mercurial-scm/hg-stable: mercurial/worker.py annotate

annotate mercurial/worker.py @ 30424:5069a8a40b1b

worker: make waitforworkers reentrant We are going to use it in the SIGCHLD handler. The handler will be executed in the main thread with the non-blocking version of waitpid, while the waitforworkers thread runs the blocking version. It's possible that one of them collects a worker and makes the other error out (no child to wait). This patch handles these errors: ECHILD is ignored. EINTR needs a retry. The "pids" set is designed to be only modifiable by "waitforworkers". And we only remove items after a successful waitpid. Since a child process can only be "waitpid"-ed once. It's guaranteed that "pids.remove(p)" won't be called with duplicated "p"s. And once a "p" is removed from "pids", that "p" does not need to be killed or waited any more.

author	Jun Wu <quark@fb.com>
date	Tue, 15 Nov 2016 02:12:16 +0000
parents	9c25a1a8c685
children	e8fb03cfbbde

rev	line source
18635 fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	1 # worker.py - master-slave parallelism support
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	2 #
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	3 # Copyright 2013 Facebook, Inc.
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	4 #
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	5 # This software may be used and distributed according to the terms of the
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	6 # GNU General Public License version 2 or any later version.
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	7
25992 2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	8 from __future__ import absolute_import
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	9
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	10 import errno
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	11 import os
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	12 import signal
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	13 import sys
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	14 import threading
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	15
2d76f8a2d831 worker: use absolute_import Gregory Szorc <gregory.szorc@gmail.com> parents: 25660 diff changeset	16 from .i18n import _
30406 78a58dcf8853 worker: migrate to util.iterfile Jun Wu <quark@fb.com> parents: 28292 diff changeset	17 from . import (
78a58dcf8853 worker: migrate to util.iterfile Jun Wu <quark@fb.com> parents: 28292 diff changeset	18 error,
78a58dcf8853 worker: migrate to util.iterfile Jun Wu <quark@fb.com> parents: 28292 diff changeset	19 util,
78a58dcf8853 worker: migrate to util.iterfile Jun Wu <quark@fb.com> parents: 28292 diff changeset	20 )
18635 fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	21
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	22 def countcpus():
fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	23 '''try to count the number of CPUs on the system'''
26568 c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	24
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	25 # posix
18635 fed06dd07665 worker: count the number of CPUs Bryan O'Sullivan <bryano@fb.com> parents: diff changeset	26 try:
26568 c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	27 n = int(os.sysconf('SC_NPROCESSORS_ONLN'))
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	28 if n > 0:
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	29 return n
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	30 except (AttributeError, ValueError):
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	31 pass
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	32
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	33 # windows
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	34 try:
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	35 n = int(os.environ['NUMBER_OF_PROCESSORS'])
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	36 if n > 0:
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	37 return n
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	38 except (KeyError, ValueError):
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	39 pass
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	40
c0501c26b05c worker: restore old countcpus code (issue4869) Gregory Szorc <gregory.szorc@gmail.com> parents: 26063 diff changeset	41 return 1
18636 dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	42
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	43 def _numworkers(ui):
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	44 s = ui.config('worker', 'numcpus')
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	45 if s:
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	46 try:
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	47 n = int(s)
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	48 if n >= 1:
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	49 return n
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	50 except ValueError:
26587 56b2bcea2529 error: get Abort from 'error' instead of 'util' Pierre-Yves David <pierre-yves.david@fb.com> parents: 26568 diff changeset	51 raise error.Abort(_('number of cpus must be an integer'))
18636 dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	52 return min(max(countcpus(), 4), 32)
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	53
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	54 if os.name == 'posix':
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	55 _startupcost = 0.01
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	56 else:
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	57 _startupcost = 1e30
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	58
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	59 def worthwhile(ui, costperop, nops):
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	60 '''try to determine whether the benefit of multiple processes can
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	61 outweigh the cost of starting them'''
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	62 linear = costperop * nops
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	63 workers = _numworkers(ui)
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	64 benefit = linear - (_startupcost * workers + linear / workers)
dcb27c153a40 worker: estimate whether it's worth running a task in parallel Bryan O'Sullivan <bryano@fb.com> parents: 18635 diff changeset	65 return benefit >= 0.15
