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Reentrantlock is a mutually exclusive synchronization machine that implements the interface lock. Its functions include:1. Lock () -- gets resources in blocking mode2. lockinterruptibly () -- Obtains resources in the interrupted mode.3. trylock () -- try to get the resource4. trylock (time) -- try to get resources within a period of time5. Unlock () -- release resources Reentrantlock implements lock in two modes: fair mode and unfair mode.The synchro

As we all know, the latest Linux kernel uses the scheduling mechanism of CFs. Many articles on the Internet have made a detailed analysis of the source code of CFS scheduling. However, most articles focus too much on details, therefore, we did not summarize the concept of CFS as a whole. For this reason, this article describes the basic principles of CFS scheduling and the entire execution process of fair scheduling. Since CFS (completely

() {Try{lock.lock (); Condition.signal (); } finally{lock.unlock (); } } } By condition an object to wait for a thread, you must first execute Lock.lock () to obtain the lock. The signal () method of the condition object can wake the thread. The Awati () method of condition is equivalent to the Wati () method in object. The signal () method of condition is equivalent to the Notify () method in object. The Signalall () method of condition is equivalent to th

This blog post mainly records Reentranctlock internal implementation principles.Reentrantlock and synchronized are more flexible to use than keywords. How to use Reentranctlock is not much to say, here the main record reentrantlock the internal implementation principle.First look at the class inheritance structure of Reentrantlock, such as:There are three internal classes within the Reentrantlock: Sync, Fairsync, Nonfairsync. The source code is as follows:Sync:Abstract static class Sync extends

Reentrantlock IntroductionReentrantlock is a repeatable mutex, also known as an exclusive lock, reentrant means: The Reentrantlock lock can be obtained multiple times by a single thread. But at the same point in time can only be held by one of the thread locksReentrantlock uses a FIFO (first-in-one-out) waiting queue to manage all threads that acquire the lock.Reentrantlock is an exclusive lock in which all operations are thread-exclusive after acquiring a lock, and other threads need to wait un

resource to be accessed by multiple read operations, or accessed by a write operation, but not both.2 fair and non-fair of LocksThe fairness and unfairness of the lock is whether the thread is allowed to queue in the process of acquiring the lock. In a fair lock, the thread acquires the lock in the order in which they make the request, while the non-

, it actually shows the allocation mechanism of locks: thread-based allocation rather than method-invocation-based allocations. Interruptible Lockis a lock that can be broken accordingly. Fair lockA fair lock is to obtain the lock in the order in which the lock is requested. For example, there are multiple threads waiting for a lock, and when the lock is released, the thread that waits the longest (

is because Lock.unlock () This method error, because all did not get the lock, can not unlock (), is the code problem, should be judged to have a lock, has locked the case only Lock.unlock ();V. Reentrantlock can also be designated as a fair lockThe default synchronized are all unfair locks;What is a fair lock, what is an unfair lock, it is assumed that many threads access the same resource at the time of

producer and the consumer, which means that the two cannot actually run in parallel, which is particularly different from the linkedblockingqueue, and according to the principle of implementation, The arrayblockingqueue can be fully split-lock, enabling full parallel operation of both producer and consumer operations. Doug Lea did not do this, perhaps because Arrayblockingqueue's data write and fetch operations are lightweight enough to introduce an independent locking mechanism that, in additi

-LockThe lock implementation provides better locking operations than using the Synchronized method and synchronized statement blocks, they allow more flexibility in building, can have quite different properties, and can support multiple related condition objectsA lock is a tool that controls access to resources that are shared by multiple threads, and in general, locks provide exclusive access to shared resources,Only one thread can acquire a lock in a single time and the thread that requires th

In the [high Concurrency Java II] Multithreaded Foundation, we have initially mentioned basic thread synchronization operations. This time, we will mention the synchronization control tool in the contract. 1. Use of various synchronization control tools 1.1 Reentrantlock Reentrantlock sense is synchronized's enhanced version, synchronized is characterized by the use of simple, all to the JVM to deal with, but the function is relatively weak. Prior to JDK1.5, Reentrantlock performance was bett

The new lock mechanism introduced in Java 5 is an explicit mutex in--java.util.concurrent.locks: The Lock interface, which provides a wider range of locking operations than synchronized. The lock interface has 3 classes that implement it: Reentrantlock, Reetrantreadwritelock.readlock, and Reetrantreadwritelock.writelock, which are re-entry locks, read locks, and write locks. Lock must be explicitly created, locked, and disposed in order to be able to use more features, which are typically instan

queue implemented using a priority queue. SynchronousQueue: a blocking queue that does not store elements. Unbounded transferqueue: an unbounded blocking queue composed of linked lists. LinkedBlockingDeque: a bidirectional blocking queue consisting of a linked list. ArrayBlockingQueue is a bounded blocking queue implemented by arrays. This queue sorts the elements according to the FIFO principle. By default, fair access queue does not guarante

matching system to a running system. The person who has been practicing for three years is the same as the person who ran for 11 seconds for the first time. The matching system is based on the level rather than experience. Q: Why do I win 60% of my teammates and 40% of my competitors? A: The winning rate cannot reflect the level. Matching the system depends not only on whether you win, but also on who you win. As in fact, the winning rate of sky in war3 is not high, but the average winning rat

Process Scheduling Algorithm Linux Process Scheduling Algorithm and scheduling algorithm linux Process This section describes the process scheduling algorithm of the operating system. There are three types of Operating System Scheduling: 1. Remote Scheduling(Create a new process); 2. Middle-end scheduling(Part of the switching function); 3. Short-range Scheduling(Which process will be executed next time) This is short-range scheduling, which can be simply described as process scheduling. When

tell me about the book fair.Speaking so much, it's time to talk about how the book fair is selling. Listen to the promoter here said that the previous words will probably be able to sell one thousand or two thousand yuan a day, especially good time, can reach more than 2000. It does seem pretty small, but it's also quite reasonable. On the one hand before also said, read the relatively few people, and on the other hand, book

: Public interface Lock { //Unconditional acquisition of Locks voidLock ();//Get a lock that responds to interrupts //Can respond to interrupts when acquiring a lock, throws an interrupt exception when interrupted voidLockinterruptibly ()throwsInterruptedexception;//Polling lock. If you can't get a lock, you're constantly trying to get a lock by polling BooleanTrylock ();//Timing lock. If a lock cannot be obtained, the lock is tried again every unit of time BooleanTrylock (Lon

In the process of learning or using Java, the process encounters a variety of lock concepts: Fair lock, unfair lock, spin lock, reentrant lock, biased lock, lightweight lock, heavyweight lock, read-write lock, mutex wait. Here to tidy up the various locks in Java, if there is a lack of hope that we are in the bottom of the message to discuss.Fair lock and non-fair lockA

wait method of the object class The signal method of the condition class is equivalent to the Notify method of the object class The Signalall method of the condition class is equivalent to the Notifyall method of the object class Lock's Fair lock and non-fair lockLock lock=new ReentrantLock(true);//公平锁Lock lock=new ReentrantLock(false);//非公平锁 Fair