运行程序时会发生什么? [英] What happens when you run a program?

问题描述

我想在这里收集在Windows，Linux和OSX上运行可执行文件时发生的情况.特别是，我想确切地了解操作的顺序:我的猜测是可执行文件格式(PE，ELF或Mach-O)是由内核加载的(但我忽略了 ELF (可执行和可链接格式)及其含义)，然后有了可以解析引用的动态链接器，然后先运行可执行文件的__init部分，然后运行主文件，然后运行__fini，然后完成程序，但是我确信它非常粗糙，并且可能是错误的.

I would like to collect here what happens when you run an executable on Windows, Linux and OSX. In particular, I would like to understand exactly the order of the operations: my guess is that the executable file format (PE, ELF or Mach-O) is loaded by the kernel (but I ignore the various sections of the ELF（Executable and Linkable Format） and their meaning), and then you have the dynamic linker that resolves the references, then the __init part of the executable is run, then the main, then the __fini, and then the program is completed, but I am sure it's very rough, and probably wrong.

编辑:现在的问题是CW.我正在为Linux加油.如果有人想对Win和OSX做同样的事情，那就太好了.

Edit: the question is now CW. I am filling up for linux. If anyone wants to do the same for Win and OSX it would be great.

推荐答案

这当然是非常抽象的级别！

This is just at a very high and abstract level of course!

Executable - No Shared Libary: 

Client request to run application
  ->Shell informs kernel to run binary
  ->Kernel allocates memory from the pool to fit the binary image into
  ->Kernel loads binary into memory
  ->Kernel jumps to specific memory address
  ->Kernel starts processing the machine code located at this location
  ->If machine code has stop
  ->Kernel releases memory back to pool

Executable - Shared Library

Client request to run application
  ->Shell informs kernel to run binary
  ->Kernel allocates memory from the pool to fit the binary image into
  ->Kernel loads binary into memory
  ->Kernel jumps to specific memory address
  ->Kernel starts processing the machine code located at this location
  ->Kernel pushes current location into an execution stack
  ->Kernel jumps out of current memory to a shared memory location
  ->Kernel executes code from this shared memory location
  ->Kernel pops back the last memory location and jumps to that address
  ->If machine code has stop
  ->Kernel releases memory back to pool

JavaScript/.NET/Perl/Python/PHP/Ruby (Interpretted Languages)

Client request to run application
  ->Shell informs kernel to run binary
  ->Kernel has a hook that recognises binary images needs a JIT
  ->Kernel calls JIT
  ->JIT loads the code and jumps to a specific address
  ->JIT reads the code and compiles the instruction into the 
    machine code that the interpretter is running on
  ->Interpretture passes machine code to the kernel
  ->kernel executes the required instruction
  ->JIT then increments the program counter
  ->If code has a stop
  ->Jit releases application from its memory pool

正如routeNpingme所说，寄存器设置在CPU内部，魔术就发生了！

As routeNpingme says, registers are set inside the CPU and the magic happens!

更新:是的，我今天不能正确讲话！

Update: Yeah, I cant speell properly today!

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