NSThread 多线程编程

在iphone上多线程开发有两种方式。一是用pthread开发，别一种是cocoa中的NSThread。本示例展示NSThread的方法，一切以代码说话：

//  main.m
//
//  Created by Christopher Wright on 2007.06.12.
#import <Foundation/Foundation.h>
NSLock *lock;
@interface MyObject : NSObject
+(void)aMethod:(id)param;
@end
@implementation MyObject
+(void)aMethod:(id)param{
    int x;
    for(x=0;x<50;++x)
    {
        [lock lock];
        printf("Object Thread says x is %i/n",x);
        usleep(1);
        [lock unlock];
    }
}
@end
int main(int argc, char *argv[])
{
    int x;
    lock = [[NSLock alloc] init];
    [NSThread detachNewThreadSelector:@selector(aMethod:) toTarget:[MyObject class] withObject:nil];
    for(x=0;x<50;++x)
    {
        [lock lock];
        printf("Main thread says x is %i/n",x);
        usleep(10000);
        printf("Main thread lets go/n",x);
        [lock unlock];
        usleep(100);
    }
	return 0;
}