1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Damien Doligez, projet Moscova, INRIA Rocquencourt */
/* */
/* Copyright 2000 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../LICENSE. */
/* */
/***********************************************************************/
/* $Id$ */
/* Handling of finalised values. */
#include "callback.h"
#include "fail.h"
#include "mlvalues.h"
#include "roots.h"
#include "signals.h"
struct final {
value fun;
value val;
};
static struct final *final_table = NULL;
static unsigned long old = 0, young = 0, active = 0, size = 0;
/* [0..old) : finalisable set
[old..young) : recent set
[young..active) : free space
[active..size) : finalising set
*/
/* Find white finalisable values, darken them, and put them in the
finalising set.
The recent set is empty.
*/
void final_update (void)
{
unsigned long i;
unsigned long oldactive = active;
Assert (young == old);
Assert (young <= active);
for (i = 0; i < old; i++){
again:
Assert (Is_block (final_table[i].val));
Assert (Is_in_heap (final_table[i].val));
if (Is_white_val (final_table[i].val)){
struct final f;
if (Tag_val (final_table[i].val) == Forward_tag){
value fv = Forward_val (final_table[i].val);
if (Is_block (fv) && (Is_young (fv) || Is_in_heap (fv))
&& (Tag_val (fv) == Forward_tag || Tag_val (fv) == Lazy_tag
|| Tag_val (fv) == Double_tag)){
/* Do not short-circuit the pointer. */
}else{
final_table[i].val = fv;
if (Is_block (final_table[i].val) && Is_in_heap (final_table[i].val)){
goto again;
}
}
}
f = final_table[i];
final_table[i] = final_table[--old];
final_table[--active] = f;
-- i;
}
}
young = old;
for (i = active; i < oldactive; i++) darken (final_table[i].val, NULL);
}
/* Call the finalisation functions for the finalising set.
Note that this function must be reentrant.
*/
void final_do_calls (void)
{
struct final f;
Assert (active <= size);
if (active < size){
gc_message (0x80, "Calling finalisation functions.\n", 0);
while (active < size){
f = final_table[active++];
callback (f.fun, f.val);
}
gc_message (0x80, "Done calling finalisation functions.\n", 0);
}
}
/* Call a scanning_action [f] on [x]. */
#define Call_action(f,x) (*(f)) ((x), &(x))
/* Call [*f] on the closures of the finalisable set and
the closures and values of the finalising set.
The recent set is empty.
This is called by the major GC and the compactor through [darken_all_roots].
*/
void final_do_strong_roots (scanning_action f)
{
unsigned long i;
Assert (old == young);
Assert (young <= active);
Assert (active <= size);
for (i = 0; i < old; i++) Call_action (f, final_table[i].fun);
for (i = active; i < size; i++){
Call_action (f, final_table[i].fun);
Call_action (f, final_table[i].val);
}
}
/* Call [*f] on the values of the finalisable set.
The recent set is empty.
This is called directly by the compactor.
*/
void final_do_weak_roots (scanning_action f)
{
unsigned long i;
Assert (old == young);
for (i = 0; i < old; i++) Call_action (f, final_table[i].val);
}
/* Call [*f] on the closures and values of the recent set.
This is called by the minor GC through [oldify_local_roots].
*/
void final_do_young_roots (scanning_action f)
{
unsigned long i;
Assert (old <= young);
for (i = old; i < young; i++){
Call_action (f, final_table[i].fun);
Call_action (f, final_table[i].val);
}
}
/* Empty the recent set into the finalisable set.
This is called at the end of each minor collection.
The minor heap must be empty when this is called.
*/
void final_empty_young (void)
{
old = young;
}
/* Put (f,v) in the recent set. */
CAMLprim value final_register (value f, value v)
{
if (!(Is_block (v) && (Is_in_heap (v) || Is_young (v)))){
invalid_argument ("Gc.finalise");
}
Assert (old <= young);
Assert (young <= active);
Assert (active <= size);
if (young >= active){
if (final_table == NULL){
unsigned long new_size = 30;
final_table = stat_alloc (new_size * sizeof (struct final));
Assert (old == 0);
Assert (young == 0);
active = size = new_size;
}else{
unsigned long new_size = size * 2;
unsigned long i;
final_table = stat_resize (final_table, new_size * sizeof (struct final));
for (i = size-1; i >= active; i--){
final_table[i + new_size - size] = final_table[i];
}
active += new_size - size;
size = new_size;
}
}
Assert (young < active);
final_table[young].fun = f;
if (Tag_val (v) == Infix_tag) v -= Infix_offset_val (v);
final_table[young].val = v;
++ young;
return Val_unit;
}
|
