##// END OF EJS Templates
localrepo: use changelog.hasnode instead of self.__contains__...
localrepo: use changelog.hasnode instead of self.__contains__ Before this patch, releasing the store lock implies the actions below, when the transaction is aborted: 1. "commithook()" scheduled in "localrepository.commit()" is invoked 2. "changectx.__init__()" is invoked via "self.__contains__()" 3. specified ID is examined against "repo.dirstate.p1()" 4. validation function is invoked in "dirstate.p1()" In subsequent patches, "dirstate.invalidate()" invocations for discarding changes are replaced with "dirstateguard", but discarding changes by "dirstateguard" is executed after releasing the store lock: resources are acquired in "wlock => dirstateguard => store lock" order, and are released in reverse order. This may cause that "dirstate.p1()" still refers to the changeset to be rolled-back at (4) above: pushing multiple patches by "hg qpush" is a typical case. When releasing the store lock, such changesets are: - not contained in "repo.changelog", if it is reloaded from ".hg/00changelog.i", as that file was already truncated by "transaction.abort()" - still contained in it, otherwise (this "dirty read" problem is discussed in "Transaction Plan" http://mercurial.selenic.com/wiki/TransactionPlan) Validation function shows "unknown working parent" warning in the former case, but reloading "repo.changelog" depends on the timestamp of ".hg/00changelog.i". This causes occasional test failures. In the case of scheduled "commithook()", it just wants to examine whether "node ID" of committed changeset is still valid or not. Other examinations implied in "changectx.__init__()" are meaningless. To avoid showing the "unknown working parent" warning irregularly, this patch uses "changelog.hasnode()" instead of "node in self" to examine existence of committed changeset.

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worker.py
158 lines | 4.4 KiB | text/x-python | PythonLexer
# worker.py - master-slave parallelism support
#
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from i18n import _
import errno, os, signal, sys, threading
import util
def countcpus():
'''try to count the number of CPUs on the system'''
# posix
try:
n = int(os.sysconf('SC_NPROCESSORS_ONLN'))
if n > 0:
return n
except (AttributeError, ValueError):
pass
# windows
try:
n = int(os.environ['NUMBER_OF_PROCESSORS'])
if n > 0:
return n
except (KeyError, ValueError):
pass
return 1
def _numworkers(ui):
s = ui.config('worker', 'numcpus')
if s:
try:
n = int(s)
if n >= 1:
return n
except ValueError:
raise util.Abort(_('number of cpus must be an integer'))
return min(max(countcpus(), 4), 32)
if os.name == 'posix':
_startupcost = 0.01
else:
_startupcost = 1e30
def worthwhile(ui, costperop, nops):
'''try to determine whether the benefit of multiple processes can
outweigh the cost of starting them'''
linear = costperop * nops
workers = _numworkers(ui)
benefit = linear - (_startupcost * workers + linear / workers)
return benefit >= 0.15
def worker(ui, costperarg, func, staticargs, args):
'''run a function, possibly in parallel in multiple worker
processes.
returns a progress iterator
costperarg - cost of a single task
func - function to run
staticargs - arguments to pass to every invocation of the function
args - arguments to split into chunks, to pass to individual
workers
'''
if worthwhile(ui, costperarg, len(args)):
return _platformworker(ui, func, staticargs, args)
return func(*staticargs + (args,))
def _posixworker(ui, func, staticargs, args):
rfd, wfd = os.pipe()
workers = _numworkers(ui)
oldhandler = signal.getsignal(signal.SIGINT)
signal.signal(signal.SIGINT, signal.SIG_IGN)
pids, problem = [], [0]
for pargs in partition(args, workers):
pid = os.fork()
if pid == 0:
signal.signal(signal.SIGINT, oldhandler)
try:
os.close(rfd)
for i, item in func(*(staticargs + (pargs,))):
os.write(wfd, '%d %s\n' % (i, item))
os._exit(0)
except KeyboardInterrupt:
os._exit(255)
# other exceptions are allowed to propagate, we rely
# on lock.py's pid checks to avoid release callbacks
pids.append(pid)
pids.reverse()
os.close(wfd)
fp = os.fdopen(rfd, 'rb', 0)
def killworkers():
# if one worker bails, there's no good reason to wait for the rest
for p in pids:
try:
os.kill(p, signal.SIGTERM)
except OSError, err:
if err.errno != errno.ESRCH:
raise
def waitforworkers():
for _pid in pids:
st = _exitstatus(os.wait()[1])
if st and not problem[0]:
problem[0] = st
killworkers()
t = threading.Thread(target=waitforworkers)
t.start()
def cleanup():
signal.signal(signal.SIGINT, oldhandler)
t.join()
status = problem[0]
if status:
if status < 0:
os.kill(os.getpid(), -status)
sys.exit(status)
try:
for line in fp:
l = line.split(' ', 1)
yield int(l[0]), l[1][:-1]
except: # re-raises
killworkers()
cleanup()
raise
cleanup()
def _posixexitstatus(code):
'''convert a posix exit status into the same form returned by
os.spawnv
returns None if the process was stopped instead of exiting'''
if os.WIFEXITED(code):
return os.WEXITSTATUS(code)
elif os.WIFSIGNALED(code):
return -os.WTERMSIG(code)
if os.name != 'nt':
_platformworker = _posixworker
_exitstatus = _posixexitstatus
def partition(lst, nslices):
'''partition a list into N slices of equal size'''
n = len(lst)
chunk, slop = n / nslices, n % nslices
end = 0
for i in xrange(nslices):
start = end
end = start + chunk
if slop:
end += 1
slop -= 1
yield lst[start:end]