mercurial/worker.py
author FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
Mon, 11 Aug 2014 22:29:43 +0900
changeset 22098 2fb3c1c0b4ef
parent 20034 1e5b38a919dd
child 22199 b3e51675f98e
permissions -rw-r--r--
largefiles: synchronize lfdirstate with dirstate after automated committing Before this patch, after successful "hg rebase" of the revision removing largefiles, "hg status" may still show ""R" for such largefiles unexpectedly. "lfilesrepo.commit" executes the special code path for automated committing while rebase/transplant, and lfdirstate entries for removed files aren't updated in this code path, even after successful committing. Then, "R" entries still existing in lfdirstate cause unexpected "hg status" output. This patch synchronizes lfdirstate with dirstate after automated committing. This patch passes False as "normallookup" to "synclfdirstate", because modified files in "files()" of the recent (= just committed) context should be "normal"-ed. This is a temporary way to fix with less changes. For fundamental resolution of this kind of problems in the future, lfdirstate should be updated with dirstate simultaneously. Hooking "markcommitted" of ctx in "localrepository.commitctx" may achieve this. This problem occurs, only when (1) the parent of the working directory is rebased and (2) it removes largefiles, because: - if the parent of the working directory isn't rebased, returning to the initial revision (= update) after rebase hides this problem - files added on "other" branch (= rebase target) are treated not as "added" but as "modified" (= "normal" status and "unset" timestamp) at merging This patch tests also the status of added largefile, but it is only for avoiding regression. In addition to conditions above, "hg status" must not take existing files to reproduce this problem, because existing files make "match._files" not empty in "lfilesrepo.status" code path below: def sfindirstate(f): sf = lfutil.standin(f) dirstate = self.dirstate return sf in dirstate or sf in dirstate.dirs() match._files = [f for f in match._files if sfindirstate(f)] Not empty "match._files" prevents "status" on lfdirstate from returning the result containing problematic "R" files. This is reason why "large1" (removed) and "largeX" (added) are checked separately in this patch. Problematic code path in "lfilesrepo.commit" is used also by "hg transplant", but this problem doesn't occur at "hg transplant", because invocation of "updatelfiles" after transplant-ing in "overridetransplant" causes cleaning lfdirstate up. This patch tests also "hg transplant" as same as "hg rebase", but it is only for avoiding regression.

# 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 _ 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]