| 1 | # Copyright 2016 Andy Chu. All rights reserved.
|
| 2 | # Licensed under the Apache License, Version 2.0 (the "License");
|
| 3 | # you may not use this file except in compliance with the License.
|
| 4 | # You may obtain a copy of the License at
|
| 5 | #
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| 6 | # http://www.apache.org/licenses/LICENSE-2.0
|
| 7 | """
|
| 8 | process.py - Launch processes and manipulate file descriptors.
|
| 9 | """
|
| 10 | from __future__ import print_function
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| 11 |
|
| 12 | from errno import EACCES, EBADF, ECHILD, EINTR, ENOENT, ENOEXEC, EEXIST
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| 13 | import fcntl as fcntl_
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| 14 | from fcntl import F_DUPFD, F_GETFD, F_SETFD, FD_CLOEXEC
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| 15 | from signal import (SIG_DFL, SIG_IGN, SIGINT, SIGPIPE, SIGQUIT, SIGTSTP,
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| 16 | SIGTTOU, SIGTTIN, SIGWINCH)
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| 17 |
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| 18 | from _devbuild.gen.id_kind_asdl import Id
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| 19 | from _devbuild.gen.runtime_asdl import (job_state_e, job_state_t,
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| 20 | job_state_str, wait_status,
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| 21 | wait_status_t, RedirValue,
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| 22 | redirect_arg, redirect_arg_e, trace,
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| 23 | trace_t)
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| 24 | from _devbuild.gen.syntax_asdl import (
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| 25 | loc_t,
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| 26 | redir_loc,
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| 27 | redir_loc_e,
|
| 28 | redir_loc_t,
|
| 29 | )
|
| 30 | from _devbuild.gen.value_asdl import (value, value_e)
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| 31 | from core import dev
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| 32 | from core import error
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| 33 | from core.error import e_die
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| 34 | from core import pyutil
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| 35 | from core import pyos
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| 36 | from core import state
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| 37 | from display import ui
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| 38 | from core import util
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| 39 | from data_lang import j8_lite
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| 40 | from frontend import location
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| 41 | from frontend import match
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| 42 | from mycpp import mylib
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| 43 | from mycpp.mylib import log, print_stderr, probe, tagswitch, iteritems
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| 44 |
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| 45 | import posix_ as posix
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| 46 | from posix_ import (
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| 47 | # translated by mycpp and directly called! No wrapper!
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| 48 | WIFSIGNALED,
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| 49 | WIFEXITED,
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| 50 | WIFSTOPPED,
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| 51 | WEXITSTATUS,
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| 52 | WSTOPSIG,
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| 53 | WTERMSIG,
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| 54 | WNOHANG,
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| 55 | O_APPEND,
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| 56 | O_CREAT,
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| 57 | O_EXCL,
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| 58 | O_NONBLOCK,
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| 59 | O_NOCTTY,
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| 60 | O_RDONLY,
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| 61 | O_RDWR,
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| 62 | O_WRONLY,
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| 63 | O_TRUNC,
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| 64 | )
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| 65 |
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| 66 | from typing import IO, List, Tuple, Dict, Optional, Any, cast, TYPE_CHECKING
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| 67 |
|
| 68 | if TYPE_CHECKING:
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| 69 | from _devbuild.gen.runtime_asdl import cmd_value
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| 70 | from _devbuild.gen.syntax_asdl import command_t
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| 71 | from builtin import trap_osh
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| 72 | from core import optview
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| 73 | from core.util import _DebugFile
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| 74 | from osh.cmd_eval import CommandEvaluator
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| 75 |
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| 76 | NO_FD = -1
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| 77 |
|
| 78 | # Minimum file descriptor that the shell can use. Other descriptors can be
|
| 79 | # directly used by user programs, e.g. exec 9>&1
|
| 80 | #
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| 81 | # Oil uses 100 because users are allowed TWO digits in frontend/lexer_def.py.
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| 82 | # This is a compromise between bash (unlimited, but requires crazy
|
| 83 | # bookkeeping), and dash/zsh (10) and mksh (24)
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| 84 | _SHELL_MIN_FD = 100
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| 85 |
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| 86 | # Style for 'jobs' builtin
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| 87 | STYLE_DEFAULT = 0
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| 88 | STYLE_LONG = 1
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| 89 | STYLE_PID_ONLY = 2
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| 90 |
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| 91 | # To save on allocations in JobList::GetJobWithSpec()
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| 92 | CURRENT_JOB_SPECS = ['', '%', '%%', '%+']
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| 93 |
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| 94 |
|
| 95 | class ctx_FileCloser(object):
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| 96 |
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| 97 | def __init__(self, f):
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| 98 | # type: (mylib.LineReader) -> None
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| 99 | self.f = f
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| 100 |
|
| 101 | def __enter__(self):
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| 102 | # type: () -> None
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| 103 | pass
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| 104 |
|
| 105 | def __exit__(self, type, value, traceback):
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| 106 | # type: (Any, Any, Any) -> None
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| 107 | self.f.close()
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| 108 |
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| 109 |
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| 110 | def InitInteractiveShell():
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| 111 | # type: () -> None
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| 112 | """Called when initializing an interactive shell."""
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| 113 |
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| 114 | # The shell itself should ignore Ctrl-\.
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| 115 | pyos.Sigaction(SIGQUIT, SIG_IGN)
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| 116 |
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| 117 | # This prevents Ctrl-Z from suspending OSH in interactive mode.
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| 118 | pyos.Sigaction(SIGTSTP, SIG_IGN)
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| 119 |
|
| 120 | # More signals from
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| 121 | # https://www.gnu.org/software/libc/manual/html_node/Initializing-the-Shell.html
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| 122 | # (but not SIGCHLD)
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| 123 | pyos.Sigaction(SIGTTOU, SIG_IGN)
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| 124 | pyos.Sigaction(SIGTTIN, SIG_IGN)
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| 125 |
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| 126 | # Register a callback to receive terminal width changes.
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| 127 | # NOTE: In line_input.c, we turned off rl_catch_sigwinch.
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| 128 |
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| 129 | # This is ALWAYS on, which means that it can cause EINTR, and wait() and
|
| 130 | # read() have to handle it
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| 131 | pyos.RegisterSignalInterest(SIGWINCH)
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| 132 |
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| 133 |
|
| 134 | def SaveFd(fd):
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| 135 | # type: (int) -> int
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| 136 | saved = fcntl_.fcntl(fd, F_DUPFD, _SHELL_MIN_FD) # type: int
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| 137 | return saved
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| 138 |
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| 139 |
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| 140 | class _RedirFrame(object):
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| 141 |
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| 142 | def __init__(self, saved_fd, orig_fd, forget):
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| 143 | # type: (int, int, bool) -> None
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| 144 | self.saved_fd = saved_fd
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| 145 | self.orig_fd = orig_fd
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| 146 | self.forget = forget
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| 147 |
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| 148 |
|
| 149 | class _FdFrame(object):
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| 150 |
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| 151 | def __init__(self):
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| 152 | # type: () -> None
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| 153 | self.saved = [] # type: List[_RedirFrame]
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| 154 | self.need_wait = [] # type: List[Process]
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| 155 |
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| 156 | def Forget(self):
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| 157 | # type: () -> None
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| 158 | """For exec 1>&2."""
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| 159 | for rf in reversed(self.saved):
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| 160 | if rf.saved_fd != NO_FD and rf.forget:
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| 161 | posix.close(rf.saved_fd)
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| 162 |
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| 163 | del self.saved[:] # like list.clear() in Python 3.3
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| 164 | del self.need_wait[:]
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| 165 |
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| 166 | def __repr__(self):
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| 167 | # type: () -> str
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| 168 | return '<_FdFrame %s>' % self.saved
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| 169 |
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| 170 |
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| 171 | class FdState(object):
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| 172 | """File descriptor state for the current process.
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| 173 |
|
| 174 | For example, you can do 'myfunc > out.txt' without forking. Child
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| 175 | processes inherit our state.
|
| 176 | """
|
| 177 |
|
| 178 | def __init__(
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| 179 | self,
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| 180 | errfmt, # type: ui.ErrorFormatter
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| 181 | job_control, # type: JobControl
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| 182 | job_list, # type: JobList
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| 183 | mem, # type: state.Mem
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| 184 | tracer, # type: Optional[dev.Tracer]
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| 185 | waiter, # type: Optional[Waiter]
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| 186 | exec_opts, # type: optview.Exec
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| 187 | ):
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| 188 | # type: (...) -> None
|
| 189 | """
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| 190 | Args:
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| 191 | errfmt: for errors
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| 192 | job_list: For keeping track of _HereDocWriterThunk
|
| 193 | """
|
| 194 | self.errfmt = errfmt
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| 195 | self.job_control = job_control
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| 196 | self.job_list = job_list
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| 197 | self.cur_frame = _FdFrame() # for the top level
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| 198 | self.stack = [self.cur_frame]
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| 199 | self.mem = mem
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| 200 | self.tracer = tracer
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| 201 | self.waiter = waiter
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| 202 | self.exec_opts = exec_opts
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| 203 |
|
| 204 | def Open(self, path):
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| 205 | # type: (str) -> mylib.LineReader
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| 206 | """Opens a path for read, but moves it out of the reserved 3-9 fd
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| 207 | range.
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| 208 |
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| 209 | Returns:
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| 210 | A Python file object. The caller is responsible for Close().
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| 211 |
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| 212 | Raises:
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| 213 | IOError or OSError if the path can't be found. (This is Python-induced wart)
|
| 214 | """
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| 215 | fd_mode = O_RDONLY
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| 216 | f = self._Open(path, 'r', fd_mode)
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| 217 |
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| 218 | # Hacky downcast
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| 219 | return cast('mylib.LineReader', f)
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| 220 |
|
| 221 | # used for util.DebugFile
|
| 222 | def OpenForWrite(self, path):
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| 223 | # type: (str) -> mylib.Writer
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| 224 | fd_mode = O_CREAT | O_RDWR
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| 225 | f = self._Open(path, 'w', fd_mode)
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| 226 |
|
| 227 | # Hacky downcast
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| 228 | return cast('mylib.Writer', f)
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| 229 |
|
| 230 | def _Open(self, path, c_mode, fd_mode):
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| 231 | # type: (str, str, int) -> IO[str]
|
| 232 | fd = posix.open(path, fd_mode, 0o666) # may raise OSError
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| 233 |
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| 234 | # Immediately move it to a new location
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| 235 | new_fd = SaveFd(fd)
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| 236 | posix.close(fd)
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| 237 |
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| 238 | # Return a Python file handle
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| 239 | f = posix.fdopen(new_fd, c_mode) # may raise IOError
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| 240 | return f
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| 241 |
|
| 242 | def _WriteFdToMem(self, fd_name, fd):
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| 243 | # type: (str, int) -> None
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| 244 | if self.mem:
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| 245 | # setvar, not setref
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| 246 | state.OshLanguageSetValue(self.mem, location.LName(fd_name),
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| 247 | value.Str(str(fd)))
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| 248 |
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| 249 | def _ReadFdFromMem(self, fd_name):
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| 250 | # type: (str) -> int
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| 251 | val = self.mem.GetValue(fd_name)
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| 252 | if val.tag() == value_e.Str:
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| 253 | try:
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| 254 | return int(cast(value.Str, val).s)
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| 255 | except ValueError:
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| 256 | return NO_FD
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| 257 | return NO_FD
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| 258 |
|
| 259 | def _PushSave(self, fd):
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| 260 | # type: (int) -> bool
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| 261 | """Save fd to a new location and remember to restore it later."""
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| 262 | #log('---- _PushSave %s', fd)
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| 263 | ok = True
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| 264 | try:
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| 265 | new_fd = SaveFd(fd)
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| 266 | except (IOError, OSError) as e:
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| 267 | ok = False
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| 268 | # Example program that causes this error: exec 4>&1. Descriptor 4 isn't
|
| 269 | # open.
