From: Eric Hodel <drbrain@...7.net>
Date: 2006-07-06T07:33:35+09:00
Subject: Re: thread mystery

On Jul 5, 2006, at 2:30 PM, ara.t.howard@noaa.gov wrote:

> any idea why this script slows downs drastically as it runs and  
> seems to leak
> memory?
>
> [...]
>
> switch.on!

def count_objs
   klasses = Hash.new 0
   ObjectSpace.each_object do |o| klasses[o.class] += 1 end
   return klasses.map { |k,v| "\t#{k}: #{v}" }.join("\n")
end

Thread.start { loop { puts count_objs; sleep 1 } }.join

Running this, then taking two snapshots, one after startup and one  
after its really slow:

$ diff -u a b
--- a   2006-07-05 15:28:29.000000000 -0700
+++ b   2006-07-05 15:28:12.000000000 -0700
@@ -2,17 +2,17 @@
          Object: 3
          Bignum: 3
          fatal: 1
-        String: 557
-        Hash: 2
+        Hash: 17
+        String: 842
          Module: 17
          SwitchToggle: 1
          Class: 153
-        Array: 16
+        Array: 414
          SystemStackError: 1
          Float: 5
          Binding: 1
-        Thread: 4
+        Thread: 152
          ThreadGroup: 1
          IO: 3
-        File: 2
+        File: 1
          Switch: 1

Why aren't those threads getting GC'd?

-- 
Eric Hodel - drbrain@segment7.net - http://blog.segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com