Mercurial > hg
view mercurial/profiling.py @ 37631:2f626233859b
wireproto: implement batching on peer executor interface
This is a bit more complicated than non-batch requests because we
need to buffer sends until the last request arrives *and* we need
to support resolving futures as data arrives from the remote.
In a classical concurrent.futures executor model, the future
"starts" as soon as it is submitted. However, we have nothing to
start until the last command is submitted.
If we did nothing, calling result() would deadlock, since the future
hasn't "started." So in the case where we queue the command, we return
a special future type whose result() will trigger sendcommands().
This eliminates the deadlock potential. It also serves as a check
against callers who may be calling result() prematurely, as it will
prevent any subsequent callcommands() from working. This behavior
is slightly annoying and a bit restrictive. But it's the world
that half duplex connections forces on us.
In order to support streaming responses, we were previously using
a generator. But with a futures-based API, we're using futures
and not generators. So in order to get streaming, we need a
background thread to read data from the server.
The approach taken in this patch is to leverage the ThreadPoolExecutor
from concurrent.futures for managing a background thread. We create
an executor and future that resolves when all response data is
processed (or an error occurs). When exiting the context manager,
we wait on that background reading before returning.
I was hoping we could manually spin up a threading.Thread and this
would be simple. But I ran into a few deadlocks when implementing.
After looking at the source code to concurrent.futures, I figured
it would just be easier to use a ThreadPoolExecutor than implement
all the code needed to manually manage a thread.
To prove this works, a use of the batch API in discovery has been
updated.
Differential Revision: https://phab.mercurial-scm.org/D3269
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 13 Apr 2018 11:02:34 -0700 |
parents | e39953fdd924 |
children | 15a1e37f80bd |
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# profiling.py - profiling functions # # Copyright 2016 Gregory Szorc <gregory.szorc@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import, print_function import contextlib from .i18n import _ from . import ( encoding, error, extensions, pycompat, util, ) def _loadprofiler(ui, profiler): """load profiler extension. return profile method, or None on failure""" extname = profiler extensions.loadall(ui, whitelist=[extname]) try: mod = extensions.find(extname) except KeyError: return None else: return getattr(mod, 'profile', None) @contextlib.contextmanager def lsprofile(ui, fp): format = ui.config('profiling', 'format') field = ui.config('profiling', 'sort') limit = ui.configint('profiling', 'limit') climit = ui.configint('profiling', 'nested') if format not in ['text', 'kcachegrind']: ui.warn(_("unrecognized profiling format '%s'" " - Ignored\n") % format) format = 'text' try: from . import lsprof except ImportError: raise error.Abort(_( 'lsprof not available - install from ' 'http://codespeak.net/svn/user/arigo/hack/misc/lsprof/')) p = lsprof.Profiler() p.enable(subcalls=True) try: yield finally: p.disable() if format == 'kcachegrind': from . import lsprofcalltree calltree = lsprofcalltree.KCacheGrind(p) calltree.output(fp) else: # format == 'text' stats = lsprof.Stats(p.getstats()) stats.sort(field) stats.pprint(limit=limit, file=fp, climit=climit) @contextlib.contextmanager def flameprofile(ui, fp): try: from flamegraph import flamegraph except ImportError: raise error.Abort(_( 'flamegraph not available - install from ' 'https://github.com/evanhempel/python-flamegraph')) # developer config: profiling.freq freq = ui.configint('profiling', 'freq') filter_ = None collapse_recursion = True thread = flamegraph.ProfileThread(fp, 1.0 / freq, filter_, collapse_recursion) start_time = util.timer() try: thread.start() yield finally: thread.stop() thread.join() print('Collected %d stack frames (%d unique) in %2.2f seconds.' % ( util.timer() - start_time, thread.num_frames(), thread.num_frames(unique=True))) @contextlib.contextmanager def statprofile(ui, fp): from . import statprof freq = ui.configint('profiling', 'freq') if freq > 0: # Cannot reset when profiler is already active. So silently no-op. if statprof.state.profile_level == 0: statprof.reset(freq) else: ui.warn(_("invalid sampling frequency '%s' - ignoring\n") % freq) statprof.start(mechanism='thread') try: yield finally: data = statprof.stop() profformat = ui.config('profiling', 'statformat') formats = { 'byline': statprof.DisplayFormats.ByLine, 'bymethod': statprof.DisplayFormats.ByMethod, 'hotpath': statprof.DisplayFormats.Hotpath, 'json': statprof.DisplayFormats.Json, 'chrome': statprof.DisplayFormats.Chrome, } if profformat in formats: displayformat = formats[profformat] else: ui.warn(_('unknown profiler output format: %s\n') % profformat) displayformat = statprof.DisplayFormats.Hotpath kwargs = {} def fraction(s): if isinstance(s, (float, int)): return float(s) if s.endswith('%'): v = float(s[:-1]) / 100 else: v = float(s) if 0 <= v <= 1: return v raise ValueError(s) if profformat == 'chrome': showmin = ui.configwith(fraction, 'profiling', 'showmin', 0.005) showmax = ui.configwith(fraction, 'profiling', 'showmax') kwargs.update(minthreshold=showmin, maxthreshold=showmax) elif profformat == 'hotpath': # inconsistent config: profiling.showmin limit = ui.configwith(fraction, 'profiling', 'showmin', 0.05) kwargs[r'limit'] = limit statprof.display(fp, data=data, format=displayformat, **kwargs) class profile(object): """Start profiling. Profiling is active when the context manager is active. When the context manager exits, profiling results will be written to the configured output. """ def __init__(self, ui, enabled=True): self._ui = ui self._output = None self._fp = None self._fpdoclose = True self._profiler = None self._enabled = enabled self._entered = False self._started = False def __enter__(self): self._entered = True if self._enabled: self.start() return self def start(self): """Start profiling. The profiling will stop at the context exit. If the profiler was already started, this has no effect.""" if not self._entered: raise error.ProgrammingError() if self._started: return self._started = True profiler = encoding.environ.get('HGPROF') proffn = None if profiler is None: profiler = self._ui.config('profiling', 'type') if profiler not in ('ls', 'stat', 'flame'): # try load profiler from extension with the same name proffn = _loadprofiler(self._ui, profiler) if proffn is None: self._ui.warn(_("unrecognized profiler '%s' - ignored\n") % profiler) profiler = 'stat' self._output = self._ui.config('profiling', 'output') try: if self._output == 'blackbox': self._fp = util.stringio() elif self._output: path = self._ui.expandpath(self._output) self._fp = open(path, 'wb') elif pycompat.iswindows: # parse escape sequence by win32print() class uifp(object): def __init__(self, ui): self._ui = ui def write(self, data): self._ui.write_err(data) def flush(self): self._ui.flush() self._fpdoclose = False self._fp = uifp(self._ui) else: self._fpdoclose = False self._fp = self._ui.ferr if proffn is not None: pass elif profiler == 'ls': proffn = lsprofile elif profiler == 'flame': proffn = flameprofile else: proffn = statprofile self._profiler = proffn(self._ui, self._fp) self._profiler.__enter__() except: # re-raises self._closefp() raise def __exit__(self, exception_type, exception_value, traceback): propagate = None if self._profiler is not None: propagate = self._profiler.__exit__(exception_type, exception_value, traceback) if self._output == 'blackbox': val = 'Profile:\n%s' % self._fp.getvalue() # ui.log treats the input as a format string, # so we need to escape any % signs. val = val.replace('%', '%%') self._ui.log('profile', val) self._closefp() return propagate def _closefp(self): if self._fpdoclose and self._fp is not None: self._fp.close()