The document shows code for incrementing a counter stored in a file. It reads the current count from "count.txt", converts it to an integer, increments it by 1, and writes it back to the file. It uses locking to prevent multiple processes from writing to the file concurrently.

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26. n = IO.read("count.txt") rescue "0"
open("count.txt","w") {|f| f.puts n.to_i + 1}
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27. n = IO.read("count.txt") rescue "0" n = IO.read("count.txt") rescue "0"
open("count.txt","w") {|f| f.puts n.to_i + 1} open("count.txt","w") {|f| f.puts n.to_i + 1}
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28. n = IO.read("count.txt") rescue "0"
open("count.txt","w") {|f| f.puts n.to_i + 1}
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31. while (true)
begin
break if Dir.mkdir("lock.txt")
rescue
sleep(1)
end
end
n = IO.read("count.txt") rescue "0"
open("count.txt","w") {|f| f.puts n.to_i + 1}
Dir.rmdir("lock.txt")
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32. lock(“a”) lock(“b”)
lock(“b”) lock(“a”)
unlock(“b”) unlock(“a”)
unlock(“a”) unlock(“b”)
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38. - (void)countThread:(id)param{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
[pool release];
}
[NSThread detachNewThreadSelector:@selector(countThread:)
toTarget:self withObject:self];
NSLog(@"Thread started.");
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41. - (int) maxOfArray:(int *)a count:(int)n {
static int max = 0;
for (int i = 0; i < n; i++) {
if (a[i] > max) max = a[i];
}
return max;
}
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42. - (int)randomNumber {
static int rand = 7654321;
rand = (rand * 12345 + 678901) & 0x7fff;
return rand;
}
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44. NSMutableDictionary *threadLoacl =
[[NSTread currentThread] threadDictonary];
[threadLocal setObject:@”Test” forKey:@”mode”];
s = [threadLocal objectForKey:@”mode”]
44

45. @interface MyInt : NSObject {
int intValue;
}
@end
@implementation MyInt
-(int) getInt {
return intValue;
}
-(void) setOddInt:(int)i {
intValue = i;
intValue = (intValue >> 1) << 1;
}
@end
45

46. @interface MyString : NSObject {
NSMutableString *str;
}
@end
@implementation MyInt
-(MyString *) getString {
return str;
}
-(void) addString:(NSString *)s {
[str appendString:s];
}
@end
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49. @interface MyPoint : NSObject {
GCPoint point;
}
@end
@implementation MyInt
-(GCPoint) getPoint {
return point;
}
-(void) setPoint:(GCPoint)p {
point = p;
}
@end
49

50. @interface MyString : NSObject {
NSString *string;
}
@property (nonatomic, retain) NSString *string;
@end
@implementation MyString
@synthesize string;
@end
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60. @interface CountOperation : NSOperation {
id delegate;
}
@implementation CountOperation
- (id)initWithDelegate:(id)aDelegate {
self = [super init];
if (self != nil) {
delegate = aDelegate;
}
return self;
}
- (void)main {
NSAutoreleasePool *pool = [NSAutoreleasePool new];
[pool release];
}
@end
queue = [[NSOperationQueue alloc] init];
CountOperation *op = [[[CountOperation alloc] initWithDelegate:self] autorelease];
[queue addOperation:op];
NSLog(@"Thread started.");
}
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64. {|ary| ^(NSArray *ary) {
s = “” NSMutableString *s = [NSMutableString string];
for a in ary for (NSString *a in ary) {
s += a [s appendString:a];
end }
s return s;
} }
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65. __block NSMutableString *s = [NSMutableString string];
^(NSArray *ary) {
for (NSString *a in ary) {
[s appendString:a];
}
}
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66. - (NSArray *)sortedArrayUsingSelector:
(SEL)comparator
- (NSArray *)sortedArrayUsingComparator:
(NSComparator)cmptr
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