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| 270 | # This seems to be ignored in dash too in savefd()?
|
| 271 | if e.errno != EBADF:
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| 272 | raise
|
| 273 | if ok:
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| 274 | posix.close(fd)
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| 275 | fcntl_.fcntl(new_fd, F_SETFD, FD_CLOEXEC)
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| 276 | self.cur_frame.saved.append(_RedirFrame(new_fd, fd, True))
|
| 277 | else:
|
| 278 | # if we got EBADF, we still need to close the original on Pop()
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| 279 | self._PushClose(fd)
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| 280 |
|
| 281 | return ok
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| 282 |
|
| 283 | def _PushDup(self, fd1, blame_loc):
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| 284 | # type: (int, redir_loc_t) -> int
|
| 285 | """Save fd2 in a higher range, and dup fd1 onto fd2.
|
| 286 |
|
| 287 | Returns whether F_DUPFD/dup2 succeeded, and the new descriptor.
|
| 288 | """
|
| 289 | UP_loc = blame_loc
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| 290 | if blame_loc.tag() == redir_loc_e.VarName:
|
| 291 | fd2_name = cast(redir_loc.VarName, UP_loc).name
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| 292 | try:
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| 293 | # F_DUPFD: GREATER than range
|
| 294 | new_fd = fcntl_.fcntl(fd1, F_DUPFD, _SHELL_MIN_FD) # type: int
|
| 295 | except (IOError, OSError) as e:
|
| 296 | if e.errno == EBADF:
|
| 297 | print_stderr('F_DUPFD fd %d: %s' %
|
| 298 | (fd1, pyutil.strerror(e)))
|
| 299 | return NO_FD
|
| 300 | else:
|
| 301 | raise # this redirect failed
|
| 302 |
|
| 303 | self._WriteFdToMem(fd2_name, new_fd)
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| 304 |
|
| 305 | elif blame_loc.tag() == redir_loc_e.Fd:
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| 306 | fd2 = cast(redir_loc.Fd, UP_loc).fd
|
| 307 |
|
| 308 | if fd1 == fd2:
|
| 309 | # The user could have asked for it to be open on descriptor 3, but open()
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| 310 | # already returned 3, e.g. echo 3>out.txt
|
| 311 | return NO_FD
|
| 312 |
|
| 313 | # Check the validity of fd1 before _PushSave(fd2)
|
| 314 | try:
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| 315 | fcntl_.fcntl(fd1, F_GETFD)
|
| 316 | except (IOError, OSError) as e:
|
| 317 | print_stderr('F_GETFD fd %d: %s' % (fd1, pyutil.strerror(e)))
|
| 318 | raise
|
| 319 |
|
| 320 | need_restore = self._PushSave(fd2)
|
| 321 |
|
| 322 | #log('==== dup2 %s %s\n' % (fd1, fd2))
|
| 323 | try:
|
| 324 | posix.dup2(fd1, fd2)
|
| 325 | except (IOError, OSError) as e:
|
| 326 | # bash/dash give this error too, e.g. for 'echo hi 1>&3'
|
| 327 | print_stderr('dup2(%d, %d): %s' %
|
| 328 | (fd1, fd2, pyutil.strerror(e)))
|
| 329 |
|
| 330 | # Restore and return error
|
| 331 | if need_restore:
|
| 332 | rf = self.cur_frame.saved.pop()
|
| 333 | posix.dup2(rf.saved_fd, rf.orig_fd)
|
| 334 | posix.close(rf.saved_fd)
|
| 335 |
|
| 336 | raise # this redirect failed
|
| 337 |
|
| 338 | new_fd = fd2
|
| 339 |
|
| 340 | else:
|
| 341 | raise AssertionError()
|
| 342 |
|
| 343 | return new_fd
|
| 344 |
|
| 345 | def _PushCloseFd(self, blame_loc):
|
| 346 | # type: (redir_loc_t) -> bool
|
| 347 | """For 2>&-"""
|
| 348 | # exec {fd}>&- means close the named descriptor
|
| 349 |
|
| 350 | UP_loc = blame_loc
|
| 351 | if blame_loc.tag() == redir_loc_e.VarName:
|
| 352 | fd_name = cast(redir_loc.VarName, UP_loc).name
|
| 353 | fd = self._ReadFdFromMem(fd_name)
|
| 354 | if fd == NO_FD:
|
| 355 | return False
|
| 356 |
|
| 357 | elif blame_loc.tag() == redir_loc_e.Fd:
|
| 358 | fd = cast(redir_loc.Fd, UP_loc).fd
|
| 359 |
|
| 360 | else:
|
| 361 | raise AssertionError()
|
| 362 |
|
| 363 | self._PushSave(fd)
|
| 364 |
|
| 365 | return True
|
| 366 |
|
| 367 | def _PushClose(self, fd):
|
| 368 | # type: (int) -> None
|
| 369 | self.cur_frame.saved.append(_RedirFrame(NO_FD, fd, False))
|
| 370 |
|
| 371 | def _PushWait(self, proc):
|
| 372 | # type: (Process) -> None
|
| 373 | self.cur_frame.need_wait.append(proc)
|
| 374 |
|
| 375 | def _ApplyRedirect(self, r):
|
| 376 | # type: (RedirValue) -> None
|
| 377 | arg = r.arg
|
| 378 | UP_arg = arg
|
| 379 | with tagswitch(arg) as case:
|
| 380 |
|
| 381 | if case(redirect_arg_e.Path):
|
| 382 | arg = cast(redirect_arg.Path, UP_arg)
|
| 383 | # noclobber flag is OR'd with other flags when allowed
|
| 384 | noclobber_mode = O_EXCL if self.exec_opts.noclobber() else 0
|
| 385 | if r.op_id in (Id.Redir_Great, Id.Redir_AndGreat): # > &>
|
| 386 | # NOTE: This is different than >| because it respects noclobber, but
|
| 387 | # that option is almost never used. See test/wild.sh.
|
| 388 | mode = O_CREAT | O_WRONLY | O_TRUNC | noclobber_mode
|
| 389 | elif r.op_id == Id.Redir_Clobber: # >|
|
| 390 | mode = O_CREAT | O_WRONLY | O_TRUNC
|
| 391 | elif r.op_id in (Id.Redir_DGreat,
|
| 392 | Id.Redir_AndDGreat): # >> &>>
|
| 393 | mode = O_CREAT | O_WRONLY | O_APPEND | noclobber_mode
|
| 394 | elif r.op_id == Id.Redir_Less: # <
|
| 395 | mode = O_RDONLY
|
| 396 | elif r.op_id == Id.Redir_LessGreat: # <>
|
| 397 | mode = O_CREAT | O_RDWR
|
| 398 | else:
|
| 399 | raise NotImplementedError(r.op_id)
|
| 400 |
|
| 401 | # NOTE: 0666 is affected by umask, all shells use it.
|
| 402 | try:
|
| 403 | open_fd = posix.open(arg.filename, mode, 0o666)
|
| 404 | except (IOError, OSError) as e:
|
| 405 | if e.errno == EEXIST and self.exec_opts.noclobber():
|
| 406 | extra = ' (noclobber)'
|
| 407 | else:
|
| 408 | extra = ''
|
| 409 | self.errfmt.Print_(
|
| 410 | "Can't open %r: %s%s" %
|
| 411 | (arg.filename, pyutil.strerror(e), extra),
|
| 412 | blame_loc=r.op_loc)
|
| 413 | raise # redirect failed
|
| 414 |
|
| 415 | new_fd = self._PushDup(open_fd, r.loc)
|
| 416 | if new_fd != NO_FD:
|
| 417 | posix.close(open_fd)
|
| 418 |
|
| 419 | # Now handle &> and &>> and their variants. These pairs are the same:
|
| 420 | #
|
| 421 | # stdout_stderr.py &> out-err.txt
|
| 422 | # stdout_stderr.py > out-err.txt 2>&1
|
| 423 | #
|
| 424 | # stdout_stderr.py 3&> out-err.txt
|
| 425 | # stdout_stderr.py 3> out-err.txt 2>&3
|
| 426 | #
|
| 427 | # Ditto for {fd}> and {fd}&>
|
| 428 |
|
| 429 | if r.op_id in (Id.Redir_AndGreat, Id.Redir_AndDGreat):
|
| 430 | self._PushDup(new_fd, redir_loc.Fd(2))
|
| 431 |
|
| 432 | elif case(redirect_arg_e.CopyFd): # e.g. echo hi 1>&2
|
| 433 | arg = cast(redirect_arg.CopyFd, UP_arg)
|
| 434 |
|
| 435 | if r.op_id == Id.Redir_GreatAnd: # 1>&2
|
| 436 | self._PushDup(arg.target_fd, r.loc)
|
| 437 |
|
| 438 | elif r.op_id == Id.Redir_LessAnd: # 0<&5
|
| 439 | # The only difference between >& and <& is the default file
|
| 440 | # descriptor argument.
|
| 441 | self._PushDup(arg.target_fd, r.loc)
|
| 442 |
|
| 443 | else:
|
| 444 | raise NotImplementedError()
|
| 445 |
|
| 446 | elif case(redirect_arg_e.MoveFd): # e.g. echo hi 5>&6-
|
| 447 | arg = cast(redirect_arg.MoveFd, UP_arg)
|
| 448 | new_fd = self._PushDup(arg.target_fd, r.loc)
|
| 449 | if new_fd != NO_FD:
|
| 450 | posix.close(arg.target_fd)
|
| 451 |
|
| 452 | UP_loc = r.loc
|
| 453 | if r.loc.tag() == redir_loc_e.Fd:
|
| 454 | fd = cast(redir_loc.Fd, UP_loc).fd
|
| 455 | else:
|
| 456 | fd = NO_FD
|
| 457 |
|
| 458 | self.cur_frame.saved.append(_RedirFrame(new_fd, fd, False))
|
| 459 |
|
| 460 | elif case(redirect_arg_e.CloseFd): # e.g. echo hi 5>&-
|
| 461 | self._PushCloseFd(r.loc)
|
| 462 |
|
| 463 | elif case(redirect_arg_e.HereDoc):
|
| 464 | arg = cast(redirect_arg.HereDoc, UP_arg)
|
| 465 |
|
| 466 | # NOTE: Do these descriptors have to be moved out of the range 0-9?
|
| 467 | read_fd, write_fd = posix.pipe()
|
| 468 |
|
| 469 | self._PushDup(read_fd, r.loc) # stdin is now the pipe
|
| 470 |
|
| 471 | # We can't close like we do in the filename case above? The writer can
|
| 472 | # get a "broken pipe".
|
| 473 | self._PushClose(read_fd)
|
| 474 |
|
| 475 | thunk = _HereDocWriterThunk(write_fd, arg.body)
|
| 476 |
|
| 477 | # Use PIPE_SIZE to save a process in the case of small here
|
| 478 | # docs, which are the common case. (dash does this.)
|
| 479 |
|
| 480 | # Note: could instrument this to see how often it happens.
|
| 481 | # Though strace -ff can also work.
|
| 482 | start_process = len(arg.body) > 4096
|
| 483 | #start_process = True
|
| 484 |
|
| 485 | if start_process:
|
| 486 | here_proc = Process(thunk, self.job_control, self.job_list,
|
| 487 | self.tracer)
|
| 488 |
|
| 489 | # NOTE: we could close the read pipe here, but it doesn't really
|
| 490 | # matter because we control the code.
|
| 491 | here_proc.StartProcess(trace.HereDoc)
|
| 492 | #log('Started %s as %d', here_proc, pid)
|
| 493 | self._PushWait(here_proc)
|
| 494 |
|
| 495 | # Now that we've started the child, close it in the parent.
|
| 496 | posix.close(write_fd)
|
| 497 |
|
| 498 | else:
|
| 499 | posix.write(write_fd, arg.body)
|
| 500 | posix.close(write_fd)
|
| 501 |
|
| 502 | def Push(self, redirects, err_out):
|
| 503 | # type: (List[RedirValue], List[error.IOError_OSError]) -> None
|
| 504 | """Apply a group of redirects and remember to undo them."""
