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// Copyright (C) 2018 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package model
import "testing"
func TestZeroByteSempahore(t *testing.T) {
// A semaphore with zero capacity is just a no-op.
s := newByteSemaphore(0)
// None of these should block or panic
s.take(123)
s.take(456)
s.give(1 << 30)
}
func TestByteSempahoreCapChangeUp(t *testing.T) {
// Waiting takes should unblock when the capacity increases
s := newByteSemaphore(100)
s.take(75)
if s.available != 25 {
t.Error("bad state after take")
}
gotit := make(chan struct{})
go func() {
s.take(75)
close(gotit)
}()
s.setCapacity(155)
<-gotit
if s.available != 5 {
t.Error("bad state after both takes")
}
}
func TestByteSempahoreCapChangeDown1(t *testing.T) {
// Things should make sense when capacity is adjusted down
s := newByteSemaphore(100)
s.take(75)
if s.available != 25 {
t.Error("bad state after take")
}
s.setCapacity(90)
if s.available != 15 {
t.Error("bad state after adjust")
}
s.give(75)
if s.available != 90 {
t.Error("bad state after give")
}
}
func TestByteSempahoreCapChangeDown2(t *testing.T) {
// Things should make sense when capacity is adjusted down, different case
s := newByteSemaphore(100)
s.take(75)
if s.available != 25 {
t.Error("bad state after take")
}
s.setCapacity(10)
if s.available != 0 {
t.Error("bad state after adjust")
}
s.give(75)
if s.available != 10 {
t.Error("bad state after give")
}
}
func TestByteSempahoreGiveMore(t *testing.T) {
// We shouldn't end up with more available than we have capacity...
s := newByteSemaphore(100)
s.take(150)
if s.available != 0 {
t.Errorf("bad state after large take")
}
s.give(150)
if s.available != 100 {
t.Errorf("bad state after large take + give")
}
s.take(150)
s.setCapacity(125)
// available was zero before, we're increasing capacity by 25
if s.available != 25 {
t.Errorf("bad state after setcap")
}
s.give(150)
if s.available != 125 {
t.Errorf("bad state after large take + give with adjustment")
}
}
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