Module: Bluepill::ProcessJournal

Defined in:
lib/bluepill/process_journal.rb

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.journal_base_dir ⇒ Object (readonly)

Returns the value of attribute journal_base_dir.



9
10
11
 
# File 'lib/bluepill/process_journal.rb', line 9

def journal_base_dir
  @journal_base_dir
end

.logger ⇒ Object

Returns the value of attribute logger.



8
9
10
 
# File 'lib/bluepill/process_journal.rb', line 8

def logger
  @logger
end

Class Method Details

.acquire_atomic_fs_lock(name) ⇒ Object

atomic operation on POSIX filesystems, since f.flock(File::LOCK_SH) is not available on all platforms



32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# File 'lib/bluepill/process_journal.rb', line 32

def acquire_atomic_fs_lock(name)
  times = 0
  name += '.lock'
  Dir.mkdir name, 0700
  logger.debug("Acquired lock #{name}")
  yield
rescue Errno::EEXIST
  times += 1
  logger.debug("Waiting for lock #{name}")
  sleep 1
  if times < 10
    retry
  else
    logger.info("Timeout waiting for lock #{name}")
    raise "Timeout waiting for lock #{name}"
  end
ensure
  clear_atomic_fs_lock(name)
end

.append_pgid_to_journal(journal_name, pgid) ⇒ Object 



169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
 
# File 'lib/bluepill/process_journal.rb', line 169

def append_pgid_to_journal(journal_name, pgid)
  if skip_pgid?(pgid)
    logger.debug("Skipping invalid pgid #{pgid} (class #{pgid.class})")
    return
  end

  filename = pgid_journal_filename(journal_name)
  acquire_atomic_fs_lock(filename) do
    if pgid_journal(filename).include?(pgid)
      logger.debug("Skipping duplicate pgid #{pgid} already in journal #{journal_name}")
    else
      logger.debug("Saving pgid #{pgid} to process journal #{journal_name}")
      File.open(filename, 'a+', 0600) { |f| f.puts(pgid) }
      logger.info("Saved pgid #{pgid} to journal #{journal_name}")
      logger.debug("Journal now = #{File.open(filename, 'r').read}")
    end
  end
end

.append_pid_to_journal(journal_name, pid) ⇒ Object 



188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
 
# File 'lib/bluepill/process_journal.rb', line 188

def append_pid_to_journal(journal_name, pid)
  begin
    append_pgid_to_journal(journal_name, ::Process.getpgid(pid))
  rescue Errno::ESRCH
  end
  if skip_pid?(pid)
    logger.debug("Skipping invalid pid #{pid} (class #{pid.class})")
    return
  end

  filename = pid_journal_filename(journal_name)
  acquire_atomic_fs_lock(filename) do
    if pid_journal(filename).include?(pid)
      logger.debug("Skipping duplicate pid #{pid} already in journal #{journal_name}")
    else
      logger.debug("Saving pid #{pid} to process journal #{journal_name}")
      File.open(filename, 'a+', 0600) { |f| f.puts(pid) }
      logger.info("Saved pid #{pid} to journal #{journal_name}")
      logger.debug("Journal now = #{File.open(filename, 'r').read}")
    end
  end
end

.base_dir=(base_dir) ⇒ Object 



15
16
17
18
19
 
# File 'lib/bluepill/process_journal.rb', line 15

def base_dir=(base_dir)
  @journal_base_dir ||= File.join(base_dir, 'journals')
  FileUtils.mkdir_p(@journal_base_dir) unless File.exist?(@journal_base_dir)
  FileUtils.chmod(0777, @journal_base_dir)
end

.clear_all_atomic_fs_locks ⇒ Object 



52
53
54
55
56
 
# File 'lib/bluepill/process_journal.rb', line 52

def clear_all_atomic_fs_locks
  Dir['.*.lock'].each do |f|
    System.delete_if_exists(f) if File.directory?(f)
  end
end

.clear_atomic_fs_lock(name) ⇒ Object 



84
85
86
87
88
 
# File 'lib/bluepill/process_journal.rb', line 84

def clear_atomic_fs_lock(name)
  return unless File.directory?(name)
  Dir.rmdir(name)
  logger.debug("Cleared lock #{name}")
end

.kill_all_from_all_journals ⇒ Object 



90
91
92
93
94
95
96
 
# File 'lib/bluepill/process_journal.rb', line 90

def kill_all_from_all_journals
  pids = Dir['.bluepill_pids_journal.*'].collect { |p| p.sub(/^\.bluepill_pids_journal\./, '') }
  pids.reject! { |p| p =~ /\.lock$/ }
  pids.each do |journal_name|
    kill_all_from_journal(journal_name)
  end
end

