Patchwork D6581: update: fix spurious unclean status bug shown by previous commit

login
register
mail settings
Submitter phabricator
Date June 27, 2019, 11:01 a.m.
Message ID <differential-rev-PHID-DREV-x7mbbbjatcy42qizoceu-req@mercurial-scm.org>
Download mbox | patch
Permalink /patch/40686/
State Superseded
Headers show

Comments

phabricator - June 27, 2019, 11:01 a.m.
valentin.gatienbaron created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  The crux of the problem is:
  
  - the dirstate is corrupted (the sizes/dates are assigned to the wrong files)
  - because when worker.worker is used with a return value (batchget in merge.py here), the return value when worker.worker effectively parallelizes is permuted
  - this is because worker.worker's partition of input and combination of output values are not inverses of one another: it split [1,2,3,4,5,6] into [[1,3,5],[2,4,6]], but combines that into [1,3,5,2,4,6].
  
  Given that worker.worker doesn't call its function argument on contiguous
  chunks on the input arguments, sticking with lists means we'd need to
  know the relation between the inputs of worker.worker function argument
  (for instance, requiring that every input element is mapped to exactly
  one output element). It seems better to instead switch return values to
  dicts, which can combined reliably with a straighforward restriction.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D6581

AFFECTED FILES
  mercurial/merge.py
  mercurial/worker.py
  tests/test-simple-update.t

CHANGE DETAILS




To: valentin.gatienbaron, #hg-reviewers
Cc: mercurial-devel
phabricator - June 27, 2019, 3:05 p.m.
This revision is now accepted and ready to land.
martinvonz added a comment.
martinvonz accepted this revision.


  Thanks for fixing this quickly! The fix looks very straight-forward too.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D6581/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D6581

To: valentin.gatienbaron, #hg-reviewers, martinvonz
Cc: martinvonz, mercurial-devel

Patch

diff --git a/tests/test-simple-update.t b/tests/test-simple-update.t
--- a/tests/test-simple-update.t
+++ b/tests/test-simple-update.t
@@ -110,24 +110,6 @@ 
   getting 100
   100 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg status
-  M 100
-  M 11
-  M 2
-  M 21
-  M 3
-  M 4
-  M 41
-  M 5
-  M 51
-  M 54
-  M 6
-  M 61
-  M 7
-  M 71
-  M 8
-  M 81
-  M 9
-  M 91
 
   $ cd ..
 
diff --git a/mercurial/worker.py b/mercurial/worker.py
--- a/mercurial/worker.py
+++ b/mercurial/worker.py
@@ -100,8 +100,9 @@ 
     workers
 
     hasretval - when True, func and the current function return an progress
-    iterator then a list (encoded as an iterator that yield many (False, ..)
-    then a (True, list)). The resulting list is in the natural order.
+    iterator then a dict (encoded as an iterator that yield many (False, ..)
+    then a (True, dict)). The dicts are joined in some arbitrary order, so
+    overlapping keys are a bad idea.
 
     threadsafe - whether work items are thread safe and can be executed using
     a thread-based worker. Should be disabled for CPU heavy tasks that don't
@@ -162,8 +163,8 @@ 
     ui.flush()
     parentpid = os.getpid()
     pipes = []
-    retvals = []
-    for i, pargs in enumerate(partition(args, workers)):
+    retval = {}
+    for pargs in partition(args, workers):
         # Every worker gets its own pipe to send results on, so we don't have to
         # implement atomic writes larger than PIPE_BUF. Each forked process has
         # its own pipe's descriptors in the local variables, and the parent
@@ -171,7 +172,6 @@ 
         # care what order they're in).
         rfd, wfd = os.pipe()
         pipes.append((rfd, wfd))
-        retvals.append(None)
         # make sure we use os._exit in all worker code paths. otherwise the
         # worker may do some clean-ups which could cause surprises like
         # deadlock. see sshpeer.cleanup for example.
@@ -192,7 +192,7 @@ 
                         os.close(w)
                     os.close(rfd)
                     for result in func(*(staticargs + (pargs,))):
-                        os.write(wfd, util.pickle.dumps((i, result)))
+                        os.write(wfd, util.pickle.dumps(result))
                     return 0
 
                 ret = scmutil.callcatch(ui, workerfunc)
@@ -226,9 +226,9 @@ 
         while openpipes > 0:
             for key, events in selector.select():
                 try:
-                    i, res = util.pickle.load(key.fileobj)
+                    res = util.pickle.load(key.fileobj)
                     if hasretval and res[0]:
-                        retvals[i] = res[1]
+                        retval.update(res[1])
                     else:
                         yield res
                 except EOFError:
@@ -249,7 +249,7 @@ 
             os.kill(os.getpid(), -status)
         sys.exit(status)
     if hasretval:
-        yield True, sum(retvals, [])
+        yield True, retval
 
