| Go's _select_ lets you wait on multiple channel operations. Combining goroutines and channels with select is a powerful feature of Go. | ||
package main |
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import ( |
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"fmt" |
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"time" |
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) |
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func main() { |
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| For our example we'll select across two channels. | c1 := make(chan string) |
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c2 := make(chan string) |
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| Each channel will receive a value after some amount of time, to simulate e.g. blocking RPC operations executing in concurrent goroutines. | go func() { |
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time.Sleep(1 * time.Second) |
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c1 <- "one" |
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}() |
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go func() { |
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time.Sleep(2 * time.Second) |
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c2 <- "two" |
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}() |
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| We'll use `select` to await both of these values simultaneously, printing each one as it arrives. | for i := 0; i < 2; i++ { |
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select { |
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case msg1 := <-c1: |
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fmt.Println("received", msg1) |
received one |
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case msg2 := <-c2: |
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fmt.Println("received", msg2) |
received two |
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} |
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} |
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} |