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authorAndy Wingo <wingo@pobox.com>2012-03-03 17:01:16 +0100
committerAndy Wingo <wingo@pobox.com>2012-03-03 17:06:02 +0100
commit9ede013f68361df731cadc62844be11d1bfea7e5 (patch)
tree5f507a75e7aa6f932a44f1ddf98045137cd6913d /libguile/dynwind.c
parent05b4d9106d301af055d675cd0ffdd3699642a0ee (diff)
downloadguile-9ede013f68361df731cadc62844be11d1bfea7e5.tar.gz
the dynamic stack is really a stack now, instead of a list
* libguile/dynstack.h: * libguile/dynstack.c: New files, implementing the dynamic stack as a true stack instead of a linked list. This lowers the cost of dynwinds: frames, winders, prompts, with-fluids, and dynamic-wind. For the most part, we allocate these items directly on the stack. * libguile/dynwinds.h: * libguile/dynwinds.c: Adapt all manipulators of the wind stack to use interfaces from dynstack.c. Remove heap-allocated winder and frame object types. (scm_dowinds, scm_i_dowinds): Remove these. The first was exported, but it was not a public interface. * libguile/continuations.c: * libguile/continuations.h (scm_t_contregs): Continuation objects reference scm_t_dynstack* values now. Adapt to the new interfaces. * libguile/control.c: * libguile/control.h: There is no longer a scm_tc7_prompt kind of object that can be allocated on the heap. Instead, the prompt flags, key, and registers are pushed on the dynwind stack. (The registers are still on the heap.) Also, since the vm_cont will reference the dynwinds, make the partial continuation stub take just one extra arg, instead of storing the intwinds separately in the object table. * libguile/fluids.c: * libguile/fluids.h: No more with-fluids objects; instead, the fluids go on the dynstack. The values still have to be on the heap, though. (scm_prepare_fluids, scm_swap_fluids): New internal functions, replacing scm_i_make_with_fluids and scm_i_swap_with_fluids. * libguile/print.c: Remove prompt and with-fluids printers. * libguile/tags.h: Revert prompt and with-fluids tc7 values to what they were before they were allocated. * libguile/vm-i-system.c (partial_cont_call): Just pop the vmcont, the intwinds will not be passed as a second arg. Rewind the dynamic stack from within the VM, so that any rewinder sees valid prompt entries. (call_cc, tail_call_cc): Adapt to pass the dynstack to scm_i_vm_capture_stack. (prompt, wind, unwind, wind_fluids, unwind_fluids): Adapt to the new interfaces. * libguile/vm.h (scm_i_capture_current_stack): Rename from scm_i_vm_capture_continuation. (scm_i_vm_capture_stack): Take a dynstack as an argument. * libguile/vm.c (vm_reinstate_partial_continuation): Don't wind here, as that could result in winders seeing invalid prompts. * libguile/eval.c: * libguile/root.c: * libguile/stacks.c: * libguile/threads.c: * libguile/threads.h: * libguile/throw.c: Adapt other users of dynwinds to use the dynstack.
Diffstat (limited to 'libguile/dynwind.c')
-rw-r--r--libguile/dynwind.c226
1 files changed, 32 insertions, 194 deletions
diff --git a/libguile/dynwind.c b/libguile/dynwind.c
index bec2dc806..05791860a 100644
--- a/libguile/dynwind.c
+++ b/libguile/dynwind.c
@@ -1,5 +1,5 @@
-/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003, 2004, 2006, 2008, 2010, 2011 Free Software Foundation, Inc.
- *
+/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003, 2004, 2006, 2008, 2010, 2011, 2012 Free Software Foundation, Inc.
