Mercurial > repos > shellac > guppy_basecaller
annotate env/lib/python3.7/site-packages/lockfile/pidlockfile.py @ 3:758bc20232e8 draft
"planemo upload commit 2a0fe2cc28b09e101d37293e53e82f61762262ec"
author | shellac |
---|---|
date | Thu, 14 May 2020 16:20:52 -0400 |
parents | 26e78fe6e8c4 |
children |
rev | line source |
---|---|
0
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
1 # -*- coding: utf-8 -*- |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
2 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
3 # pidlockfile.py |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
4 # |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
5 # Copyright © 2008–2009 Ben Finney <ben+python@benfinney.id.au> |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
6 # |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
7 # This is free software: you may copy, modify, and/or distribute this work |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
8 # under the terms of the Python Software Foundation License, version 2 or |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
9 # later as published by the Python Software Foundation. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
10 # No warranty expressed or implied. See the file LICENSE.PSF-2 for details. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
11 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
12 """ Lockfile behaviour implemented via Unix PID files. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
13 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
14 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
15 from __future__ import absolute_import |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
16 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
17 import errno |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
18 import os |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
19 import time |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
20 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
21 from . import (LockBase, AlreadyLocked, LockFailed, NotLocked, NotMyLock, |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
22 LockTimeout) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
23 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
24 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
25 class PIDLockFile(LockBase): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
26 """ Lockfile implemented as a Unix PID file. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
27 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
28 The lock file is a normal file named by the attribute `path`. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
29 A lock's PID file contains a single line of text, containing |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
30 the process ID (PID) of the process that acquired the lock. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
31 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
32 >>> lock = PIDLockFile('somefile') |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
33 >>> lock = PIDLockFile('somefile') |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
34 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
35 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
36 def __init__(self, path, threaded=False, timeout=None): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
37 # pid lockfiles don't support threaded operation, so always force |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
38 # False as the threaded arg. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
39 LockBase.__init__(self, path, False, timeout) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
40 self.unique_name = self.path |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
41 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
42 def read_pid(self): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
43 """ Get the PID from the lock file. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
44 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
45 return read_pid_from_pidfile(self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
46 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
47 def is_locked(self): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
48 """ Test if the lock is currently held. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
49 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
50 The lock is held if the PID file for this lock exists. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
51 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
52 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
53 return os.path.exists(self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
54 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
55 def i_am_locking(self): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
56 """ Test if the lock is held by the current process. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
57 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
58 Returns ``True`` if the current process ID matches the |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
59 number stored in the PID file. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
60 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
61 return self.is_locked() and os.getpid() == self.read_pid() |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
62 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
63 def acquire(self, timeout=None): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
64 """ Acquire the lock. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
65 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
66 Creates the PID file for this lock, or raises an error if |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
67 the lock could not be acquired. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
68 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
69 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
70 timeout = timeout if timeout is not None else self.timeout |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
71 end_time = time.time() |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
72 if timeout is not None and timeout > 0: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
73 end_time += timeout |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
74 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
75 while True: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
76 try: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
77 write_pid_to_pidfile(self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
78 except OSError as exc: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
79 if exc.errno == errno.EEXIST: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
80 # The lock creation failed. Maybe sleep a bit. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
81 if time.time() > end_time: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
82 if timeout is not None and timeout > 0: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
83 raise LockTimeout("Timeout waiting to acquire" |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
84 " lock for %s" % |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
85 self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
86 else: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
87 raise AlreadyLocked("%s is already locked" % |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
88 self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
89 time.sleep(timeout is not None and timeout / 10 or 0.1) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
90 else: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
91 raise LockFailed("failed to create %s" % self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
92 else: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
93 return |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
94 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
95 def release(self): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
96 """ Release the lock. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
97 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
98 Removes the PID file to release the lock, or raises an |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
99 error if the current process does not hold the lock. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
100 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
101 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
102 if not self.is_locked(): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
103 raise NotLocked("%s is not locked" % self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
104 if not self.i_am_locking(): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
105 raise NotMyLock("%s is locked, but not by me" % self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
106 remove_existing_pidfile(self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
107 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
108 def break_lock(self): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
109 """ Break an existing lock. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
110 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
111 Removes the PID file if it already exists, otherwise does |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
112 nothing. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
113 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
114 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
115 remove_existing_pidfile(self.path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
116 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
117 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
118 def read_pid_from_pidfile(pidfile_path): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
119 """ Read the PID recorded in the named PID file. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
120 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
121 Read and return the numeric PID recorded as text in the named |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
122 PID file. If the PID file cannot be read, or if the content is |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
123 not a valid PID, return ``None``. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
124 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
125 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
126 pid = None |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
127 try: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
128 pidfile = open(pidfile_path, 'r') |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
129 except IOError: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
130 pass |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
131 else: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
132 # According to the FHS 2.3 section on PID files in /var/run: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
133 # |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
134 # The file must consist of the process identifier in |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
135 # ASCII-encoded decimal, followed by a newline character. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
136 # |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
137 # Programs that read PID files should be somewhat flexible |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
138 # in what they accept; i.e., they should ignore extra |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
139 # whitespace, leading zeroes, absence of the trailing |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
140 # newline, or additional lines in the PID file. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
141 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
142 line = pidfile.readline().strip() |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
143 try: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
144 pid = int(line) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
145 except ValueError: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
146 pass |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
147 pidfile.close() |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
148 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
149 return pid |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
150 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
151 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
152 def write_pid_to_pidfile(pidfile_path): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
153 """ Write the PID in the named PID file. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
154 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
155 Get the numeric process ID (“PID”) of the current process |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
156 and write it to the named file as a line of text. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
157 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
158 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
159 open_flags = (os.O_CREAT | os.O_EXCL | os.O_WRONLY) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
160 open_mode = 0o644 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
161 pidfile_fd = os.open(pidfile_path, open_flags, open_mode) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
162 pidfile = os.fdopen(pidfile_fd, 'w') |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
163 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
164 # According to the FHS 2.3 section on PID files in /var/run: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
165 # |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
166 # The file must consist of the process identifier in |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
167 # ASCII-encoded decimal, followed by a newline character. For |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
168 # example, if crond was process number 25, /var/run/crond.pid |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
169 # would contain three characters: two, five, and newline. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
170 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
171 pid = os.getpid() |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
172 pidfile.write("%s\n" % pid) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
173 pidfile.close() |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
174 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
175 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
176 def remove_existing_pidfile(pidfile_path): |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
177 """ Remove the named PID file if it exists. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
178 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
179 Removing a PID file that doesn't already exist puts us in the |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
180 desired state, so we ignore the condition if the file does not |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
181 exist. |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
182 |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
183 """ |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
184 try: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
185 os.remove(pidfile_path) |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
186 except OSError as exc: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
187 if exc.errno == errno.ENOENT: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
188 pass |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
189 else: |
26e78fe6e8c4
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
shellac
parents:
diff
changeset
|
190 raise |