# procutil.py - utility for managing processes and executable environment
#
# Copyright 2005 K. Thananchayan <thananck@yahoo.com>
# Copyright 2005-2007 Olivia Mackall <olivia@selenic.com>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@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.
import contextlib
import errno
import io
import os
import signal
import subprocess
import sys
import threading
import time
from ..i18n import _
from ..pycompat import (
getattr,
open,
)
from .. import (
encoding,
error,
policy,
pycompat,
)
# Import like this to keep import-checker happy
from ..utils import resourceutil
osutil = policy.importmod('osutil')
if pycompat.iswindows:
from .. import windows as platform
else:
from .. import posix as platform
def isatty(fp):
try:
return fp.isatty()
except AttributeError:
return False
class BadFile(io.RawIOBase):
"""Dummy file object to simulate closed stdio behavior"""
def readinto(self, b):
raise IOError(errno.EBADF, 'Bad file descriptor')
def write(self, b):
raise IOError(errno.EBADF, 'Bad file descriptor')
class LineBufferedWrapper:
def __init__(self, orig):
self.orig = orig
def __getattr__(self, attr):
return getattr(self.orig, attr)
def write(self, s):
orig = self.orig
res = orig.write(s)
if s.endswith(b'\n'):
orig.flush()
return res
# pytype: disable=attribute-error
io.BufferedIOBase.register(LineBufferedWrapper)
# pytype: enable=attribute-error
def make_line_buffered(stream):
if not isinstance(stream, io.BufferedIOBase):
# On Python 3, buffered streams can be expected to subclass
# BufferedIOBase. This is definitively the case for the streams
# initialized by the interpreter. For unbuffered streams, we don't need
# to emulate line buffering.
return stream
if isinstance(stream, LineBufferedWrapper):
return stream
return LineBufferedWrapper(stream)
def unwrap_line_buffered(stream):
if isinstance(stream, LineBufferedWrapper):
assert not isinstance(stream.orig, LineBufferedWrapper)
return stream.orig
return stream
class WriteAllWrapper:
def __init__(self, orig):
self.orig = orig
def __getattr__(self, attr):
return getattr(self.orig, attr)
def write(self, s):
write1 = self.orig.write
m = memoryview(s)
total_to_write = len(s)
total_written = 0
while total_written < total_to_write:
c = write1(m[total_written:])
if c:
total_written += c
return total_written
# pytype: disable=attribute-error
io.IOBase.register(WriteAllWrapper)
# pytype: enable=attribute-error
def _make_write_all(stream):
if isinstance(stream, WriteAllWrapper):
return stream
if isinstance(stream, io.BufferedIOBase):
# The io.BufferedIOBase.write() contract guarantees that all data is
# written.
return stream
# In general, the write() method of streams is free to write only part of
# the data.
return WriteAllWrapper(stream)
# Python 3 implements its own I/O streams. Unlike stdio of C library,
# sys.stdin/stdout/stderr may be None if underlying fd is closed.
# TODO: .buffer might not exist if std streams were replaced; we'll need
# a silly wrapper to make a bytes stream backed by a unicode one.
if sys.stdin is None:
stdin = BadFile()
else:
stdin = sys.stdin.buffer
if sys.stdout is None:
stdout = BadFile()
else:
stdout = _make_write_all(sys.stdout.buffer)
if sys.stderr is None:
stderr = BadFile()
else:
stderr = _make_write_all(sys.stderr.buffer)
if pycompat.iswindows:
# Work around Windows bugs.
stdout = platform.winstdout(stdout) # pytype: disable=module-attr
stderr = platform.winstdout(stderr) # pytype: disable=module-attr
if isatty(stdout):
