Why does double-checked locking not work?
DoubleCheckedLocking, a common CeePlusPlus and JavaLanguage Idiom for lazy initialization in multi-thread programs, commonly used for implementing singletons, turns out to not work reliably because of issues with optimizing compilers and shared memory multiprocessors.
Is double-checked locking thread safe?
In multi-threaded environments, initialization is usually not thread safe, so locking is required to protect the critical section. Since only the first access requires locking, double-checked locking is used to avoid locking overhead of subsequent accesses.
Can the double-checked locking fail on single processor system?
Ans. There is no mapping of single ton with number of processor of the system. So double check locking will not fail depending on number of processor.
Why double check locking?
Why is it called Double Checked Locking? It is called double-checked locking because there are two checks for instance == null, one without locking and other with locking (inside synchronized) block.
How do you say double check?
Double-check Synonyms – WordHippo Thesaurus….What is another word for double-check?
| check | verify |
|---|---|
| make sure | reassure yourself |
| confirm | make certain |
| ascertain | establish |
| see | check out |
What is synchronized in Kotlin?
Marks the JVM method generated from the annotated function as synchronized , meaning that the method will be protected from concurrent execution by multiple threads by the monitor of the instance (or, for static methods, the class) on which the method is defined.
What is the benefit of using a double checking lock mechanism in singleton?
This double check lock is only necessary if you are worried about many threads calling the singleton simultaneously, or the cost of obtaining a lock in general. Its purpose is to prevent unnecessary synchronization, thereby keeping your code fast in a multi-threaded environment.
Why volatile is used in singleton?
The volatile prevents memory writes from being re-ordered, making it impossible for other threads to read uninitialized fields of your singleton through the singleton’s pointer.
What is double lock door?
Double lock means that all opening handles are released mechanically when locking from the outside, which makes it impossible to open the doors from the inside. Double lock is activated when locking with a remote control key or with keyless locking, and takes place with a delay of approx.
What can I say instead of double check?
synonyms for double check
- confirm.
- determine.
- divine.
- double-check.
- find out.
- verify.
- check.
- dig.
Is Kotlin object synchronized?
Unlike Java, Kotlin doesn’t have the synchronized keyword. Therefore, to synchronize multiple background operations, you are expected to use either the @Synchronized annotation or the synchronized() standard library inline function.