One article to understand golang error stack

Golang is a very popular programming language that is often used to develop high-performance network service applications. Compared with other languages, Golang is very convenient and competitive in development and deployment. However, errors caused by irregular coding or other factors during operation can cause errors or crashes in Golang applications. In order to solve the error problem that occurs when the Golang application is running, we need to understand the Golang error stack.

1. What is Golang’s error stack?

Golang’s error stack, or error tracking, refers to tracking and printing out the line number and function call stack of the error message when the program terminates abnormally, so that development members can quickly locate the problem and debug it.

This stack is implemented through a loosely coupled call tracking mechanism and has been provided as a standard library function in Golang. By using the panic and recover functions in our code, we can capture previous panics and perform error handling before the program crashes.

2. Why do you need an error stack?

In the development process, errors are inevitable. Error stack is an essential tool for developers in the debugging and troubleshooting process. If you don't have an error stack, you may not be able to effectively track down bugs in your application and fix them. Additionally, error stacks provide developers with more accurate and reliable error information to troubleshoot issues.

3. How to use Golang’s error stack?

We can use Golang's error stack by following the following steps:

a) Use the panic function in the code to throw an exception.

if err != nil {
  panic(err)
}

b) Use the recover function to capture the panic in the same function that handles the exception, and then print the error tracking information through the fmt.Printf function.

func handleError() {
  if r := recover(); r != nil {
    fmt.Printf("recover: %v\n", r)
    debug.PrintStack()
  }
}

c) We can also use the function runtime.HandleCrash at the top level of the application to handle uncaught panics.

import "runtime"
func main() {
  defer handleError()
  runtime.Goexit()
}

4. The output format of the error stack

According to the official documentation, the output format of the Golang error stack is as follows:

goroutine xx [running]:
runtime/debug.Stack()
    /usr/local/go/src/runtime/debug/print.go:renderLine()

Among them, the front of each line is in the form goroutine id [state] identifier. id is the ID of the thread, state is the status of the thread, where [running] indicates that the thread is currently active. The next few lines provide the complete relationship of the item that was closed (before the error occurred), and the function call stack after the error occurred. The first few lines at the error location show the call frame information, and the following lines show the source file, line number, and function name.

goroutine 18 [running]:
main.main()
    /Users/Larry/example.go:14 +0x80

The error stack information above indicates that the ID of the goroutine that has not been closed is 18, which corresponds to the main.main() function and is located on line 14. This paragraph should help us start locating the problem in our code.

5. Summary

Through error stacks, developers can more quickly and accurately track exceptions in applications, thereby increasing productivity and reducing stress during the development process. In Golang, we can capture and handle exceptions and error messages by using the panic and recover functions. In addition, for students who don’t know much about programming, you can refer to the translations on some foreign websites, which will help you further learn and understand Golang’s error stack.

In short, the Golang bug stack is the key to ensuring the normal operation of Golang applications and quickly troubleshooting problems. It is recommended to include it among the tools before writing.

The above is the detailed content of One article to understand golang error stack. For more information, please follow other related articles on the PHP Chinese website!