X wcfs: tests: Split tDB into -> tDB + tWCFS

tWCFS is responsible for starting/mounting/unmounting/stopping wcfs
tDB uses tWCFS and provides commit/test service on top.

We'll use tWCFS in the next patch to unmount/stop WCFS processes that
are automatically spawned during test.py

wcfs/internal/wcfs_test.pyx

@@ -36,12 +36,12 @@ from cpython.exc cimport PyErr_SetFromErrno
 from golang cimport chan, pychan, select, panic, topyexc, cbool
 from golang cimport sync, time
 
-# _tDB is pyx part of tDB.
-cdef class _tDB:
+# _tWCFS is pyx part of tWCFS.
+cdef class _tWCFS:
     cdef readonly pychan _closed            # chan[structZ]
     cdef readonly pychan _wcfuseaborted     # chan[structZ]
 
-    def __cinit__(_tDB t):
+    def __cinit__(_tWCFS t):
         t._closed        = pychan(dtype='C.structZ')
         t._wcfuseaborted = pychan(dtype='C.structZ')
 
@@ -53,7 +53,7 @@ cdef class _tDB:
     # but pin handler is failing one way or another - select will wake-up
     # but, if _abort_ontimeout uses GIL, won't continue to run trying to lock
     # GIL -> deadlock.
-    def _abort_ontimeout(_tDB t, double dt, pychan nogilready not None):
+    def _abort_ontimeout(_tWCFS t, double dt, pychan nogilready not None):
         cdef chan[double] timeoutch = time.after(dt)
         cdef int fdabort = t._wcfuseabort.fileno()
         emsg1 = "\nC: test timed out after %.1fs\n" % (dt / time.second)
@@ -63,7 +63,7 @@ cdef class _tDB:
             nogilready.chan_structZ().close()
             t.__abort_ontimeout(dt, timeoutch, fdabort, _emsg1)
 
-    cdef void __abort_ontimeout(_tDB t, double dt, chan[double] timeoutch,
+    cdef void __abort_ontimeout(_tWCFS t, double dt, chan[double] timeoutch,
                 int fdabort, const char *emsg1) nogil except +topyexc:
         _ = select([
             timeoutch.recvs(),                  # 0

wcfs/wcfs_test.py

@@ -53,7 +53,7 @@ from zodbtools.util import ashex as h, fromhex
 import pytest; xfail = pytest.mark.xfail
 from pytest import raises, fail
 from wendelin.wcfs.internal import io, mm
-from wendelin.wcfs.internal.wcfs_test import _tDB, read_nogil, install_sigbus_trap, fadvise_dontneed
+from wendelin.wcfs.internal.wcfs_test import _tWCFS, read_nogil, install_sigbus_trap, fadvise_dontneed
 from wendelin.wcfs.client._wcfs import _tpywlinkwrite as _twlinkwrite
 
 
@@ -195,7 +195,7 @@ class DFile:
         # rev set from outside
         dfile.ddata = {}
 
-# tDB provides database/wcfs testing environment.
+# tDB/tWCFS provides database/wcfs testing environment.
 #
 # Database root and wcfs connection are represented by .root and .wc correspondingly.
 # The database is initialized with one ZBigFile created and opened via ZODB connection as .zfile .
@@ -212,16 +212,9 @@ class DFile:
 # tDB must be explicitly closed once no longer used.
 #
 # XXX print -> t.trace/debug() + t.verbose depending on py.test -v -v ?
-class tDB(_tDB):
+class tWCFS(_tWCFS):
     @func
     def __init__(t):
-        t.root = testdb.dbopen()
-        def _(): # close/unlock db if __init__ fails
-            exc = sys.exc_info()[1]
-            if exc is not None:
-                dbclose(t.root)
-        defer(_)
-
         assert not os.path.exists(testmntpt)
         t.wc = wcfs.join(testzurl, autostart=True)
         assert t.wc.mountpoint == testmntpt
@@ -239,6 +232,62 @@ class tDB(_tDB):
         go(t._abort_ontimeout, 10*time.second, nogilready)   # NOTE must be: with_timeout << · << wcfs_pin_timeout
         nogilready.recv()   # wait till _abort_ontimeout enters nogil
 
