package pool import (	"context"	"errors"	"fmt"	"math/rand"	"sync"	"testing"	"time" 	"github.com/rclone/rclone/fs"	"github.com/rclone/rclone/fstest/testy"	"github.com/stretchr/testify/assert") // makes the allocations be unreliablefunc makeUnreliable(bp *Pool) {	var allocCount int	tests := rand.Intn(4) + 1	bp.alloc = func(size int) ([]byte, error) {		allocCount++		if allocCount%tests != 0 {			return nil, errors.New("failed to allocate memory")		}		return make([]byte, size), nil	}	var freeCount int	bp.free = func(b []byte) error {		freeCount++		if freeCount%tests != 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()) 	bs := bp.GetN(3)	assert.Equal(t, 6, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 6, bp.Alloced()) 	bp.Put(b1)	assert.Equal(t, 5, bp.InUse())	assert.Equal(t, 1, bp.InPool())	assert.Equal(t, 6, bp.Alloced()) 	bp.Put(b2)	assert.Equal(t, 4, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 6, bp.Alloced()) 	bp.Put(b3)	assert.Equal(t, 3, bp.InUse())	assert.Equal(t, 2, bp.InPool())	assert.Equal(t, 5, bp.Alloced()) 	bp.PutN(bs)	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()) 	bsa := bp.GetN(3)	assert.Equal(t, addr(b1), addr(bsa[1]))	assert.Equal(t, addr(b2), addr(bsa[0]))	assert.Equal(t, 3, bp.InUse())	assert.Equal(t, 0, bp.InPool())	assert.Equal(t, 3, bp.Alloced()) 	bp.PutN(bsa)	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 range 10 {			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)			})		})	}} func TestPoolMaxBufferMemory(t *testing.T) {	ctx := context.Background()	ci := fs.GetConfig(ctx)	ci.MaxBufferMemory = 4 * 4096	defer func() {		ci.MaxBufferMemory = 0		totalMemory = nil	}()	totalMemoryInit = sync.Once{} // reset the sync.Once as it likely has been used	totalMemory = nil	bp := New(60*time.Second, 4096, 2, true)	assert.NotNil(t, totalMemory) 	assert.Equal(t, bp.alloced, 0)	buf := bp.Get()	bp.Put(buf)	assert.Equal(t, bp.alloced, 1) 	var (		wg       sync.WaitGroup		mu       sync.Mutex		bufs     int		maxBufs  int		countBuf = func(i int) {			mu.Lock()			defer mu.Unlock()			bufs += i			if bufs > maxBufs {				maxBufs = bufs			}		}	)	const trials = 50	for i := range trials {		wg.Go(func() {			if i < trials/2 {				n := i%4 + 1				buf := bp.GetN(n)				countBuf(n)				time.Sleep(1 * time.Millisecond)				countBuf(-n)				bp.PutN(buf)			} else {				buf := bp.Get()				countBuf(1)				time.Sleep(1 * time.Millisecond)				countBuf(-1)				bp.Put(buf)			}		})	} 	wg.Wait() 	assert.Equal(t, bufs, 0)	assert.Equal(t, maxBufs, 4)	assert.Equal(t, bp.alloced, 2)}