rhel atomic

This question is seldom met, but the answer is of course not.Atomic added a lock in the set method, preventing multi-threading from writing to the property, causing difficult-to-predict values. But it's also just a read-write lock. and thread safety is actually worse. Look underneath. @interface monperson: nsobject @property (copy) nsstring * firstName; @property (copy) NSString * LastName; -(nsstring *) FullName; @endThread a:p.firstname = @ "Rob "; Thread b:p.firstname = @ "Robert"; Thread

One is to use boost::atomic; a direct lock; The code is simple:#include The test results are as follows:[email protected]:~/code$./test 0 1000loopnum:10000 test_atomic Cost 0 ms[Email protected]:~/code$./test 1 1000Loopnum:10000test_lock Cost 0 ms[Email protected]:~/code$./test 1 100000Loopnum:10000test_lock Cost 9 ms[email protected]:~/code$./test 0 100000loopnum:10000 test_atomic cost 2 msAs the number of loops increases, the gap becomes larger, and

accumulated value is not immediately output, resulting in output confusion, but still can be added to 600. Knowledge output is unsafe.3. Using an atomic type, such as changing the int count type of the above code to Atomicinteger count type, we know that getting the value of count and then adding another 1 is a problem that can occur, that is, the result is a repeating number. The Atomicinteger type solves this problem in a synchronous way. Such as:R

1000), or the operation that failed together (a account returned to its original state and B account back to its original state) was called an atomic operation.If a transaction can be thought of as a program, it is either completely executed or not executed at all. This property is called atomicity.The use of [mutex mutex] in Python prevents multiple threads from simultaneously modifying a variable caused by an error.Mutex = Threading. Lock () Create

Tags: collect atomic concept date basic reading for nbspFirst, in principle, MONGDB has no concept of business.A transaction has an acid concept, such as atomicity, in which a transaction either succeeds or fails altogether.For example, considering a transfer business, a transfer from a 100 to B will be divided into two steps:A = A-100;b = b + 100;In Mongdb, if a = A-100 is executed, it will be put into effect directly, there is no concept of rollback

Setting up Samba in RHEL 5 is easier than other systems. Next we will describe how to set up Samba in RHEL 5, in addition, it makes a simple comparison with the construction of Samba servers in other systems. To share files with windows in RHEL 5, nfs can be used on RHEL 5, but related software must be installed on win

Java has a lot of thread-safe basic module classes, and in general, these basic module classes can meet all of the operations we need, but more often than not, they do not meet all of our needs. At this point, we need to find a way to add a new atomic operation without destroying the existing thread-safe class. The following 4 scenarios are available:1 Modify the source code of the class to add a new atomic

In the multi-threaded environment to count, you need to ensure that the consistency of the count variables and thread safety to ensure that the count is correct in multi-threaded environment.The atomic count is the feature that provides this requirement, which guarantees that the count operation will never be interrupted by any other practice or event when it is completed, and the following is an atomic cou

The java.util.concurrent.atomic provides classes on atomic operations, including: Atomiclong, Atomicinteger, Atomicboolean. And the Atomicintegerarray, Atomiclongarray of the array operation.The initial understanding of the thread is DEMO2 because of the security issues caused by atomic operations. The use of Atomicinteger can be solved. Public classDemo2 {PrivateAtomicinteger value =NewAtomicinteger (1);

Objective-C keywords: retain, assgin, copy, readonly, atomic, nonatomic, objective-cassginUse of declarative attributes: declarative attributes are called the compile-time syntax @ property (retain, nonatomic) Some * s; @ property (parameter 1, parameter 2) Some * s; parameter 1: retain: Modify reference (object) Data Type assgin: Modify basic data type (default) copy: Some objects need to be copied to use NSString readonly: Read-only, only setter met

The Java class library includes a number of useful "base module" classes. In general, we should prefer to reuse these existing classes instead of creating new ones. : Reuse can reduce development effort, develop risk (because existing classes are already tested), and maintenance costs. Sometimes, a thread-safe class can support all the operations we need, but many other times, the existing class can only support most of the operations, and it is necessary to add a new operation without breaking

What operations does Linux support have atomic characteristics? Knowing these things is the basis for understanding and designing a non-locking programming algorithm.__sync_fetch_and_add series of commands, found this series of commands to say the best of an article, English good students can go directly to the original text. Multithreaded simple data type access and atomic variables__sync_fetch_and_add Ser

In a multithreaded environment, access to shared variables can be implemented using the lock free technology based on compare and swap, the benefit of which is high efficiency.An extract of atomic operation1.1 AndroidSource: system/core/libcutils/atomic.c (for X86):1#elif defined (__i386__) | | Defined (__x86_64__)23void Android_atomic_write (int32_t value,Volatile int32_t*Addr) {4int32_t OldValue;5Do{6 OldValue = *Addr7}While(Android_atomic_cmpxchg (

Depending on the type of data being modified, the atomic action classes in the JUC package can be grouped into 4 classes. 1. Basic types: Atomicinteger, Atomiclong, Atomicboolean; 2. Array type: Atomicintegerarray, Atomiclongarray, Atomicreferencearray; 3. Reference type: Atomicreference, atomicstampedrerence, atomicmarkablereference; 4. Object's property modification type: Atomicintegerfieldupdater, Atomiclongfieldupdater, Atomicreferencefieldupd

This article will introduce you to a graphic tutorial on RHEL 6.5 installation and configuration in linux, hoping to help you. Note: The latest version of RHEL 6.x is RHEL 6.5. The following describes the specific installation and configuration process of RHEL 6.5. The server settings are as follows: Operating System:

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