|
| 505 |
|
| 506 | #log('> fd_state.Push %s', redirects)
|
| 507 | new_frame = _FdFrame()
|
| 508 | self.stack.append(new_frame)
|
| 509 | self.cur_frame = new_frame
|
| 510 |
|
| 511 | for r in redirects:
|
| 512 | #log('apply %s', r)
|
| 513 | with ui.ctx_Location(self.errfmt, r.op_loc):
|
| 514 | try:
|
| 515 | self._ApplyRedirect(r)
|
| 516 | except (IOError, OSError) as e:
|
| 517 | err_out.append(e)
|
| 518 | # This can fail too
|
| 519 | self.Pop(err_out)
|
| 520 | return # for bad descriptor, etc.
|
| 521 |
|
| 522 | def PushStdinFromPipe(self, r):
|
| 523 | # type: (int) -> bool
|
| 524 | """Save the current stdin and make it come from descriptor 'r'.
|
| 525 |
|
| 526 | 'r' is typically the read-end of a pipe. For 'lastpipe'/ZSH
|
| 527 | semantics of
|
| 528 |
|
| 529 | echo foo | read line; echo $line
|
| 530 | """
|
| 531 | new_frame = _FdFrame()
|
| 532 | self.stack.append(new_frame)
|
| 533 | self.cur_frame = new_frame
|
| 534 |
|
| 535 | self._PushDup(r, redir_loc.Fd(0))
|
| 536 | return True
|
| 537 |
|
| 538 | def Pop(self, err_out):
|
| 539 | # type: (List[error.IOError_OSError]) -> None
|
| 540 | frame = self.stack.pop()
|
| 541 | #log('< Pop %s', frame)
|
| 542 | for rf in reversed(frame.saved):
|
| 543 | if rf.saved_fd == NO_FD:
|
| 544 | #log('Close %d', orig)
|
| 545 | try:
|
| 546 | posix.close(rf.orig_fd)
|
| 547 | except (IOError, OSError) as e:
|
| 548 | err_out.append(e)
|
| 549 | log('Error closing descriptor %d: %s', rf.orig_fd,
|
| 550 | pyutil.strerror(e))
|
| 551 | return
|
| 552 | else:
|
| 553 | try:
|
| 554 | posix.dup2(rf.saved_fd, rf.orig_fd)
|
| 555 | except (IOError, OSError) as e:
|
| 556 | err_out.append(e)
|
| 557 | log('dup2(%d, %d) error: %s', rf.saved_fd, rf.orig_fd,
|
| 558 | pyutil.strerror(e))
|
| 559 | #log('fd state:')
|
| 560 | #posix.system('ls -l /proc/%s/fd' % posix.getpid())
|
| 561 | return
|
| 562 | posix.close(rf.saved_fd)
|
| 563 | #log('dup2 %s %s', saved, orig)
|
| 564 |
|
| 565 | # Wait for here doc processes to finish.
|
| 566 | for proc in frame.need_wait:
|
| 567 | unused_status = proc.Wait(self.waiter)
|
| 568 |
|
| 569 | def MakePermanent(self):
|
| 570 | # type: () -> None
|
| 571 | self.cur_frame.Forget()
|
| 572 |
|
| 573 |
|
| 574 | class ChildStateChange(object):
|
| 575 |
|
| 576 | def __init__(self):
|
| 577 | # type: () -> None
|
| 578 | """Empty constructor for mycpp."""
|
| 579 | pass
|
| 580 |
|
| 581 | def Apply(self):
|
| 582 | # type: () -> None
|
| 583 | raise NotImplementedError()
|
| 584 |
|
| 585 | def ApplyFromParent(self, proc):
|
| 586 | # type: (Process) -> None
|
| 587 | """Noop for all state changes other than SetPgid for mycpp."""
|
| 588 | pass
|
| 589 |
|
| 590 |
|
| 591 | class StdinFromPipe(ChildStateChange):
|
| 592 |
|
| 593 | def __init__(self, pipe_read_fd, w):
|
| 594 | # type: (int, int) -> None
|
| 595 | self.r = pipe_read_fd
|
| 596 | self.w = w
|
| 597 |
|
| 598 | def __repr__(self):
|
| 599 | # type: () -> str
|
| 600 | return '<StdinFromPipe %d %d>' % (self.r, self.w)
|
| 601 |
|
| 602 | def Apply(self):
|
| 603 | # type: () -> None
|
| 604 | posix.dup2(self.r, 0)
|
| 605 | posix.close(self.r) # close after dup
|
| 606 |
|
| 607 | posix.close(self.w) # we're reading from the pipe, not writing
|
| 608 | #log('child CLOSE w %d pid=%d', self.w, posix.getpid())
|
| 609 |
|
| 610 |
|
| 611 | class StdoutToPipe(ChildStateChange):
|
| 612 |
|
| 613 | def __init__(self, r, pipe_write_fd):
|
| 614 | # type: (int, int) -> None
|
| 615 | self.r = r
|
| 616 | self.w = pipe_write_fd
|
| 617 |
|
| 618 | def __repr__(self):
|
| 619 | # type: () -> str
|
| 620 | return '<StdoutToPipe %d %d>' % (self.r, self.w)
|
| 621 |
|
| 622 | def Apply(self):
|
| 623 | # type: () -> None
|
| 624 | posix.dup2(self.w, 1)
|
| 625 | posix.close(self.w) # close after dup
|
| 626 |
|
| 627 | posix.close(self.r) # we're writing to the pipe, not reading
|
| 628 | #log('child CLOSE r %d pid=%d', self.r, posix.getpid())
|
| 629 |
|
| 630 |
|
| 631 | INVALID_PGID = -1
|
| 632 | # argument to setpgid() that means the process is its own leader
|
| 633 | OWN_LEADER = 0
|
| 634 |
|
| 635 |
|
| 636 | class SetPgid(ChildStateChange):
|
| 637 |
|
| 638 | def __init__(self, pgid, tracer):
|
| 639 | # type: (int, dev.Tracer) -> None
|
| 640 | self.pgid = pgid
|
| 641 | self.tracer = tracer
|
| 642 |
|
| 643 | def Apply(self):
|
| 644 | # type: () -> None
|
| 645 | try:
|
| 646 | posix.setpgid(0, self.pgid)
|
| 647 | except (IOError, OSError) as e:
|
| 648 | self.tracer.OtherMessage(
|
| 649 | 'osh: child %d failed to set its process group to %d: %s' %
|
| 650 | (posix.getpid(), self.pgid, pyutil.strerror(e)))
|
| 651 |
|
| 652 | def ApplyFromParent(self, proc):
|
| 653 | # type: (Process) -> None
|
| 654 | try:
|
| 655 | posix.setpgid(proc.pid, self.pgid)
|
| 656 | except (IOError, OSError) as e:
|
| 657 | self.tracer.OtherMessage(
|
| 658 | 'osh: parent failed to set process group for PID %d to %d: %s'
|
| 659 | % (proc.pid, self.pgid, pyutil.strerror(e)))
|
| 660 |
|
| 661 |
|
| 662 | class ExternalProgram(object):
|
| 663 | """The capability to execute an external program like 'ls'."""
|
| 664 |
|
| 665 | def __init__(
|
| 666 | self,
|
| 667 | hijack_shebang, # type: str
|
| 668 | fd_state, # type: FdState
|
| 669 | errfmt, # type: ui.ErrorFormatter
|
| 670 | debug_f, # type: _DebugFile
|
| 671 | ):
|
| 672 | # type: (...) -> None
|
| 673 | """
|
| 674 | Args:
|
| 675 | hijack_shebang: The path of an interpreter to run instead of the one
|
| 676 | specified in the shebang line. May be empty.
|
| 677 | """
|
| 678 | self.hijack_shebang = hijack_shebang
|
| 679 | self.fd_state = fd_state
|
| 680 | self.errfmt = errfmt
|
| 681 | self.debug_f = debug_f
|
| 682 |
|
| 683 | def Exec(self, argv0_path, cmd_val, environ):
|
| 684 | # type: (str, cmd_value.Argv, Dict[str, str]) -> None
|
| 685 | """Execute a program and exit this process.
|
| 686 |
|
| 687 | Called by: ls / exec ls / ( ls / )
|
| 688 | """
|
| 689 | probe('process', 'ExternalProgram_Exec', argv0_path)
|
| 690 | self._Exec(argv0_path, cmd_val.argv, cmd_val.arg_locs[0], environ,
|
| 691 | True)
|
| 692 | assert False, "This line should never execute" # NO RETURN
|
| 693 |
|
| 694 | def _Exec(self, argv0_path, argv, argv0_loc, environ, should_retry):
|
| 695 | # type: (str, List[str], loc_t, Dict[str, str], bool) -> None
|
| 696 | if len(self.hijack_shebang):
|
| 697 | opened = True
|
| 698 | try:
|
| 699 | f = self.fd_state.Open(argv0_path)
|
| 700 | except (IOError, OSError) as e:
|
| 701 | opened = False
|
| 702 |
|
| 703 | if opened:
|
| 704 | with ctx_FileCloser(f):
|
| 705 | # Test if the shebang looks like a shell. TODO: The file might be
|
| 706 | # binary with no newlines, so read 80 bytes instead of readline().
|
| 707 |
|
| 708 | #line = f.read(80) # type: ignore # TODO: fix this
|
| 709 | line = f.readline()
|
| 710 |
|
| 711 | if match.ShouldHijack(line):
|
| 712 | h_argv = [self.hijack_shebang, argv0_path]
|
| 713 | h_argv.extend(argv[1:])
|
| 714 | argv = h_argv
|
| 715 | argv0_path = self.hijack_shebang
|
| 716 | self.debug_f.writeln('Hijacked: %s' % argv0_path)
|
| 717 | else:
|
| 718 | #self.debug_f.log('Not hijacking %s (%r)', argv, line)
|
| 719 | pass
|
| 720 |
|
| 721 | try:
|
| 722 | posix.execve(argv0_path, argv, environ)
|
| 723 | except (IOError, OSError) as e:
|
| 724 | # Run with /bin/sh when ENOEXEC error (no shebang). All shells do this.
|
| 725 | if e.errno == ENOEXEC and should_retry:
|
| 726 | new_argv = ['/bin/sh', argv0_path]
|
| 727 | new_argv.extend(argv[1:])
|
| 728 | self._Exec('/bin/sh', new_argv, argv0_loc, environ, False)
|
| 729 | # NO RETURN
|
| 730 |
|
| 731 | # Would be nice: when the path is relative and ENOENT: print PWD and do
|
| 732 | # spelling correction?
|
| 733 |
|
| 734 | self.errfmt.Print_(
|
| 735 | "Can't execute %r: %s" % (argv0_path, pyutil.strerror(e)),
|
| 736 | argv0_loc)
|
| 737 |
|
| 738 | # POSIX mentions 126 and 127 for two specific errors. The rest are
|
| 739 | # unspecified.
|
| 740 | #
|
| 741 | # http://pubs.opengroup.org/onlinepubs/9699919799.2016edition/utilities/V3_chap02.html#tag_18_08_02
|
| 742 | if e.errno == EACCES:
|
| 743 | status = 126
|
| 744 | elif e.errno == ENOENT:
|
| 745 | # TODO: most shells print 'command not found', rather than strerror()
|
| 746 | # == "No such file or directory". That's better because it's at the
|
| 747 | # end of the path search, and we're never searching for a directory.
|
| 748 | status = 127
|
| 749 | else:
|
| 750 | # dash uses 2, but we use that for parse errors. This seems to be
|
| 751 | # consistent with mksh and zsh.
