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Authors
- Scott Christley (
scottc@net-community.com)
-
- Andrew Kachites McCallum (
mccallum@gnu.ai.mit.edu)
-
- Richard Frith-Macdonald (
richard@brainstorm.co.uk)
-
- Nicola Pero (
n.pero@mi.flashnet.it)
-
Version: 27590
Date: 2009-01-13 15:57:38 +0000 (Tue, 13 Jan 2009)
Copyright: (C) 1996-2000 Free Software Foundation, Inc.
- Declared in:
- Foundation/NSThread.h
Availability: OpenStep
This class encapsulates OpenStep threading. See
NSLock
and its subclasses for handling synchronisation between
threads.
Each process begins with a main
thread and additional threads can be created using
NSThread. The GNUstep implementation of OpenStep
has been carefully designed so that the internals of
the base library do not use threading (except for
methods which explicitly deal with threads of
course) so that you can write applications without
threading. Non-threaded applications are more
efficient (no locking is required) and are easier
to debug during development.
+ (
NSArray*)
callStackReturnAddresses;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns an array of the call stack return
addresses.
+ (
NSThread*)
currentThread;
Availability: OpenStep
Returns the NSThread object corresponding to the
current thread.
NB. In GNUstep the library internals use the
GSCurrentThread()
function as a more efficient mechanism for doing
this job - so you cannot use a category to override
this method and expect the library internals to use
your implementation.
+ (void)
detachNewThreadSelector: (SEL)aSelector
toTarget: (id)aTarget
withObject: (id)anArgument;
Availability: OpenStep
Create a new thread - use this method rather than
alloc-init. The new thread will begin
executing the message given by
aSelector, aTarget, and
anArgument. This should have no return
value, and must set up an autorelease pool if
retain/release memory management is used.
It should free this pool before it finishes execution.
+ (void)
exit;
Availability: OpenStep
Terminates the current thread.
Normally
you don't need to call this method explicitly, since
exiting the method with which the thread was
detached causes this method to be called
automatically.
+ (BOOL)
isMainThread;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns a boolean indicating whether this thread is
the main thread of the process.
+ (BOOL)
isMultiThreaded;
Availability: OpenStep
Returns a flag to say whether the application is
multi-threaded or not.
An application
is considered to be multi-threaded if any thread other
than the main thread has been started, irrespective of
whether that thread has since terminated.
NB. This method returns YES if called
within a handler processing
NSWillBecomeMultiThreadedNotification
+ (
NSThread*)
mainThread;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns the main thread of the process.
+ (void)
setThreadPriority: (double)pri;
Availability: Not in OpenStep/MacOS-X, Base 1.2.0
Set the priority of the current thread. This is a value
in the range 0.0 (lowest) to 1.0 (highest) which is
mapped to the underlying system priorities. The
current gnu objc runtime supports three priority
levels which you can obtain using values of 0.0,
0.5, and 1.0
+ (void)
sleepForTimeInterval: (
NSTimeInterval)ti;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Suspends execution of the process for the
specified period.
+ (void)
sleepUntilDate: (
NSDate*)date;
Availability: OpenStep
Delaying a thread... pause until the specified
date.
+ (double)
threadPriority;
Availability: Not in OpenStep/MacOS-X, Base 1.2.0
Return the priority of the current thread.
- (void)
cancel;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Cancels the receiving thread.
- (id)
init;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
This is a designated initialiser for the class.
Description forthcoming.
- (id)
initWithTarget: (id)aTarget
selector: (SEL)aSelector
object: (id)anArgument;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Initialises the receiver to send the message
aSelector to the object aTarget
with the argument anArgument (which may be
nil).
The arguments
aTarget and aSelector are
retained while the thread is running.
- (BOOL)
isCancelled;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns a boolean indicating whether the receiving
thread has been cancelled.
- (BOOL)
isExecuting;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns a boolean indicating whether the receiving
thread has been started (and has not yet finished or
been cancelled).
