[Help-smalltalk] Re: current startup time standings

[Paolo Bonzini]

> Nice. Do you have any feel for how much these figures would change 
> depending on what's in the image? In other words, how will an image 
> loaded with a couple of libraries compare with a basic image?

There are two factors:

1) image loading time.  With the copy-on-write code, the startup time 
only depends on the number of OOPs, not on the size of the objects in 
the image.  However, huge libraries such as GTK+ will create three or 
four OOPs for each method (CompiledMethod, MethodInfo, 
CFunctionDescriptor, possibly a Symbol too).  Another factor is the 
number of symbols in the image, which slows down 
init_dictionary_on_image_load (this takes about 8ms on a default image 
and is the next candidate for a speedup...).

2) #returnFromSnapshot execution time.  Right now it is close to zero, 
but the code in DLD is not efficient at all, because it dlopens all the 
libraries at startup: it can be sizable for something like GTK+.  I did 
not change it yet just because it does not run at all in the default 
image.  It would be interesting to attach a library name in a 
CFunctionDescriptor, and dlopen the libraries lazily; you may give it a 
try.  However, if you'd find out that dlopening takes time even for 
(say) GNU Smalltalk's own tcp.so, I'd seriously consider moving tcp.so 
to the main executable.

Paolo