.

wcfs/wcfs.go

@@ -622,7 +622,7 @@ type Watch struct {
 	link *WatchLink // link to client
 	file *BigFile	// XXX needed?
 
-	mu     sync.Mutex	// XXX ok ?
+	mu     sync.Mutex	// XXX split -> atMu(RW) + pinnedMu
 	at     zodb.Tid               // requested to be watched @at
 	pinned map[int64]*blkPinState // {} blk -> {... rev}  blocks that are already pinned to be ≤ at
 }
@@ -1298,7 +1298,7 @@ func (w *Watch) _pin(ctx context.Context, blk int64, rev zodb.Tid) (err error) {
 
 	w.mu.Lock()
 
-	// XXX ignore vvv ? (w.at could be ↑ after precheck in read (XXX or setupBlk)
+	// XXX ignore vvv ? (w.at could be ↑ after precheck in read (XXX or setupWatch)
 	if wat := w.at; !(rev == zodb.TidMax || rev <= wat) {
 		w.mu.Unlock()
 		panicf("f<%s>: wlink%d: pin #%d @%s: watch.at (%s) < rev",
@@ -1383,7 +1383,7 @@ func (w *Watch) _pin(ctx context.Context, blk int64, rev zodb.Tid) (err error) {
 //
 // XXX do we really need to use/propagate caller context here? ideally update
 // watchers should be synchronous, and in practice we just use 30s timeout.
-// Should a READ interrupt cause watch update failure?
+// Should a READ interrupt cause watch update failure? -> probably no
 func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btree.LONode, zblk zBlk, blkrevMax zodb.Tid) {
 	// only head/ is being watched for
 	if f.head.rev != 0 {
@@ -1418,7 +1418,7 @@ func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btr
 		// XXX locking (w)
 
 		// the block is already covered by @w.at database view
-		if blkrev <= w.at {
+		if blkrev <= w.at {	// XXX locking
 			continue
 		}
 
@@ -1429,7 +1429,7 @@ func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btr
 			blkrevRough = false
 
 			// XXX w.at could be only ↑ ? if not - locking is more complex
-			if blkrev <= w.at {
+			if blkrev <= w.at {	// XXX locking
 				continue
 			}
 		}
@@ -1440,7 +1440,7 @@ func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btr
 		// and most of them would be on different w.at - cache of the file will
 		// be lost. Via pinning to particular block revision, we make sure the
 		// revision to pin is the same on all clients, and so file cache is shared.
-		pinrev, _ := w.file.LastBlkRev(ctx, blk, w.at)	// XXX move into go?
+		pinrev, _ := w.file.LastBlkRev(ctx, blk, w.at)	// XXX locking (w), move into go?
 
 		wg.Go(func() error {
 			// XXX close watcher on any error

wcfs/wcfs_test.py

@@ -60,7 +60,7 @@ def setup_module():
     install_sigbus_trap()
 
     # if wcfs.go is built with race detector and detects a race - make it fail
-    # current test loudly on the first wcfs.go race
+    # current test loudly on the first wcfs.go race.
     gorace = os.environ.get("GORACE", "")
     if gorace != "":
         gorace += " "