18637 ac4dbceeb14a worker: partition a list (of tasks) into equal-sized chunks Bryan O'Sullivan <bryano@fb.com> parents: 18636 diff changeset	66
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	67 def worker(ui, costperarg, func, staticargs, args):
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	68 '''run a function, possibly in parallel in multiple worker
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	69 processes.
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	70
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	71 returns a progress iterator
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	72
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	73 costperarg - cost of a single task
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	74
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	75 func - function to run
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	76
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	77 staticargs - arguments to pass to every invocation of the function
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	78
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	79 args - arguments to split into chunks, to pass to individual
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	80 workers
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	81 '''
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	82 if worthwhile(ui, costperarg, len(args)):
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	83 return _platformworker(ui, func, staticargs, args)
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	84 return func(*staticargs + (args,))
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	85
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	86 def _posixworker(ui, func, staticargs, args):
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	87 rfd, wfd = os.pipe()
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	88 workers = _numworkers(ui)
18708 86524a70c0f6 worker: fix a race in SIGINT handling Bryan O'Sullivan <bryano@fb.com> parents: 18707 diff changeset	89 oldhandler = signal.getsignal(signal.SIGINT)
86524a70c0f6 worker: fix a race in SIGINT handling Bryan O'Sullivan <bryano@fb.com> parents: 18707 diff changeset	90 signal.signal(signal.SIGINT, signal.SIG_IGN)
30423 9c25a1a8c685 worker: change "pids" to a set Jun Wu <quark@fb.com> parents: 30422 diff changeset	91 pids, problem = set(), [0]
30420 7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	92 def killworkers():
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	93 # if one worker bails, there's no good reason to wait for the rest
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	94 for p in pids:
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	95 try:
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	96 os.kill(p, signal.SIGTERM)
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	97 except OSError as err:
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	98 if err.errno != errno.ESRCH:
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	99 raise
30422 7bc25549e084 worker: allow waitforworkers to be non-blocking Jun Wu <quark@fb.com> parents: 30421 diff changeset	100 def waitforworkers(blocking=True):
30424 5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	101 for pid in pids.copy():
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	102 p = st = 0
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	103 while True:
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	104 try:
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	105 p, st = os.waitpid(pid, (0 if blocking else os.WNOHANG))
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	106 except OSError as e:
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	107 if e.errno == errno.EINTR:
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	108 continue
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	109 elif e.errno == errno.ECHILD:
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	110 break # ignore ECHILD
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	111 else:
5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	112 raise
30422 7bc25549e084 worker: allow waitforworkers to be non-blocking Jun Wu <quark@fb.com> parents: 30421 diff changeset	113 if p:
30424 5069a8a40b1b worker: make waitforworkers reentrant Jun Wu <quark@fb.com> parents: 30423 diff changeset	114 pids.remove(p)
30422 7bc25549e084 worker: allow waitforworkers to be non-blocking Jun Wu <quark@fb.com> parents: 30421 diff changeset	115 st = _exitstatus(st)
30420 7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	116 if st and not problem[0]:
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	117 problem[0] = st
7a5d6e2fd2d5 worker: move killworkers and waitforworkers up Jun Wu <quark@fb.com> parents: 30406 diff changeset	118 killworkers()
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	119 for pargs in partition(args, workers):
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	120 pid = os.fork()
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	121 if pid == 0:
18708 86524a70c0f6 worker: fix a race in SIGINT handling Bryan O'Sullivan <bryano@fb.com> parents: 18707 diff changeset	122 signal.signal(signal.SIGINT, oldhandler)
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	123 try:
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	124 os.close(rfd)
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	125 for i, item in func(*(staticargs + (pargs,))):
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	126 os.write(wfd, '%d %s\n' % (i, item))
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	127 os._exit(0)
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	128 except KeyboardInterrupt:
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	129 os._exit(255)
19408 c7ec39c1a381 worker: properly report errors from worker processes (issue3982) Matt Mackall <mpm@selenic.com> parents: 19406 diff changeset	130 # other exceptions are allowed to propagate, we rely
c7ec39c1a381 worker: properly report errors from worker processes (issue3982) Matt Mackall <mpm@selenic.com> parents: 19406 diff changeset	131 # on lock.py's pid checks to avoid release callbacks
30423 9c25a1a8c685 worker: change "pids" to a set Jun Wu <quark@fb.com> parents: 30422 diff changeset	132 pids.add(pid)
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	133 os.close(wfd)
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	134 fp = os.fdopen(rfd, 'rb', 0)
18709 9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	135 t = threading.Thread(target=waitforworkers)
