Golang 中 runtime 的使用

runtimeruntime

cpuCPUCPUgoroutinedefer

NumCPU

package main

import (
    "fmt"
    "runtime"
)

func main() {
    fmt.Println("cpus:", runtime.NumCPU())
    fmt.Println("goroot:", runtime.GOROOT())
    fmt.Println("archive:", runtime.GOOS)
}

运行结果：

GOMAXPROCS

Golangcpugoroutineruntime.GOMAXPROCS

package main

import (
    "fmt"
    "runtime"
)

func init() {
    runtime.GOMAXPROCS(1)
}

func main() {
    // 任务逻辑...

}

Gosched

goroutineCPUgoroutineGogoroutinegoroutinegoroutine

package main

import (
    "fmt"
    "runtime"
)

func init() {
    runtime.GOMAXPROCS(1)  //使用单核
}

func main() {
    exit := make(chan int)
    go func() {
        defer close(exit)
        go func() {
            fmt.Println("b")
        }()
    }()

    for i := 0; i < 4; i++ {
        fmt.Println("a:", i)

        if i == 1 {
            runtime.Gosched()  //切换任务
        }
    }
    <-exit

}

结果：

使用多核测试：

package main

import (
    "fmt"
    "runtime"
)

func init() {
    runtime.GOMAXPROCS(4)  //使用多核
}

func main() {
    exit := make(chan int)
    go func() {
        defer close(exit)
        go func() {
            fmt.Println("b")
        }()
    }()

    for i := 0; i < 4; i++ {
        fmt.Println("a:", i)

        if i == 1 {
            runtime.Gosched()  //切换任务
        }
    }
    <-exit

}

结果：

main

CPUIOCPU