Menu
Can a single thread of a Java program automatically make use of multiple cores on the CPU?
581
About core activityIt's not possible to split a single thread across multiple cores, although a single core may run multiple threads at the same time. This is one reason that you may sometimes see uneven load distributions across the available cores on your computer.
Multithreading is a form of parallelization or dividing up work for simultaneous processing. Instead of giving a large workload to a single core, threaded programs split the work into multiple software threads. These threads are processed in parallel by different CPU cores to save time.
single thread performance is the amount of work completed by some software that runs as a single stream of instructions in a certain amount of time.
Can a single thread of a Java program automatically make use of multiple cores on the CPU?
Yes and no. A single threaded Java program will use multiple threads in that the GC, JMX, finalizer, and other background threads can run in different CPUs (whether CPU or core). The GC threads especially give a significant performance boost if they can be running in another CPU. However, your single threaded application code, although it may move between CPUs, will never be running in 2 CPUs at the same time.
how to find out that?
That's a harder question and it depends on what architecture you are running on. ps under *nix will be able to show if you have multiple threads in the run queue but even then it may not show that they are actually executing in multiple CPUs.
65
Your own code will not run on multiple cores if it is by definition single threaded. No single threaded application can run simultaneously on multiple cores - unless your using underluing multithreaded calls/libraries without knowing.
23
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
