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A bloodcase caused by a lock-free Message Queue: how to be a real programmer? (2) -- month: spin lock, queue spinPrefix A bloodcase caused by a lock-free Message Queue: how to be a real programmer? (1) -- location: Cause A bloodcase caused by a lock-free Message Queue: how to be a real programmer? (2) -- month: spin lo

TTASLock());private static volatile int value = 0;public static void method(){lock.lock();//System.out.println("Value: " + ++value);lock.unlock();}public static void main(String[] args) {for(int i = 0; i In the case of 100 concurrent threads, The average time for arraylock to obtain the lock is: 719550 ns. The average time for clhlock to obtain the lock is: 488577 NS As you can see, the queue lock reduc

Java concurrent packet source code learning-AQS framework (2) CLH lock queue and spin lock, aqsclh As mentioned in the previous article, AQS is based onCLH lock queueSo what is CLH lock queue? complexity is complicated, simple, and simple. The so-called greatest truths are simple: CLH lock queue is actually a FIFO queue, and each node (thread) in the queue only needs to wait for its previous step to release

security point (at which no bytecode is executing), pauses the thread that holds the biased lock first, and then checks to see if the thread holding the biased lock is alive, and if the thread is not active, the object header is set to a lock-free State, and if the thread is still alive, A stack with a biased lock is executed, traversing the lock record of the biased object, the lock record in the stack, and the object header's mark Word either re-biased to another thread, or reverts to a lock-

part above, multiple callback calls will be called when a message is subscribed. 2. when a subscribed message is received, ballback is in the R. call when sleep () time gap, so the callback execution time cannot exceed R. the gap time provided by sleep (). For example, setting sleep (1) in callback consumes R. sleep (), and then run print 'after sleep 1S '. At this time, flg = 0, so the while loop jumps o

database fails(2) Reduce the time of instance recovery(3) Ensure that all submitted data is written to the data file during a consistent shutdownInstance recovery time:Refers to the time required to push the last checkpoint (checkpoint location) of the data file to the latest SCN recorded in the control file. Administrators can control the time by setting the mttr target and resizing the redo log group.MTTR:Mean time to Repair, that is, the mean dura