.kill_all_from_journal(journal_name) ⇒ Object 



98
99
100
101
 
# File 'lib/bluepill/process_journal.rb', line 98

def kill_all_from_journal(journal_name)
  kill_all_pids_from_journal(journal_name)
  kill_all_pgids_from_journal(journal_name)
end

.kill_all_pgids_from_journal(journal_name) ⇒ Object 



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
 
# File 'lib/bluepill/process_journal.rb', line 103

def kill_all_pgids_from_journal(journal_name)
  filename = pgid_journal_filename(journal_name)
  j = pgid_journal(filename)
  if !j.empty?
    acquire_atomic_fs_lock(filename) do
      j.each do |pgid|
        begin
          ::Process.kill('TERM', -pgid)
          logger.info("Termed old process group #{pgid}")
        rescue Errno::ESRCH
          logger.debug("Unable to term missing process group #{pgid}")
        end
      end

      if j.count { |pgid| System.pid_alive?(pgid) } > 1
        sleep(1)
        j.each do |pgid|
          begin
            ::Process.kill('KILL', -pgid)
            logger.info("Killed old process group #{pgid}")
          rescue Errno::ESRCH
            logger.debug("Unable to kill missing process group #{pgid}")
          end
        end
      end
      System.delete_if_exists(filename) # reset journal
      logger.debug('Journal cleanup completed')
    end
  else
    logger.debug('No previous process journal - Skipping cleanup')
  end
end

.kill_all_pids_from_journal(journal_name) ⇒ Object 



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
 
# File 'lib/bluepill/process_journal.rb', line 136

def kill_all_pids_from_journal(journal_name)
  filename = pid_journal_filename(journal_name)
  j = pid_journal(filename)
  if !j.empty?
    acquire_atomic_fs_lock(filename) do
      j.each do |pid|
        begin
          ::Process.kill('TERM', pid)
          logger.info("Termed old process #{pid}")
        rescue Errno::ESRCH
          logger.debug("Unable to term missing process #{pid}")
        end
      end

      if j.count { |pid| System.pid_alive?(pid) } > 1
        sleep(1)
        j.each do |pid|
          begin
            ::Process.kill('KILL', pid)
            logger.info("Killed old process #{pid}")
          rescue Errno::ESRCH
            logger.debug("Unable to kill missing process #{pid}")
          end
        end
      end
      System.delete_if_exists(filename) # reset journal
      logger.debug('Journal cleanup completed')
    end
  else
    logger.debug('No previous process journal - Skipping cleanup')
  end
end

.pgid_journal(filename) ⇒ Object 



75
76
77
78
79
80
81
82
 
# File 'lib/bluepill/process_journal.rb', line 75

def pgid_journal(filename)
  logger.debug("pgid journal file: #{filename}")
  result = File.open(filename, 'r').readlines.collect(&:to_i).reject { |pgid| skip_pgid?(pgid) }
  logger.debug("pgid journal = #{result.join(' ')}")
  result
rescue Errno::ENOENT
  []
end

.pgid_journal_filename(journal_name) ⇒ Object 



62
63
64
 
# File 'lib/bluepill/process_journal.rb', line 62

def pgid_journal_filename(journal_name)
  File.join(@journal_base_dir, ".bluepill_pgids_journal.#{journal_name}")
end

.pid_journal(filename) ⇒ Object 



66
67
68
69
70
71
72
73
 
# File 'lib/bluepill/process_journal.rb', line 66

def pid_journal(filename)
  logger.debug("pid journal file: #{filename}")
  result = File.open(filename, 'r').readlines.collect(&:to_i).reject { |pid| skip_pid?(pid) }
  logger.debug("pid journal = #{result.join(' ')}")
  result
rescue Errno::ENOENT
  []
end

.pid_journal_filename(journal_name) ⇒ Object 



58
59
60
 
# File 'lib/bluepill/process_journal.rb', line 58

def pid_journal_filename(journal_name)
  File.join(@journal_base_dir, ".bluepill_pids_journal.#{journal_name}")
end

.skip_pgid?(pgid) ⇒ Boolean

Returns:

  • (Boolean) 


26
27
28
 
# File 'lib/bluepill/process_journal.rb', line 26

def skip_pgid?(pgid)
  !pgid.is_a?(Integer) || pgid <= 1
end

.skip_pid?(pid) ⇒ Boolean

Returns:

  • (Boolean) 


22
23
24
 
# File 'lib/bluepill/process_journal.rb', line 22

def skip_pid?(pid)
  !pid.is_a?(Integer) || pid <= 1
end