affects the behaviour of the getNextObject method, which is defined in the OSIterator superclass. Other methods will override this behaviour. kIORegistryIterateParents may be set to iterate the parents of each entry, by default the children are iterated.
 822     @result A created IORegistryIterator instance, to be released by the caller when it has finished with it. */
 823
 824     static IORegistryIterator * iterateOver( IORegistryEntry * start,
 825                                              const IORegistryPlane * plane,
 826                                              IOOptionBits options = 0 );
 827
 828 /*! @function iterateOver
 829     @abstract Create an iterator rooted at the registry root.
 830     @discussion This method creates an IORegistryIterator that is set up with options to iterate children of the registry root entry, and to recurse automatically into entries as they are returned, or only when instructed. The iterator object keeps track of entries that have been recursed into previously to avoid loops.
 831     @param plane A plane object must be specified.
 832     @param options kIORegistryIterateRecursively may be set to recurse automatically into each entry as it is returned. This option affects the behaviour of the getNextObject method, which is defined in the OSIterator superclass. Other methods will override this behaviour. kIORegistryIterateParents may be set to iterate the parents of each entry, by default the children are iterated.
 833     @result A created IORegistryIterator instance, to be released by the caller when it has finished with it. */
 834
 835     static IORegistryIterator * iterateOver( const IORegistryPlane * plane,
 836                                              IOOptionBits options = 0 );
 837
 838 /*! @function getNextObject
 839     @abstract Return the next object in the registry iteration.
 840     @discussion This method calls either getNextObjectFlat or getNextObjectRecursive depending on the options the iterator was created with. This implements the OSIterator defined getNextObject method. The object returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it.
 841     @result The next registry entry in the iteration (the current entry), or zero if the iteration has finished at this level of recursion. The entry returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it. */
 842
 843     virtual IORegistryEntry * getNextObject( void );
 844
 845 /*! @function getNextObjectFlat
 846     @abstract Return the next object in the registry iteration, ignoring the kIORegistryIterateRecursively option.
 847     @discussion This method returns the next child, or parent if the kIORegistryIterateParents option was used to create the iterator, of the current root entry. The object returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it.
 848     @result The next registry entry in the iteration (the current entry), or zero if the iteration has finished at this level of recursion, or the iteration is invalid (see isValid). The entry returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it. */
 849
 850     virtual IORegistryEntry * getNextObjectFlat( void );
 851
 852 /*! @function getNextObjectRecursive
 853     @abstract Return the next object in the registry iteration, and enter it.
 854     @discussion If the iterator has a current entry, and the iterator has not already entered previously, enterEntry is called to recurse into it, ie. make it the new root, and the next child, or parent if the kIORegistryIterateParents option was used to create the iterator, at this new level of recursion is returned. If there is no current entry at this level of recursion, exitEntry is called and the process repeats, until the iteration returns to the entry the iterator was created with and zero is returned. The object returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it.
 855     @result The next registry entry in the iteration (the current entry), or zero if its finished, or the iteration is invalid (see isValid). The entry returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it. */
 856
 857     virtual IORegistryEntry * getNextObjectRecursive( void );
 858
 859 /*! @function getCurrentEntry
 860     @abstract Return the current entry in the registry iteration.
 861     @discussion This method returns the current entry, last returned by getNextObject et al. The object returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it. If the iteration is no longer valid (see isValid), the current entry is zero.
 862     @result The current registry entry in the iteration, or zero if the last iteration returned zero, or the iteration is invalid (see isValid). The entry returned is retained while the iterator is pointing at it (its the current entry), or recursing into it. The caller should not release it. */
 863
 864     virtual IORegistryEntry * getCurrentEntry( void );
 865
 866 /*! @function enterEntry
 867     @abstract Recurse into the current entry in the registry iteration.
 868     @discussion This method makes the current entry, ie. the last entry returned by getNextObject et al., the root in a new level of recursion. */
 869
 870     virtual void enterEntry( void );
 871
 872 /*! @function enterEntry
 873     @abstract Recurse into the current entry in the registry iteration.
 874     @discussion This method recurses into an entry as with enterEntry, but also switches from the current plane to a new one set by the caller.
 875     @param plane The new plane to switch into. */
 876
 877     virtual void enterEntry( const IORegistryPlane * plane );
 878
 879 /*! @function exitEntry
 880     @abstract Exits a level of recursion, restoring the current entry.
 881     @discussion This method undoes an enterEntry, restoring the current entry. If there are no more levels of recursion to exit false is returned, otherwise true is returned.
 882     @result true if a level of recursion was undone, false if no recursive levels are left in the iteration. */
 883
 884     virtual bool exitEntry( void );
 885
 886 /*! @function reset
 887     @abstract Exits all levels of recursion, restoring the iterator to its state at creation.
 888     @discussion This method exits all levels of recursion, and restores the iterator to its state at creation. */
 889
 890     virtual void reset( void );
 891
 892 /*! @function isValid
 893     @abstract Checks that no registry changes have invalidated the iteration.
 894     @discussion If a registry iteration is invalidated by changes to the registry, it will be made invalid, the currentEntry will be considered zero, and further calls to getNextObject et al. will return zero. The iterator should be reset to restart the iteration when this happens.
 895     @result false if the iterator has been invalidated by changes to the registry, true otherwise. */
 896
 897     virtual bool isValid( void );
 898
 899 /*! @function iterateAll
 900     @abstract Iterates all entries (with getNextObject) and returns a set of all returned entries.
 901     @discussion This method will reset, then iterate all entries in the iteration (with getNextObject) until successful (ie. the iterator is valid at the end of the iteration).
 902     @result A set of entries returned by the iteration. The caller should release the set when it has finished with it. Zero is returned on a resource failure. */
 903
 904     virtual OSOrderedSet * iterateAll( void );
 905 };
 906
 907 #endif /* _IOKIT_IOREGISTRYENTRY_H */