Thread invocation with varargs in Objective C

example.m

[SEThreadInvocation detachNewThreadSelector:@selector(request:processData:)
                                   toTarget:self
                                withObjects:request, data, nil];

SEThreadInvocation.h

//
//  SEThreadInvocation.h
//

#import <Foundation/Foundation.h>

@interface SEThreadInvocation : NSObject
{
    NSThread * _thread;
    NSInvocation * _invocation;
}

@property(nonatomic,retain) NSThread * thread;
@property(nonatomic,retain) NSInvocation * invocation;

- (id) initWithTarget:(id)target selector:(SEL)selector arguments:(NSArray *)arguments;
+ (void) detachNewThreadSelector:(SEL)selector toTarget:(id)target withObjects:(id)firstObject, ... NS_REQUIRES_NIL_TERMINATION;
- (void) start;

@end

SEThreadInvocation.m

//
//  SEThreadInvocation.m
//

#import "SEThreadInvocation.h"

@implementation SEThreadInvocation

@synthesize thread = _thread;
@synthesize invocation = _invocation;

- (id) initWithTarget:(id)target selector:(SEL)selector arguments:(NSArray *)arguments
{
    if (self = [super init])
    {
        _thread = [[NSThread alloc] initWithTarget:self selector:@selector(run) object:nil];
        _thread.name = @"SEThreadInvocation";

        NSMethodSignature * signature = [target methodSignatureForSelector:selector];

        self.invocation = [NSInvocation invocationWithMethodSignature:signature];

        [_invocation setTarget:target];
        [_invocation setSelector:selector];

        NSInteger i = 2; // self, _cmd, ...
        
        for (id argument in arguments)
        {
            [_invocation setArgument:&argument atIndex:i++];
        }
        
        [_invocation retainArguments];
    }
    return self;
}

- (void)start
{
    [_thread start];
}

- (void)run
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    [_invocation invoke];

    [pool release];
}


+ (void) detachNewThreadSelector:(SEL)selector toTarget:(id)target withObjects:(id)firstObject, ...
{
    NSMutableArray * arguments = [NSMutableArray array];
    
    if (firstObject)
    {
        [arguments addObject:firstObject];
        
        id argument;
        va_list objectList;
        va_start(objectList, firstObject);

        while (argument = va_arg(objectList, id))
        {
            [arguments addObject:argument];
        }
        
        va_end(objectList);
    }

    SEThreadInvocation * threadInvocation = [[SEThreadInvocation alloc] initWithTarget:target selector:selector arguments:arguments];
    [threadInvocation start];
    [threadInvocation autorelease];
}

- (void) dealloc
{
    [_invocation release];
    [_thread release];

    [super dealloc];
}

@end