|
| 752 | status = 127
|
| 753 |
|
| 754 | posix._exit(status)
|
| 755 | # NO RETURN
|
| 756 |
|
| 757 |
|
| 758 | class Thunk(object):
|
| 759 | """Abstract base class for things runnable in another process."""
|
| 760 |
|
| 761 | def __init__(self):
|
| 762 | # type: () -> None
|
| 763 | """Empty constructor for mycpp."""
|
| 764 | pass
|
| 765 |
|
| 766 | def Run(self):
|
| 767 | # type: () -> None
|
| 768 | """Returns a status code."""
|
| 769 | raise NotImplementedError()
|
| 770 |
|
| 771 | def UserString(self):
|
| 772 | # type: () -> str
|
| 773 | """Display for the 'jobs' list."""
|
| 774 | raise NotImplementedError()
|
| 775 |
|
| 776 | def __repr__(self):
|
| 777 | # type: () -> str
|
| 778 | return self.UserString()
|
| 779 |
|
| 780 |
|
| 781 | class ExternalThunk(Thunk):
|
| 782 | """An external executable."""
|
| 783 |
|
| 784 | def __init__(self, ext_prog, argv0_path, cmd_val, environ):
|
| 785 | # type: (ExternalProgram, str, cmd_value.Argv, Dict[str, str]) -> None
|
| 786 | self.ext_prog = ext_prog
|
| 787 | self.argv0_path = argv0_path
|
| 788 | self.cmd_val = cmd_val
|
| 789 | self.environ = environ
|
| 790 |
|
| 791 | def UserString(self):
|
| 792 | # type: () -> str
|
| 793 |
|
| 794 | # NOTE: This is the format the Tracer uses.
|
| 795 | # bash displays sleep $n & (code)
|
| 796 | # but OSH displays sleep 1 & (argv array)
|
| 797 | # We could switch the former but I'm not sure it's necessary.
|
| 798 | tmp = [j8_lite.MaybeShellEncode(a) for a in self.cmd_val.argv]
|
| 799 | return '[process] %s' % ' '.join(tmp)
|
| 800 |
|
| 801 | def Run(self):
|
| 802 | # type: () -> None
|
| 803 | """An ExternalThunk is run in parent for the exec builtin."""
|
| 804 | self.ext_prog.Exec(self.argv0_path, self.cmd_val, self.environ)
|
| 805 |
|
| 806 |
|
| 807 | class SubProgramThunk(Thunk):
|
| 808 | """A subprogram that can be executed in another process."""
|
| 809 |
|
| 810 | def __init__(self, cmd_ev, node, trap_state, multi_trace, inherit_errexit,
|
| 811 | inherit_errtrace):
|
| 812 | # type: (CommandEvaluator, command_t, trap_osh.TrapState, dev.MultiTracer, bool, bool) -> None
|
| 813 | self.cmd_ev = cmd_ev
|
| 814 | self.node = node
|
| 815 | self.trap_state = trap_state
|
| 816 | self.multi_trace = multi_trace
|
| 817 | self.inherit_errexit = inherit_errexit # for bash errexit compatibility
|
| 818 | self.inherit_errtrace = inherit_errtrace # for bash errtrace compatibility
|
| 819 |
|
| 820 | def UserString(self):
|
| 821 | # type: () -> str
|
| 822 |
|
| 823 | # NOTE: These can be pieces of a pipeline, so they're arbitrary nodes.
|
| 824 | # TODO: Extract SPIDS from node to display source? Note that
|
| 825 | # CompoundStatus also has locations of each pipeline component; see
|
| 826 | # Executor.RunPipeline()
|
| 827 | thunk_str = ui.CommandType(self.node)
|
| 828 | return '[subprog] %s' % thunk_str
|
| 829 |
|
| 830 | def Run(self):
|
| 831 | # type: () -> None
|
| 832 | #self.errfmt.OneLineErrExit() # don't quote code in child processes
|
| 833 | probe('process', 'SubProgramThunk_Run')
|
| 834 |
|
| 835 | # TODO: break circular dep. Bit flags could go in ASDL or headers.
|
| 836 | from osh import cmd_eval
|
| 837 |
|
| 838 | # signal handlers aren't inherited
|
| 839 | self.trap_state.ClearForSubProgram(self.inherit_errtrace)
|
| 840 |
|
| 841 | # NOTE: may NOT return due to exec().
|
| 842 | if not self.inherit_errexit:
|
| 843 | self.cmd_ev.mutable_opts.DisableErrExit()
|
| 844 | try:
|
| 845 | # optimize to eliminate redundant subshells like ( echo hi ) | wc -l etc.
|
| 846 | self.cmd_ev.ExecuteAndCatch(self.node, cmd_flags=cmd_eval.Optimize)
|
| 847 | status = self.cmd_ev.LastStatus()
|
| 848 | # NOTE: We ignore the is_fatal return value. The user should set -o
|
| 849 | # errexit so failures in subprocesses cause failures in the parent.
|
| 850 | except util.UserExit as e:
|
| 851 | status = e.status
|
| 852 |
|
| 853 | # Handle errors in a subshell. These two cases are repeated from main()
|
| 854 | # and the core/completion.py hook.
|
| 855 | except KeyboardInterrupt:
|
| 856 | print('')
|
| 857 | status = 130 # 128 + 2
|
| 858 | except (IOError, OSError) as e:
|
| 859 | print_stderr('oils I/O error (subprogram): %s' %
|
| 860 | pyutil.strerror(e))
|
| 861 | status = 2
|
| 862 |
|
| 863 | # If ProcessInit() doesn't turn off buffering, this is needed before
|
| 864 | # _exit()
|
| 865 | pyos.FlushStdout()
|
| 866 |
|
| 867 | self.multi_trace.WriteDumps()
|
| 868 |
|
| 869 | # We do NOT want to raise SystemExit here. Otherwise dev.Tracer::Pop()
|
| 870 | # gets called in BOTH processes.
|
| 871 | # The crash dump seems to be unaffected.
|
| 872 | posix._exit(status)
|
| 873 |
|
| 874 |
|
| 875 | class _HereDocWriterThunk(Thunk):
|
| 876 | """Write a here doc to one end of a pipe.
|
| 877 |
|
| 878 | May be be executed in either a child process or the main shell
|
| 879 | process.
|
| 880 | """
|
| 881 |
|
| 882 | def __init__(self, w, body_str):
|
| 883 | # type: (int, str) -> None
|
| 884 | self.w = w
|
| 885 | self.body_str = body_str
|
| 886 |
|
| 887 | def UserString(self):
|
| 888 | # type: () -> str
|
| 889 |
|
| 890 | # You can hit Ctrl-Z and the here doc writer will be suspended! Other
|
| 891 | # shells don't have this problem because they use temp files! That's a bit
|
| 892 | # unfortunate.
|
| 893 | return '[here doc writer]'
|
| 894 |
|
| 895 | def Run(self):
|
| 896 | # type: () -> None
|
| 897 | """do_exit: For small pipelines."""
|
| 898 | probe('process', 'HereDocWriterThunk_Run')
|
| 899 | #log('Writing %r', self.body_str)
|
| 900 | posix.write(self.w, self.body_str)
|
| 901 | #log('Wrote %r', self.body_str)
|
| 902 | posix.close(self.w)
|
| 903 | #log('Closed %d', self.w)
|
| 904 |
|
| 905 | posix._exit(0)
|
| 906 |
|
| 907 |
|
| 908 | class Job(object):
|
| 909 | """Interface for both Process and Pipeline.
|
| 910 |
|
| 911 | They both can be put in the background and waited on.
|
| 912 |
|
| 913 | Confusing thing about pipelines in the background: They have TOO MANY NAMES.
|
| 914 |
|
| 915 | sleep 1 | sleep 2 &
|
| 916 |
|
| 917 | - The LAST PID is what's printed at the prompt. This is $!, a PROCESS ID and
|
| 918 | not a JOB ID.
|
| 919 | # https://www.gnu.org/software/bash/manual/html_node/Special-Parameters.html#Special-Parameters
|
| 920 | - The process group leader (setpgid) is the FIRST PID.
|
| 921 | - It's also %1 or %+. The last job started.
|
| 922 | """
|
| 923 |
|
| 924 | def __init__(self):
|
| 925 | # type: () -> None
|
| 926 | # Initial state with & or Ctrl-Z is Running.
|
| 927 | self.state = job_state_e.Running
|
| 928 | self.job_id = -1
|
| 929 | self.in_background = False
|
| 930 |
|
| 931 | def DisplayJob(self, job_id, f, style):
|
| 932 | # type: (int, mylib.Writer, int) -> None
|
| 933 | raise NotImplementedError()
|
| 934 |
|
| 935 | def State(self):
|
| 936 | # type: () -> job_state_t
|
| 937 | return self.state
|
| 938 |
|
| 939 | def ProcessGroupId(self):
|
| 940 | # type: () -> int
|
| 941 | """Return the process group ID associated with this job."""
|
| 942 | raise NotImplementedError()
|
| 943 |
|
| 944 | def JobWait(self, waiter):
|
| 945 | # type: (Waiter) -> wait_status_t
|
| 946 | """Wait for this process/pipeline to be stopped or finished."""
|
| 947 | raise NotImplementedError()
|
| 948 |
|
| 949 | def SetBackground(self):
|
| 950 | # type: () -> None
|
| 951 | """Record that this job is running in the background."""
|
| 952 | self.in_background = True
|
| 953 |
|
| 954 | def SetForeground(self):
|
| 955 | # type: () -> None
|
| 956 | """Record that this job is running in the foreground."""
|
| 957 | self.in_background = False
|
| 958 |
|
| 959 |
|
| 960 | class Process(Job):
|
| 961 | """A process to run.
|
| 962 |
|
| 963 | TODO: Should we make it clear that this is a FOREGROUND process? A
|
| 964 | background process is wrapped in a "job". It is unevaluated.
|
| 965 |
|
| 966 | It provides an API to manipulate file descriptor state in parent and child.
|
| 967 | """
|
| 968 |
|
| 969 | def __init__(self, thunk, job_control, job_list, tracer):
|
| 970 | # type: (Thunk, JobControl, JobList, dev.Tracer) -> None
|
| 971 | """
|
| 972 | Args:
|
| 973 | thunk: Thunk instance
|
| 974 | job_list: for process bookkeeping
|
| 975 | """
|
| 976 | Job.__init__(self)
|
| 977 | assert isinstance(thunk, Thunk), thunk
|
| 978 | self.thunk = thunk
|
| 979 | self.job_control = job_control
|
| 980 | self.job_list = job_list
|
| 981 | self.tracer = tracer
|
| 982 |
|
| 983 | # For pipelines
|
| 984 | self.parent_pipeline = None # type: Pipeline
|
| 985 | self.state_changes = [] # type: List[ChildStateChange]
|
| 986 | self.close_r = -1
|
| 987 | self.close_w = -1
|
| 988 |
|
| 989 | self.pid = -1
|
| 990 | self.status = -1
|
| 991 |
|
| 992 | def Init_ParentPipeline(self, pi):
|
| 993 | # type: (Pipeline) -> None
|
| 994 | """For updating PIPESTATUS."""
|
| 995 | self.parent_pipeline = pi
|
| 996 |
|
| 997 | def __repr__(self):
|
| 998 | # type: () -> str
|
| 999 |
|
| 1000 | # note: be wary of infinite mutual recursion
|
| 1001 | #s = ' %s' % self.parent_pipeline if self.parent_pipeline else ''
|
| 1002 | #return '<Process %s%s>' % (self.thunk, s)
|
| 1003 | return '<Process %s %s>' % (_JobStateStr(self.state), self.thunk)
|
| 1004 |
|
| 1005 | def ProcessGroupId(self):
|
| 1006 | # type: () -> int
|
| 1007 | """Returns the group ID of this process."""
|
| 1008 | # This should only ever be called AFTER the process has started
|
| 1009 | assert self.pid != -1
|
| 1010 | if self.parent_pipeline:
|
| 1011 | # XXX: Maybe we should die here instead? Unclear if this branch
|
| 1012 | # should even be reachable with the current builtins.
