1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
# Copyright 2010-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
import io
import signal
import sys
import traceback
import errno
import fcntl
import portage
from portage import os, _unicode_decode
import portage.elog.messages
from portage.util._async.ForkProcess import ForkProcess
class MergeProcess(ForkProcess):
"""
Merge packages in a subprocess, so the Scheduler can run in the main
thread while files are moved or copied asynchronously.
"""
__slots__ = ('mycat', 'mypkg', 'settings', 'treetype',
'vartree', 'blockers', 'pkgloc', 'infloc', 'myebuild',
'mydbapi', 'prev_mtimes', 'unmerge', '_elog_reader_fd', '_elog_reg_id',
'_buf', '_elog_keys', '_locked_vdb')
def _start(self):
# Portage should always call setcpv prior to this
# point, but here we have a fallback as a convenience
# for external API consumers. It's important that
# this metadata access happens in the parent process,
# since closing of file descriptors in the subprocess
# can prevent access to open database connections such
# as that used by the sqlite metadata cache module.
cpv = "%s/%s" % (self.mycat, self.mypkg)
settings = self.settings
if cpv != settings.mycpv or \
"EAPI" not in settings.configdict["pkg"]:
settings.reload()
settings.reset()
settings.setcpv(cpv, mydb=self.mydbapi)
# Inherit stdin by default, so that the pdb SIGUSR1
# handler is usable for the subprocess.
if self.fd_pipes is None:
self.fd_pipes = {}
self.fd_pipes.setdefault(0, sys.stdin.fileno())
super(MergeProcess, self)._start()
def _lock_vdb(self):
"""
Lock the vdb if FEATURES=parallel-install is NOT enabled,
otherwise do nothing. This is implemented with
vardbapi.lock(), which supports reentrance by the
subprocess that we spawn.
"""
if "parallel-install" not in self.settings.features:
self.vartree.dbapi.lock()
self._locked_vdb = True
def _unlock_vdb(self):
"""
Unlock the vdb if we hold a lock, otherwise do nothing.
"""
if self._locked_vdb:
self.vartree.dbapi.unlock()
self._locked_vdb = False
def _elog_output_handler(self, fd, event):
output = None
if event & self.scheduler.IO_IN:
try:
output = os.read(fd, self._bufsize)
except OSError as e:
if e.errno not in (errno.EAGAIN, errno.EINTR):
raise
if output:
lines = _unicode_decode(output).split('\n')
if len(lines) == 1:
self._buf += lines[0]
else:
lines[0] = self._buf + lines[0]
self._buf = lines.pop()
out = io.StringIO()
for line in lines:
funcname, phase, key, msg = line.split(' ', 3)
self._elog_keys.add(key)
reporter = getattr(portage.elog.messages, funcname)
reporter(msg, phase=phase, key=key, out=out)
if event & self.scheduler.IO_HUP:
self.scheduler.source_remove(self._elog_reg_id)
self._elog_reg_id = None
os.close(self._elog_reader_fd)
self._elog_reader_fd = None
return False
return True
def _spawn(self, args, fd_pipes, **kwargs):
"""
Fork a subprocess, apply local settings, and call
dblink.merge(). TODO: Share code with ForkProcess.
"""
elog_reader_fd, elog_writer_fd = os.pipe()
fcntl.fcntl(elog_reader_fd, fcntl.F_SETFL,
fcntl.fcntl(elog_reader_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
blockers = None
if self.blockers is not None:
# Query blockers in the main process, since closing
# of file descriptors in the subprocess can prevent
# access to open database connections such as that
# used by the sqlite metadata cache module.
blockers = self.blockers()
mylink = portage.dblink(self.mycat, self.mypkg, settings=self.settings,
treetype=self.treetype, vartree=self.vartree,
blockers=blockers, scheduler=self.scheduler,
pipe=elog_writer_fd)
fd_pipes[elog_writer_fd] = elog_writer_fd
self._elog_reg_id = self.scheduler.io_add_watch(elog_reader_fd,
self._registered_events, self._elog_output_handler)
