package pool import (	"errors"	"fmt"	"math/rand"	"testing"	"time" 	"github.com/rclone/rclone/fstest/testy"	"github.com/stretchr/testify/assert") // makes the allocations be unreliablefunc makeUnreliable(bp *Pool) {	bp.alloc = func(size int) ([]byte, error) {		if rand.Intn(3) != 0 {			return nil, errors.New("failed to allocate memory")		}		return make([]byte, size), nil	}	bp.free = func(b []byte) error {		if rand.Intn(3) != 0 {			return errors.New("failed to free memory")		}		return nil	}} func testGetPut(t *testing.T, useMmap bool, unreliable bool) {	bp := New(60*time.Second, 4096, 2, useMmap)	if unreliable {		makeUnreliable(bp)	} 	assert.Equal(t, 0, bp.InUse()) 	b1 := bp.Get()	assert.Equal(t, 1, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 1, bp.Alloced()) 	b2 := bp.Get()	assert.Equal(t, 2, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 2, bp.Alloced()) 	b3 := bp.Get()	assert.Equal(t, 3, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 3, bp.Alloced()) 	bp.Put(b1)	assert.Equal(t, 2, bp.InUse())	assert.Equal(t, 1, bp.InPool())	assert.Equal(t, 3, bp.Alloced()) 	bp.Put(b2)	assert.Equal(t, 1, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 3, bp.Alloced()) 	bp.Put(b3)	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 2, bp.Alloced()) 	addr := func(b []byte) string {		return fmt.Sprintf("%p", &b[0])	}	b1a := bp.Get()	assert.Equal(t, addr(b2), addr(b1a))	assert.Equal(t, 1, bp.InUse())	assert.Equal(t, 1, bp.InPool())	assert.Equal(t, 2, bp.Alloced()) 	b2a := bp.Get()	assert.Equal(t, addr(b1), addr(b2a))	assert.Equal(t, 2, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 2, bp.Alloced()) 	bp.Put(b1a)	bp.Put(b2a)	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 2, bp.Alloced()) 	assert.Panics(t, func() {		bp.Put(make([]byte, 1))	}) 	bp.Flush()	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 0, bp.Alloced())} func testFlusher(t *testing.T, useMmap bool, unreliable bool) {	bp := New(50*time.Millisecond, 4096, 2, useMmap)	if unreliable {		makeUnreliable(bp)	} 	b1 := bp.Get()	b2 := bp.Get()	b3 := bp.Get()	bp.Put(b1)	bp.Put(b2)	bp.Put(b3)	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 2, bp.Alloced())	bp.mu.Lock()	assert.Equal(t, 0, bp.minFill)	assert.Equal(t, true, bp.flushPending)	bp.mu.Unlock() 	checkFlushHasHappened := func(desired int) {		var n int		for i := 0; i < 10; i++ {			time.Sleep(100 * time.Millisecond)			n = bp.InPool()			if n <= desired {				break			}		}		assert.Equal(t, desired, n)	} 	checkFlushHasHappened(0)	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 0, bp.Alloced())	bp.mu.Lock()	assert.Equal(t, 0, bp.minFill)	assert.Equal(t, false, bp.flushPending)	bp.mu.Unlock() 	// Now do manual aging to check it is working properly	bp = New(100*time.Second, 4096, 2, useMmap) 	// Check the new one doesn't get flushed	b1 = bp.Get()	b2 = bp.Get()	bp.Put(b1)	bp.Put(b2) 	bp.mu.Lock()	assert.Equal(t, 0, bp.minFill)	assert.Equal(t, true, bp.flushPending)	bp.mu.Unlock() 	bp.flushAged() 	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 2, bp.Alloced())	bp.mu.Lock()	assert.Equal(t, 2, bp.minFill)	assert.Equal(t, true, bp.flushPending)	bp.mu.Unlock() 	bp.Put(bp.Get()) 	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 2, bp.Alloced())	bp.mu.Lock()	assert.Equal(t, 1, bp.minFill)	assert.Equal(t, true, bp.flushPending)	bp.mu.Unlock() 	bp.flushAged() 	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 1, bp.InPool())	assert.Equal(t, 1, bp.Alloced())	bp.mu.Lock()	assert.Equal(t, 1, bp.minFill)	assert.Equal(t, true, bp.flushPending)	bp.mu.Unlock() 	bp.flushAged() 	assert.Equal(t, 0, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 0, bp.Alloced())	bp.mu.Lock()	assert.Equal(t, 0, bp.minFill)	assert.Equal(t, false, bp.flushPending)	bp.mu.Unlock()} func TestPool(t *testing.T) {	for _, test := range []struct {		name       string		useMmap    bool		unreliable bool	}{		{			name:       "make",			useMmap:    false,			unreliable: false,		},		{			name:       "mmap",			useMmap:    true,			unreliable: false,		},		{			name:       "canFail",			useMmap:    false,			unreliable: true,		},	} {		t.Run(test.name, func(t *testing.T) {			t.Run("GetPut", func(t *testing.T) { testGetPut(t, test.useMmap, test.unreliable) })			t.Run("Flusher", func(t *testing.T) {				if test.name == "canFail" {					testy.SkipUnreliable(t) // fails regularly on macOS				}				testFlusher(t, test.useMmap, test.unreliable)			})		})	}}