X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/2cc6a07f5492912f35d103bcc57753f21ee09ecf..ff5d52b0d2dc025cedadb3b9d06f46e8954d7a38:/doc/todo/mercurial.mdwn

diff --git a/doc/todo/mercurial.mdwn b/doc/todo/mercurial.mdwn
index 26888131e..2f844db03 100644
--- a/doc/todo/mercurial.mdwn
+++ b/doc/todo/mercurial.mdwn
@@ -29,23 +29,51 @@ This should update the working directory and run ikiwiki every time a change is
 > It can deadlock if the post-commit hook runs with --refresh in the
 > former case. --[[Joey]]
 
-The problem with --post-commit is that if you delete some pages in $SRC, ikiwiki --setup setupfile --post-commit will not delete them in $DEST.
-
-I add the following to .hg/hgrc:
+The problem with --post-commit is that if you delete some pages in $SRC, ikiwiki --setup setupfile --post-commit will not delete them in $DEST. --[[weakish]]
+
+> You should really be using a setup file that has `mercurial_wrapper`
+> set, and running the wrapper generated by that from your hook.
+> That will work. I think that the `--setup --post-commit` on the command
+> line is currently broken and does the same expensive rebuild process as --setup
+> alone (which doesn't delete files from $DEST either). Will fix that.
+> --[[Joey]] 
+
+>> Mercurial doesn't support put hooks in .hg/hooks/* (like git). In Mercurial, the only way to run
+>> your own hooks is specifying them in the hgrc file. (Or write a new extension.)
+>> I guess use a very long command will work.
+>> (e.g. ikiwiki --post-commit --a-lot-of-switches --set var=value $SRC $DEST)
+>> (Fortunately ikiwiki supports --set var=value so without --setup works.)
+>>
+>> Alternative is always editing via cgi or pushing.  Never work on the $SRC/repo directly.
+>> --[[weakish]]
+
+I add the following to .hg/hgrc:(I use changegroup since I don't think we need refresh per changeset, please point out if I am wrong.)
 
     [hooks]
     changegroup = hg update >&2 && ikiwiki --setup path.to.setup.file --refresh
-    post-commit = ikiwiki --setup path.to.setup.file --refresh
-
-I tried the follwing commands in $SRC:
-
-    touch deadlocktest.mdwn
-    hg add
-    hg ci
-
-No deadlock happens.  (Also I push to the $SRC from another machine, again, no deadlock.)  
 
-Of course these tests are too simple.  The problem is I have no idea when the deadlock will happen. If someone is kind enough to point out, I will run more test.
+<p><del>post-commit = ikiwiki --setup path.to.setup.file --refresh</del><strong>This will cause deadlock! See bleow!</strong></p>
+
+I have no idea when the deadlock will happen.  --[[weakish]]
+
+> For the deadlock to occur, a edit has to be made via the web.
+> 
+> Ikiwiki,
+> running as a CGI, takes a lock on the wiki, and commits the edit,
+> continuing to run in the background, with the lock still held.
+> When the edit is committed, the hg hook runs, running `ikwiki --refresh`.
+> Nearly the first thing that process does it try to lock the wiki..
+> which is already locked. This lock is taken in a blocking manner,
+> thus the deadlock -- the cgi is waiting for the commit to finish before
+> dropping the lock, and the commit is blocked waiting for the lock to be
+> released.
+> 
+> --post-commit avoids this problem by checking if the cgi is running
+> and avoiding doing anything in that case. (While still handing the
+> refresh if the commit was not made by the CGI.)
+> So in that case, the commit finishes w/o ikiwiki doing anything,
+> and the ikiwiki CGI handles the wiki refresh.
+> --[[Joey]]  
 
 
 ***