 def _posixexitstatus(code):
     '''convert a posix exit status into the same form returned by
@@ -281,9 +281,9 @@ 
             try:
                 while not self._taskqueue.empty():
                     try:
-                        i, args = self._taskqueue.get_nowait()
+                        args = self._taskqueue.get_nowait()
                         for res in self._func(*self._staticargs + (args,)):
-                            self._resultqueue.put((i, res))
+                            self._resultqueue.put(res)
                             # threading doesn't provide a native way to
                             # interrupt execution. handle it manually at every
                             # iteration.
@@ -318,11 +318,10 @@ 
     workers = _numworkers(ui)
     resultqueue = pycompat.queue.Queue()
     taskqueue = pycompat.queue.Queue()
-    retvals = []
+    retval = {}
     # partition work to more pieces than workers to minimize the chance
     # of uneven distribution of large tasks between the workers
-    for pargs in enumerate(partition(args, workers * 20)):
-        retvals.append(None)
+    for pargs in partition(args, workers * 20):
         taskqueue.put(pargs)
     for _i in range(workers):
         t = Worker(taskqueue, resultqueue, func, staticargs)
@@ -331,9 +330,9 @@ 
     try:
         while len(threads) > 0:
             while not resultqueue.empty():
-                (i, res) = resultqueue.get()
+                res = resultqueue.get()
                 if hasretval and res[0]:
-                    retvals[i] = res[1]
+                    retval.update(res[1])
                 else:
                     yield res
             threads[0].join(0.05)
@@ -346,13 +345,13 @@ 
         trykillworkers()
         raise
     while not resultqueue.empty():
-        (i, res) = resultqueue.get()
+        res = resultqueue.get()
         if hasretval and res[0]:
-            retvals[i] = res[1]
+            retval.update(res[1])
         else:
             yield res
     if hasretval:
-        yield True, sum(retvals, [])
+        yield True, retval
 
 if pycompat.iswindows:
     _platformworker = _windowsworker
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -1472,10 +1472,10 @@ 
 
     Yields arbitrarily many (False, tuple) for progress updates, followed by
     exactly one (True, filedata). When wantfiledata is false, filedata is an
-    empty list. When wantfiledata is true, filedata[i] is a triple (mode, size,
-    mtime) of the file written for action[i].
+    empty dict. When wantfiledata is true, filedata[f] is a triple (mode, size,
+    mtime) of the file f written for each action.
     """
-    filedata = []
+    filedata = {}
     verbose = repo.ui.verbose
     fctx = mctx.filectx
     ui = repo.ui
@@ -1509,7 +1509,7 @@ 
                 s = wfctx.lstat()
                 mode = s.st_mode
                 mtime = s[stat.ST_MTIME]
-                filedata.append((mode, size, mtime)) # for dirstate.normal
+                filedata[f] = ((mode, size, mtime)) # for dirstate.normal
             if i == 100:
                 yield False, (i, f)
                 i = 0
@@ -1670,7 +1670,7 @@ 
                          actions[ACTION_GET],
                          threadsafe=threadsafe,
                          hasretval=True)
-    getfiledata = []
+    getfiledata = {}
     for final, res in prog:
         if final:
             getfiledata = res
@@ -1803,7 +1803,8 @@ 
             actions[k].extend(acts)
             if k == ACTION_GET and wantfiledata:
                 # no filedata until mergestate is updated to provide it
-                getfiledata.extend([None] * len(acts))
+                for a in acts:
+                    getfiledata[a[0]] = None
             # Remove these files from actions[ACTION_MERGE] as well. This is
             # important because in recordupdates, files in actions[ACTION_MERGE]
             # are processed after files in other actions, and the merge driver
@@ -1873,11 +1874,11 @@ 
         pass
 
     # get
-    for i, (f, args, msg) in enumerate(actions.get(ACTION_GET, [])):
+    for f, args, msg in actions.get(ACTION_GET, []):
         if branchmerge:
             repo.dirstate.otherparent(f)
         else:
-            parentfiledata = getfiledata[i] if getfiledata else None
+            parentfiledata = getfiledata[f] if getfiledata else None
             repo.dirstate.normal(f, parentfiledata=parentfiledata)
 
     # merge