If I try to use the Java List a warning message comes up “This class shouldn’t be used in Kotlin…” Java lists (and other collections) are mapped types in Kotlin. So you can use Collections.synchronizedList, and it takes and returns a Kotlin List or MutableList. OTOH, synchronizedList is rarely what you actually want: it works … Read more
I think the answer depends on the compiler. The language specifies: At run-time, the result of the assignment expression is the value of the variable after the assignment has occurred. I suppose that theoretically the value could be changed before the second (leftmost) assignment occurs. However, with Sun’s javac compiler, method1 will will turn into: … Read more
This is sort of a side note explanation on some of the details of volatile. Writing this here because it is too much for an comment. I want to give some examples which show how volatile affects visibility, and how that changed in jdk 1.5. Given the following example code: public class MyClass { private … Read more
I have simply used BlockingQueue<Map.Entry<K,V>> in the past. But recently, I came across this Blocking Map for Java. Haven’t used it myself, though.
From the Go Language Spec: For a channel c, the built-in function close(c) records that no more values will be sent on the channel. It is an error if c is a receive-only channel. Sending to or closing a closed channel causes a run-time panic. Closing the nil channel also causes a run-time panic. After … Read more
The most important question here is what is the bottleneck in your case. If the bottleneck is your disk IO, then there isn’t much you can do at the software part. Parallelizing the computation will only make things worse, because reading the file from different parts simultaneously will degrade disk performance. If the bottleneck is … Read more
This is partly because an AtomicInteger is not a general purpose replacement for an Integer. The java.util.concurrent.atomic package summary states: Atomic classes are not general purpose replacements for java.lang.Integer and related classes. They do not define methods such as hashCode and compareTo. (Because atomic variables are expected to be mutated, they are poor choices for … Read more
You’re probably looking forwith (updlock, holdlock). This will make a select grab an exclusive lock, which is required for updates, instead of a shared lock. The holdlock hint tells SQL Server to keep the lock until the transaction ends. FROM TABLE_ITEM with (updlock, holdlock)
Isn’t this what BlockingCollection is designed for? As I understand it, you can wrap your ConcurrentQueue with one of these, and then call Take.