Is the standard output thread-safe?

[=?iso-8859-1?Q?Fernando=20Rodr=edguez?=]

Hi,

Is the standard output thread-safe? Can I use print from several threads
without having to use a mutex?

Thanks

 

[danmcleran]

Is the standard output thread-safe?
No.

You'll need to synchronize access.

 

[Fredrik Lundh]

Is the standard output thread-safe? Can I use print from several threads
without having to use a mutex?

if you use sys.stdout.write on the standard sys.stdout stream, each write
operation is "atomic" (thanks to the GIL).

if you use other approaches (including print statements, or sys.stdout re-
direction via python code), data from different streams may appear out of
order. python won't crash, though.

</F>

 

[=?iso-8859-1?Q?Fernando=20Rodr=edguez?=]

Hello Fredrik,

if you use sys.stdout.write on the standard sys.stdout stream, each
write operation is "atomic" (thanks to the GIL).

GIL?

 

[Felipe Almeida Lessa]

Em Qui, 2006-03-09 às 16:37 +0000, Fernando Rodríguez escreveu:

Hello Fredrik,


GIL?

Global Interpreter Lock

--
"Quem excele em empregar a força militar subjulga os exércitos dos
outros povos sem travar batalha, toma cidades fortificadas dos outros
povos sem as atacar e destrói os estados dos outros povos sem lutas
prolongadas. Deve lutar sob o Céu com o propósito primordial da
'preservação'. Desse modo suas armas não se embotarão, e os ganhos
poderão ser preservados. Essa é a estratégia para planejar ofensivas."

-- Sun Tzu, em "A arte da guerra"

 

[Skull]

Hi,

Is the standard output thread-safe? Can I use print from several
threads without having to use a mutex?

Thanks

Check this: http://me.in-berlin.de/doc/python/f...inds-of-global-value-mutation-are-thread-safe

from my experience, it seems 'print' is not thread-safe. especially
when it is called with formated string, such as:

print "id:%d", my_id

I think it is not an "atomic" operation.

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