X bytearray turned out to be copying data

-> use memoryview instead

wcfs/wcfs_test.py

@@ -115,7 +115,7 @@ def timeout(parent=context.background()):   # -> ctx
 
 # XXX
 def tdelay():
-    time.sleep(10*time.millisecond)     # XXX -> 1ms ?
+    time.sleep(1*time.millisecond)     # XXX -> 10ms ?
 
 
 # ---- test join/autostart ----
@@ -401,10 +401,10 @@ class tFile:
         mm.unmap(t.fmmap)
         t.f.close()
 
-    # blk returns bytearray view of file[blk].
+    # blk returns memoryview of file[blk].
     def blk(t, blk):
         assert blk <= t._max_tracked
-        return bytearray(t.fmmap[blk*t.blksize:(blk+1)*t.blksize])
+        return memoryview(t.fmmap[blk*t.blksize:(blk+1)*t.blksize])
 
     # cached returns [] with indicating whether a file block is cached or not.
     # 1 - cached, 0 - not cached, fractional (0,1) - some pages of the block are cached some not.
@@ -973,8 +973,10 @@ def test_wcfs():
         ev.append('pin ack')
         pin.ack()
 
-    ev.append('read pre')
+    assert f.cached()[2] == 0
     blk = f.blk(2)
+    assert f.cached()[2] == 0
+    ev.append('read pre')
     blk[0] # read access -> XXX without GIL
     ev.append('read post')