Reimplement dynamic states

There are two goals: one, to use less memory per dynamic state in order
to allow millions of dynamic states to be allocated in light-weight
threading scenarios.  The second goal is to prevent dynamic states from
being actively mutated in two threads at once.  This second goal does
mean that dynamic states object that escape into scheme are now copies
that won't receive further updates; an incompatible change, but one
which we hope doesn't affect anyone.

* libguile/cache-internal.h: New file.
* libguile/fluids.c (is_dynamic_state, get_dynamic_state)
  (save_dynamic_state, restore_dynamic_state, add_entry)
  (copy_value_table): New functions.
  (scm_i_fluid_print, scm_i_dynamic_state_print): Move up.
  (new_fluid): No need for a number.
  (scm_fluid_p: scm_is_fluid): Inline IS_FLUID uses.
  (fluid_set_x, fluid_ref): Adapt to dynamic state changes.
  (scm_fluid_set_x, scm_fluid_unset_x): Call fluid_set_x.
  (scm_swap_fluid): Rewrite in terms of fluid_ref and fluid_set.
  (swap_fluid): Use internal fluid_set_x.
  (scm_i_make_initial_dynamic_state): Adapt to dynamic state
  representation change.
  (scm_dynamic_state_p, scm_is_dynamic_state): Use new accessors.
  (scm_current_dynamic_state): Use make_dynamic_state.
  (scm_dynwind_current_dynamic_state): Use new accessor.
* libguile/fluids.h: Remove internal definitions.  Add new struct
  definition.
* libguile/threads.h (scm_i_thread): Use scm_t_dynamic_state for dynamic
  state.
* libguile/threads.c (guilify_self_1, guilify_self_2):
  (scm_i_init_thread_for_guile, scm_init_guile):
  (scm_call_with_new_thread):
  (scm_init_threads, scm_init_threads_default_dynamic_state): Adapt to
  scm_i_thread change.
  (scm_i_with_guile, with_guile): Remove "and parent" suffix.
  (scm_i_reset_fluid): Remove unneeded function.
* doc/ref/api-scheduling.texi (Fluids and Dynamic States): Remove
  scm_make_dynamic_state docs.  Update current-dynamic-state docs.
* libguile/vm-engine.c (vm_engine): Update fluid-ref and fluid-set!
  inlined fast paths for dynamic state changes.
* libguile/vm.c (vm_error_unbound_fluid): Remove now-unused function.
* NEWS: Update.
* module/ice-9/deprecated.scm (make-dynamic-state): New definition.
* libguile/deprecated.h:
* libguile/deprecated.c (scm_make_dynamic_state): Move here.
* libguile/__scm.h (scm_t_dynamic_state): New typedef.
* libguile/dynstack.h:
* libguile/dynstack.c (scm_dynstack_push_fluid):
  (scm_dynstack_unwind_fluid): Take raw dynstate in these internal
  functions.
* libguile/throw.c (catch): Adapt to dynstack changes.

1 files changed, 13 insertions, 1 deletions

diff --git a/libguile/deprecated.c b/libguile/deprecated.c
index 0ea4b5e20..c3d4935d0 100644
--- a/libguile/deprecated.c
+++ b/libguile/deprecated.c
@@ -853,7 +853,7 @@ scm_internal_cwdr (scm_t_catch_body body, void *body_data,
   scm_dynstack_unwind (dynstack, SCM_DYNSTACK_FIRST (dynstack));
 
   scm_dynwind_begin (SCM_F_DYNWIND_REWINDABLE);
-  scm_dynwind_current_dynamic_state (scm_make_dynamic_state (SCM_UNDEFINED));
+  scm_dynwind_current_dynamic_state (scm_current_dynamic_state ());
 
   my_handler_data.run_handler = 0;
   answer = scm_i_with_continuation_barrier (body, body_data,
@@ -928,6 +928,18 @@ scm_apply_with_dynamic_root (SCM proc, SCM a1, SCM args, SCM handler)
 
 
 
+SCM
+scm_make_dynamic_state (SCM parent)
+{
+  scm_c_issue_deprecation_warning
+    ("scm_make_dynamic_state is deprecated.  Dynamic states are "
+     "now immutable; just use the parent directly.");
+  return SCM_UNBNDP (parent) ? scm_current_dynamic_state () : parent;
+}
+
+
+
+
 void
 scm_i_init_deprecated ()
 {