Mercurial > hg
view doc/gendoc.py @ 27192:a01d3d32b53a
commands: make commit acquire locks before processing (issue4368)
Before this patch, "hg commit" (process A) executes steps below:
1. get current branch heads via 'repo.branchheads()'
- cache 'repo.changelog'
2. invoke 'repo.commit()'
3. acquire wlock
- invalidate 'repo.dirstate'
4. access 'repo.dirstate'
- re-read '.hg/dirstate'
- check validity of parent revisions with 'repo.changelog'
5. invoke 'repo.commitctx()'
6. acquire store lock (slock)
- invalidate 'repo.changelog'
7. do committing
8. release slock
9. release wlock
10. check new branch head (via 'cmdutil.commitstatus()')
If acquisition of wlock at (3) above waits for another "hg commit"
(process B) or so running parallelly to release wlock, process A
causes creating orphan revision, because:
- '.hg/dirstate' refers the revision, which is newly added by
process B, as its parent
- but already cached 'repo.changelog' doesn't contain such revision
- therefore, validating parents of '.hg/dirstate' at (4) above
replaces such revision with 'nullid'
Then, process A creates "orphan" revision, of which parent is "null"
revision.
In addition to it, "created new head" may be shown at the end of
process A unintentionally, if store is updated parallelly, because
both getting branch heads (1) and checking new branch head (10) are
executed outside slock scope.
To avoid this issue, this patch makes "hg commit" acquire wlock and
slock before processing.
This patch resolves the issue between "hg commit" processes, but not
one between "hg commit" and other commands. Subsequent patches resolve
the latter.
Even after this patch, there are still corner case problems below:
- filecache may overlook changes of '.hg/dirstate', and it causes
similar issue (see below for detail)
https://bz.mercurial-scm.org/show_bug.cgi?id=4368#c10
- 3rd party extension may cause similar issue, if it directly uses
'repo.commit()' without acquisition of wlock and slock
This can be fixed by acquisition of slock at the beginning of
'repo.commit()', but it seems suitable for "default" branch
In fact, acquisition of slock itself is already introduced at
"default" branch by 4414d500604f, but acquisition is not at the
beginning of 'repo.commit()'.
This patch also changes some tests:
- test-fncache.t needs this tricky wrapping, to release (= forced
failure of) wlock certainly
- order of "hg commit" output is changed by widening scope of locks,
because some hooks are fired after releasing wlock
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Wed, 02 Dec 2015 03:12:07 +0900 |
parents | e0c572d4d112 |
children | 6fbf1159a85a |
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"""usage: %s DOC ... where DOC is the name of a document """ import os, sys, textwrap # import from the live mercurial repo sys.path.insert(0, "..") # fall back to pure modules if required C extensions are not available sys.path.append(os.path.join('..', 'mercurial', 'pure')) from mercurial import demandimport; demandimport.enable() from mercurial import minirst from mercurial.commands import table, globalopts from mercurial.i18n import gettext, _ from mercurial.help import helptable, loaddoc from mercurial import extensions from mercurial import ui as uimod def get_desc(docstr): if not docstr: return "", "" # sanitize docstr = docstr.strip("\n") docstr = docstr.rstrip() shortdesc = docstr.splitlines()[0].strip() i = docstr.find("\n") if i != -1: desc = docstr[i + 2:] else: desc = shortdesc desc = textwrap.dedent(desc) return (shortdesc, desc) def get_opts(opts): for opt in opts: if len(opt) == 5: shortopt, longopt, default, desc, optlabel = opt else: shortopt, longopt, default, desc = opt optlabel = _("VALUE") allopts = [] if shortopt: allopts.append("-%s" % shortopt) if longopt: allopts.append("--%s" % longopt) if isinstance(default, list): allopts[-1] += " <%s[+]>" % optlabel elif (default is not None) and not isinstance(default, bool): allopts[-1] += " <%s>" % optlabel if '\n' in desc: # only remove line breaks and indentation desc = ' '.join(l.lstrip() for l in desc.split('\n')) desc += default and _(" (default: %s)") % default or "" yield (", ".join(allopts), desc) def get_cmd(cmd, cmdtable): d = {} attr = cmdtable[cmd] cmds = cmd.lstrip("^").split("|") d['cmd'] = cmds[0] d['aliases'] = cmd.split("|")[1:] d['desc'] = get_desc(gettext(attr[0].