From: Eric Hodel <drbrain@...7.net>
Date: 2009-05-31T00:21:59+09:00
Subject: Re: Runnin code at a certain time?

On May 29, 2009, at 12:49, Caleb Clausen wrote:
> On 5/28/09, Eric Hodel <drbrain@segment7.net> wrote:
>> On May 25, 2009, at 13:36, Caleb Clausen wrote:
>>> Do you want your whole program to stop until some target time? In  
>>> that
>>> case, something as simple as
>>>
>>> sleep(target_time-Time.now)
>>> code_to_be_delayed
>>>
>>> will do the trick nicely.
>>
>> Note that #sleep won't necessarily sleep as long as you like (second
>> sentence):
>>
>> $ ri Kernel#sleep
>> -----------------------------------------------------------  
>> Kernel#sleep
>>      sleep([duration])    => fixnum
>>
>>      From Ruby 1.8
>> ------------------------------------------------------------------------
>>      Suspends the current thread for duration seconds (which may be  
>> any
>>      number, including a Float with fractional seconds). Returns the
>>      actual number of seconds slept (rounded), which may be less than
>>      that asked for if another thread calls Thread#run. Zero  
>> arguments
>>      causes sleep to sleep forever.
>> [...]
>
> Is there some particular danger that Thread#run will be called on my
> threads without my asking?

If it's library code, yes.  If it's application code, probably not.