+ *
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 3 of
@@ -26,125 +26,72 @@
#include <assert.h>
#include "libguile/_scm.h"
-#include "libguile/control.h"
+#include "libguile/dynstack.h"
#include "libguile/eval.h"
-#include "libguile/alist.h"
-#include "libguile/fluids.h"
#include "libguile/ports.h"
-#include "libguile/smob.h"
#include "libguile/dynwind.h"
-
-
-/* {Dynamic wind}
-
- Things that can be on the wind list:
-
- #<frame>
- #<winder>
- #<with-fluids>
- #<prompt>
- (enter-proc . leave-proc) dynamic-wind
-
-*/
+
SCM
scm_dynamic_wind (SCM in_guard, SCM thunk, SCM out_guard)
#define FUNC_NAME "dynamic-wind"
{
- SCM ans, old_winds;
- SCM_ASSERT (scm_is_true (scm_thunk_p (out_guard)),
- out_guard,
+ SCM ans;
+ scm_i_thread *thread = SCM_I_CURRENT_THREAD;
+
+ SCM_ASSERT (scm_is_true (scm_thunk_p (out_guard)), out_guard,
SCM_ARG3, FUNC_NAME);
+
scm_call_0 (in_guard);
- old_winds = scm_i_dynwinds ();
- scm_i_set_dynwinds (scm_acons (in_guard, out_guard, old_winds));
+ scm_dynstack_push_dynwind (&thread->dynstack, in_guard, out_guard);
+
ans = scm_call_0 (thunk);
- scm_i_set_dynwinds (old_winds);
+
+ scm_dynstack_pop (&thread->dynstack);
scm_call_0 (out_guard);
+
return ans;
}
#undef FUNC_NAME
-/* Frames and winders. */
-
-static scm_t_bits tc16_frame;
-#define FRAME_P(f) SCM_SMOB_PREDICATE (tc16_frame, (f))
-
-#define FRAME_F_REWINDABLE (1 << 0)
-#define FRAME_REWINDABLE_P(f) (SCM_SMOB_FLAGS(f) & FRAME_F_REWINDABLE)
-
-static scm_t_bits tc16_winder;
-#define WINDER_P(w) SCM_SMOB_PREDICATE (tc16_winder, (w))
-#define WINDER_PROC(w) ((void (*)(void *))SCM_SMOB_DATA (w))
-#define WINDER_DATA(w) ((void *)SCM_SMOB_DATA_2 (w))
-
-#define WINDER_F_EXPLICIT (1 << 0)
-#define WINDER_F_REWIND (1 << 1)
-#define WINDER_F_MARK (1 << 2)
-#define WINDER_EXPLICIT_P(w) (SCM_SMOB_FLAGS(w) & WINDER_F_EXPLICIT)
-#define WINDER_REWIND_P(w) (SCM_SMOB_FLAGS(w) & WINDER_F_REWIND)
-#define WINDER_MARK_P(w) (SCM_SMOB_FLAGS(w) & WINDER_F_MARK)
void
scm_dynwind_begin (scm_t_dynwind_flags flags)
{
- SCM f;
- SCM_NEWSMOB (f, tc16_frame, 0);
- if (flags & SCM_F_DYNWIND_REWINDABLE)
- SCM_SET_SMOB_FLAGS (f, FRAME_F_REWINDABLE);
- scm_i_set_dynwinds (scm_cons (f, scm_i_dynwinds ()));
+ scm_i_thread *thread = SCM_I_CURRENT_THREAD;
+
+ scm_dynstack_push_frame (&thread->dynstack, flags);
}
+/* FIXME -- breaking abstractions */
void
scm_dynwind_end (void)
{
- SCM winds;
-
- /* Unwind upto and including the next frame entry. We can only
- encounter #<winder> entries on the way.
- */
-
- winds = scm_i_dynwinds ();
- while (scm_is_pair (winds))
- {
- SCM entry = SCM_CAR (winds);
- winds = SCM_CDR (winds);
-
- scm_i_set_dynwinds (winds);
-
- if (FRAME_P (entry))
- return;
-
- assert (WINDER_P (entry));
- if (!WINDER_REWIND_P (entry) && WINDER_EXPLICIT_P (entry))
- WINDER_PROC(entry) (WINDER_DATA (entry));
- }
-
- assert (0);
+ scm_dynstack_unwind_frame (&SCM_I_CURRENT_THREAD->dynstack);
}
void
scm_dynwind_unwind_handler (void (*proc) (void *), void *data,
scm_t_wind_flags flags)
{
- SCM w;
- SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, (scm_t_bits) data);
- if (flags & SCM_F_WIND_EXPLICITLY)
- SCM_SET_SMOB_FLAGS (w, WINDER_F_EXPLICIT);
- scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ()));
+ scm_i_thread *thread = SCM_I_CURRENT_THREAD;
+ scm_t_dynstack *dynstack = &thread->dynstack;
+
+ scm_dynstack_push_unwinder (dynstack, flags, proc, data);
}
void
scm_dynwind_rewind_handler (void (*proc) (void *), void *data,
scm_t_wind_flags flags)
{
- SCM w;
- SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, (scm_t_bits) data);
- SCM_SET_SMOB_FLAGS (w, WINDER_F_REWIND);
- scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ()));
