" + " the reentrant lock needs to be set；else Adds the current thread to the blocking ...
java中基本类型中,long和double的长度都是8个字节,32位(4字节)处理器对其读写操作无法一次完成,那么,JVM,long和double是原子性的吗? JVM中对long的操作是不是原子操作? 首先,通过一段程序对long的原子性进行判断。测试程序如下: public class LongAtomTest implements Runnable { private static long field = 0;...
上面这段代码每次访问getHelper()方法都要同步进行,双重检查锁定(double-checked locking )试图避免在helpser对象创建后的同步化。 // Broken multithreaded version // "Double-Checked Locking" idiom class Foo { private Helper helper = null; public Helper getHelper() { if (helper == null) synchronized(...
For the purposes of the Java programming language memory model, a single write to a non-volatile long or double value is treated astwo separate writes: one to each 32-bit half. This can result in a situation where a thread sees the first 32 bits of a 64-bit value from one write, a...
single write action on a 64-bit long or double value into two write actions on adjacent 32-bit values. For efficiency's sake, this behavior is implementation-specific; an implementation of the Java Virtual Machine is free to perform writes to long and double values atomically or in two ...
private double x, y; private final StampedLock sl = new StampedLock(); void move(double deltaX, double deltaY) { // an exclusively locked method long stamp = sl.writeLock(); try { x += deltaX; y += deltaY; } finally { sl.unlockWrite(stamp); ...
论文《Implementing Lock-Free Queues》给出一这么一个方法——使用结点内存引用计数refcnt! 代码语言:javascript 代码运行次数:0 运行 AI代码解释 SafeRead(q){loop:p=q->next;if(p==NULL){returnp;}Fetch&Add(p->refcnt,1);if(p==q->next){returnp;}else{Release(p);}goto loop;} ...
tools to identify the reasons that threads are blocked. (Such tools may access blockers using method#getBlocker(Thread).) The use of these forms rather than the original forms without this parameter is strongly encouraged. The normal argument to supply as abloc...
Guardguard (lock_); // Double check. tmp = instance_; if (tmp == 0) { tmp = new TYPE; // Insert the CPU-specific memory barrier instruction // to synchronize the cache lines on multi-processor. asm ("memoryBarrier"); instance_ = tmp; ...
Rectangle2D.Double Rectangle2D.Float RectangularShape ReentrantLock ReentrantReadWriteLock ReentrantReadWriteLock.ReadLock ReentrantReadWriteLock.WriteLock Ref RefAddr Reference Reference Reference Referenceable ReferenceQueue ReferenceType ReferenceUriSchemesSupported ReferralException Reflection...