# The standard library doesn't offer line-buffered binary streams.
stdout = make_line_buffered(stdout)
findexe = platform.findexe
_gethgcmd = platform.gethgcmd
getuser = platform.getuser
getpid = os.getpid
hidewindow = platform.hidewindow
readpipe = platform.readpipe
setbinary = platform.setbinary
setsignalhandler = platform.setsignalhandler
shellquote = platform.shellquote
shellsplit = platform.shellsplit
spawndetached = platform.spawndetached
sshargs = platform.sshargs
testpid = platform.testpid
try:
setprocname = osutil.setprocname
except AttributeError:
pass
try:
unblocksignal = osutil.unblocksignal
except AttributeError:
pass
closefds = pycompat.isposix
def explainexit(code):
"""return a message describing a subprocess status
(codes from kill are negative - not os.system/wait encoding)"""
if code >= 0:
return _(b"exited with status %d") % code
return _(b"killed by signal %d") % -code
class _pfile:
"""File-like wrapper for a stream opened by subprocess.Popen()"""
def __init__(self, proc, fp):
self._proc = proc
self._fp = fp
def close(self):
# unlike os.popen(), this returns an integer in subprocess coding
self._fp.close()
return self._proc.wait()
def __iter__(self):
return iter(self._fp)
def __getattr__(self, attr):
return getattr(self._fp, attr)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, exc_tb):
self.close()
def popen(cmd, mode=b'rb', bufsize=-1):
if mode == b'rb':
return _popenreader(cmd, bufsize)
elif mode == b'wb':
return _popenwriter(cmd, bufsize)
raise error.ProgrammingError(b'unsupported mode: %r' % mode)
def _popenreader(cmd, bufsize):
p = subprocess.Popen(
tonativestr(cmd),
shell=True,
bufsize=bufsize,
close_fds=closefds,
stdout=subprocess.PIPE,
)
return _pfile(p, p.stdout)
def _popenwriter(cmd, bufsize):
p = subprocess.Popen(
tonativestr(cmd),
shell=True,
bufsize=bufsize,
close_fds=closefds,
stdin=subprocess.PIPE,
)
return _pfile(p, p.stdin)
def popen2(cmd, env=None):
# Setting bufsize to -1 lets the system decide the buffer size.
# The default for bufsize is 0, meaning unbuffered. This leads to
# poor performance on Mac OS X: http://bugs.python.org/issue4194
p = subprocess.Popen(
tonativestr(cmd),
shell=True,
bufsize=-1,
close_fds=closefds,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
env=tonativeenv(env),
)
return p.stdin, p.stdout
def popen3(cmd, env=None):
stdin, stdout, stderr, p = popen4(cmd, env)
return stdin, stdout, stderr
def popen4(cmd, env=None, bufsize=-1):
p = subprocess.Popen(
tonativestr(cmd),
shell=True,
bufsize=bufsize,
close_fds=closefds,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
env=tonativeenv(env),
)
return p.stdin, p.stdout, p.stderr, p
def pipefilter(s, cmd):
'''filter string S through command CMD, returning its output'''
p = subprocess.Popen(
tonativestr(cmd),
shell=True,
close_fds=closefds,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
)
pout, perr = p.communicate(s)
return pout
def tempfilter(s, cmd):
"""filter string S through a pair of temporary files with CMD.
CMD is used as a template to create the real command to be run,
with the strings INFILE and OUTFILE replaced by the real names of
the temporary files generated."""
inname, outname = None, None
try:
infd, inname = pycompat.mkstemp(prefix=b'hg-filter-in-')
fp = os.fdopen(infd, 'wb')
fp.write(s)
fp.close()
outfd, outname = pycompat.mkstemp(prefix=b'hg-filter-out-')
os.close(outfd)
cmd = cmd.replace(b'INFILE', inname)
cmd = cmd.replace(b'OUTFILE', outname)
code = system(cmd)
if pycompat.sysplatform == b'OpenVMS' and code & 1:
code = 0
if code:
raise error.Abort(
_(b"command '%s' failed: %s") % (cmd, explainexit(code))
)
with open(outname, b'rb') as fp:
return fp.read()
finally:
try:
if inname:
os.unlink(inname)
except OSError:
pass
try:
if outname:
os.unlink(outname)
except OSError:
pass
_filtertable = {
b'tempfile:': tempfilter,
b'pipe:': pipefilter,
}
def filter(s, cmd):
"""filter a string through a command that transforms its input to its
output"""
for name, fn in _filtertable.items():
if cmd.startswith(name):
return fn(s, cmd[len(name) :].lstrip())
return pipefilter(s, cmd)
_hgexecutable = None
def hgexecutable():
"""return location of the 'hg' executable.