+    # close closes connection to wcfs, unmounts the filesystem and makes sure
+    # that wcfs server exits.
+    @func
+    def close(t):
+        defer(t._wcfuseabort.close)
+        defer(t._closed.close)
+
+        # unmount and wait for wcfs to exit
+        def _():
+            assert not is_mountpoint(t.wc.mountpoint)
+            os.rmdir(t.wc.mountpoint)
+        defer(_)
+        def _():
+            # kill wcfs.go in case it is deadlocked and does not exit by itself
+            if procwait_(timeout(), t.wc._proc):
+                return
+            eprint("\nC: wcfs.go does not exit")
+            eprint("-> kill -QUIT wcfs.go ...\n")
+            os.kill(t.wc._proc.pid, SIGQUIT)
+
+            if procwait_(timeout(), t.wc._proc):
+                return
+            eprint("\nC: wcfs.go does not exit (after SIGQUIT)")
+            eprint("-> kill -KILL wcfs.go ...\n")
+            os.kill(t.wc._proc.pid, SIGKILL)
+
+            if procwait_(timeout(), t.wc._proc):
+                return
+            eprint("\nC: wcfs.go does not exit (after SIGKILL; probably it is stuck in kernel)")
+            eprint("-> nothing we can do...\n")  # XXX dump /proc/pid/task/*/stack instead  (ignore EPERM)
+            fail("wcfs.go does not exit even after SIGKILL")
+        defer(_)
+        def _():
+            #if not ready(t._wcfuseaborted):    XXX kill _wcfuseaborted ?
+            #    assert 0 == subprocess.call(["mountpoint", "-q", t.wc.mountpoint])
+            assert is_mountpoint(t.wc.mountpoint)
+            subprocess.check_call(["fusermount", "-u", t.wc.mountpoint])
+        defer(_)
+
+        t.wc.close()
+
+
+class tDB(tWCFS):
+    @func
+    def __init__(t):
+        t.root = testdb.dbopen()
+        def _(): # close/unlock db if __init__ fails
+            exc = sys.exc_info()[1]
+            if exc is not None:
+                dbclose(t.root)
+        defer(_)
+
+        # start wcfs after testdb is created
+        super(tDB, t).__init__()
+
+
         # ZBigFile(s) scheduled for commit
         t._changed = {} # ZBigFile -> {} blk -> data
 
@@ -278,42 +327,9 @@ class tDB(_tDB):
     # it also prints change history to help developer overview current testcase.
     @func
     def close(t):
-        defer(t._wcfuseabort.close)
-        defer(t._closed.close)
+        defer(super(tDB, t).close)
         defer(lambda: dbclose(t.root))
 
-        # unmount and wait for wcfs to exit
-        def _():
-            assert not is_mountpoint(t.wc.mountpoint)
-            os.rmdir(t.wc.mountpoint)
-        defer(_)
-        def _():
-            # kill wcfs.go in case it is deadlocked and does not exit by itself
-            if procwait_(timeout(), t.wc._proc):
-                return
-            eprint("\nC: wcfs.go does not exit")
-            eprint("-> kill -QUIT wcfs.go ...\n")
-            os.kill(t.wc._proc.pid, SIGQUIT)
-
-            if procwait_(timeout(), t.wc._proc):
-                return
-            eprint("\nC: wcfs.go does not exit (after SIGQUIT)")
-            eprint("-> kill -KILL wcfs.go ...\n")
-            os.kill(t.wc._proc.pid, SIGKILL)
-
-            if procwait_(timeout(), t.wc._proc):
-                return
-            eprint("\nC: wcfs.go does not exit (after SIGKILL; probably it is stuck in kernel)")
-            eprint("-> nothing we can do...\n")  # XXX dump /proc/pid/task/*/stack instead  (ignore EPERM)
-            fail("wcfs.go does not exit even after SIGKILL")
-        defer(_)
-        def _():
-            #if not ready(t._wcfuseaborted):    XXX kill _wcfuseaborted ?
-            #    assert 0 == subprocess.call(["mountpoint", "-q", t.wc.mountpoint])
-            assert is_mountpoint(t.wc.mountpoint)
-            subprocess.check_call(["fusermount", "-u", t.wc.mountpoint])
-        defer(_)
-
         defer(t.dump_history)
         for tf in t._files.copy():
             tf.close()
@@ -322,7 +338,6 @@ class tDB(_tDB):
         assert len(t._files)   == 0
         assert len(t._wlinks)  == 0
         t._wc_zheadfh.close()
-        t.wc.close()
 
     # open opens wcfs file corresponding to zf@at and starts to track it.
     # see returned tFile for details.