Sha256: c7b5c21622e32ba82456744121f4162de6991311cc4f1381196f2a489dcef1ca
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Size: 1.86 KB
Versions: 7
Compression:
Stored size: 1.86 KB
Contents
class RFlow
class PIDFile
private
attr_reader :path
public
def initialize(path)
@path = path
end
def read
return nil unless File.exist? path
File.read(path).to_i
end
def write(pid = $$)
return unless validate?
RFlow.logger.debug "Writing PID #{pid} file '#{to_s}'"
pid_fp = begin
tmp_path = File.join(File.dirname(path), ".#{File.basename(path)}")
File.open(tmp_path, File::RDWR|File::CREAT|File::EXCL, 0644)
rescue Errno::EEXIST
retry
end
pid_fp.syswrite("#{pid}\n")
File.rename(pid_fp.path, path)
pid_fp.close
pid
end
def running?
return false unless exist?
pid = read
return false unless pid
Process.kill(0, pid)
pid
rescue Errno::ESRCH, Errno::ENOENT
nil
end
# unlinks a PID file at given if it contains the current PID still
# potentially racy without locking the directory (which is
# non-portable and may interact badly with other programs), but the
# window for hitting the race condition is small
def safe_unlink
(current_process? and unlink) rescue nil
end
def signal(sig)
Process.kill(sig, read)
end
def to_s
File.expand_path(path)
end
private
def validate?
if current_process?
return nil
elsif running?
raise ArgumentError, "Process #{read.to_s} referenced in stale PID file '#{to_s}' still exists; probably attempting to run duplicate RFlow instances"
elsif exist?
RFlow.logger.warn "Found stale PID #{read.to_s} in PID file '#{to_s}', removing"
unlink
end
true
end
def exist?
File.exist? path
end
def current_process?
read == $$
end
def unlink
File.unlink(path)
end
end
end
Version data entries
7 entries across 7 versions & 1 rubygems