Class: RFlow::PIDFile
- Inherits:
-
Object
- Object
- RFlow::PIDFile
- Defined in:
- lib/rflow/pid_file.rb
Instance Method Summary collapse
-
#initialize(path) ⇒ PIDFile
constructor
A new instance of PIDFile.
- #read ⇒ Object
- #running? ⇒ Boolean
-
#safe_unlink ⇒ Object
unlinks a PID file at given if it contains the current PID still potentially racy without locking the directory (which is non-portable and may interact badly with other programs), but the window for hitting the race condition is small.
- #signal(sig) ⇒ Object
- #to_s ⇒ Object
- #write(pid = $$) ⇒ Object
Constructor Details
#initialize(path) ⇒ PIDFile
Returns a new instance of PIDFile.
7 8 9 |
# File 'lib/rflow/pid_file.rb', line 7 def initialize(path) @path = path end |
Instance Method Details
#read ⇒ Object
11 12 13 14 15 16 17 18 19 20 |
# File 'lib/rflow/pid_file.rb', line 11 def read return nil unless File.exist? path contents = File.read(path) if contents.empty? RFlow.logger.warn "Ignoring empty PID file #{path}" nil else contents.to_i end end |
#running? ⇒ Boolean
45 46 47 48 49 50 51 52 53 |
# File 'lib/rflow/pid_file.rb', line 45 def running? return false unless exist? pid = read return false unless pid Process.kill(0, pid) pid rescue Errno::ESRCH, Errno::ENOENT nil end |
#safe_unlink ⇒ Object
unlinks a PID file at given if it contains the current PID still potentially racy without locking the directory (which is non-portable and may interact badly with other programs), but the window for hitting the race condition is small
59 60 61 |
# File 'lib/rflow/pid_file.rb', line 59 def safe_unlink (current_process? and unlink) rescue nil end |
#signal(sig) ⇒ Object
63 64 65 |
# File 'lib/rflow/pid_file.rb', line 63 def signal(sig) Process.kill(sig, read) end |
#to_s ⇒ Object
67 68 69 |
# File 'lib/rflow/pid_file.rb', line 67 def to_s File.(path) end |
#write(pid = $$) ⇒ Object
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 |
# File 'lib/rflow/pid_file.rb', line 22 def write(pid = $$) return unless validate? RFlow.logger.debug "Writing PID #{pid} to file '#{to_s}'" tmp_path = File.join(File.dirname(path), ".#{File.basename(path)}") if File.exist? tmp_path RFlow.logger.warn "Deleting stale temp PID file #{tmp_path}" File.delete(tmp_path) end pid_fp = begin File.open(tmp_path, File::RDWR|File::CREAT|File::EXCL, 0644) rescue Errno::EACCES => e RFlow.logger.fatal "Access error while writing temp PID file '#{tmp_path}'" RFlow.logger.fatal "Exception #{e.class}: #{e.message}" abort end pid_fp.syswrite("#{pid}\n") File.rename(pid_fp.path, path) pid_fp.close pid end |