is socket thread safe?

[Carl J. Van Arsdall]

Steve Horsley wrote:
> e2wugui at gmail.com wrote:
>   
>> thread1:
>>     while 1:
>>         buf = s.read()
>>         process(buf)
>>
>> thread2:
>>     while 1:
>>         buf = getdata()
>>         s.write(buf)
>>
>>     
>
> It is safe, but watch out for this gotcha: If thread B calls 
> s.close() while thread A is blocked in s.read(), thread A will 
> never return from the read. My preferred solution is to set 
> socket timeout to a few seconds, and loop checking a status flag 
> so I know when to quit.
>
>   
I think a better thing would be to use something like a condition object 
to tie the two threads together and not use any polling loops.

i.e.  consumer goes to sleep while data buffer is empty, producer 
produces and signals condition object, consumer wakes up and consumes.

To take this a step further, you have a status flag that is set to 
something like QUIT or CONSUME and when the condition is triggered wake 
up, then examine the status flag to determine if the consumer should 
then quit, consume, or whatever else you'd want your consumer thread to do.


-carl



-- 

Carl J. Van Arsdall
cvanarsdall at mvista.com
Build and Release
MontaVista Software