In the above code, the getInstance() method is not thread-safe. Multiple threads can access it at the same time. For the first few threads when the instance variable is not initialized, multiple threads can enter the if loop and create multiple instances. It will break our singleton implemen...
In software engineering, thesingleton patternis a design pattern that restricts theinstantiationof a class toone object. This is useful when exactlyone objectis needed to coordinate actions across the system. The concept is sometimes generalized to systems that operate moreefficientlywhen only one obje...
(which is already protected by _mon) The reference assignment is already atomic which means when I check for null outside the synchronized, it's either null or a valid reference (ref https://stackoverflow.com/questions/44283378/why-is-reference-assignment-atomic-in-java#44287276) Thus, there...
Make a method thread-safe – Method 2 In this particular counter example, we actually can makecount++atomic by using AtomicInteger from the package “java.util.concurrent.atomic”. importjava.util.concurrent.atomic.AtomicInteger;publicclassMyCounter{privatestaticAtomicInteger counter=newAtomicInteger(0);p...
(JavaVirtualMachine)does not cachevolatilevalues in registers. On every use, it fetches the value from main sharedRAM(RandomAccessMemory). On every assignment it saves the value to main sharedRAM. In a multicpu machine with cache coherency, the value may not actually be stored all the way ...
Some Swing component methods are labelled "thread safe" in the API specification; these can be safely invoked from any thread. All other Swing component methods must be invoked from the event dispatch thread. Programs that ignore this rule may function correctly most of the time, but are ...
A blazingly fast and memory efficient (thread-safe) Java client on top of the BrowsCap CSV source files. - blueconic/browscap-java
That's all about how to create thread-safe Singleton in Java, but this is not the only way to create the thread-safe singleton. You can useEnum as Singletonthen Java itself will guarantee that only one instance will be created even in the case of multiple threads trying to access it at...
The other way can be to use a concurrent set from the java concurrent package. The set that is returned from the map is backed by the map itself -- meaning wrapping it in a synchronizedSet() is definitely not enough. I would recommend using synchronizedMap on the private map variable ...
Advanced Java Redis client for thread-safe sync, async, and reactive usage. Supports Cluster, Sentinel, Pipelining, and codecs. - redis/lettuce