view tests/test-mq-header-from.t @ 38732:be4984261611

merge: mark file gets as not thread safe (issue5933)

In default installs, this has the effect of disabling the thread-based
worker on Windows when manifesting files in the working directory. My
measurements have shown that with revlog-based repositories, Mercurial
spends a lot of CPU time in revlog code resolving file data. This ends
up incurring a lot of context switching across threads and slows down
`hg update` operations when going from an empty working directory to
the tip of the repo.

On mozilla-unified (246,351 files) on an i7-6700K (4+4 CPUs):

before: 487s wall
after:  360s wall (equivalent to worker.enabled=false)
cpus=2: 379s wall

Even with only 2 threads, the thread pool is still slower.

The introduction of the thread-based worker (02b36e860e0b) states that
it resulted in a "~50%" speedup for `hg sparse --enable-profile` and
`hg sparse --disable-profile`. This disagrees with my measurement
above. I theorize a few reasons for this:

1) Removal of files from the working directory is I/O - not CPU - bound
   and should benefit from a thread pool (unless I/O is insanely fast
   and the GIL release is near instantaneous). So tests like `hg sparse
   --enable-profile` may exercise deletion throughput and aren't good
   benchmarks for worker tasks that are CPU heavy.
2) The patch was authored by someone at Facebook. The results were
   likely measured against a repository using remotefilelog. And I
   believe that revision retrieval during working directory updates with
   remotefilelog will often use a remote store, thus being I/O and not
   CPU bound. This probably resulted in an overstated performance gain.

Since there appears to be a need to enable the thread-based worker with
some stores, I've made the flagging of file gets as thread safe
configurable. I've made it experimental because I don't want to formalize
a boolean flag for this option and because this attribute is best
captured against the store implementation. But we don't have a proper
store API for this yet. I'd rather cross this bridge later.

It is possible there are revlog-based repositories that do benefit from
a thread-based worker. I didn't do very comprehensive testing. If there
are, we may want to devise a more proper algorithm for whether to use
the thread-based worker, including possibly config options to limit the
number of threads to use. But until I see evidence that justifies
complexity, simplicity wins.

Differential Revision: https://phab.mercurial-scm.org/D3963

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ echo "[diff]" >> $HGRCPATH
  $ echo "nodates=true" >> $HGRCPATH
  $ catlog() {
  >     cat .hg/patches/$1.patch | sed -e "s/^diff \-r [0-9a-f]* /diff -r ... /" \
  >                                    -e "s/^\(# Parent \).*/\1/"
  >     hg log --template "{rev}: {node|short} {desc} - {author}\n"
  > }
  $ runtest() {
  >     echo ==== init
  >     hg init a
  >     cd a
  >     hg qinit
  > 
  > 
  >     echo ==== qnew -U
  >     hg qnew -U 1.patch
  >     catlog 1
  > 
  >     echo ==== qref
  >     echo "1" >1
  >     hg add
  >     hg qref
  >     catlog 1
  > 
  >     echo ==== qref -u
  >     hg qref -u mary
  >     catlog 1
  > 
  >     echo ==== qnew
  >     hg qnew 2.patch
  >     echo "2" >2
  >     hg add
  >     hg qref
  >     catlog 2
  > 
  >     echo ==== qref -u
  >     hg qref -u jane
  >     catlog 2
  > 
  > 
  >     echo ==== qnew -U -m
  >     hg qnew -U -m "Three" 3.patch
  >     catlog 3
  > 
  >     echo ==== qref
  >     echo "3" >3
  >     hg add
  >     hg qref
  >     catlog 3
  > 
  >     echo ==== qref -m
  >     hg qref -m "Drei"
  >     catlog 3
  > 
  >     echo ==== qref -u
  >     hg qref -u mary
  >     catlog 3
  > 
  >     echo ==== qref -u -m
  >     hg qref -u maria -m "Three (again)"
  >     catlog 3
  > 
  >     echo ==== qnew -m
  >     hg qnew -m "Four" 4.patch
  >     echo "4" >4of t
  >     hg add
  >     hg qref
  >     catlog 4
  > 
  >     echo ==== qref -u
  >     hg qref -u jane
  >     catlog 4
  > 
  > 
  >     echo ==== qnew with HG header
  >     hg qnew --config 'mq.plain=true' 5.patch
  >     hg qpop
  >     echo "# HG changeset patch" >>.hg/patches/5.patch
  >     echo "# User johndoe" >>.hg/patches/5.patch
  >     hg qpush 2>&1 | grep 'now at'
  >     catlog 5
  > 
  >     echo ==== hg qref
  >     echo "5" >5
  >     hg add
  >     hg qref
  >     catlog 5
  > 
  >     echo ==== hg qref -U
  >     hg qref -U
  >     catlog 5
  > 
  >     echo ==== hg qref -u
  >     hg qref -u johndeere
  >     catlog 5
  > 
  > 
  >     echo ==== qnew with plain header
  >     hg qnew --config 'mq.plain=true' -U 6.patch
  >     hg qpop
  >     hg qpush 2>&1 | grep 'now at'
  >     catlog 6
  > 
  >     echo ==== hg qref
  >     echo "6" >6
  >     hg add
  >     hg qref
  >     catlog 6
  > 
  >     echo ==== hg qref -U
  >     hg qref -U
  >     catlog 6
  > 
  >     echo ==== hg qref -u
  >     hg qref -u johndeere
  >     catlog 6
  > 
  > 
  >     echo ==== "qpop -a / qpush -a"
  >     hg qpop -a
  >     hg qpush -a
  >     hg log --template "{rev}: {node|short} {desc} - {author}\n"
  > }

