多线程在JAVA中进程或线程需要什么样的资源

Question

我偶然发现了Java文档，上面说

Both processes and threads provide an execution environment, but creating a new thread requires fewer resources than creating a new process.

参考：https://docs.oracle.com/javase/tutorial/essential/concurrency/procthread.html

在这种情况下，我们所说的资源究竟是什么意思

EDIT1:

还有为什么Runnable比Threads快

什么是通用资源

双方使用的资源有什么不同

Answer 1

生成一个新进程将创建一个新的Java虚拟机

其中as线程将共享内存、JVM等

JVM不是轻量级程序，因此会消耗更多内存等

有些JVM是多进程的，允许多个进程共享一个JVM

从问题中的链接教程： https://docs.oracle.com/javase/tutorial/essential/concurrency/procthread.html

A process generally has a complete, private set of basic run-time resources; in particular, each process has its own memory space.

及

Threads share the process's resources, including memory and open files. This makes for efficient, but potentially problematic, communication.

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要解决编辑1

首先让我们定义一些通用的计算术语

操作系统概念

资源 从https://en.wikipedia.org/wiki/System_resource

In computing, a system resource, or simply resource, is any physical or virtual component of limited availability within a computer system. Every device connected to a computer system is a resource. Every internal system component is a resource. Virtual system resources include files (concretely file handles), network connections (concretely network sockets), and memory areas

过程 https://en.wikipedia.org/wiki/Process_(computing)

In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system (OS), a process may be made up of multiple threads of execution that execute instructions concurrently.

线程 https://en.wikipedia.org/wiki/Thread_(computing)

In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system.

Java概念

过程

与Java有关，一个进程通常运行一个单独的JVM、不同的堆等

线程

线程共享一个JVM，并且能够访问相同的类和内存，但由于它们是Java之外的一个概念，与操作系统有关，因此在交互/创建它们时存在开销

可运行-https://docs.oracle.com/javase/7/docs/api/java/lang/Runnable.html

Runnable是一个仅包含在Java中的概念，操作系统并不知道，它实际上只是一个带有一个名为run的方法的接口，但是您需要自己处理运行它

将其从线程中抽象出来的原因是，涉及线程本身的类必须考虑与底层操作系统绑定的兼容性，您的runnable不需要知道这些，它只是预期在Java上下文中运行的代码

它实际上只是一个标记，向其他人显示您计划通过线程或其他形式的计划执行来运行它

其中as线程是由操作系统管理的外部概念，因此与内存、上下文切换等相关的成本

进程的成本甚至更高，并且有不共享的独立程序内存

Answer 2

与环境有关的一切，如cpu、内存、磁盘、网络等