|
| 1013 | return self.parent_pipeline.ProcessGroupId()
|
| 1014 |
|
| 1015 | return self.pid
|
| 1016 |
|
| 1017 | def DisplayJob(self, job_id, f, style):
|
| 1018 | # type: (int, mylib.Writer, int) -> None
|
| 1019 | if job_id == -1:
|
| 1020 | job_id_str = ' '
|
| 1021 | else:
|
| 1022 | job_id_str = '%%%d' % job_id
|
| 1023 | if style == STYLE_PID_ONLY:
|
| 1024 | f.write('%d\n' % self.pid)
|
| 1025 | else:
|
| 1026 | f.write('%s %d %7s ' %
|
| 1027 | (job_id_str, self.pid, _JobStateStr(self.state)))
|
| 1028 | f.write(self.thunk.UserString())
|
| 1029 | f.write('\n')
|
| 1030 |
|
| 1031 | def AddStateChange(self, s):
|
| 1032 | # type: (ChildStateChange) -> None
|
| 1033 | self.state_changes.append(s)
|
| 1034 |
|
| 1035 | def AddPipeToClose(self, r, w):
|
| 1036 | # type: (int, int) -> None
|
| 1037 | self.close_r = r
|
| 1038 | self.close_w = w
|
| 1039 |
|
| 1040 | def MaybeClosePipe(self):
|
| 1041 | # type: () -> None
|
| 1042 | if self.close_r != -1:
|
| 1043 | posix.close(self.close_r)
|
| 1044 | posix.close(self.close_w)
|
| 1045 |
|
| 1046 | def StartProcess(self, why):
|
| 1047 | # type: (trace_t) -> int
|
| 1048 | """Start this process with fork(), handling redirects."""
|
| 1049 | pid = posix.fork()
|
| 1050 | if pid < 0:
|
| 1051 | # When does this happen?
|
| 1052 | e_die('Fatal error in posix.fork()')
|
| 1053 |
|
| 1054 | elif pid == 0: # child
|
| 1055 | # Note: this happens in BOTH interactive and non-interactive shells.
|
| 1056 | # We technically don't need to do most of it in non-interactive, since we
|
| 1057 | # did not change state in InitInteractiveShell().
|
| 1058 |
|
| 1059 | for st in self.state_changes:
|
| 1060 | st.Apply()
|
| 1061 |
|
| 1062 | # Python sets SIGPIPE handler to SIG_IGN by default. Child processes
|
| 1063 | # shouldn't have this.
|
| 1064 | # https://docs.python.org/2/library/signal.html
|
| 1065 | # See Python/pythonrun.c.
|
| 1066 | pyos.Sigaction(SIGPIPE, SIG_DFL)
|
| 1067 |
|
| 1068 | # Respond to Ctrl-\ (core dump)
|
| 1069 | pyos.Sigaction(SIGQUIT, SIG_DFL)
|
| 1070 |
|
| 1071 | # Only standalone children should get Ctrl-Z. Pipelines remain in the
|
| 1072 | # foreground because suspending them is difficult with our 'lastpipe'
|
| 1073 | # semantics.
|
| 1074 | pid = posix.getpid()
|
| 1075 | if posix.getpgid(0) == pid and self.parent_pipeline is None:
|
| 1076 | pyos.Sigaction(SIGTSTP, SIG_DFL)
|
| 1077 |
|
| 1078 | # More signals from
|
| 1079 | # https://www.gnu.org/software/libc/manual/html_node/Launching-Jobs.html
|
| 1080 | # (but not SIGCHLD)
|
| 1081 | pyos.Sigaction(SIGTTOU, SIG_DFL)
|
| 1082 | pyos.Sigaction(SIGTTIN, SIG_DFL)
|
| 1083 |
|
| 1084 | self.tracer.OnNewProcess(pid)
|
| 1085 | # clear foreground pipeline for subshells
|
| 1086 | self.thunk.Run()
|
| 1087 | # Never returns
|
| 1088 |
|
| 1089 | #log('STARTED process %s, pid = %d', self, pid)
|
| 1090 | self.tracer.OnProcessStart(pid, why)
|
| 1091 |
|
| 1092 | # Class invariant: after the process is started, it stores its PID.
|
| 1093 | self.pid = pid
|
| 1094 |
|
| 1095 | # SetPgid needs to be applied from the child and the parent to avoid
|
| 1096 | # racing in calls to tcsetpgrp() in the parent. See APUE sec. 9.2.
|
| 1097 | for st in self.state_changes:
|
| 1098 | st.ApplyFromParent(self)
|
| 1099 |
|
| 1100 | # Program invariant: We keep track of every child process!
|
| 1101 | self.job_list.AddChildProcess(pid, self)
|
| 1102 |
|
| 1103 | return pid
|
| 1104 |
|
| 1105 | def Wait(self, waiter):
|
| 1106 | # type: (Waiter) -> int
|
| 1107 | """Wait for this process to finish."""
|
| 1108 | while self.state == job_state_e.Running:
|
| 1109 | # Only return if there's nothing to wait for. Keep waiting if we were
|
| 1110 | # interrupted with a signal.
|
| 1111 | if waiter.WaitForOne() == W1_ECHILD:
|
| 1112 | break
|
| 1113 |
|
| 1114 | assert self.status >= 0, self.status
|
| 1115 | return self.status
|
| 1116 |
|
| 1117 | def JobWait(self, waiter):
|
| 1118 | # type: (Waiter) -> wait_status_t
|
| 1119 | # wait builtin can be interrupted
|
| 1120 | while self.state == job_state_e.Running:
|
| 1121 | result = waiter.WaitForOne()
|
| 1122 |
|
| 1123 | if result >= 0: # signal
|
| 1124 | return wait_status.Cancelled(result)
|
| 1125 |
|
| 1126 | if result == W1_ECHILD:
|
| 1127 | break
|
| 1128 |
|
| 1129 | return wait_status.Proc(self.status)
|
| 1130 |
|
| 1131 | def WhenStopped(self, stop_sig):
|
| 1132 | # type: (int) -> None
|
| 1133 |
|
| 1134 | # 128 is a shell thing
|
| 1135 | # https://www.gnu.org/software/bash/manual/html_node/Exit-Status.html
|
| 1136 | self.status = 128 + stop_sig
|
| 1137 | self.state = job_state_e.Stopped
|
| 1138 |
|
| 1139 | if self.job_id == -1:
|
| 1140 | # This process was started in the foreground
|
| 1141 | self.job_list.AddJob(self)
|
| 1142 |
|
| 1143 | if not self.in_background:
|
| 1144 | self.job_control.MaybeTakeTerminal()
|
| 1145 | self.SetBackground()
|
| 1146 |
|
| 1147 | def WhenDone(self, pid, status):
|
| 1148 | # type: (int, int) -> None
|
| 1149 | """Called by the Waiter when this Process finishes."""
|
| 1150 |
|
| 1151 | #log('WhenDone %d %d', pid, status)
|
| 1152 | assert pid == self.pid, 'Expected %d, got %d' % (self.pid, pid)
|
| 1153 | self.status = status
|
| 1154 | self.state = job_state_e.Done
|
| 1155 | if self.parent_pipeline:
|
| 1156 | self.parent_pipeline.WhenDone(pid, status)
|
| 1157 | else:
|
| 1158 | if self.job_id != -1:
|
| 1159 | # Job might have been brought to the foreground after being
|
| 1160 | # assigned a job ID.
|
| 1161 | if self.in_background:
|
| 1162 | print_stderr('[%d] Done PID %d' % (self.job_id, self.pid))
|
| 1163 |
|
| 1164 | self.job_list.RemoveJob(self.job_id)
|
| 1165 |
|
| 1166 | self.job_list.RemoveChildProcess(self.pid)
|
| 1167 |
|
| 1168 | if not self.in_background:
|
| 1169 | self.job_control.MaybeTakeTerminal()
|
| 1170 |
|
| 1171 | def RunProcess(self, waiter, why):
|
| 1172 | # type: (Waiter, trace_t) -> int
|
| 1173 | """Run this process synchronously."""
|
| 1174 | self.StartProcess(why)
|
| 1175 | # ShellExecutor might be calling this for the last part of a pipeline.
|
| 1176 | if self.parent_pipeline is None:
|
| 1177 | # QUESTION: Can the PGID of a single process just be the PID? i.e. avoid
|
| 1178 | # calling getpgid()?
|
| 1179 | self.job_control.MaybeGiveTerminal(posix.getpgid(self.pid))
|
| 1180 | return self.Wait(waiter)
|
| 1181 |
|
| 1182 |
|
| 1183 | class ctx_Pipe(object):
|
| 1184 |
|
| 1185 | def __init__(self, fd_state, fd, err_out):
|
| 1186 | # type: (FdState, int, List[error.IOError_OSError]) -> None
|
| 1187 | fd_state.PushStdinFromPipe(fd)
|
| 1188 | self.fd_state = fd_state
|
| 1189 | self.err_out = err_out
|
| 1190 |
|
| 1191 | def __enter__(self):
|
| 1192 | # type: () -> None
|
| 1193 | pass
|
| 1194 |
|
| 1195 | def __exit__(self, type, value, traceback):
|
| 1196 | # type: (Any, Any, Any) -> None
|
| 1197 | self.fd_state.Pop(self.err_out)
|
| 1198 |
|
| 1199 |
|
| 1200 | class Pipeline(Job):
|
| 1201 | """A pipeline of processes to run.
|
| 1202 |
|
| 1203 | Cases we handle:
|
| 1204 |
|
| 1205 | foo | bar
|
| 1206 | $(foo | bar)
|
| 1207 | foo | bar | read v
|
| 1208 | """
|
| 1209 |
|
| 1210 | def __init__(self, sigpipe_status_ok, job_control, job_list, tracer):
|
| 1211 | # type: (bool, JobControl, JobList, dev.Tracer) -> None
|
| 1212 | Job.__init__(self)
|
| 1213 | self.job_control = job_control
|
| 1214 | self.job_list = job_list
|
| 1215 | self.tracer = tracer
|
| 1216 |
|
| 1217 | self.procs = [] # type: List[Process]
|
| 1218 | self.pids = [] # type: List[int] # pids in order
|
| 1219 | self.pipe_status = [] # type: List[int] # status in order
|
| 1220 | self.status = -1 # for 'wait' jobs
|
| 1221 |
|
| 1222 | self.pgid = INVALID_PGID
|
| 1223 |
|
| 1224 | # Optional for foreground
|
| 1225 | self.last_thunk = None # type: Tuple[CommandEvaluator, command_t]
|
| 1226 | self.last_pipe = None # type: Tuple[int, int]
|
| 1227 |
|
| 1228 | self.sigpipe_status_ok = sigpipe_status_ok
|
| 1229 |
|
| 1230 | def ProcessGroupId(self):
|
| 1231 | # type: () -> int
|
| 1232 | """Returns the group ID of this pipeline."""
|
| 1233 | return self.pgid
|
| 1234 |
|
| 1235 | def DisplayJob(self, job_id, f, style):
|
| 1236 | # type: (int, mylib.Writer, int) -> None
|
| 1237 | if style == STYLE_PID_ONLY:
|
| 1238 | f.write('%d\n' % self.procs[0].pid)
|
| 1239 | else:
|
| 1240 | # Note: this is STYLE_LONG.
