“调用堆栈”和“任务队列”之间的区别

Question

I'm a developer having difficulties in differentiating between the terms Call Stack and Task Queue . Is there anyone who can help me explain the difference?

Thanks in advance.

Answer 1

eg.

in JavaScript there is function called timeout. when you call the function timeout on the "call stack" it would register in "job queue". It won't fire immediately, but will be triggered once the time is reached.

timeout(function(){
    console.log("one");
}, 100);

console.log("two");

in call stack, console.log("one") is triggered first, but in job queue, the result will display after two .

Answer 2

A job queue (sometimes batch queue), is a data structure maintained by job scheduler software containing jobs to run.

https://en.wikipedia.org/wiki/Job_queue

A call stack is a stack data structure that stores information about the active subroutines of a computer program. This kind of stack is also known as an execution stack, control stack, run-time stack, or machine stack, and is often shortened to just "the stack".

https://en.wikipedia.org/wiki/Call_stack

So in short, a job queue is a queue of things to do (usually stored persistant) and a call stack is a stack of routines.

A job would have variables assigned to it, and a call stack would be the abstract implementation.

So a job could "call" a method from a call stack.

EDIT: There could be a list of jobs;

• Resize foo.jpg to 100x100
• Resize bar.png to 100x100

and each job would run a call stack multiple times;

First job

• Copy foo.jpg into memory
• Resize it to be 100x100
• Store the resized foo.jpg in the thumbs folder

Second job:

• Copy bar.png into memory
• Resize it to be 100x100
• Store the resized foo.jpg in the thumbs folder