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NSObject class reference

Authors

Andrew Kachites McCallum (mccallum@gnu.ai.mit.edu)

Version: 33774

Date: 2011-08-22 05:02:10 -0600 (Mon, 22 Aug 2011)

Copyright: (C) 1995, 1996, 1998 Free Software Foundation, Inc.


Contents -

  1. Software documentation for the NSObject(GNUstep) category
  2. Software documentation for the NSObject(NEXTSTEP) category
  3. Software documentation for the NSObject(TimedPerformers) informal protocol
  4. Software documentation for the NSDiscardableContent protocol
  5. Software documentation for the NSObject protocol

Software documentation for the NSObject(GNUstep) category

NSObject(GNUstep)

Declared in:
Foundation/NSObject.h
Availability: Not in OpenStep/MacOS-X, Base Likely to be changed/moved/removed at 1.17.0

Some non-standard extensions mainly needed for backwards compatibility and internal utility reasons.
Method summary

enableDoubleReleaseCheck: 

+ (void) enableDoubleReleaseCheck: (BOOL)enable;
Availability: Not in OpenStep/MacOS-X, Base Likely to be changed/moved/removed at 1.17.0

Enables runtime checking of retain/release/autorelease operations.

Whenever either -autorelease or -release is called, the contents of any autorelease pools will be checked to see if there are more outstanding release operations than the objects retain count. In which case an exception is raised to say that the object is released too many times.

Beware, since this feature entails examining all active autorelease pools every time an object is released or autoreleased, it can cause a massive performance degradation... it should only be enabled for debugging.

When you are having memory allocation problems, it may make more sense to look at the memory allocation debugging functions documented in NSDebug.h, or use the NSZombie features.


Software documentation for the NSObject(NEXTSTEP) category

NSObject(NEXTSTEP)

Declared in:
Foundation/NSObject.h
Availability: Not in OpenStep/MacOS-X

Methods for compatibility with the NEXTSTEP (pre-OpenStep) 'Object' class.
Method summary

error: ,...

- (id) error: (const char*)aString,...;
Availability: Not in OpenStep/MacOS-X

Logs a message. Deprecated. Use NSLog() in new code.

Software documentation for the NSObject(TimedPerformers) informal protocol

NSObject(TimedPerformers)

Declared in:
Foundation/NSObject.h
Availability: OpenStep

Declares some methods for sending messages to self after a fixed delay. (These methods are in OpenStep and OS X.)
Method summary

cancelPreviousPerformRequestsWithTarget: 

+ (void) cancelPreviousPerformRequestsWithTarget: (id)obj;
Availability: OpenStep

Cancels any perform operations set up for the specified target in the current run loop.

cancelPreviousPerformRequestsWithTarget: selector: object: 

+ (void) cancelPreviousPerformRequestsWithTarget: (id)obj selector: (SEL)s object: (id)arg;
Availability: OpenStep

Cancels any perform operations set up for the specified target in the current loop, but only if the value of aSelector and argument with which the performs were set up match those supplied.
Matching of the argument may be either by pointer equality or by use of the [NSObject -isEqual:] method.

performSelector: withObject: afterDelay: 

- (void) performSelector: (SEL)s withObject: (id)arg afterDelay: (NSTimeInterval)seconds;
Availability: OpenStep

Sets given message to be sent to this instance after given delay, in any run loop mode. See NSRunLoop .

performSelector: withObject: afterDelay: inModes: 

- (void) performSelector: (SEL)s withObject: (id)arg afterDelay: (NSTimeInterval)seconds inModes: (NSArray*)modes;
Availability: OpenStep

Sets given message to be sent to this instance after given delay, in given run loop modes. See NSRunLoop .

Software documentation for the NSDiscardableContent protocol

NSDiscardableContent

Declared in:
Foundation/NSObject.h
Availability: Not in OpenStep/MacOS-X

The NSDiscardableContent protocol is used by objects which encapsulate data which may be discarded if resource constraints are exceeded. These constraints are typically, but not always, related memory.
Method summary

beginContentAccess 

- (BOOL) beginContentAccess;
Availability: Not in OpenStep/MacOS-X

This method is called before any access to the object. It returns YES if the object's content is still valid. The caller must call -endContentAccess once for every call to -beginContentAccess ;

discardContentIfPossible 

- (void) discardContentIfPossible;
Availability: Not in OpenStep/MacOS-X

Discards the contents of the object if it is not currently being edited.

endContentAccess 

- (void) endContentAccess;
Availability: Not in OpenStep/MacOS-X

This method indicates that the caller has finished accessing the contents of the object adopting this protocol. Every call to -beginContentAccess must be be paired with a call to this method after the caller has finished accessing the contents.

isContentDiscarded 

- (BOOL) isContentDiscarded;
Availability: Not in OpenStep/MacOS-X

Returns YES if the contents of the object have been discarded, either via a call to -discardContentIfPossible while the object is not in use, or by some implementation dependent mechanism.

Software documentation for the NSObject protocol

NSObject

Declared in:
Foundation/NSObject.h
Availability: OpenStep

The NSObject protocol describes a minimal set of methods that all objects are expected to support. You should be able to send any of the messages listed in this protocol to an object, and be safe in assuming that the receiver can handle it.

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