Re: Thread-unsafe initialization problems in Guile

[Mark H Weaver]

Here's an article from a reputable source that backs up my claim that
the lazy-initialization pattern that we use in a few places is not
thread-safe:

  http://www.ibm.com/developerworks/java/library/j-dcl/index.html

Here are the thread-unsafe lazy initializations that I'm aware of:

./posix.c:1375:            make_rw_port = scm_c_private_variable ("ice-9 popen",
./debug.c:217:    local_eval_var = scm_c_public_variable ("ice-9 local-eval", 
"local-eval");
./strports.c:541:      eval_string = scm_c_public_lookup ("ice-9 eval-string", 
"eval-string");

In each of these cases, we have two options: (1) synchronize on every
access of the lazily-initialized variable (including reads), or (2)
abandon lazy initialization.

  Thoughts?
    Mark