A story about a programmer who is not familiar with the inside of Java and investigated HotSpot VM
Background
--Investigate the internal implementation of String
--@HotSpotIntrinsicCandidate <-What? Temee ……
--It seems that something called HotSpot VM is related, so check it
HotSpot VM: JVM that implements HotSpot HotSpot: Oracle's JVM Acceleration Description
To summarize very roughly, "Technology that caches frequently used parts and speeds up Java execution"
Experience shows that a small number of processes are often called, and others are rarely called (for example, 20% of all processes occupy 80% of the execution time). Therefore, it seems that if you cache 20% of it, it will be faster.
When executing Java, Java code written by humans is converted into bytecode (JVM language), and the JVM language is interpreted by the JVM interpreter and the program is executed. Without HotSpot, the JVM interprets the Java code in the heap area one by one and executes the process, but this has the problem of slow processing speed. When the same bytecode is called many times by the JVM, HotSpot compiles that part into machine language and caches it. In this way, the processing of frequently called parts of the program is speeded up.
https://www.atmarkit.co.jp/fjava/special/jvmhistory/jvmhistory01.html https://www.atmarkit.co.jp/ait/articles/0403/11/news096.html https://ja.wikipedia.org/wiki/HotSpot
Recommended Posts