[Scons-dev] please try latest default branch

[Dirk Bächle]

On 13.01.2014 20:18, Gary Oberbrunner wrote:

> Dirk, and others: I tracked down my spurious rebuild to the addition 

> of caching changed-status in File.changed() in Node/FS.py.  If I 

> remove that caching code I don't get the rebuilds:

>

> diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py

> --- a/src/engine/SCons/Node/FS.py

> +++ b/src/engine/SCons/Node/FS.py

> @@ -3043,13 +3043,15 @@

>          but we allow the return value to get cached after the reference

>          to the Executor got released in release_target_info().

>          """

> -        if node is None:

> +        allow_caching = False

> +        if node is None and allow_caching: # try this

>              try:

>                  return self._memo['changed']

>              except KeyError:

>                  pass

>          has_changed = SCons.Node.Node.changed(self, node)

> +        if allow_caching:

>          self._memo['changed'] = has_changed

>          return has_changed

> I also had to add this code to fix an exception when the file doesn't 

> have an executor.

>

> diff --git a/src/engine/SCons/Node/__init__.py 

> b/src/engine/SCons/Node/__init__.py

> --- a/src/engine/SCons/Node/__init__.py

> +++ b/src/engine/SCons/Node/__init__.py

> @@ -1090,7 +1090,10 @@

>                  if t: Trace(': %s changed' % child)

>                  result = True

> +        if self.get_executor():

>          contents = self.get_executor().get_contents()

> +        else:

> +            contents = None

>          if self.has_builder():

>              import SCons.Util

>              newsig = SCons.Util.MD5signature(contents)

>

> Dirk, what do you think?  I'll play with this version for a while.

>


Okay, these both places are related by the call of 
SCons.Node.Node.changed() from SCons.Node.FS.File.changed() (one calls 
the other). What's supposed to happen is: in File.release_target_info() 
the executor gets released. Before this, the changed() method is called, 
such that it caches its value in self._memo['changed'].
If this doesn't work as expected, this would mean the File.changed() 
gets called much later sometimes, after the executor got released *and* 
the self._memo was reset. Can you try and get a stacktrace for when that 
happens?

It's crucial to be able to release the executor early...if we can't do 
it, there won't be much of a memory improvement.

Regards,

Dirk