On 12 Oct 2010, at 22:51, Andreas Raab wrote:

> On 10/12/2010 6:14 AM, Igor Stasenko wrote:
>> Hello, i just thought, that it would be cool to have a special bytecode,
>> which guarantees atomicity for swapping values between two variables.
>> 
>> To swap two values, you usually do:
>> 
>> | var1 var2 temp |
>> 
>> temp := var1.
>> var1 := var2.
>> var2 := temp.
>> 
>> But since its non-atomic, a process can be interrupted and such operation
>> is not thread-safe.
> 
> Actually, this is thread-safe. Process switches happen only on sends and backwards branches.
Please, do not rely on such implementation details, and please do not advocate them.
You will never know where your code is running on tomorrow...

http://permalink.gmane.org/gmane.comp.lang.smalltalk.squeak.general/152184

Best regards
Stefan


-- 
Stefan Marr
Software Languages Lab
Vrije Universiteit Brussel
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http://soft.vub.ac.be/~smarr
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