JVM学习笔记---栈帧

The stack frame has three parts: local variables, operand stack, and frame data. The sizes of the local variables and operand stack, which are measured in words, depend upon the needs of each individual method. These sizes are determined at compile time and included in the class file data for each method. The size of the frame data is implementation dependent.

栈帧由两部分组成：局部变量区，操作数栈和帧数据区。局部变量区和操作数栈的大小要视对应的方法而定，它们是按字长计算的。编译器在编译时就确定了这些值并放在class文件中。而帧数据区的大小依赖于具体的实现。

 

When the Java Virtual Machine invokes a Java method, it checks the class data to determine the number of words required by the method in the local variables and operand stack. It creates a stack frame of the proper size for the method and pushes it onto the Java stack.

当虚拟机调用一个Java方法时，它从对应类的类型信息中得到此方法的局部变量区和操作数栈的大小，并据此分配栈帧内存，然后压入Java栈中。