Defaults to $HG or 'hg' in the search path.
"""
if _hgexecutable is None:
hg = encoding.environ.get(b'HG')
mainmod = sys.modules['__main__']
if hg:
_sethgexecutable(hg)
elif resourceutil.mainfrozen():
if getattr(sys, 'frozen', None) == 'macosx_app':
# Env variable set by py2app
_sethgexecutable(encoding.environ[b'EXECUTABLEPATH'])
else:
_sethgexecutable(pycompat.sysexecutable)
elif (
not pycompat.iswindows
and os.path.basename(getattr(mainmod, '__file__', '')) == 'hg'
):
_sethgexecutable(pycompat.fsencode(mainmod.__file__))
else:
_sethgexecutable(
findexe(b'hg') or os.path.basename(pycompat.sysargv[0])
)
return _hgexecutable
def _sethgexecutable(path):
"""set location of the 'hg' executable"""
global _hgexecutable
_hgexecutable = path
def _testfileno(f, stdf):
fileno = getattr(f, 'fileno', None)
try:
return fileno and fileno() == stdf.fileno()
except io.UnsupportedOperation:
return False # fileno() raised UnsupportedOperation
def isstdin(f):
return _testfileno(f, sys.__stdin__)
def isstdout(f):
return _testfileno(f, sys.__stdout__)
def protectstdio(uin, uout):
"""Duplicate streams and redirect original if (uin, uout) are stdio
If uin is stdin, it's redirected to /dev/null. If uout is stdout, it's
redirected to stderr so the output is still readable.
Returns (fin, fout) which point to the original (uin, uout) fds, but
may be copy of (uin, uout). The returned streams can be considered
"owned" in that print(), exec(), etc. never reach to them.
"""
uout.flush()
fin, fout = uin, uout
if _testfileno(uin, stdin):
newfd = os.dup(uin.fileno())
nullfd = os.open(os.devnull, os.O_RDONLY)
os.dup2(nullfd, uin.fileno())
os.close(nullfd)
fin = os.fdopen(newfd, 'rb')
if _testfileno(uout, stdout):
newfd = os.dup(uout.fileno())
os.dup2(stderr.fileno(), uout.fileno())
fout = os.fdopen(newfd, 'wb')
return fin, fout
def restorestdio(uin, uout, fin, fout):
"""Restore (uin, uout) streams from possibly duplicated (fin, fout)"""
uout.flush()
for f, uif in [(fin, uin), (fout, uout)]:
if f is not uif:
os.dup2(f.fileno(), uif.fileno())
f.close()
def shellenviron(environ=None):
"""return environ with optional override, useful for shelling out"""
def py2shell(val):
"""convert python object into string that is useful to shell"""
if val is None or val is False:
return b'0'
if val is True:
return b'1'
return pycompat.bytestr(val)
env = dict(encoding.environ)
if environ:
env.update((k, py2shell(v)) for k, v in environ.items())
env[b'HG'] = hgexecutable()
return env
if pycompat.iswindows:
def shelltonative(cmd, env):
return platform.shelltocmdexe( # pytype: disable=module-attr
cmd, shellenviron(env)
)
tonativestr = encoding.strfromlocal
else:
def shelltonative(cmd, env):
return cmd
tonativestr = pycompat.identity
def tonativeenv(env):
"""convert the environment from bytes to strings suitable for Popen(), etc."""