|
| 1241 | for i, proc in enumerate(self.procs):
|
| 1242 | if i == 0: # show job ID for first element in pipeline
|
| 1243 | job_id_str = '%%%d' % job_id
|
| 1244 | else:
|
| 1245 | job_id_str = ' ' # 2 spaces
|
| 1246 |
|
| 1247 | f.write('%s %d %7s ' %
|
| 1248 | (job_id_str, proc.pid, _JobStateStr(proc.state)))
|
| 1249 | f.write(proc.thunk.UserString())
|
| 1250 | f.write('\n')
|
| 1251 |
|
| 1252 | def DebugPrint(self):
|
| 1253 | # type: () -> None
|
| 1254 | print('Pipeline in state %s' % _JobStateStr(self.state))
|
| 1255 | if mylib.PYTHON: # %s for Process not allowed in C++
|
| 1256 | for proc in self.procs:
|
| 1257 | print(' proc %s' % proc)
|
| 1258 | _, last_node = self.last_thunk
|
| 1259 | print(' last %s' % last_node)
|
| 1260 | print(' pipe_status %s' % self.pipe_status)
|
| 1261 |
|
| 1262 | def Add(self, p):
|
| 1263 | # type: (Process) -> None
|
| 1264 | """Append a process to the pipeline."""
|
| 1265 | if len(self.procs) == 0:
|
| 1266 | self.procs.append(p)
|
| 1267 | return
|
| 1268 |
|
| 1269 | r, w = posix.pipe()
|
| 1270 | #log('pipe for %s: %d %d', p, r, w)
|
| 1271 | prev = self.procs[-1]
|
| 1272 |
|
| 1273 | prev.AddStateChange(StdoutToPipe(r, w)) # applied on StartPipeline()
|
| 1274 | p.AddStateChange(StdinFromPipe(r, w)) # applied on StartPipeline()
|
| 1275 |
|
| 1276 | p.AddPipeToClose(r, w) # MaybeClosePipe() on StartPipeline()
|
| 1277 |
|
| 1278 | self.procs.append(p)
|
| 1279 |
|
| 1280 | def AddLast(self, thunk):
|
| 1281 | # type: (Tuple[CommandEvaluator, command_t]) -> None
|
| 1282 | """Append the last noden to the pipeline.
|
| 1283 |
|
| 1284 | This is run in the CURRENT process. It is OPTIONAL, because
|
| 1285 | pipelines in the background are run uniformly.
|
| 1286 | """
|
| 1287 | self.last_thunk = thunk
|
| 1288 |
|
| 1289 | assert len(self.procs) != 0
|
| 1290 |
|
| 1291 | r, w = posix.pipe()
|
| 1292 | prev = self.procs[-1]
|
| 1293 | prev.AddStateChange(StdoutToPipe(r, w))
|
| 1294 |
|
| 1295 | self.last_pipe = (r, w) # So we can connect it to last_thunk
|
| 1296 |
|
| 1297 | def StartPipeline(self, waiter):
|
| 1298 | # type: (Waiter) -> None
|
| 1299 |
|
| 1300 | # If we are creating a pipeline in a subshell or we aren't running with job
|
| 1301 | # control, our children should remain in our inherited process group.
|
| 1302 | # the pipelines's group ID.
|
| 1303 | if self.job_control.Enabled():
|
| 1304 | self.pgid = OWN_LEADER # first process in pipeline is the leader
|
| 1305 |
|
| 1306 | for i, proc in enumerate(self.procs):
|
| 1307 | if self.pgid != INVALID_PGID:
|
| 1308 | proc.AddStateChange(SetPgid(self.pgid, self.tracer))
|
| 1309 |
|
| 1310 | # Figure out the pid
|
| 1311 | pid = proc.StartProcess(trace.PipelinePart)
|
| 1312 | if i == 0 and self.pgid != INVALID_PGID:
|
| 1313 | # Mimic bash and use the PID of the FIRST process as the group for the
|
| 1314 | # whole pipeline.
|
| 1315 | self.pgid = pid
|
| 1316 |
|
| 1317 | self.pids.append(pid)
|
| 1318 | self.pipe_status.append(-1) # uninitialized
|
| 1319 |
|
| 1320 | # NOTE: This is done in the SHELL PROCESS after every fork() call.
|
| 1321 | # It can't be done at the end; otherwise processes will have descriptors
|
| 1322 | # from non-adjacent pipes.
|
| 1323 | proc.MaybeClosePipe()
|
| 1324 |
|
| 1325 | if self.last_thunk:
|
| 1326 | self.pipe_status.append(-1) # for self.last_thunk
|
| 1327 |
|
| 1328 | def LastPid(self):
|
| 1329 | # type: () -> int
|
| 1330 | """For the odd $! variable.
|
| 1331 |
|
| 1332 | It would be better if job IDs or PGIDs were used consistently.
|
| 1333 | """
|
| 1334 | return self.pids[-1]
|
| 1335 |
|
| 1336 | def Wait(self, waiter):
|
| 1337 | # type: (Waiter) -> List[int]
|
| 1338 | """Wait for this pipeline to finish."""
|
| 1339 |
|
| 1340 | assert self.procs, "no procs for Wait()"
|
| 1341 | # waitpid(-1) zero or more times
|
| 1342 | while self.state == job_state_e.Running:
|
| 1343 | # Keep waiting until there's nothing to wait for.
|
| 1344 | if waiter.WaitForOne() == W1_ECHILD:
|
| 1345 | break
|
| 1346 |
|
| 1347 | return self.pipe_status
|
| 1348 |
|
| 1349 | def JobWait(self, waiter):
|
| 1350 | # type: (Waiter) -> wait_status_t
|
| 1351 | """Called by 'wait' builtin, e.g. 'wait %1'."""
|
| 1352 | # wait builtin can be interrupted
|
| 1353 | assert self.procs, "no procs for Wait()"
|
| 1354 | while self.state == job_state_e.Running:
|
| 1355 | result = waiter.WaitForOne()
|
| 1356 |
|
| 1357 | if result >= 0: # signal
|
| 1358 | return wait_status.Cancelled(result)
|
| 1359 |
|
| 1360 | if result == W1_ECHILD:
|
| 1361 | break
|
| 1362 |
|
| 1363 | return wait_status.Pipeline(self.pipe_status)
|
| 1364 |
|
| 1365 | def RunLastPart(self, waiter, fd_state):
|
| 1366 | # type: (Waiter, FdState) -> List[int]
|
| 1367 | """Run this pipeline synchronously (foreground pipeline).
|
| 1368 |
|
| 1369 | Returns:
|
| 1370 | pipe_status (list of integers).
|
| 1371 | """
|
| 1372 | assert len(self.pids) == len(self.procs)
|
| 1373 |
|
| 1374 | # TODO: break circular dep. Bit flags could go in ASDL or headers.
|
| 1375 | from osh import cmd_eval
|
| 1376 |
|
| 1377 | # This is tcsetpgrp()
|
| 1378 | # TODO: fix race condition -- I believe the first process could have
|
| 1379 | # stopped already, and thus getpgid() will fail
|
| 1380 | self.job_control.MaybeGiveTerminal(self.pgid)
|
| 1381 |
|
| 1382 | # Run the last part of the pipeline IN PARALLEL with other processes. It
|
| 1383 | # may or may not fork:
|
| 1384 | # echo foo | read line # no fork, the builtin runs in THIS shell process
|
| 1385 | # ls | wc -l # fork for 'wc'
|
| 1386 |
|
| 1387 | cmd_ev, last_node = self.last_thunk
|
| 1388 |
|
| 1389 | assert self.last_pipe is not None
|
| 1390 | r, w = self.last_pipe # set in AddLast()
|
| 1391 | posix.close(w) # we will not write here
|
| 1392 |
|
| 1393 | # Fix lastpipe / job control / DEBUG trap interaction
|
| 1394 | cmd_flags = cmd_eval.NoDebugTrap if self.job_control.Enabled() else 0
|
| 1395 |
|
| 1396 | # The ERR trap only runs for the WHOLE pipeline, not the COMPONENTS in
|
| 1397 | # a pipeline.
|
| 1398 | cmd_flags |= cmd_eval.NoErrTrap
|
| 1399 |
|
| 1400 | io_errors = [] # type: List[error.IOError_OSError]
|
| 1401 | with ctx_Pipe(fd_state, r, io_errors):
|
| 1402 | cmd_ev.ExecuteAndCatch(last_node, cmd_flags)
|
| 1403 |
|
| 1404 | if len(io_errors):
|
| 1405 | e_die('Error setting up last part of pipeline: %s' %
|
| 1406 | pyutil.strerror(io_errors[0]))
|
| 1407 |
|
| 1408 | # We won't read anymore. If we don't do this, then 'cat' in 'cat
|
| 1409 | # /dev/urandom | sleep 1' will never get SIGPIPE.
|
| 1410 | posix.close(r)
|
| 1411 |
|
| 1412 | self.pipe_status[-1] = cmd_ev.LastStatus()
|
| 1413 | if self.AllDone():
|
| 1414 | self.state = job_state_e.Done
|
| 1415 |
|
| 1416 | #log('pipestatus before all have finished = %s', self.pipe_status)
|
| 1417 | return self.Wait(waiter)
|
| 1418 |
|
| 1419 | def AllDone(self):
|
| 1420 | # type: () -> bool
|
| 1421 |
|
| 1422 | # mycpp rewrite: all(status != -1 for status in self.pipe_status)
|
| 1423 | for status in self.pipe_status:
|
| 1424 | if status == -1:
|
| 1425 | return False
|
| 1426 | return True
|
| 1427 |
|
| 1428 | def WhenDone(self, pid, status):
|
| 1429 | # type: (int, int) -> None
|
| 1430 | """Called by Process.WhenDone."""
|
| 1431 | #log('Pipeline WhenDone %d %d', pid, status)
|
| 1432 | i = self.pids.index(pid)
|
| 1433 | assert i != -1, 'Unexpected PID %d' % pid
|
| 1434 |
|
| 1435 | if status == 141 and self.sigpipe_status_ok:
|
| 1436 | status = 0
|
| 1437 |
|
| 1438 | self.job_list.RemoveChildProcess(pid)
|
| 1439 | self.pipe_status[i] = status
|
| 1440 | if self.AllDone():
|
| 1441 | if self.job_id != -1:
|
| 1442 | # Job might have been brought to the foreground after being
|
| 1443 | # assigned a job ID.
|
| 1444 | if self.in_background:
|
| 1445 | print_stderr('[%d] Done PGID %d' %
|
| 1446 | (self.job_id, self.pids[0]))
|
| 1447 |
|
| 1448 | self.job_list.RemoveJob(self.job_id)
|
| 1449 |
|
| 1450 | # status of pipeline is status of last process
|
| 1451 | self.status = self.pipe_status[-1]
|
| 1452 | self.state = job_state_e.Done
|
| 1453 | if not self.in_background:
|
| 1454 | self.job_control.MaybeTakeTerminal()
|
| 1455 |
|
| 1456 |
|
| 1457 | def _JobStateStr(i):
|
| 1458 | # type: (job_state_t) -> str
|
| 1459 | return job_state_str(i)[10:] # remove 'job_state.'
|
| 1460 |
|
| 1461 |
|
| 1462 | def _GetTtyFd():
|
| 1463 | # type: () -> int
|
| 1464 | """Returns -1 if stdio is not a TTY."""
|
| 1465 | try:
|
| 1466 | return posix.open("/dev/tty", O_NONBLOCK | O_NOCTTY | O_RDWR, 0o666)
|
| 1467 | except (IOError, OSError) as e:
|
| 1468 | return -1
|
| 1469 |
|
| 1470 |
|
| 1471 | class ctx_TerminalControl(object):
|
| 1472 |
|
| 1473 | def __init__(self, job_control, errfmt):
|
| 1474 | # type: (JobControl, ui.ErrorFormatter) -> None
|
| 1475 | job_control.InitJobControl()
|
| 1476 | self.job_control = job_control
|
| 1477 | self.errfmt = errfmt
|
| 1478 |
|
| 1479 | def __enter__(self):
|
| 1480 | # type: () -> None
|
| 1481 | pass
|
| 1482 |
|
| 1483 | def __exit__(self, type, value, traceback):
|
| 1484 | # type: (Any, Any, Any) -> None
|
| 1485 |
|
| 1486 | # Return the TTY to the original owner before exiting.
