通常，线程被称为轻量级进程。如果我们把内存分成三个部分，那么它将是:代码，数据和堆栈。 每个进程都有自己的代码、数据和堆栈部分，由于这种上下文切换时间有点高。为了减少上下文切换的时间，人们提出了线程的概念，它与其他线程/进程共享数据和代码段，并拥有自己的堆栈段。

In an x86 framework, one can divide as many segments (up to 2^16-1). The ASM directives SEGMENT/ENDS allows this, and the operators SEG and OFFSET allows initialization of segment registers. CS:IP are usually initialized by the loader, but for DS, ES, SS the application is responsible with initialization. Many environments allow the so-called "simplified segment definitions" like .code, .data, .bss, .stack etc. and, depending also on the "memory model" (small, large, compact etc.) the loader initializes segment registers accordingly. Usually .data, .bss, .stack and other usual segments (I haven't done this since 20 years so I don't remember all) are grouped in one single group - that is why usually DS, ES and SS points to teh same area, but this is only to simplify things.

一般来说，所有段寄存器在运行时都可以有不同的值。 所以，面试的问题是正确的:CODE、DATA和STACK中的哪一个在线程之间共享。堆管理是另一回事——它只是对操作系统的一系列调用。但是如果你根本没有操作系统，比如在嵌入式系统中，你还能在你的代码中新建/删除吗?

我给年轻人的建议是——读一些好的汇编编程书。似乎大学的课程在这方面相当贫乏。

线程共享堆(有一个关于线程特定堆的研究)，但当前的实现共享堆。(当然还有代码)

线程共享数据和代码，而进程不共享。栈不是为两者共享的。

进程也可以共享内存，更精确的代码，例如Fork()之后，但这是一个实现细节和(操作系统)优化。由多个进程共享的代码将(希望)在第一次写入代码时复制—这被称为写时复制。我不确定线程代码的确切语义，但我假设是共享代码。

           Process   Thread

   Stack   private   private
   Data    private   shared
   Code    private1  shared2

代码在逻辑上是私有的，但出于性能原因可能会被共享。 我不能百分之百肯定。

通常，线程被称为轻量级进程。如果我们把内存分成三个部分，那么它将是:代码，数据和堆栈。 每个进程都有自己的代码、数据和堆栈部分，由于这种上下文切换时间有点高。为了减少上下文切换的时间，人们提出了线程的概念，它与其他线程/进程共享数据和代码段，并拥有自己的堆栈段。

A process has code, data, heap and stack segments. Now, the Instruction Pointer (IP) of a thread OR threads points to the code segment of the process. The data and heap segments are shared by all the threads. Now what about the stack area? What is actually the stack area? Its an area created by the process just for its thread to use... because stacks can be used in a much faster way than heaps etc. The stack area of the process is divided among threads, i.e. if there are 3 threads, then the stack area of the process is divided into 3 parts and each is given to the 3 threads. In other words, when we say that each thread has its own stack, that stack is actually a part of the process stack area allocated to each thread. When a thread finishes its execution, the stack of the thread is reclaimed by the process. In fact, not only the stack of a process is divided among threads, but all the set of registers that a thread uses like SP, PC and state registers are the registers of the process. So when it comes to sharing, the code, data and heap areas are shared, while the stack area is just divided among threads.