- (BOOL)
isFinished;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns a boolean indicating whether the receiving
thread has completed executing.
- (BOOL)
isMainThread;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns a boolean indicating whether this thread is
the main thread of the process.
- (void)
main;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
FIXME... what does this do?
- (
NSString*)
name;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns the name of the receiver.
- (void)
setName: (
NSString*)aName;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Sets the name of the receiver.
- (void)
setStackSize: (unsigned)stackSize;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Sets the size of the receiver's stack.
- (unsigned)
stackSize;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Returns the size of the receiver's stack.
- (void)
start;
Availability: Not in OpenStep/MacOS-X, Base 1.15.1
Starts the receiver executing.
- (
NSMutableDictionary*)
threadDictionary;
Availability: OpenStep
Return the thread dictionary. This dictionary can be
used to store arbitrary thread specific data.
NB. This cannot be autoreleased, since we cannot be
sure that the autorelease pool for the thread will
continue to exist for the entire life of the
thread!
- Declared in:
- Foundation/NSThread.h
Availability: OpenStep
Extra methods to permit messages to be sent to an
object such that they are executed in another
thread.
The main thread is the thread in which
the GNUstep system is started, and where the GNUstep gui
is used, it is the thread in which gui drawing operations
must be performed.
Method summary
- (void)
performSelector: (SEL)aSelector
onThread: (
NSThread*)aThread
withObject: (id)anObject
waitUntilDone: (BOOL)aFlag;
Availability: Base
- (void)
performSelector: (SEL)aSelector
onThread: (
NSThread*)aThread
withObject: (id)anObject
waitUntilDone: (BOOL)aFlag
modes: (
NSArray*)anArray;
Availability: Base
This method performs aSelector on the
receiver, passing anObject as an
argument, but does so in the specified thread.
The receiver and anObject are both
retained until the method is performed.
The selector is performed when the runloop of
aThread next runs in one of the modes
specified in anArray.
Where
this method has been called more than once before
the runloop of the thread runs in the required mode,
the order in which the operations in the thread is
done is the same as that in which they were added
using this method.
If there are no modes in anArray, the
method has no effect and simply returns
immediately.
The argument aFlag specifies whether the
method should wait until the selector has been
performed before returning.
NB. This method does
not cause the runloop of aThread
to be run... so if the runloop is not executed by some
code in aThread, the thread waiting for
the perform to complete will block forever.
As a special case, if aFlag ==
YES and the current thread is
aThread, the modes array is ignored and
the selector is performed immediately. This behavior
is necessary to avoid the current thread being blocked
by waiting for a perform which will never happen
because the runloop is not executing.
- (void)
performSelectorOnMainThread: (SEL)aSelector
withObject: (id)anObject
waitUntilDone: (BOOL)aFlag;
Availability: Base
- (void)
performSelectorOnMainThread: (SEL)aSelector
withObject: (id)anObject
waitUntilDone: (BOOL)aFlag
modes: (
NSArray*)anArray;
Availability: Base
This method performs aSelector on the
receiver, passing anObject as an
argument, but does so in the main thread of the
program. The receiver and anObject
are both retained until the method is performed.
The selector is performed when the runloop of the
main thread next runs in one of the modes specified
in anArray.
Where this method has
been called more than once before the runloop of the
main thread runs in the required mode, the order in
which the operations in the main thread is done is
the same as that in which they were added using this
method.
If there are no modes in anArray, the
method has no effect and simply returns
immediately.
The argument aFlag specifies whether the
method should wait until the selector has been
performed before returning.
NB. This method does
not cause the runloop of the main thread to
be run... so if the runloop is not executed by some
code in the main thread, the thread waiting for the
perform to complete will block forever.
As a special case, if aFlag ==
YES and the current thread is the
main thread, the modes array is ignored and the
selector is performed immediately. This behavior
is necessary to avoid the main thread being blocked by
waiting for a perform which will never happen
because the runloop is not executing.
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