======= plain headers

  $ echo "[mq]" >> $HGRCPATH
  $ echo "plain=true" >> $HGRCPATH
  $ mkdir sandbox
  $ (cd sandbox ; runtest)
  ==== init
  ==== qnew -U
  From: test
  
  0: a054644889e5 [mq]: 1.patch - test
  ==== qref
  adding 1
  From: test
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: 2905f1e46ee0 [mq]: 1.patch - test
  ==== qref -u
  From: mary
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew
  adding 2
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: 527f98a12a7a [mq]: 2.patch - test
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  From: jane
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew -U -m
  From: test
  
  Three
  
  2: 0ffa16a9088e Three - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref
  adding 3
  From: test
  
  Three
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: 83f1290c6086 Three - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -m
  From: test
  
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: b0d856328d4d Drei - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  From: mary
  
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: bb9d4b28e6a6 Drei - mary
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u -m
  From: maria
  
  Three (again)
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew -m
  adding 4of
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: b9f922d0da40 Four - test
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  From: jane
  
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew with HG header
  popping 5.patch
  now at: 4.patch
  now at: 5.patch
  # HG changeset patch
  # User johndoe
  4: 72bc4a0467ef imported patch 5.patch - johndoe
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref
  adding 5
  # HG changeset patch
  # User johndoe
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: ff5c06112e5a [mq]: 5.patch - johndoe
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -U
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: c947416c22b1 [mq]: 5.patch - test
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -u
  # HG changeset patch
  # User johndeere
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew with plain header
  popping 6.patch
  now at: 5.patch
  now at: 6.patch
  From: test
  
  5: 7825a18ec839 imported patch 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref
  adding 6
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 09d19592680d [mq]: 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -U
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 09d19592680d [mq]: 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -u
  From: johndeere
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 32641ee07196 [mq]: 6.patch - johndeere
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qpop -a / qpush -a
  popping 6.patch
  popping 5.patch
  popping 4.patch
  popping 3.patch
  popping 2.patch
  popping 1.patch
  patch queue now empty
  applying 1.patch
  applying 2.patch
  applying 3.patch
  applying 4.patch
  applying 5.patch
  applying 6.patch
  now at: 6.patch
  5: 1fb083c80457 imported patch 6.patch - johndeere
  4: 7e96e969691d imported patch 5.patch - johndeere
  3: c7147533d3cd Four - jane
  2: b383d04401ea Three (again) - maria
  1: fac2da4efc3c imported patch 2.patch - jane
  0: b6e237e8771b imported patch 1.patch - mary
  $ rm -r sandbox

======= hg headers

  $ echo "plain=false" >> $HGRCPATH
  $ mkdir sandbox
  $ (cd sandbox ; runtest)
  ==== init
  ==== qnew -U
  # HG changeset patch
  # User test
  # Parent 
  