return pycompat.rapply(tonativestr, env)
def system(cmd, environ=None, cwd=None, out=None):
"""enhanced shell command execution.
run with environment maybe modified, maybe in different dir.
if out is specified, it is assumed to be a file-like object that has a
write() method. stdout and stderr will be redirected to out."""
try:
stdout.flush()
except Exception:
pass
env = shellenviron(environ)
if out is None or isstdout(out):
rc = subprocess.call(
tonativestr(cmd),
shell=True,
close_fds=closefds,
env=tonativeenv(env),
cwd=pycompat.rapply(tonativestr, cwd),
)
else:
proc = subprocess.Popen(
tonativestr(cmd),
shell=True,
close_fds=closefds,
env=tonativeenv(env),
cwd=pycompat.rapply(tonativestr, cwd),
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
)
for line in iter(proc.stdout.readline, b''):
out.write(line)
proc.wait()
rc = proc.returncode
if pycompat.sysplatform == b'OpenVMS' and rc & 1:
rc = 0
return rc
_is_gui = None
def _gui():
'''Are we running in a GUI?'''
if pycompat.isdarwin:
if b'SSH_CONNECTION' in encoding.environ:
# handle SSH access to a box where the user is logged in
return False
elif getattr(osutil, 'isgui', None):
# check if a CoreGraphics session is available
return osutil.isgui()
else:
# pure build; use a safe default
return True
else:
return (
pycompat.iswindows
or encoding.environ.get(b"DISPLAY")
or encoding.environ.get(b"WAYLAND_DISPLAY")
)
def gui():
global _is_gui
if _is_gui is None:
_is_gui = _gui()
return _is_gui
def hgcmd():
"""Return the command used to execute current hg
This is different from hgexecutable() because on Windows we want
to avoid things opening new shell windows like batch files, so we
get either the python call or current executable.
"""
if resourceutil.mainfrozen():
if getattr(sys, 'frozen', None) == 'macosx_app':
# Env variable set by py2app
return [encoding.environ[b'EXECUTABLEPATH']]
else:
return [pycompat.sysexecutable]
return _gethgcmd()
def rundetached(args, condfn):
"""Execute the argument list in a detached process.
condfn is a callable which is called repeatedly and should return
True once the child process is known to have started successfully.
At this point, the child process PID is returned. If the child
process fails to start or finishes before condfn() evaluates to
True, return -1.
"""
# Windows case is easier because the child process is either
# successfully starting and validating the condition or exiting
# on failure. We just poll on its PID. On Unix, if the child
# process fails to start, it will be left in a zombie state until
# the parent wait on it, which we cannot do since we expect a long
# running process on success. Instead we listen for SIGCHLD telling
# us our child process terminated.
terminated = set()
def handler(signum, frame):
terminated.add(os.wait())
prevhandler = None
SIGCHLD = getattr(signal, 'SIGCHLD', None)
if SIGCHLD is not None:
prevhandler = signal.signal(SIGCHLD, handler)
try:
pid = spawndetached(args)
while not condfn():
if (pid in terminated or not testpid(pid)) and not condfn():
return -1
time.sleep(0.1)
return pid
finally:
if prevhandler is not None:
signal.signal(signal.SIGCHLD, prevhandler)
@contextlib.contextmanager
def uninterruptible(warn):
"""Inhibit SIGINT handling on a region of code.
Note that if this is called in a non-main thread, it turns into a no-op.
Args:
warn: A callable which takes no arguments, and returns True if the
previous signal handling should be restored.