|
| 1487 | try:
|
| 1488 | self.job_control.MaybeReturnTerminal()
|
| 1489 | except error.FatalRuntime as e:
|
| 1490 | # Don't abort the shell on error, just print a message.
|
| 1491 | self.errfmt.PrettyPrintError(e)
|
| 1492 |
|
| 1493 |
|
| 1494 | class JobControl(object):
|
| 1495 | """Interface to setpgid(), tcsetpgrp(), etc."""
|
| 1496 |
|
| 1497 | def __init__(self):
|
| 1498 | # type: () -> None
|
| 1499 |
|
| 1500 | # The main shell's PID and group ID.
|
| 1501 | self.shell_pid = -1
|
| 1502 | self.shell_pgid = -1
|
| 1503 |
|
| 1504 | # The fd of the controlling tty. Set to -1 when job control is disabled.
|
| 1505 | self.shell_tty_fd = -1
|
| 1506 |
|
| 1507 | # For giving the terminal back to our parent before exiting (if not a login
|
| 1508 | # shell).
|
| 1509 | self.original_tty_pgid = -1
|
| 1510 |
|
| 1511 | def InitJobControl(self):
|
| 1512 | # type: () -> None
|
| 1513 | self.shell_pid = posix.getpid()
|
| 1514 | orig_shell_pgid = posix.getpgid(0)
|
| 1515 | self.shell_pgid = orig_shell_pgid
|
| 1516 | self.shell_tty_fd = _GetTtyFd()
|
| 1517 |
|
| 1518 | # If we aren't the leader of our process group, create a group and mark
|
| 1519 | # ourselves as the leader.
|
| 1520 | if self.shell_pgid != self.shell_pid:
|
| 1521 | try:
|
| 1522 | posix.setpgid(self.shell_pid, self.shell_pid)
|
| 1523 | self.shell_pgid = self.shell_pid
|
| 1524 | except (IOError, OSError) as e:
|
| 1525 | self.shell_tty_fd = -1
|
| 1526 |
|
| 1527 | if self.shell_tty_fd != -1:
|
| 1528 | self.original_tty_pgid = posix.tcgetpgrp(self.shell_tty_fd)
|
| 1529 |
|
| 1530 | # If stdio is a TTY, put the shell's process group in the foreground.
|
| 1531 | try:
|
| 1532 | posix.tcsetpgrp(self.shell_tty_fd, self.shell_pgid)
|
| 1533 | except (IOError, OSError) as e:
|
| 1534 | # We probably aren't in the session leader's process group. Disable job
|
| 1535 | # control.
|
| 1536 | self.shell_tty_fd = -1
|
| 1537 | self.shell_pgid = orig_shell_pgid
|
| 1538 | posix.setpgid(self.shell_pid, self.shell_pgid)
|
| 1539 |
|
| 1540 | def Enabled(self):
|
| 1541 | # type: () -> bool
|
| 1542 |
|
| 1543 | # TODO: get rid of this syscall? SubProgramThunk should set a flag I
|
| 1544 | # think.
|
| 1545 | curr_pid = posix.getpid()
|
| 1546 | # Only the main shell should bother with job control functions.
|
| 1547 | return curr_pid == self.shell_pid and self.shell_tty_fd != -1
|
| 1548 |
|
| 1549 | # TODO: This isn't a PID. This is a process group ID?
|
| 1550 | #
|
| 1551 | # What should the table look like?
|
| 1552 | #
|
| 1553 | # Do we need the last PID? I don't know why bash prints that. Probably so
|
| 1554 | # you can do wait $!
|
| 1555 | # wait -n waits for any node to go from job_state_e.Running to job_state_e.Done?
|
| 1556 | #
|
| 1557 | # And it needs a flag for CURRENT, for the implicit arg to 'fg'.
|
| 1558 | # job_id is just an integer. This is sort of lame.
|
| 1559 | #
|
| 1560 | # [job_id, flag, pgid, job_state, node]
|
| 1561 |
|
| 1562 | def MaybeGiveTerminal(self, pgid):
|
| 1563 | # type: (int) -> None
|
| 1564 | """If stdio is a TTY, move the given process group to the
|
| 1565 | foreground."""
|
| 1566 | if not self.Enabled():
|
| 1567 | # Only call tcsetpgrp when job control is enabled.
|
| 1568 | return
|
| 1569 |
|
| 1570 | try:
|
| 1571 | posix.tcsetpgrp(self.shell_tty_fd, pgid)
|
| 1572 | except (IOError, OSError) as e:
|
| 1573 | e_die('osh: Failed to move process group %d to foreground: %s' %
|
| 1574 | (pgid, pyutil.strerror(e)))
|
| 1575 |
|
| 1576 | def MaybeTakeTerminal(self):
|
| 1577 | # type: () -> None
|
| 1578 | """If stdio is a TTY, return the main shell's process group to the
|
| 1579 | foreground."""
|
| 1580 | self.MaybeGiveTerminal(self.shell_pgid)
|
| 1581 |
|
| 1582 | def MaybeReturnTerminal(self):
|
| 1583 | # type: () -> None
|
| 1584 | """Called before the shell exits."""
|
| 1585 | self.MaybeGiveTerminal(self.original_tty_pgid)
|
| 1586 |
|
| 1587 |
|
| 1588 | class JobList(object):
|
| 1589 | """Global list of jobs, used by a few builtins."""
|
| 1590 |
|
| 1591 | def __init__(self):
|
| 1592 | # type: () -> None
|
| 1593 |
|
| 1594 | # job_id -> Job instance
|
| 1595 | self.jobs = {} # type: Dict[int, Job]
|
| 1596 |
|
| 1597 | # pid -> Process. This is for STOP notification.
|
| 1598 | self.child_procs = {} # type: Dict[int, Process]
|
| 1599 | self.debug_pipelines = [] # type: List[Pipeline]
|
| 1600 |
|
| 1601 | # Counter used to assign IDs to jobs. It is incremented every time a job
|
| 1602 | # is created. Once all active jobs are done it is reset to 1. I'm not
|
| 1603 | # sure if this reset behavior is mandated by POSIX, but other shells do
|
| 1604 | # it, so we mimic for the sake of compatibility.
|
| 1605 | self.job_id = 1
|
| 1606 |
|
| 1607 | def AddJob(self, job):
|
| 1608 | # type: (Job) -> int
|
| 1609 | """Add a background job to the list.
|
| 1610 |
|
| 1611 | A job is either a Process or Pipeline. You can resume a job with 'fg',
|
| 1612 | kill it with 'kill', etc.
|
| 1613 |
|
| 1614 | Two cases:
|
| 1615 |
|
| 1616 | 1. async jobs: sleep 5 | sleep 4 &
|
| 1617 | 2. stopped jobs: sleep 5; then Ctrl-Z
|
| 1618 | """
|
| 1619 | job_id = self.job_id
|
| 1620 | self.jobs[job_id] = job
|
| 1621 | job.job_id = job_id
|
| 1622 | self.job_id += 1
|
| 1623 | return job_id
|
| 1624 |
|
| 1625 | def RemoveJob(self, job_id):
|
| 1626 | # type: (int) -> None
|
| 1627 | """Process and Pipeline can call this."""
|
| 1628 | mylib.dict_erase(self.jobs, job_id)
|
| 1629 |
|
| 1630 | if len(self.jobs) == 0:
|
| 1631 | self.job_id = 1
|
| 1632 |
|
| 1633 | def AddChildProcess(self, pid, proc):
|
| 1634 | # type: (int, Process) -> None
|
| 1635 | """Every child process should be added here as soon as we know its PID.
|
| 1636 |
|
| 1637 | When the Waiter gets an EXITED or STOPPED notification, we need
|
| 1638 | to know about it so 'jobs' can work.
|
| 1639 | """
|
| 1640 | self.child_procs[pid] = proc
|
| 1641 |
|
| 1642 | def RemoveChildProcess(self, pid):
|
| 1643 | # type: (int) -> None
|
| 1644 | """Remove the child process with the given PID."""
|
| 1645 | mylib.dict_erase(self.child_procs, pid)
|
| 1646 |
|
| 1647 | if mylib.PYTHON:
|
| 1648 |
|
| 1649 | def AddPipeline(self, pi):
|
| 1650 | # type: (Pipeline) -> None
|
| 1651 | """For debugging only."""
|
| 1652 | self.debug_pipelines.append(pi)
|
| 1653 |
|
| 1654 | def ProcessFromPid(self, pid):
|
| 1655 | # type: (int) -> Process
|
| 1656 | """For wait $PID.
|
| 1657 |
|
| 1658 | There's no way to wait for a pipeline with a PID. That uses job
|
| 1659 | syntax, e.g. %1. Not a great interface.
|
| 1660 | """
|
| 1661 | return self.child_procs.get(pid)
|
| 1662 |
|
| 1663 | def GetCurrentAndPreviousJobs(self):
|
| 1664 | # type: () -> Tuple[Optional[Job], Optional[Job]]
|
| 1665 | """Return the "current" and "previous" jobs (AKA `%+` and `%-`).
|
| 1666 |
|
| 1667 | See the POSIX specification for the `jobs` builtin for details:
|
| 1668 | https://pubs.opengroup.org/onlinepubs/007904875/utilities/jobs.html
|
| 1669 |
|
| 1670 | IMPORTANT NOTE: This method assumes that the jobs list will not change
|
| 1671 | during its execution! This assumption holds for now because we only ever
|
| 1672 | update the jobs list from the main loop after WaitPid() informs us of a
|
| 1673 | change. If we implement `set -b` and install a signal handler for
|
| 1674 | SIGCHLD we should be careful to synchronize it with this function. The
|
| 1675 | unsafety of mutating GC data structures from a signal handler should
|
| 1676 | make this a non-issue, but if bugs related to this appear this note may
|
| 1677 | be helpful...
|
| 1678 | """
|
| 1679 | # Split all active jobs by state and sort each group by decreasing job
|
| 1680 | # ID to approximate newness.
|
| 1681 | stopped_jobs = [] # type: List[Job]
|
| 1682 | running_jobs = [] # type: List[Job]
|
| 1683 | for i in xrange(0, self.job_id):
|
| 1684 | job = self.jobs.get(i, None)
|
| 1685 | if not job:
|
| 1686 | continue
|
| 1687 |
|
| 1688 | if job.state == job_state_e.Stopped:
|
| 1689 | stopped_jobs.append(job)
|
| 1690 |
|
| 1691 | elif job.state == job_state_e.Running:
|
| 1692 | running_jobs.append(job)
|
| 1693 |
|
| 1694 | current = None # type: Optional[Job]
|
| 1695 | previous = None # type: Optional[Job]
|
| 1696 | # POSIX says: If there is any suspended job, then the current job shall
|
| 1697 | # be a suspended job. If there are at least two suspended jobs, then the
|
| 1698 | # previous job also shall be a suspended job.
|
| 1699 | #
|
| 1700 | # So, we will only return running jobs from here if there are no recent
|
| 1701 | # stopped jobs.
|
| 1702 | if len(stopped_jobs) > 0:
|
| 1703 | current = stopped_jobs.pop()
|
| 1704 |
|
| 1705 | if len(stopped_jobs) > 0:
|
| 1706 | previous = stopped_jobs.pop()
|
| 1707 |
|
| 1708 | if len(running_jobs) > 0 and not current:
|
| 1709 | current = running_jobs.pop()
|
| 1710 |
|
| 1711 | if len(running_jobs) > 0 and not previous:
|
| 1712 | previous = running_jobs.pop()
|
| 1713 |
|
| 1714 | if not previous:
|
| 1715 | previous = current
|
| 1716 |
|
| 1717 | return current, previous
|
| 1718 |
|
| 1719 | def GetJobWithSpec(self, job_spec):
|
| 1720 | # type: (str) -> Optional[Job]
|
| 1721 | """Parse the given job spec and return the matching job. If there is no
|
| 1722 | matching job, this function returns None.
