test: factor out the "wait" logic in bookrace

The test is currently not testing the race it is supposed to test. The
synchronisation is still valid, but needs to run at a different point.

We start with extracting the synchronisation logic for clarity.

tests/test-bookmarks-corner-case.t

@@ -1,236 +1,240 b''
 ================================
 Test corner case around bookmark
 ================================
 
 This test file is meant to gather test around bookmark that are specific
  enough to not find a place elsewhere.
 
 Test bookmark/changelog race condition
 ======================================
 
 The data from the bookmark file are filtered to only contains bookmark with
 node known to the changelog. If the cache invalidation between these two bits
 goes wrong, bookmark can be dropped.
 
 global setup
 ------------
 
   $ cat >> $HGRCPATH << EOF
   > [ui]
   > ssh = "$PYTHON" "$TESTDIR/dummyssh"
   > [server]
   > concurrent-push-mode=check-related
   > EOF
 
 Setup
 -----
 
 initial repository setup
 
   $ hg init bookrace-server
   $ cd bookrace-server
   $ echo a > a
   $ hg add a
   $ hg commit -m root
   $ echo a >> a
   $ hg bookmark book-A
   $ hg commit -m A0
   $ hg up 'desc(root)'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (leaving bookmark book-A)
   $ echo b > b
   $ hg add b
   $ hg bookmark book-B
   $ hg commit -m B0
   created new head
   $ hg up null
   0 files updated, 0 files merged, 2 files removed, 0 files unresolved
   (leaving bookmark book-B)
   $ hg phase --public --rev 'all()'
   $ hg log -G
   o  changeset:   2:c79985706978
   |  bookmark:    book-B
   |  tag:         tip
   |  parent:      0:6569b5a81c7e
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     B0
   |
   | o  changeset:   1:39c28d785860
   |/   bookmark:    book-A
   |    user:        test
   |    date:        Thu Jan 01 00:00:00 1970 +0000
   |    summary:     A0
   |
   o  changeset:   0:6569b5a81c7e
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     root
   
   $ hg book
      book-A                    1:39c28d785860
      book-B                    2:c79985706978
   $ cd ..
 
 Add new changeset on each bookmark in distinct clones
 
   $ hg clone ssh://user@dummy/bookrace-server client-A
   requesting all changes
   adding changesets
   adding manifests
   adding file changes
   added 3 changesets with 3 changes to 2 files (+1 heads)
   new changesets 6569b5a81c7e:c79985706978
   updating to branch default
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg -R client-A update book-A
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (activating bookmark book-A)
   $ echo a >> client-A/a
   $ hg -R client-A commit -m A1
   $ hg clone ssh://user@dummy/bookrace-server client-B
   requesting all changes
   adding changesets
   adding manifests
   adding file changes
   added 3 changesets with 3 changes to 2 files (+1 heads)
   new changesets 6569b5a81c7e:c79985706978
   updating to branch default
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg -R client-B update book-B
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (activating bookmark book-B)
   $ echo b >> client-B/b
   $ hg -R client-B commit -m B1
 
 extension to reproduce the race
 -------------------------------
 
 If two process are pushing we want to make sure the following happens:
 
 * process A read changelog
 * process B to its full push
 * process A read bookmarks
 * process A proceed with rest of the push
 
 We build a server side extension for this purpose
 
   $ cat > bookrace.py << EOF
   > import os
   > import time
   > import atexit
   > from mercurial import error, extensions, bookmarks
-  > def wrapinit(orig, self, repo):
+  > 
+  > def wait():
   >     if not os.path.exists('push-A-started'):
   >         print('setting raced push up')
   >         with open('push-A-started', 'w'):
   >             pass
   >     clock = 300
   >     while not os.path.exists('push-B-done'):
   >         clock -= 1
   >         if clock <= 0:
   >             raise error.Abort("race scenario timed out")
   >         time.sleep(0.1)
+  > 
+  > def wrapinit(orig, self, repo):
+  >     wait()
   >     return orig(self, repo)
   > def uisetup(ui):
   >     extensions.wrapfunction(bookmarks.bmstore, '__init__', wrapinit)
   > def e():
   >     with open('push-A-done', 'w'):
   >         pass
   > atexit.register(e)
   > EOF
 
 Actual test
 -----------
 
 Start the raced push.
 
   $ cat >> bookrace-server/.hg/hgrc << EOF
   > [extensions]
   > bookrace=$TESTTMP/bookrace.py
   > EOF
   $ hg push -R client-A -r book-A >push-output.txt 2>&1 &
 
 Wait up to 30 seconds for that push to start.
 
   $ clock=30
   $ while [ ! -f push-A-started ] && [ $clock -gt 0 ] ; do
   >    clock=`expr $clock - 1`
   >    sleep 1
   > done
 
 Do the other push.
 
   $ cat >> bookrace-server/.hg/hgrc << EOF
   > [extensions]
   > bookrace=!
   > EOF
 
   $ hg push -R client-B -r book-B
   pushing to ssh://user@dummy/bookrace-server
   searching for changes
   remote: adding changesets
   remote: adding manifests
   remote: adding file changes
   remote: added 1 changesets with 1 changes to 1 files
   updating bookmark book-B
 
 Signal the raced put that we are done (it waits up to 30 seconds).
 
   $ touch push-B-done
 
 Wait for the raced push to finish (with the remaning of the initial 30 seconds).
 
   $ while [ ! -f push-A-done ] && [ $clock -gt 0 ] ; do
   >    clock=`expr $clock - 1`
   >    sleep 1
   > done
 
 Check raced push output.
 
   $ cat push-output.txt
   pushing to ssh://user@dummy/bookrace-server
   searching for changes
   remote: setting raced push up
   remote: adding changesets
   remote: adding manifests
   remote: adding file changes
   remote: added 1 changesets with 1 changes to 1 files
   updating bookmark book-A
 
 Check result of the push.
 
   $ hg -R bookrace-server log -G
   o  changeset:   4:9ce3b28c16de
   |  bookmark:    book-A
   |  tag:         tip
   |  parent:      1:39c28d785860
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     A1
   |
   | o  changeset:   3:f26c3b5167d1
   | |  bookmark:    book-B
   | |  user:        test
   | |  date:        Thu Jan 01 00:00:00 1970 +0000
   | |  summary:     B1
   | |
   | o  changeset:   2:c79985706978
   | |  parent:      0:6569b5a81c7e
   | |  user:        test
   | |  date:        Thu Jan 01 00:00:00 1970 +0000
   | |  summary:     B0
   | |
   o |  changeset:   1:39c28d785860
   |/   user:        test
   |    date:        Thu Jan 01 00:00:00 1970 +0000
   |    summary:     A0
   |
   o  changeset:   0:6569b5a81c7e
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     root
   
   $ hg -R bookrace-server book
      book-A                    4:9ce3b28c16de
      book-B                    3:f26c3b5167d1