From 5e67dc27e396e3d4f534e028c8cf06d57f7cd508 Mon Sep 17 00:00:00 2001 From: Ludovic Courtes Date: Tue, 30 May 2006 21:23:44 +0000 Subject: [PATCH] Added support for the free function of structures. * libguile/struct.c (struct_finalizer_trampoline): New. (scm_struct_gc_init): Removed. (scm_i_structs_to_free): Removed. (scm_free_structs): Removed. (scm_make_struct): Register a finalizer for the new struct if need be. (scm_struct_prehistory): Cleared. * libguile/struct.h (scm_i_structs_to_free): Removed. git-archimport-id: lcourtes@laas.fr--2005-libre/guile-core--boehm-gc--1.9--patch-33 --- libguile/struct.c | 127 +++++++++++++++++++++------------------------- libguile/struct.h | 1 - 2 files changed, 58 insertions(+), 70 deletions(-) diff --git a/libguile/struct.c b/libguile/struct.c index ab79e6d9b..b7a0016ed 100644 --- a/libguile/struct.c +++ b/libguile/struct.c @@ -39,6 +39,8 @@ #include #endif +#include + static SCM required_vtable_fields = SCM_BOOL_F; @@ -312,6 +314,38 @@ scm_alloc_struct (int n_words, int n_extra, const char *what) return p; } + +/* Finalization. */ + + +/* Invoke the finalizer of the struct pointed to by PTR. */ +static void +struct_finalizer_trampoline (GC_PTR ptr, GC_PTR unused_data) +{ + SCM obj = PTR2SCM (ptr); + + /* XXX - use less explicit code. */ + scm_t_bits word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_struct; + scm_t_bits *vtable_data = (scm_t_bits *) word0; + scm_t_bits *data = SCM_STRUCT_DATA (obj); + scm_t_struct_free free_struct_data + = ((scm_t_struct_free) vtable_data[scm_struct_i_free]); + + SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); + +#if 0 + /* A sanity check. However, this check can fail if the free function + changed between the `make-struct' time and now. */ + if (free_struct_data != (scm_t_struct_free)unused_data) + abort (); +#endif + + if (free_struct_data) + free_struct_data (vtable_data, data); +} + + + void scm_struct_free_0 (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data SCM_UNUSED) @@ -341,67 +375,8 @@ scm_struct_free_entity (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data) scm_gc_free ((void *) data[scm_struct_i_ptr], n, "entity struct"); } -static void * -scm_struct_gc_init (void *dummy1 SCM_UNUSED, - void *dummy2 SCM_UNUSED, - void *dummy3 SCM_UNUSED) -{ - scm_i_structs_to_free = SCM_EOL; - return 0; -} - - -/* During collection, this accumulates structures which are to be freed. - */ -SCM scm_i_structs_to_free; - -static void * -scm_free_structs (void *dummy1 SCM_UNUSED, - void *dummy2 SCM_UNUSED, - void *dummy3 SCM_UNUSED) -{ -#if 0 - SCM newchain = scm_i_structs_to_free; - do - { - /* Mark vtables in GC chain. GC mark set means delay freeing. */ - SCM chain = newchain; - while (!scm_is_null (chain)) - { - SCM vtable = SCM_STRUCT_VTABLE (chain); - if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain) - SCM_SET_GC_MARK (vtable); - chain = SCM_STRUCT_GC_CHAIN (chain); - } - /* Free unmarked structs. */ - chain = newchain; - newchain = SCM_EOL; - while (!scm_is_null (chain)) - { - SCM obj = chain; - chain = SCM_STRUCT_GC_CHAIN (chain); - if (SCM_GC_MARK_P (obj)) - { - SCM_CLEAR_GC_MARK (obj); - SCM_SET_STRUCT_GC_CHAIN (obj, newchain); - newchain = obj; - } - else - { - scm_t_bits * vtable_data = SCM_STRUCT_VTABLE_DATA (obj); - scm_t_bits * data = SCM_STRUCT_DATA (obj); - scm_t_struct_free free_struct_data - = ((scm_t_struct_free) vtable_data[scm_struct_i_free]); - SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); - free_struct_data (vtable_data, data); - } - } - } - while (!scm_is_null (newchain)); - return 0; -#endif -} + SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, (SCM vtable, SCM tail_array_size, SCM init), "Create a new structure.\n\n" @@ -428,17 +403,19 @@ SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, SCM layout; size_t basic_size; size_t tail_elts; - scm_t_bits * data; + scm_t_bits *data, *c_vtable; SCM handle; SCM_VALIDATE_VTABLE (1, vtable); SCM_VALIDATE_REST_ARGUMENT (init); - layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]); + c_vtable = SCM_STRUCT_DATA (vtable); + + layout = SCM_PACK (c_vtable [scm_vtable_index_layout]); basic_size = scm_i_symbol_length (layout) / 2; tail_elts = scm_to_size_t (tail_array_size); SCM_CRITICAL_SECTION_START; - if (SCM_STRUCT_DATA (vtable)[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) + if (c_vtable[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) { data = scm_alloc_struct (basic_size + tail_elts, scm_struct_entity_n_extra_words, @@ -450,10 +427,26 @@ SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, data = scm_alloc_struct (basic_size + tail_elts, scm_struct_n_extra_words, "struct"); - handle = scm_double_cell ((((scm_t_bits) SCM_STRUCT_DATA (vtable)) + handle = scm_double_cell ((((scm_t_bits) c_vtable) + scm_tc3_struct), (scm_t_bits) data, 0, 0); scm_struct_init (handle, layout, data, tail_elts, init); + + if (c_vtable[scm_struct_i_free]) + { + /* Register a finalizer for the newly created instance. */ + GC_finalization_proc prev_finalizer; + GC_PTR prev_finalizer_data; + scm_t_struct_free free_struct = + (scm_t_struct_free)c_vtable[scm_struct_i_free]; + + GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (handle), + struct_finalizer_trampoline, + free_struct, + &prev_finalizer, + &prev_finalizer_data); + } + SCM_CRITICAL_SECTION_END; return handle; } @@ -838,11 +831,7 @@ scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) void scm_struct_prehistory () { - scm_i_structs_to_free = SCM_EOL; - scm_c_hook_add (&scm_before_sweep_c_hook, scm_struct_gc_init, 0, 0); - /* With the new lazy sweep GC, the point at which the entire heap is - swept is just before the mark phase. */ - scm_c_hook_add (&scm_before_mark_c_hook, scm_free_structs, 0, 0); + /* Empty. */ } void diff --git a/libguile/struct.h b/libguile/struct.h index fcd8ec858..04f5e3e02 100644 --- a/libguile/struct.h +++ b/libguile/struct.h @@ -79,7 +79,6 @@ SCM_API SCM scm_struct_table; #define SCM_STRUCT_GC_CHAIN(X) SCM_CELL_OBJECT_3 (X) #define SCM_SET_STRUCT_GC_CHAIN(X, Y) SCM_SET_CELL_OBJECT_3 (X, Y) -SCM_API SCM scm_i_structs_to_free;