"""
oldsiginthandler = [signal.getsignal(signal.SIGINT)]
shouldbail = []
def disabledsiginthandler(*args):
if warn():
signal.signal(signal.SIGINT, oldsiginthandler[0])
del oldsiginthandler[0]
shouldbail.append(True)
try:
try:
signal.signal(signal.SIGINT, disabledsiginthandler)
except ValueError:
# wrong thread, oh well, we tried
del oldsiginthandler[0]
yield
finally:
if oldsiginthandler:
signal.signal(signal.SIGINT, oldsiginthandler[0])
if shouldbail:
raise KeyboardInterrupt
if pycompat.iswindows:
# no fork on Windows, but we can create a detached process
# https://msdn.microsoft.com/en-us/library/windows/desktop/ms684863.aspx
# No stdlib constant exists for this value
DETACHED_PROCESS = 0x00000008
# Following creation flags might create a console GUI window.
# Using subprocess.CREATE_NEW_CONSOLE might helps.
# See https://phab.mercurial-scm.org/D1701 for discussion
_creationflags = (
DETACHED_PROCESS
| subprocess.CREATE_NEW_PROCESS_GROUP # pytype: disable=module-attr
)
def runbgcommand(
script,
env,
shell=False,
stdout=None,
stderr=None,
ensurestart=True,
record_wait=None,
stdin_bytes=None,
):
'''Spawn a command without waiting for it to finish.'''
# we can't use close_fds *and* redirect stdin. I'm not sure that we
# need to because the detached process has no console connection.
try:
stdin = None
if stdin_bytes is not None:
stdin = pycompat.unnamedtempfile()
stdin.write(stdin_bytes)
stdin.flush()
stdin.seek(0)
p = subprocess.Popen(
pycompat.rapply(tonativestr, script),
shell=shell,
env=tonativeenv(env),
close_fds=True,
creationflags=_creationflags,
stdin=stdin,
stdout=stdout,
stderr=stderr,
)
if record_wait is not None:
record_wait(p.wait)
finally:
if stdin is not None:
stdin.close()
else:
def runbgcommand(
cmd,
env,
shell=False,
stdout=None,
stderr=None,
ensurestart=True,
record_wait=None,
stdin_bytes=None,
):
"""Spawn a command without waiting for it to finish.
When `record_wait` is not None, the spawned process will not be fully
detached and the `record_wait` argument will be called with a the
`Subprocess.wait` function for the spawned process. This is mostly
useful for developers that need to make sure the spawned process
finished before a certain point. (eg: writing test)"""
if pycompat.isdarwin:
# avoid crash in CoreFoundation in case another thread
# calls gui() while we're calling fork().
gui()
if shell:
script = cmd
else:
if isinstance(cmd, bytes):
cmd = [cmd]
script = b' '.join(shellquote(x) for x in cmd)
if record_wait is None:
# double-fork to completely detach from the parent process
script = b'( %s ) &' % script
start_new_session = True
else:
start_new_session = False
ensurestart = True
stdin = None
try:
if stdin_bytes is None:
stdin = subprocess.DEVNULL
else:
stdin = pycompat.unnamedtempfile()
stdin.write(stdin_bytes)
stdin.flush()
stdin.seek(0)
if stdout is None:
stdout = subprocess.DEVNULL
if stderr is None:
stderr = subprocess.DEVNULL
p = subprocess.Popen(
script,
shell=True,
env=env,
close_fds=True,
stdin=stdin,
stdout=stdout,
stderr=stderr,
start_new_session=start_new_session,
)
except Exception:
if record_wait is not None:
record_wait(255)
raise
finally:
if stdin_bytes is not None and stdin is not None:
assert not isinstance(stdin, int)
stdin.close()
if not ensurestart:
# Even though we're not waiting on the child process,
# we still must call waitpid() on it at some point so
# it's not a zombie/defunct. This is especially relevant for
# chg since the parent process won't die anytime soon.
# We use a thread to make the overhead tiny.
t = threading.Thread(target=lambda: p.wait)
t.daemon = True
t.start()
else:
returncode = p.wait
if record_wait is not None:
record_wait(returncode)