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32 lines
680 B
Go
32 lines
680 B
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 261.
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//!+
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// Package bank provides a concurrency-safe bank with one account.
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package bank
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var deposits = make(chan int) // send amount to deposit
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var balances = make(chan int) // receive balance
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func Deposit(amount int) { deposits <- amount }
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func Balance() int { return <-balances }
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func teller() {
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var balance int // balance is confined to teller goroutine
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for {
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select {
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case amount := <-deposits:
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balance += amount
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case balances <- balance:
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}
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}
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}
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func init() {
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go teller() // start the monitor goroutine
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}
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//!-
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