java - 不同的 (HotSpot) JVM 线程类型有什么作用？

Question

我看到在 HotSpot JVM 中实现了六种线程类型:VMThread、CGCThread、PGCThread、JavaThread、CompilerThread 和 WatcherThread。但是我不知道哪种线程类型在做什么。到目前为止，这是我的理解:

• VMThread:运行 VM 任务，如垃圾收集器。
• CGCThread:并发垃圾收集器。
• PGCThread:并行垃圾收集器(与 CGC 的区别？)。
• JavaThread:我猜是程序的线程。
• CompilerThread:编译器线程？
• 观察线程: ?

附加问题:其他 JVM 呢？

Answer 1

您可以在 OpenJDK website 上找到简要说明。 :

The main kinds of VM threads are as follows:

• VM thread: This singleton instance of VMThread is responsible for executing VM operations, which are discussed below
• Periodic task thread: This singleton instance of WatcherThread simulates timer interrupts for executing periodic operations within the VM
• GC threads: These threads, of different types, support parallel and concurrent garbage collection
• Compiler threads: These threads perform runtime compilation of bytecode to native code
• Signal dispatcher thread: This thread waits for process directed signals and dispatches them to a Java level signal handling method

您可能想阅读整个线程管理段落，因为它继续进行进一步的解释，例如VM 线程负责什么。