java volatile

What does the volatile keyword in Java mean? How to use it ?, Volatile keywords Once a concurrent shared variable (class member variable, static member variable) being modified by the volatile keyword gives visibility (that is, the value of a variable modified by a thread is immediately visible to another thread) and o

Java multithreading-Volatile keyword parsing, multithreading-volatile The volatile keyword can be analyzed from these three aspects: What is the atomicity of the program, what is the visibility of the program, and what is the orderliness of the programWhat is the atomicity of a program? Which of the following statement

[Java multithreading] correct use of volatile keywords, multi-thread volatile The volatile variable hassynchronizedBut not Atomic. In a multi-threaded environment, variables using the volatile keyword can only read the latest modified variable values when reading variables f

Characteristics of volatileWhen we declare that the shared variable is volatile, the read/write to this variable will be very special. A good way to understand the volatile characteristics is to use a single read/write of the volatile variable as a synchronization of these individual read/write operations using the same monitor lock. Let's take a look at the samp

correctly implement the volatile write-read memory semantics. This means that in x86 processors, the cost of volatile writes is much higher than that of volatile reads (because the overhead of executing the storeload barrier is larger).JSR-133 why to enhance the volatile memory semanticsIn the old

platform can be optimized to:As mentioned earlier, the x86 processor will only reorder write-read operations. X86 does not reorder read-read, read-write, and write-write operations, so the memory barrier corresponding to these three types of operations is omitted from the x86 processor. In x86, JMM only needs to insert a storeload barrier after the volatile write to correctly implement the volatile write-r

This article belongs to author original, the original text is published in Infoq:http://www.infoq.com/cn/articles/java-memory-model-4Characteristics of volatileWhen we declare that the shared variable is volatile, the read/write to this variable will be very special. A good way to understand the volatile characteristics is to treat a single read/write of the

This article transferred from: http://www.infoq.com/cn/articles/java-memory-model-4Characteristics of volatileWhen we declare that the shared variable is volatile, the read/write to this variable will be very special. A good way to understand the volatile characteristics is to treat a single read/write of the volatile

platform can be optimized to:As mentioned earlier, the x86 processor will only reorder write-read operations. X86 does not reorder read-read, read-write, and write-write operations, so the memory barrier corresponding to these three types of operations is omitted from the x86 processor. In x86, JMM only needs to insert a storeload barrier after the volatile write to correctly implement the volatile write-r

to correctly implement the volatile write-read memory semantics. This means that in x86 processors, the cost of volatile writes is much higher than that of volatile reads (because the overhead of executing the storeload barrier is larger).JSR-133 why to enhance the volatile memory semanticsIn the old

earlier, the x86 processor will only reorder write-read operations. X86 does not reorder read-read, read-write, and write-write operations, so the memory barrier corresponding to these three types of operations is omitted from the x86 processor. In x86, JMM only needs to insert a storeload barrier after the volatile write to correctly implement the volatile write-read memory semantics. This means that in x

in x86 processors, the cost of volatile writes is much higher than that of volatile reads (because the overhead of executing the storeload barrier is larger).JSR-133 why to enhance the volatile memory semanticsIn the old Java memory model prior to JSR-133, although reordering between

The following information is transferred from http://tutorials.jenkov.com/java-concurrency/volatile.html (using Google Translate):The Java volatile keyword is used to mark Java variables as "stored in primary storage". More precisely, this means that each read volatile varia

Reprint please specify the source:description of volatile use prior to JDK1.2, Java's memory model implementations always read variables from main memory (that is, shared memory) without special attention. with the maturation and optimization of the JVM, the use of volatile keywords is now very important in multithreaded environments . in the current Java memory

Original source: http://www.ibm.com/developerworks/cn/java/j-jtp06197.htmlGuidelines for using volatile variablesThe Java™ language contains two intrinsic synchronization mechanisms: synchronous blocks (or methods) and volatile variables. Both of these mechanisms are proposed to achieve the security of code threads. Wh

1.Java Memory Model Reference: Http://www.infoq.com/cn/special-column/articles/Java memory model Column 2.volatile understanding of keywords The volatile variable in the Java language can be viewed as a "lighter synchronized", and the