+ scm_i_thread *thread = SCM_I_CURRENT_THREAD;
+ scm_t_dynstack *dynstack = &thread->dynstack;
+
+ scm_dynstack_push_rewinder (dynstack, 0, proc, data);
+
if (flags & SCM_F_WIND_EXPLICITLY)
proc (data);
}
@@ -153,23 +100,16 @@ void
scm_dynwind_unwind_handler_with_scm (void (*proc) (SCM), SCM data,
scm_t_wind_flags flags)
{
- SCM w;
- scm_t_bits fl = ((flags&SCM_F_WIND_EXPLICITLY)? WINDER_F_EXPLICIT : 0);
- SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, SCM_UNPACK (data));
- SCM_SET_SMOB_FLAGS (w, fl | WINDER_F_MARK);
- scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ()));
+ /* FIXME: This is not a safe cast. */
+ scm_dynwind_unwind_handler ((scm_t_guard) proc, SCM2PTR (data), flags);
}
void
scm_dynwind_rewind_handler_with_scm (void (*proc) (SCM), SCM data,
scm_t_wind_flags flags)
{
- SCM w;
- SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, SCM_UNPACK (data));
- SCM_SET_SMOB_FLAGS (w, WINDER_F_REWIND | WINDER_F_MARK);
- scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ()));
- if (flags & SCM_F_WIND_EXPLICITLY)
- proc (data);
+ /* FIXME: This is not a safe cast. */
+ scm_dynwind_rewind_handler ((scm_t_guard) proc, SCM2PTR (data), flags);
}
void
@@ -178,19 +118,6 @@ scm_dynwind_free (void *mem)
scm_dynwind_unwind_handler (free, mem, SCM_F_WIND_EXPLICITLY);
}
-#ifdef GUILE_DEBUG
-SCM_DEFINE (scm_wind_chain, "wind-chain", 0, 0, 0,
- (),
- "Return the current wind chain. The wind chain contains all\n"
- "information required by @code{dynamic-wind} to call its\n"
- "argument thunks when entering/exiting its scope.")
-#define FUNC_NAME s_scm_wind_chain
-{
- return scm_i_dynwinds ();
-}
-#undef FUNC_NAME
-#endif
-
void
scm_swap_bindings (SCM vars, SCM vals)
{
@@ -206,97 +133,8 @@ scm_swap_bindings (SCM vars, SCM vals)
}
void
-scm_dowinds (SCM to, long delta)
-{
- scm_i_dowinds (to, delta, NULL, NULL);
-}
-
-void
-scm_i_dowinds (SCM to, long delta, void (*turn_func) (void *), void *data)
-{
- tail:
- if (scm_is_eq (to, scm_i_dynwinds ()))
- {
- if (turn_func)
- turn_func (data);
- }
- else if (delta < 0)
- {
- SCM wind_elt;
-
- scm_i_dowinds (SCM_CDR (to), 1 + delta, turn_func, data);
- wind_elt = SCM_CAR (to);
-
- if (FRAME_P (wind_elt))
- {
- if (!FRAME_REWINDABLE_P (wind_elt))
- scm_misc_error ("dowinds",
- "cannot invoke continuation from this context",
- SCM_EOL);
- }
- else if (WINDER_P (wind_elt))
- {
- if (WINDER_REWIND_P (wind_elt))
- WINDER_PROC (wind_elt) (WINDER_DATA (wind_elt));
- }
- else if (SCM_WITH_FLUIDS_P (wind_elt))
- {
- scm_i_swap_with_fluids (wind_elt,
- SCM_I_CURRENT_THREAD->dynamic_state);
- }
- else if (SCM_PROMPT_P (wind_elt))
- ; /* pass -- see vm_reinstate_partial_continuation */
- else if (scm_is_pair (wind_elt))
- scm_call_0 (SCM_CAR (wind_elt));
- else
- /* trash on the wind list */
- abort ();
-
- scm_i_set_dynwinds (to);
- }
- else
- {
- SCM wind;
- SCM wind_elt;
-
- wind = scm_i_dynwinds ();
- wind_elt = SCM_CAR (wind);
- scm_i_set_dynwinds (SCM_CDR (wind));
-
- if (FRAME_P (wind_elt))
- {
- /* Nothing to do. */
- }
- else if (WINDER_P (wind_elt))
- {
- if (!WINDER_REWIND_P (wind_elt))
- WINDER_PROC (wind_elt) (WINDER_DATA (wind_elt));
- }
- else if (SCM_WITH_FLUIDS_P (wind_elt))
- {
- scm_i_swap_with_fluids (wind_elt,
- SCM_I_CURRENT_THREAD->dynamic_state);
- }
- else if (SCM_PROMPT_P (wind_elt))
- ; /* pass -- though we could invalidate the prompt */
- else if (scm_is_pair (wind_elt))
- scm_call_0 (SCM_CDR (wind_elt));
- else
- /* trash on the wind list */
- abort ();
-
- delta--;
- goto tail; /* scm_dowinds(to, delta-1); */
- }
-}
-
-void
scm_init_dynwind ()
{
- tc16_frame = scm_make_smob_type ("frame", 0);
-
- tc16_winder = scm_make_smob_type ("winder", 0);
-
#include "libguile/dynwind.x"
}