lock: fixed race condition in trylock/testlock (issue3506)
Suppose the following scenario:
1. Process A takes the lock (e.g. on commit).
2. Process B wants to grab the lock. Since lock file exists
the exception is raised. In the catch block the testlock
function is called.
3. Process A releases the lock.
4. Process B tries to read the lock file as a part of testlock
function. This results in OSError (ENOENT) and since we're
not inside the exception handler function this is propagated
and aborts the whole operation.
To fix this we now check in testlock function whether lock file
actually exists and if not (i.e. if readlock fails) we just return.
# If you want to change PREFIX, do not just edit it below. The changed
# value wont get passed on to recursive make calls. You should instead
# override the variable on the command like:
#
# % make PREFIX=/opt/ install
PREFIX=/usr/local
export PREFIX
PYTHON=python
PURE=
PYFILES:=$(shell find mercurial hgext doc -name '*.py')
DOCFILES=mercurial/help/*.txt
help:
@echo 'Commonly used make targets:'
@echo ' all - build program and documentation'
@echo ' install - install program and man pages to PREFIX ($(PREFIX))'
@echo ' install-home - install with setup.py install --home=HOME ($(HOME))'
@echo ' local - build for inplace usage'
@echo ' tests - run all tests in the automatic test suite'
@echo ' test-foo - run only specified tests (e.g. test-merge1.t)'
@echo ' dist - run all tests and create a source tarball in dist/'
@echo ' clean - remove files created by other targets'
@echo ' (except installed files or dist source tarball)'
@echo ' update-pot - update i18n/hg.pot'
@echo
@echo 'Example for a system-wide installation under /usr/local:'
@echo ' make all && su -c "make install" && hg version'
@echo
@echo 'Example for a local installation (usable in this directory):'
@echo ' make local && ./hg version'
all: build doc
local:
$(PYTHON) setup.py $(PURE) build_py -c -d . build_ext -i build_hgexe -i build_mo
$(PYTHON) hg version
build:
$(PYTHON) setup.py $(PURE) build
doc:
$(MAKE) -C doc
clean:
-$(PYTHON) setup.py clean --all # ignore errors from this command
find . \( -name '*.py[cdo]' -o -name '*.so' \) -exec rm -f '{}' ';'
rm -f $(addprefix mercurial/,$(notdir $(wildcard mercurial/pure/[a-z]*.py)))
rm -f MANIFEST MANIFEST.in mercurial/__version__.py tests/*.err
rm -rf build mercurial/locale
$(MAKE) -C doc clean
install: install-bin install-doc
install-bin: build
$(PYTHON) setup.py $(PURE) install --root="$(DESTDIR)/" --prefix="$(PREFIX)" --force
install-doc: doc
cd doc && $(MAKE) $(MFLAGS) install
install-home: install-home-bin install-home-doc
install-home-bin: build
$(PYTHON) setup.py $(PURE) install --home="$(HOME)" --force
install-home-doc: doc
cd doc && $(MAKE) $(MFLAGS) PREFIX="$(HOME)" install
MANIFEST-doc:
$(MAKE) -C doc MANIFEST
MANIFEST.in: MANIFEST-doc
hg manifest | sed -e 's/^/include /' > MANIFEST.in
echo include mercurial/__version__.py >> MANIFEST.in
sed -e 's/^/include /' < doc/MANIFEST >> MANIFEST.in
dist: tests dist-notests
dist-notests: doc MANIFEST.in
TAR_OPTIONS="--owner=root --group=root --mode=u+w,go-w,a+rX-s" $(PYTHON) setup.py -q sdist
check: tests
tests:
cd tests && $(PYTHON) run-tests.py $(TESTFLAGS)
test-%:
cd tests && $(PYTHON) run-tests.py $(TESTFLAGS) $@
update-pot: i18n/hg.pot
i18n/hg.pot: $(PYFILES) $(DOCFILES)
$(PYTHON) i18n/hggettext mercurial/commands.py \
hgext/*.py hgext/*/__init__.py \
mercurial/fileset.py mercurial/revset.py \
mercurial/templatefilters.py mercurial/templatekw.py \
mercurial/filemerge.py \
$(DOCFILES) > i18n/hg.pot
# All strings marked for translation in Mercurial contain
# ASCII characters only. But some files contain string
# literals like this '\037\213'. xgettext thinks it has to
# parse them even though they are not marked for translation.
# Extracting with an explicit encoding of ISO-8859-1 will make
# xgettext "parse" and ignore them.
echo $(PYFILES) | xargs \
xgettext --package-name "Mercurial" \
--msgid-bugs-address "<mercurial-devel@selenic.com>" \
--copyright-holder "Matt Mackall <mpm@selenic.com> and others" \
--from-code ISO-8859-1 --join --sort-by-file --add-comments=i18n: \
-d hg -p i18n -o hg.pot
$(PYTHON) i18n/posplit i18n/hg.pot
%.po: i18n/hg.pot
msgmerge --no-location --update $@ $^
.PHONY: help all local build doc clean install install-bin install-doc \
install-home install-home-bin install-home-doc dist dist-notests tests \
update-pot