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javajvmjvm-arguments

What does the ":=" indicate in the JVM arguments list, in OpenJDK?

I wanted to see all the JVM arguments available in openjdk 1.8, and executed the following command:

java -XX:+PrintFlagsFinal -version

It outputted all the available arguments in JVM, and I observed that a few flags are having the following format:

uintx MaxHeapSize   := 9449766912  {product} 

bool UseParallelGC  := true        {product}

In the above flags, what does the ":=" indicate?

Solution

  • := denotes that the flag value was overriden either by JVM ergonomics or manually via a command line option.

    Here is the source of the function that prints flags.