Module Timeout
In: lib/active_ldap/timeout_stub.rb
lib/active_ldap/timeout.rb
Timeout dot/f_3.png

Methods

alarm   alarm  

Public Class methods

alarm(sec, exception=Timeout::Error, &block)

STUB

[Source]

   # File lib/active_ldap/timeout_stub.rb, line 5
5:   def Timeout.alarm(sec, exception=Timeout::Error, &block)
6:     timeout(sec, exception, &block)
7:   end
alarm(sec, exception=Timeout::Error, &block)

A forking timeout implementation that relies on signals to interrupt blocking I/O instead of passing that code to run in a separate process.

A process is fork()ed, sleeps for sec, then sends a ALRM signal to the Process.ppid process. ALRM is used to avoid conflicts with sleep()

This overwrites any signal

[Source]

    # File lib/active_ldap/timeout.rb, line 14
14:   def Timeout.alarm(sec, exception=Timeout::Error, &block)
15:     return block.call if sec == nil or sec.zero?
16:  
17:   
18:     # Trap an alarm in case it comes before we're ready
19:     orig_alrm = trap(:ALRM, 'IGNORE')
20: 
21:     # Setup a fallback in case of a race condition of an
22:     # alarm before we set the other trap
23:     trap(:ALRM) do 
24:       # Don't leave zombies
25:       Process.wait2()
26:       # Restore the original handler
27:       trap('ALRM', orig_alrm)
28:       # Now raise an exception!
29:       raise exception, 'execution expired'
30:     end
31: 
32:     # Spawn the sleeper
33:     pid = Process.fork {
34:       begin
35:         # Sleep x seconds then send SIGALRM 
36:         sleep(sec)
37:         # Send alarm!
38:         Process.kill(:ALRM, Process.ppid)
39:       end
40:       exit! 0
41:     }
42: 
43:     # Setup the real handler
44:     trap(:ALRM) do
45:       # Make sure we clean up any zombies
46:       Process.waitpid(pid)
47:       # Restore the original handler
48:       trap(:ALRM, orig_alrm)
49:       # Now raise an exception!
50:       raise exception, 'execution expired'
51:     end
52: 
53:     begin
54:       # Run the code!
55:       return block.call
56:     ensure
57:       # Restore old alarm handler since we're done
58:       trap(:ALRM, orig_alrm)
59:       # Make sure the process is dead
60:       # This may be run twice (trap occurs during execution) so ignore ESRCH
61:       Process.kill(:TERM, pid) rescue Errno::ESRCH
62:       # Don't leave zombies
63:       Process.waitpid(pid) rescue Errno::ECHILD
64:     end
65:   end

[Validate]