.

go/neo/client/cache.go

@@ -26,6 +26,7 @@ import (
 	"sync"
 	"unsafe"
 
+//	"github.com/kylelemons/godebug/pretty"
 	"lab.nexedi.com/kirr/neo/go/zodb"
 )
 
@@ -103,7 +104,12 @@ type revCacheEntry struct {
 // NewCache creates new cache backed up by loader
 // XXX +sizeMax
 func NewCache(loader storLoader) *Cache {
-	return &Cache{loader: loader, entryMap: make(map[zodb.Oid]*oidCacheEntry)}
+	c := &Cache{
+		loader: loader,
+		entryMap: make(map[zodb.Oid]*oidCacheEntry),
+	}
+	c.lru.Init()
+	return c
 }
 
 // newRevEntry creates new revCacheEntry with .before and inserts it into .rcev @i.
@@ -182,6 +188,7 @@ func (c *Cache) Load(xid zodb.Xid) (data []byte, serial zodb.Tid, err error) {
 
 	// rce is already in cache - use it
 	if !rceNew {
+		//panic(0)
 		<-rce.ready
 		c.gcMu.Lock()
 		rce.inLRU.MoveBefore(&c.lru)
@@ -375,7 +382,14 @@ func (c *Cache) loadRCE(rce *revCacheEntry, oid zodb.Oid) {
 
 	// update lru & cache size
 	c.gcMu.Lock()
+	//xv1 := map[string]interface{}{"lru": &c.lru, "rce": &rce.inLRU}
+	//fmt.Printf("aaa:\n%s\n", pretty.Sprint(xv1))
 	rce.inLRU.MoveBefore(&c.lru)
+	//xv2 := map[string]interface{}{"lru": &c.lru, "rce": &rce.inLRU}
+	//fmt.Printf("\n--------\n%s\n\n\n", pretty.Sprint(xv2))
+
+	//panic(1)
+
 	c.size += δsize
 	if c.size > c.sizeMax {
 		// XXX -> run gc

go/neo/client/cache_test.go

@@ -108,6 +108,8 @@ func xideq(oid zodb.Oid, tid zodb.Tid) zodb.Xid {
 func TestCache(t *testing.T) {
 	// XXX hack; place=ok?
 	pretty.CompareConfig.PrintStringers = true
+	debug := pretty.DefaultConfig
+	debug.IncludeUnexported = true
 
 	// XXX <100 <90 <80
 	//	q<110	-> a) 110 <= cache.before   b) otherwise
@@ -172,19 +174,39 @@ func TestCache(t *testing.T) {
 		t.Helper()
 		oce := c.entryMap[oid]
 		if !reflect.DeepEqual(oce.rcev, rcev) {
-			t.Fatalf("oce(%v):\n%s", oid, pretty.Compare(rcev, oce.rcev))
+			t.Fatalf("oce(%v):\n%s\n", oid, pretty.Compare(rcev, oce.rcev))
+		}
+	}
+
+	checkMRU := func(mruvOk ...*revCacheEntry) {
+		t.Helper()
+		var mruv []*revCacheEntry
+		for hp, h := &c.lru, c.lru.prev; h != &c.lru; hp, h = h, h.prev {
+			xv := []interface{}{&c.lru, h.rceFromInLRU()}
+			debug.Print(xv)	// &c.lru, h.rceFromInLRU())
+			if h.next != hp {
+				t.Fatalf("LRU list .next/.prev broken for\nh:\n%s\n\nhp:\n%s\n",
+					debug.Sprint(h), debug.Sprint(hp))
+			}
+			mruv = append(mruv, h.rceFromInLRU())
+		}
+		if !reflect.DeepEqual(mruv, mruvOk) {
+			t.Fatalf("MRU:\n%s\n", pretty.Compare(mruv, mruvOk))
 		}
 	}
 
 	// ---- verify cache behaviour for must be loaded/merged entries ----
 	// (this excercises mostly loadRCE/tryMerge)
 
+	checkMRU()
+
 	// load <3 -> new rce entry
 	checkLoad(xidlt(1,3), nil, 0, &zodb.ErrXidMissing{xidlt(1,3)})
 	oce1 := c.entryMap[1]
 	ok1(len(oce1.rcev) == 1)
 	rce1_b3 := oce1.rcev[0]
 	checkRCE(rce1_b3, 3, 0, nil, &zodb.ErrXidMissing{xidlt(1,3)})
+	checkMRU(rce1_b3)
 
 	// load <4 -> <3 merged with <4
 	checkLoad(xidlt(1,4), nil, 0, &zodb.ErrXidMissing{xidlt(1,4)})
@@ -192,6 +214,7 @@ func TestCache(t *testing.T) {
 	rce1_b4 := oce1.rcev[0]
 	ok1(rce1_b4 != rce1_b3) // rce1_b3 was merged into rce1_b4
 	checkRCE(rce1_b4, 4, 0, nil, &zodb.ErrXidMissing{xidlt(1,4)})
+	checkMRU(rce1_b4)
 
 	// load <2 -> <2 merged with <4
 	checkLoad(xidlt(1,2), nil, 0, &zodb.ErrXidMissing{xidlt(1,2)})

go/neo/client/list.go

@@ -49,7 +49,7 @@ func (a *listHead) MoveBefore(b *listHead) {
 	a.Delete()
 
 	a.next = b
-	b.prev = a
 	a.prev = b.prev
+	b.prev = a
 	a.prev.next = a
 }