|
| 1723 |
|
| 1724 | See the POSIX spec for the `jobs` builtin for details about job specs:
|
| 1725 | https://pubs.opengroup.org/onlinepubs/007904875/utilities/jobs.html
|
| 1726 | """
|
| 1727 | if job_spec in CURRENT_JOB_SPECS:
|
| 1728 | current, _ = self.GetCurrentAndPreviousJobs()
|
| 1729 | return current
|
| 1730 |
|
| 1731 | if job_spec == '%-':
|
| 1732 | _, previous = self.GetCurrentAndPreviousJobs()
|
| 1733 | return previous
|
| 1734 |
|
| 1735 | # TODO: Add support for job specs based on prefixes of process argv.
|
| 1736 | m = util.RegexSearch(r'^%([0-9]+)$', job_spec)
|
| 1737 | if m is not None:
|
| 1738 | assert len(m) == 2
|
| 1739 | job_id = int(m[1])
|
| 1740 | if job_id in self.jobs:
|
| 1741 | return self.jobs[job_id]
|
| 1742 |
|
| 1743 | return None
|
| 1744 |
|
| 1745 | def DisplayJobs(self, style):
|
| 1746 | # type: (int) -> None
|
| 1747 | """Used by the 'jobs' builtin.
|
| 1748 |
|
| 1749 | https://pubs.opengroup.org/onlinepubs/9699919799/utilities/jobs.html
|
| 1750 |
|
| 1751 | "By default, the jobs utility shall display the status of all stopped jobs,
|
| 1752 | running background jobs and all jobs whose status has changed and have not
|
| 1753 | been reported by the shell."
|
| 1754 | """
|
| 1755 | # NOTE: A job is a background process or pipeline.
|
| 1756 | #
|
| 1757 | # echo hi | wc -l -- this starts two processes. Wait for TWO
|
| 1758 | # echo hi | wc -l & -- this starts a process which starts two processes
|
| 1759 | # Wait for ONE.
|
| 1760 | #
|
| 1761 | # 'jobs -l' GROUPS the PIDs by job. It has the job number, + - indicators
|
| 1762 | # for %% and %-, PID, status, and "command".
|
| 1763 | #
|
| 1764 | # Every component of a pipeline is on the same line with 'jobs', but
|
| 1765 | # they're separated into different lines with 'jobs -l'.
|
| 1766 | #
|
| 1767 | # See demo/jobs-builtin.sh
|
| 1768 |
|
| 1769 | # $ jobs -l
|
| 1770 | # [1]+ 24414 Stopped sleep 5
|
| 1771 | # 24415 | sleep 5
|
| 1772 | # [2] 24502 Running sleep 6
|
| 1773 | # 24503 | sleep 6
|
| 1774 | # 24504 | sleep 5 &
|
| 1775 | # [3]- 24508 Running sleep 6
|
| 1776 | # 24509 | sleep 6
|
| 1777 | # 24510 | sleep 5 &
|
| 1778 |
|
| 1779 | f = mylib.Stdout()
|
| 1780 | for job_id, job in iteritems(self.jobs):
|
| 1781 | # Use the %1 syntax
|
| 1782 | job.DisplayJob(job_id, f, style)
|
| 1783 |
|
| 1784 | def DebugPrint(self):
|
| 1785 | # type: () -> None
|
| 1786 |
|
| 1787 | f = mylib.Stdout()
|
| 1788 | f.write('\n')
|
| 1789 | f.write('[process debug info]\n')
|
| 1790 |
|
| 1791 | for pid, proc in iteritems(self.child_procs):
|
| 1792 | proc.DisplayJob(-1, f, STYLE_DEFAULT)
|
| 1793 | #p = ' |' if proc.parent_pipeline else ''
|
| 1794 | #print('%d %7s %s%s' % (pid, _JobStateStr(proc.state), proc.thunk.UserString(), p))
|
| 1795 |
|
| 1796 | if len(self.debug_pipelines):
|
| 1797 | f.write('\n')
|
| 1798 | f.write('[pipeline debug info]\n')
|
| 1799 | for pi in self.debug_pipelines:
|
| 1800 | pi.DebugPrint()
|
| 1801 |
|
| 1802 | def ListRecent(self):
|
| 1803 | # type: () -> None
|
| 1804 | """For jobs -n, which I think is also used in the interactive
|
| 1805 | prompt."""
|
| 1806 | pass
|
| 1807 |
|
| 1808 | def NumRunning(self):
|
| 1809 | # type: () -> int
|
| 1810 | """Return the number of running jobs.
|
| 1811 |
|
| 1812 | Used by 'wait' and 'wait -n'.
|
| 1813 | """
|
| 1814 | count = 0
|
| 1815 | for _, job in iteritems(self.jobs): # mycpp rewrite: from itervalues()
|
| 1816 | if job.State() == job_state_e.Running:
|
| 1817 | count += 1
|
| 1818 | return count
|
| 1819 |
|
| 1820 |
|
| 1821 | # Some WaitForOne() return values
|
| 1822 | W1_OK = -2 # waitpid(-1) returned
|
| 1823 | W1_ECHILD = -3 # no processes to wait for
|
| 1824 | W1_AGAIN = -4 # WNOHANG was passed and there were no state changes
|
| 1825 |
|
| 1826 |
|
| 1827 | class Waiter(object):
|
| 1828 | """A capability to wait for processes.
|
| 1829 |
|
| 1830 | This must be a singleton (and is because CommandEvaluator is a singleton).
|
| 1831 |
|
| 1832 | Invariants:
|
| 1833 | - Every child process is registered once
|
| 1834 | - Every child process is waited for
|
| 1835 |
|
| 1836 | Canonical example of why we need a GLOBAL waiter:
|
| 1837 |
|
| 1838 | { sleep 3; echo 'done 3'; } &
|
| 1839 | { sleep 4; echo 'done 4'; } &
|
| 1840 |
|
| 1841 | # ... do arbitrary stuff ...
|
| 1842 |
|
| 1843 | { sleep 1; exit 1; } | { sleep 2; exit 2; }
|
| 1844 |
|
| 1845 | Now when you do wait() after starting the pipeline, you might get a pipeline
|
| 1846 | process OR a background process! So you have to distinguish between them.
|
| 1847 | """
|
| 1848 |
|
| 1849 | def __init__(self, job_list, exec_opts, signal_safe, tracer):
|
| 1850 | # type: (JobList, optview.Exec, pyos.SignalSafe, dev.Tracer) -> None
|
| 1851 | self.job_list = job_list
|
| 1852 | self.exec_opts = exec_opts
|
| 1853 | self.signal_safe = signal_safe
|
| 1854 | self.tracer = tracer
|
| 1855 | self.last_status = 127 # wait -n error code
|
| 1856 |
|
| 1857 | def WaitForOne(self, waitpid_options=0):
|
| 1858 | # type: (int) -> int
|
| 1859 | """Wait until the next process returns (or maybe Ctrl-C).
|
| 1860 |
|
| 1861 | Returns:
|
| 1862 | One of these negative numbers:
|
| 1863 | W1_ECHILD Nothing to wait for
|
| 1864 | W1_OK Caller should keep waiting
|
| 1865 | UNTRAPPED_SIGWINCH
|
| 1866 | Or
|
| 1867 | result > 0 Signal that waitpid() was interrupted with
|
| 1868 |
|
| 1869 | In the interactive shell, we return 0 if we get a Ctrl-C, so the caller
|
| 1870 | will try again.
|
| 1871 |
|
| 1872 | Callers:
|
| 1873 | wait -n -- loop until there is one fewer process (TODO)
|
| 1874 | wait -- loop until there are no processes
|
| 1875 | wait $! -- loop until job state is Done (process or pipeline)
|
| 1876 | Process::Wait() -- loop until Process state is done
|
| 1877 | Pipeline::Wait() -- loop until Pipeline state is done
|
| 1878 |
|
| 1879 | Comparisons:
|
| 1880 | bash: jobs.c waitchld() Has a special case macro(!) CHECK_WAIT_INTR for
|
| 1881 | the wait builtin
|
| 1882 |
|
| 1883 | dash: jobs.c waitproc() uses sigfillset(), sigprocmask(), etc. Runs in a
|
| 1884 | loop while (gotsigchld), but that might be a hack for System V!
|
| 1885 |
|
| 1886 | Should we have a cleaner API like named posix::wait_for_one() ?
|
| 1887 |
|
| 1888 | wait_result =
|
| 1889 | ECHILD -- nothing to wait for
|
| 1890 | | Done(int pid, int status) -- process done
|
| 1891 | | EINTR(bool sigint) -- may or may not retry
|
| 1892 | """
|
| 1893 | pid, status = pyos.WaitPid(waitpid_options)
|
| 1894 | if pid == 0: # WNOHANG passed, and no state changes
|
| 1895 | return W1_AGAIN
|
| 1896 | elif pid < 0: # error case
|
| 1897 | err_num = status
|
| 1898 | #log('waitpid() error => %d %s', e.errno, pyutil.strerror(e))
|
| 1899 | if err_num == ECHILD:
|
| 1900 | return W1_ECHILD # nothing to wait for caller should stop
|
| 1901 | elif err_num == EINTR: # Bug #858 fix
|
| 1902 | #log('WaitForOne() => %d', self.trap_state.GetLastSignal())
|
| 1903 | return self.signal_safe.LastSignal() # e.g. 1 for SIGHUP
|
| 1904 | else:
|
| 1905 | # The signature of waitpid() means this shouldn't happen
|
| 1906 | raise AssertionError()
|
| 1907 |
|
| 1908 | # All child processes are supposed to be in this dict. But this may
|
| 1909 | # legitimately happen if a grandchild outlives the child (its parent).
|
| 1910 | # Then it is reparented under this process, so we might receive
|
| 1911 | # notification of its exit, even though we didn't start it. We can't have
|
| 1912 | # any knowledge of such processes, so print a warning.
|
| 1913 | if pid not in self.job_list.child_procs:
|
| 1914 | print_stderr("osh: PID %d stopped, but osh didn't start it" % pid)
|
| 1915 | return W1_OK
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| 1916 |
|
| 1917 | proc = self.job_list.child_procs[pid]
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| 1918 | if 0:
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| 1919 | self.job_list.DebugPrint()
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| 1920 |
|
| 1921 | if WIFSIGNALED(status):
|
| 1922 | term_sig = WTERMSIG(status)
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| 1923 | status = 128 + term_sig
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| 1924 |
|
| 1925 | # Print newline after Ctrl-C.
|
| 1926 | if term_sig == SIGINT:
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| 1927 | print('')
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| 1928 |
|
| 1929 | proc.WhenDone(pid, status)
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| 1930 |
|
| 1931 | elif WIFEXITED(status):
|
| 1932 | status = WEXITSTATUS(status)
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| 1933 | #log('exit status: %s', status)
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| 1934 | proc.WhenDone(pid, status)
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| 1935 |
|
| 1936 | elif WIFSTOPPED(status):
|
| 1937 | #status = WEXITSTATUS(status)
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| 1938 | stop_sig = WSTOPSIG(status)
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| 1939 |
|
| 1940 | print_stderr('')
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| 1941 | print_stderr('[PID %d] Stopped with signal %d' % (pid, stop_sig))
|
| 1942 | proc.WhenStopped(stop_sig)
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| 1943 |
|
| 1944 | else:
|
| 1945 | raise AssertionError(status)
|
| 1946 |
|
| 1947 | self.last_status = status # for wait -n
|
| 1948 | self.tracer.OnProcessEnd(pid, status)
|
| 1949 | return W1_OK
|
| 1950 |
|
| 1951 | def PollNotifications(self):
|
| 1952 | # type: () -> None
|
| 1953 | """
|
| 1954 | Process all pending state changes.
|
| 1955 | """
|
| 1956 | while self.WaitForOne(waitpid_options=WNOHANG) == W1_OK:
|
| 1957 | continue
|