# If a concurrent emerge process tries to install a package
# in the same SLOT as this one at the same time, there is an
# extremely unlikely chance that the COUNTER values will not be
# ordered correctly unless we lock the vdb here.
# FEATURES=parallel-install skips this lock in order to
# improve performance, and the risk is practically negligible.
self._lock_vdb()
counter = None
if not self.unmerge:
counter = self.vartree.dbapi.counter_tick()
pid = os.fork()
if pid != 0:
if not isinstance(pid, int):
raise AssertionError(
"fork returned non-integer: %s" % (repr(pid),))
os.close(elog_writer_fd)
self._elog_reader_fd = elog_reader_fd
self._buf = ""
self._elog_keys = set()
# invalidate relevant vardbapi caches
if self.vartree.dbapi._categories is not None:
self.vartree.dbapi._categories = None
self.vartree.dbapi._pkgs_changed = True
self.vartree.dbapi._clear_pkg_cache(mylink)
portage.process.spawned_pids.append(pid)
return [pid]
os.close(elog_reader_fd)
portage.locks._close_fds()
# Disable close_fds since we don't exec (see _setup_pipes docstring).
portage.process._setup_pipes(fd_pipes, close_fds=False)
# Use default signal handlers since the ones inherited
# from the parent process are irrelevant here.
signal.signal(signal.SIGINT, signal.SIG_DFL)
signal.signal(signal.SIGTERM, signal.SIG_DFL)
portage.output.havecolor = self.settings.get('NOCOLOR') \
not in ('yes', 'true')
# In this subprocess we want mylink._display_merge() to use
# stdout/stderr directly since they are pipes. This behavior
# is triggered when mylink._scheduler is None.
mylink._scheduler = None
# Avoid wastful updates of the vdb cache.
self.vartree.dbapi._flush_cache_enabled = False
# In this subprocess we don't want PORTAGE_BACKGROUND to
# suppress stdout/stderr output since they are pipes. We
# also don't want to open PORTAGE_LOG_FILE, since it will
# already be opened by the parent process, so we set the
# "subprocess" value for use in conditional logging code
# involving PORTAGE_LOG_FILE.
if not self.unmerge:
# unmerge phases have separate logs
if self.settings.get("PORTAGE_BACKGROUND") == "1":
self.settings["PORTAGE_BACKGROUND_UNMERGE"] = "1"
else:
self.settings["PORTAGE_BACKGROUND_UNMERGE"] = "0"
self.settings.backup_changes("PORTAGE_BACKGROUND_UNMERGE")
self.settings["PORTAGE_BACKGROUND"] = "subprocess"
self.settings.backup_changes("PORTAGE_BACKGROUND")
rval = 1
try:
if self.unmerge:
if not mylink.exists():
rval = os.EX_OK
elif mylink.unmerge(
ldpath_mtimes=self.prev_mtimes) == os.EX_OK:
mylink.lockdb()
try:
mylink.delete()
finally:
mylink.unlockdb()
rval = os.EX_OK
else:
rval = mylink.merge(self.pkgloc, self.infloc,
myebuild=self.myebuild, mydbapi=self.mydbapi,
prev_mtimes=self.prev_mtimes, counter=counter)
except SystemExit:
raise
except:
traceback.print_exc()
finally:
# Call os._exit() from finally block, in order to suppress any
# finally blocks from earlier in the call stack. See bug #345289.
os._exit(rval)
def _unregister(self):
"""
Unregister from the scheduler and close open files.
"""
if not self.unmerge:
# Populate the vardbapi cache for the new package
# while its inodes are still hot.
try:
self.vartree.dbapi.aux_get(self.settings.mycpv, ["EAPI"])
except KeyError:
pass
self._unlock_vdb()
if self._elog_reg_id is not None:
self.scheduler.source_remove(self._elog_reg_id)
self._elog_reg_id = None
if self._elog_reader_fd is not None:
os.close(self._elog_reader_fd)
self._elog_reader_fd = None
if self._elog_keys is not None:
for key in self._elog_keys:
portage.elog.elog_process(key, self.settings,
phasefilter=("prerm", "postrm"))
self._elog_keys = None
super(MergeProcess, self)._unregister()
|