9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	136 t.start()
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	137 def cleanup():
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	138 signal.signal(signal.SIGINT, oldhandler)
18709 9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	139 t.join()
9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	140 status = problem[0]
9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	141 if status:
9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	142 if status < 0:
9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	143 os.kill(os.getpid(), -status)
9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	144 sys.exit(status)
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	145 try:
30406 78a58dcf8853 worker: migrate to util.iterfile Jun Wu <quark@fb.com> parents: 28292 diff changeset	146 for line in util.iterfile(fp):
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	147 l = line.split(' ', 1)
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	148 yield int(l[0]), l[1][:-1]
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	149 except: # re-raises
18709 9955fc5ee24b worker: handle worker failures more aggressively Bryan O'Sullivan <bryano@fb.com> parents: 18708 diff changeset	150 killworkers()
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	151 cleanup()
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	152 raise
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	153 cleanup()
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	154
18707 d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	155 def _posixexitstatus(code):
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	156 '''convert a posix exit status into the same form returned by
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	157 os.spawnv
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	158
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	159 returns None if the process was stopped instead of exiting'''
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	160 if os.WIFEXITED(code):
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	161 return os.WEXITSTATUS(code)
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	162 elif os.WIFSIGNALED(code):
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	163 return -os.WTERMSIG(code)
d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	164
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	165 if os.name != 'nt':
047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	166 _platformworker = _posixworker
18707 d1a2b086d058 worker: on error, exit similarly to the first failing worker Bryan O'Sullivan <bryano@fb.com> parents: 18638 diff changeset	167 _exitstatus = _posixexitstatus
18638 047110c0e2a8 worker: allow a function to be run in multiple worker processes Bryan O'Sullivan <bryano@fb.com> parents: 18637 diff changeset	168
18637 ac4dbceeb14a worker: partition a list (of tasks) into equal-sized chunks Bryan O'Sullivan <bryano@fb.com> parents: 18636 diff changeset	169 def partition(lst, nslices):
28181 f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	170 '''partition a list into N slices of roughly equal size
f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	171
f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	172 The current strategy takes every Nth element from the input. If
f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	173 we ever write workers that need to preserve grouping in input
f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	174 we should consider allowing callers to specify a partition strategy.
28292 3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	175
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	176 mpm is not a fan of this partitioning strategy when files are involved.
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	177 In his words:
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	178
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	179 Single-threaded Mercurial makes a point of creating and visiting
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	180 files in a fixed order (alphabetical). When creating files in order,
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	181 a typical filesystem is likely to allocate them on nearby regions on
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	182 disk. Thus, when revisiting in the same order, locality is maximized
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	183 and various forms of OS and disk-level caching and read-ahead get a
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	184 chance to work.
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	185
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	186 This effect can be quite significant on spinning disks. I discovered it
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	187 circa Mercurial v0.4 when revlogs were named by hashes of filenames.
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	188 Tarring a repo and copying it to another disk effectively randomized
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	189 the revlog ordering on disk by sorting the revlogs by hash and suddenly
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	190 performance of my kernel checkout benchmark dropped by ~10x because the
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	191 "working set" of sectors visited no longer fit in the drive's cache and
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	192 the workload switched from streaming to random I/O.
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	193
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	194 What we should really be doing is have workers read filenames from a
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	195 ordered queue. This preserves locality and also keeps any worker from
3eb7faf6d958 worker: document poor partitioning scheme impact Gregory Szorc <gregory.szorc@gmail.com> parents: 28181 diff changeset	196 getting more than one file out of balance.
28181 f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	197 '''
f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	198 for i in range(nslices):
f8efc8a3a991 worker: change partition strategy to every Nth element Gregory Szorc <gregory.szorc@gmail.com> parents: 26587 diff changeset	199 yield lst[i::nslices]

Mercurial > public > mercurial-scm > hg-stable

annotate mercurial/worker.py @ 30424:5069a8a40b1b