  0: a054644889e5 [mq]: 1.patch - test
  ==== qref
  adding 1
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: 2905f1e46ee0 [mq]: 1.patch - test
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew
  adding 2
  # HG changeset patch
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: 527f98a12a7a [mq]: 2.patch - test
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew -U -m
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  2: 0ffa16a9088e Three - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref
  adding 3
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: 83f1290c6086 Three - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -m
  # HG changeset patch
  # User test
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: b0d856328d4d Drei - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: bb9d4b28e6a6 Drei - mary
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u -m
  # HG changeset patch
  # User maria
  # Parent 
  Three (again)
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew -m
  adding 4of
  # HG changeset patch
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: b9f922d0da40 Four - test
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew with HG header
  popping 5.patch
  now at: 4.patch
  now at: 5.patch
  # HG changeset patch
  # User johndoe
  4: 72bc4a0467ef imported patch 5.patch - johndoe
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref
  adding 5
  # HG changeset patch
  # User johndoe
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: ff5c06112e5a [mq]: 5.patch - johndoe
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -U
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: c947416c22b1 [mq]: 5.patch - test
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -u
  # HG changeset patch
  # User johndeere
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew with plain header
  popping 6.patch
  now at: 5.patch
  now at: 6.patch
  From: test
  
  5: 7825a18ec839 imported patch 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref
  adding 6
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 09d19592680d [mq]: 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -U
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 09d19592680d [mq]: 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -u
  From: johndeere
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 32641ee07196 [mq]: 6.patch - johndeere
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qpop -a / qpush -a
  popping 6.patch
  popping 5.patch
  popping 4.patch
  popping 3.patch
  popping 2.patch
  popping 1.patch
  patch queue now empty
  applying 1.patch
  applying 2.patch
  applying 3.patch
  applying 4.patch
  applying 5.patch
  applying 6.patch
  now at: 6.patch
  5: 1fb083c80457 imported patch 6.patch - johndeere
  4: 7e96e969691d imported patch 5.patch - johndeere
  3: c7147533d3cd Four - jane
  2: b383d04401ea Three (again) - maria
  1: fac2da4efc3c imported patch 2.patch - jane
  0: b6e237e8771b imported patch 1.patch - mary
  $ rm -r sandbox
  $ runtest
  ==== init
  ==== qnew -U
  # HG changeset patch
  # User test
  # Parent 
  
  0: a054644889e5 [mq]: 1.patch - test
  ==== qref
  adding 1
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: 2905f1e46ee0 [mq]: 1.patch - test
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew
  adding 2
  # HG changeset patch
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: 527f98a12a7a [mq]: 2.patch - test
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew -U -m
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  2: 0ffa16a9088e Three - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref
  adding 3
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: 83f1290c6086 Three - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -m
  # HG changeset patch
  # User test
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: b0d856328d4d Drei - test
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: bb9d4b28e6a6 Drei - mary
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u -m
  # HG changeset patch
  # User maria
  # Parent 
  Three (again)
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew -m
  adding 4of
  # HG changeset patch
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: b9f922d0da40 Four - test
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew with HG header
  popping 5.patch
  now at: 4.patch
  now at: 5.patch
  # HG changeset patch
  # User johndoe
  4: 72bc4a0467ef imported patch 5.patch - johndoe
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref
  adding 5
  # HG changeset patch
  # User johndoe
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: ff5c06112e5a [mq]: 5.patch - johndoe
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -U
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: c947416c22b1 [mq]: 5.patch - test
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -u
  # HG changeset patch
  # User johndeere
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qnew with plain header
  popping 6.patch
  now at: 5.patch
  now at: 6.patch
  From: test
  
  5: 7825a18ec839 imported patch 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref
  adding 6
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 09d19592680d [mq]: 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -U
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 09d19592680d [mq]: 6.patch - test
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== hg qref -u
  From: johndeere
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: 32641ee07196 [mq]: 6.patch - johndeere
  4: 1d898e201a22 [mq]: 5.patch - johndeere
  3: 0dfb3111e7ee Four - jane
  2: a6686ee84fc3 Three (again) - maria
  1: a425cde5f493 [mq]: 2.patch - jane
  0: 3682f830e656 [mq]: 1.patch - mary
  ==== qpop -a / qpush -a
  popping 6.patch
  popping 5.patch
  popping 4.patch
  popping 3.patch
  popping 2.patch
  popping 1.patch
  patch queue now empty
  applying 1.patch
  applying 2.patch
  applying 3.patch
  applying 4.patch
  applying 5.patch
  applying 6.patch
  now at: 6.patch
  5: 1fb083c80457 imported patch 6.patch - johndeere
  4: 7e96e969691d imported patch 5.patch - johndeere
  3: c7147533d3cd Four - jane
  2: b383d04401ea Three (again) - maria
  1: fac2da4efc3c imported patch 2.patch - jane
  0: b6e237e8771b imported patch 1.patch - mary

  $ cd ..