NSRecursiveLock *lock = [[NSRecursiveLock alloc] init]; dispatch_async(dispatch_get_global_queue(0, 0), ^{ static void (^MyBlock)(int); MyBlock = ^(int value) { [lock lock]; //这行代码加锁执行了多次 if (value > 0) { NSLog(@"value = %d %@", value, [NSThread currentThread...
/* * @function: dispatch_sync * @abstract: 在当前线程同步执行任务,会阻塞当前线程直到这个任务完成。 * @para queue 队列。开发者可以指定在哪个队列执行这个任务 * @para block 任务。开发者在这个 Block 内执行具体任务。 * @result: 无返回值 */ //void //dispatch_sync(dispatch_queue_t queue, DIS...
Why not? First, an inline keyword doesn't force the compiler to inline the function, but only advises to do so. Second, for a recursive function it's possible to inline several levels of recursion and then actually perform a recursive call (just like loop unrolling). In MSVC it's even...
用NSObject的类方法 performSelectorInBackground:withObject: 创建一个线程: [Obj performSelectorInBackground:@selector(doSomething) withObject:nil]; 下载图片的例子: 新建singeView app 新建项目,并在xib文件上放置一个imageView控件。按住control键拖到viewController.h文件中创建imageView IBOutlet ViewController...
Let RR be the transform found by the recursive algorithm, now we should apply R−1R−1 to (AB)(AB) to get rk−1rkrk−1rk. If after that the condition above holds, we return RR. Otherwise, we advance one step in continued fraction computation, from rk−1rkrk−1rk to rk...
GCD(GCD(a, b), c) = GCD(a, b, c),so that means one can calculate it recursively. However, DAX does not support recursive calculations. What remains is the following algorithm.1. Gather all the numbers for the ID.2. For each number generate all the divisors by brute force....
In this program, we will create a recursive function to calculate the GCD and return the result to the calling function. Program/Source Code: The source code to calculate the GCD using recursion is given below. The given program is compiled and executed successfully. ...
NSRecursiveLock,多次调用不会阻塞已获取该锁的线程。 NSRecursiveLock *theLock =[[NSRecursiveLock alloc] init]; void MyRecursiveFunction(int value) { [theLock lock]; if (value != 0) { –value; MyRecursiveFunction(value); } [theLock unlock]; ...
C Program to Find the GCD of Two Numbers Below is the C program to find the GCD of two numbers: // C program to find GCD/HCF of 2 numbers #include<stdio.h> // Recursive function to find GCD/HCF of 2 numbers intcalculateGCD(intnum1,intnum2) { if(num2==0) { returnnum1; } ...
907c __os_unfair_lock_lock_slow (in libsystem_platform.dylib) + 284 2 CoreFoundation 0x000000019429b44c _CFSocketInvalidate (in CoreFoundation) + 132 3 CFNetwork 0x0000000195346770 _CFNetworkErrorGetLocalizedDescription + 314456 4 CoreFoundation 0x00000001941e3e88 _CFArrayApplyFunction (in Core...