From 43a123c1ae6613b3efeed291fa552ecd909d3acf Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:23:18 +0200 Subject: Adding upstream version 1.20.14. Signed-off-by: Daniel Baumann --- test/sieve.go | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 test/sieve.go (limited to 'test/sieve.go') diff --git a/test/sieve.go b/test/sieve.go new file mode 100644 index 0000000..0cd120c --- /dev/null +++ b/test/sieve.go @@ -0,0 +1,45 @@ +// build + +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Test basic concurrency: the classic prime sieve. +// Do not run - loops forever. + +package main + +// Send the sequence 2, 3, 4, ... to channel 'ch'. +func Generate(ch chan<- int) { + for i := 2; ; i++ { + ch <- i // Send 'i' to channel 'ch'. + } +} + +// Copy the values from channel 'in' to channel 'out', +// removing those divisible by 'prime'. +func Filter(in <-chan int, out chan<- int, prime int) { + for { + i := <-in // Receive value of new variable 'i' from 'in'. + if i%prime != 0 { + out <- i // Send 'i' to channel 'out'. + } + } +} + +// The prime sieve: Daisy-chain Filter processes together. +func Sieve() { + ch := make(chan int) // Create a new channel. + go Generate(ch) // Start Generate() as a subprocess. + for { + prime := <-ch + print(prime, "\n") + ch1 := make(chan int) + go Filter(ch, ch1, prime) + ch = ch1 + } +} + +func main() { + Sieve() +} -- cgit v1.2.3