Hi Ryan!
On 24 Sep., 18:13, Ryan Hinton <[email protected]> wrote:
> Have you considered Python's tempfile module?
>
> http://docs.python.org/library/tempfile.html
No, I didn't, yet.
Since the different Gap instances in the parallelised function have
different pid, it would solve the problem to make the _local_tmpfile
dependent on the pid:
sage: @parallel
....: def f(n):
....: return gap.pid()
....:
sage: L = [t[1] for t in f(range(5))]
sage: len(set(L))
5
sage: print gap._local_tmpfile()
/home/king/.sage//temp/gauss/20166//interface//tmp20222
sage: L = [t[1] for t in f(range(5))]
sage: len(set(L))
5
So, a viable solution would be to define
def _local_tmpfile(self):
return '%s/tmp'%SAGE_TMP_INTERFACE + str(self.pid())
However, for efficiency reasons, the current _local_tmpfile method
caches the result, using an attribute __local_tmpfile (double
underscore). I tried to do the same. With printing some debugging
information, I did
def _local_tmpfile(self):
try:
out = self.__local_tmpfile
print 'have local tmpfile'
return out
except AttributeError:
self.__local_tmpfile = '%s/tmp'%SAGE_TMP_INTERFACE +
str(self.pid())
return self.__local_tmpfile
With that definition, one obtains
sage: @parallel
....: def f(n):
....: return gap._local_tmpfile()
....:
sage: L = [t[1] for t in f(range(5))]
sage: len(set(L))
5
sage: print gap._local_tmpfile()
/home/king/.sage//temp/gauss/20333//interface//tmp20360
sage: L = [t[1] for t in f(range(5))]
have local tmpfile
have local tmpfile
have local tmpfile
have local tmpfile
have local tmpfile
sage: gap.__local_tmpfile
---------------------------------------------------------------------------
AttributeError Traceback (most recent call
last)
...
AttributeError:
sage: print gap._local_tmpfile()
have local tmpfile
/home/king/.sage//temp/gauss/20333//interface//tmp20360
%%%%%%%%%%%%%%%%%%%%
Now I wonder:
* Why do the gap instances in the parallelised method inherit the
attribute __local_tmpfile from the gap instance of the main sage
process? Note that they do not inherit the pid!
* Why is it not possible to access gap.__local_tmpfile, even though
this attribute *can* be accessed from inside the method?
The Expect interfaces seem to have a custom __setattr__, but I can
not find its definition:
sage: from sage.interfaces.expect import Expect
sage: Expect.__setattr__??
Error getting source: arg is not a module, class, method, function,
traceback, frame, or code object
Type: wrapper_descriptor
Base Class: <type 'wrapper_descriptor'>
String Form: <slot wrapper '__setattr__' of 'object' objects>
Namespace: Interactive
Docstring [source file open failed]:
x.__setattr__('name', value) <==> x.name = value
Could it be that, when doing
self.__local_tmpfile = '%s/tmp'%SAGE_TMP_INTERFACE +
str(self.pid())
inside the method, __setattr__ associates this attribute with the
*class* sage.interfaces.gap.Gap, rather than with only a single
instance of that class?
Cheers,
Simon
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