github.com/panjjo/go@v0.0.0-20161104043856-d62b31386338/misc/cgo/stdio/chain.go (about)

     1  // cmpout
     2  
     3  // Copyright 2009 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // +build test_run
     8  
     9  // Pass numbers along a chain of threads.
    10  
    11  package main
    12  
    13  import (
    14  	"runtime"
    15  	"strconv"
    16  
    17  	"../stdio"
    18  )
    19  
    20  const N = 10
    21  const R = 5
    22  
    23  func link(left chan<- int, right <-chan int) {
    24  	// Keep the links in dedicated operating system
    25  	// threads, so that this program tests coordination
    26  	// between pthreads and not just goroutines.
    27  	runtime.LockOSThread()
    28  	for {
    29  		v := <-right
    30  		stdio.Stdout.WriteString(strconv.Itoa(v) + "\n")
    31  		left <- 1 + v
    32  	}
    33  }
    34  
    35  func main() {
    36  	leftmost := make(chan int)
    37  	var left chan int
    38  	right := leftmost
    39  	for i := 0; i < N; i++ {
    40  		left, right = right, make(chan int)
    41  		go link(left, right)
    42  	}
    43  	for i := 0; i < R; i++ {
    44  		right <- 0
    45  		x := <-leftmost
    46  		stdio.Stdout.WriteString(strconv.Itoa(x) + "\n")
    47  	}
    48  }