Golang is a powerful programming language that is gradually becoming more and more popular when writing high-concurrency and high-availability applications. In Golang, we can implement blocking in a very simple and intuitive way. In this article, we will take a deep dive into how blocking mechanism is implemented in Golang.
First of all, we need to understand what blocking is. Blocking means that when a task is in a waiting state and cannot proceed to the next step, the system or thread is blocked. When a system or thread is blocked, it cannot respond to any requests or operations until the block is released.
In Golang, the way we implement blocking is by waiting for the goroutine to complete or receive data from the channel. Let's take a look at the implementation of these methods:
Waiting for goroutine to complete
Goroutine is an important feature of Golang, which allows us to create lightweight threads that can perform multiple tasks at the same time . In Golang, we can use goroutine to implement concurrent operations. When using goroutines, we need to wait for them to complete their tasks.
In order to wait for goroutine to complete the task, we can use WaitGroup in Golang. WaitGroup is a counting semaphore. When its value is 0, goroutine will continue to execute. We can use the Add() method to add tasks, the Done() method to decrement the task count, and then use the Wait() method to wait for all tasks to complete.
The following is a sample code that uses WaitGroup to wait for goroutine to complete:
package main import ( "fmt" "sync" "time" ) func main() { var wg sync.WaitGroup for i := 0; i < 5; i++ { wg.Add(1) go func(i int) { defer wg.Done() time.Sleep(time.Second) fmt.Println("goroutine ", i, "done") }(i) } wg.Wait() fmt.Println("all goroutines done") }
In the above code, we use WaitGroup to wait for 5 goroutines to complete the task. We use the Add() method to add tasks, and then use the Done() method to decrement the task count after the goroutine execution is completed. Finally, we use the Wait() method to wait for all goroutines to complete their tasks.
Receive channel data
In Golang, we can also use channels to implement blocking mechanisms. A channel is a special data structure used to pass data between goroutines. In Golang, we can use select statements to wait for channel data.
The following is a sample code that uses a channel to wait for data:
package main import ( "fmt" "time" ) func main() { ch := make(chan string) go func() { time.Sleep(time.Second) ch <- "goroutine done" }() select { case res := <-ch: fmt.Println(res) case <-time.After(time.Second * 2): fmt.Println("timeout") } }
In the above code, we create a channel ch and use goroutine to input data to the channel. Then, we use a select statement to wait for data from the channel. If no data is received within a certain period of time, the timeout branch will be triggered.
The above are examples of using WaitGroup and channels to implement blocking in Golang. In actual development, we can choose the appropriate blocking method as needed.
To sum up, Golang provides a variety of ways to implement blocking. We can use WaitGroup to wait for the goroutine to complete the task, or we can use the select statement to wait for the channel data. Using these methods, we can easily implement the blocking mechanism in Golang to write high-concurrency and high-availability applications.
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