* libguile/finalizers.h:
* libguile/finalizers.c (run_finalizers_async_thunk): Call the new
scm_run_finalizers helper.
(scm_set_automatic_finalization_enabled, scm_run_finalizers): New
functions.
(scm_init_finalizers): Only set a finalizer notifier if automatic
finalization is enabled.
* doc/ref/libguile-smobs.texi (Garbage Collecting Smobs): Add discussion
of concurrency.
* doc/ref/api-smobs.texi (Smobs): Document new functions.
* libguile/finalizers.c: New excitement! We'll be running finalizers
asynchronously, from asyncs. This will make it safer to allocate
while holding a mutex.
(GC_set_finalizer_notifier): Add back-compat shim.
* libguile/init.c (scm_i_init_guile): Init the async finalizer mechanism
during boot.
* libguile/gc.c (scm_storage_prehistory): Tell libgc we'll be finalizing
on demand.
(scm_gc): Explicitly run finalizers here.
* libguile/threads.c (guilify_self_2): Run finalizers here if
queue_finalizer_async happened to run during guilify_self_1.
* configure.ac: Add check for GC_set_finalizer_notifier.