__doc__)) d['opts'] = list(get_opts(attr[1])) s = 'hg ' + cmds[0] if len(attr) > 2: if not attr[2].startswith('hg'): s += ' ' + attr[2] else: s = attr[2] d['synopsis'] = s.strip() return d def showdoc(ui): # print options ui.write(minirst.section(_("Options"))) multioccur = False for optstr, desc in get_opts(globalopts): ui.write("%s\n %s\n\n" % (optstr, desc)) if optstr.endswith("[+]>"): multioccur = True if multioccur: ui.write(_("\n[+] marked option can be specified multiple times\n")) ui.write("\n") # print cmds ui.write(minirst.section(_("Commands"))) commandprinter(ui, table, minirst.subsection) # print help topics # The config help topic is included in the hgrc.5 man page. helpprinter(ui, helptable, minirst.section, exclude=['config']) ui.write(minirst.section(_("Extensions"))) ui.write(_("This section contains help for extensions that are " "distributed together with Mercurial. Help for other " "extensions is available in the help system.")) ui.write("\n\n" ".. contents::\n" " :class: htmlonly\n" " :local:\n" " :depth: 1\n\n") for extensionname in sorted(allextensionnames()): mod = extensions.load(None, extensionname, None) ui.write(minirst.subsection(extensionname)) ui.write("%s\n\n" % gettext(mod.__doc__)) cmdtable = getattr(mod, 'cmdtable', None) if cmdtable: ui.write(minirst.subsubsection(_('Commands'))) commandprinter(ui, cmdtable, minirst.subsubsubsection) def showtopic(ui, topic): extrahelptable = [ (["common"], '', loaddoc('common')), (["hg.1"], '', loaddoc('hg.1')), (["hgignore.5"], '', loaddoc('hgignore.5')), (["hgrc.5"], '', loaddoc('hgrc.5')), (["hgignore.5.gendoc"], '', loaddoc('hgignore')), (["hgrc.5.gendoc"], '', loaddoc('config')), ] helpprinter(ui, helptable + extrahelptable, None, include=[topic]) def helpprinter(ui, helptable, sectionfunc, include=[], exclude=[]): for names, sec, doc in helptable: if exclude and names[0] in exclude: continue if include and names[0] not in include: continue for name in names: ui.write(".. _%s:\n" % name) ui.write("\n") if sectionfunc: ui.write(sectionfunc(sec)) if callable(doc): doc = doc(ui) ui.write(doc) ui.write("\n") def commandprinter(ui, cmdtable, sectionfunc): h = {} for c, attr in cmdtable.items(): f = c.split("|")[0] f = f.lstrip("^") h[f] = c cmds = h.keys() cmds.sort() for f in cmds: if f.startswith("debug"): continue d = get_cmd(h[f], cmdtable) ui.write(sectionfunc(d['cmd'])) # short description ui.write(d['desc'][0]) # synopsis ui.write("::\n\n") synopsislines = d['synopsis'].splitlines() for line in synopsislines: # some commands (such as rebase) have a multi-line # synopsis ui.write(" %s\n" % line) ui.write('\n') # description ui.write("%s\n\n" % d['desc'][1]) # options opt_output = list(d['opts']) if opt_output: opts_len = max([len(line[0]) for line in opt_output]) ui.write(_("Options:\n\n")) multioccur = False for optstr, desc in opt_output: if desc: s = "%-*s %s" % (opts_len, optstr, desc) else: s = optstr ui.write("%s\n" % s) if optstr.endswith("[+]>"): multioccur = True if multioccur: ui.write(_("\n[+] marked option can be specified" " multiple times\n")) ui.write("\n") # aliases if d['aliases']: ui.write(_(" aliases: %s\n\n") % " ".join(d['aliases'])) def allextensionnames(): return extensions.enabled().keys() + extensions.disabled().keys() if __name__ == "__main__": doc = 'hg.1.gendoc' if len(sys.argv) > 1: doc = sys.argv[1] ui = uimod.ui() if doc == 'hg.1.gendoc': showdoc(ui) else: showtopic(ui, sys.argv[1])