File: gcj_mlc.c

package info (click to toggle)
libgc 1:7.6.4-0.4
  • links: PTS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 4,956 kB
  • sloc: ansic: 35,613; sh: 4,193; cpp: 1,247; makefile: 163; asm: 99
file content (270 lines) | stat: -rw-r--r-- 9,541 bytes parent folder | download
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
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
/*
 * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
 * Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P.
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose,  provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

#include "private/gc_pmark.h"  /* includes gc_priv.h */

#ifdef GC_GCJ_SUPPORT

/*
 * This is an allocator interface tuned for gcj (the GNU static
 * java compiler).
 *
 * Each allocated object has a pointer in its first word to a vtable,
 * which for our purposes is simply a structure describing the type of
 * the object.
 * This descriptor structure contains a GC marking descriptor at offset
 * MARK_DESCR_OFFSET.
 *
 * It is hoped that this interface may also be useful for other systems,
 * possibly with some tuning of the constants.  But the immediate goal
 * is to get better gcj performance.
 *
 * We assume:
 *  1) Counting on explicit initialization of this interface is OK;
 *  2) FASTLOCK is not a significant win.
 */

#include "gc_gcj.h"
#include "private/dbg_mlc.h"

#ifdef GC_ASSERTIONS
  GC_INNER /* variable is also used in thread_local_alloc.c */
#else
  STATIC
#endif
GC_bool GC_gcj_malloc_initialized = FALSE;

int GC_gcj_kind = 0;    /* Object kind for objects with descriptors     */
                        /* in "vtable".                                 */
int GC_gcj_debug_kind = 0;
                        /* The kind of objects that is always marked    */
                        /* with a mark proc call.                       */

GC_INNER ptr_t * GC_gcjobjfreelist = NULL;

STATIC struct GC_ms_entry * GC_gcj_fake_mark_proc(word * addr GC_ATTR_UNUSED,
                        struct GC_ms_entry *mark_stack_ptr,
                        struct GC_ms_entry * mark_stack_limit GC_ATTR_UNUSED,
                        word env GC_ATTR_UNUSED)
{
    ABORT_RET("No client gcj mark proc is specified");
    return mark_stack_ptr;
}

/* Caller does not hold allocation lock. */
GC_API void GC_CALL GC_init_gcj_malloc(int mp_index,
                                       void * /* really GC_mark_proc */mp)
{
    GC_bool ignore_gcj_info;
    DCL_LOCK_STATE;

    if (mp == 0)        /* In case GC_DS_PROC is unused.        */
      mp = (void *)(word)GC_gcj_fake_mark_proc;

    GC_init();  /* In case it's not already done.       */
    LOCK();
    if (GC_gcj_malloc_initialized) {
      UNLOCK();
      return;
    }
    GC_gcj_malloc_initialized = TRUE;
#   ifdef GC_IGNORE_GCJ_INFO
      /* This is useful for debugging on platforms with missing getenv(). */
      ignore_gcj_info = 1;
#   else
      ignore_gcj_info = (0 != GETENV("GC_IGNORE_GCJ_INFO"));
#   endif
    if (ignore_gcj_info) {
      GC_COND_LOG_PRINTF("Gcj-style type information is disabled!\n");
    }
    GC_ASSERT(GC_mark_procs[mp_index] == (GC_mark_proc)0); /* unused */
    GC_mark_procs[mp_index] = (GC_mark_proc)(word)mp;
    if ((unsigned)mp_index >= GC_n_mark_procs)
        ABORT("GC_init_gcj_malloc: bad index");
    /* Set up object kind gcj-style indirect descriptor. */
      GC_gcjobjfreelist = (ptr_t *)GC_new_free_list_inner();
      if (ignore_gcj_info) {
        /* Use a simple length-based descriptor, thus forcing a fully   */
        /* conservative scan.                                           */
        GC_gcj_kind = GC_new_kind_inner((void **)GC_gcjobjfreelist,
                                        /* 0 | */ GC_DS_LENGTH,
                                        TRUE, TRUE);
      } else {
        GC_gcj_kind = GC_new_kind_inner(
                        (void **)GC_gcjobjfreelist,
                        (((word)(-(signed_word)MARK_DESCR_OFFSET
                                 - GC_INDIR_PER_OBJ_BIAS))
                         | GC_DS_PER_OBJECT),
                        FALSE, TRUE);
      }
    /* Set up object kind for objects that require mark proc call.      */
      if (ignore_gcj_info) {
        GC_gcj_debug_kind = GC_gcj_kind;
      } else {
        GC_gcj_debug_kind = GC_new_kind_inner(GC_new_free_list_inner(),
                                GC_MAKE_PROC(mp_index,
                                             1 /* allocated with debug info */),
                                FALSE, TRUE);
      }
    UNLOCK();
}

#define GENERAL_MALLOC_INNER(lb,k) \
    GC_clear_stack(GC_generic_malloc_inner(lb, k))

#define GENERAL_MALLOC_INNER_IOP(lb,k) \
    GC_clear_stack(GC_generic_malloc_inner_ignore_off_page(lb, k))

/* We need a mechanism to release the lock and invoke finalizers.       */
/* We don't really have an opportunity to do this on a rarely executed  */
/* path on which the lock is not held.  Thus we check at a              */
/* rarely executed point at which it is safe to release the lock.       */
/* We do this even where we could just call GC_INVOKE_FINALIZERS,       */
/* since it's probably cheaper and certainly more uniform.              */
/* FIXME - Consider doing the same elsewhere?                           */
static void maybe_finalize(void)
{
   static word last_finalized_no = 0;
   DCL_LOCK_STATE;

   if (GC_gc_no == last_finalized_no ||
       !EXPECT(GC_is_initialized, TRUE)) return;
   UNLOCK();
   GC_INVOKE_FINALIZERS();
   LOCK();
   last_finalized_no = GC_gc_no;
}

/* Allocate an object, clear it, and store the pointer to the   */
/* type structure (vtable in gcj).                              */
/* This adds a byte at the end of the object if GC_malloc would.*/
#ifdef THREAD_LOCAL_ALLOC
  GC_INNER void * GC_core_gcj_malloc(size_t lb,
                                     void * ptr_to_struct_containing_descr)
#else
  GC_API GC_ATTR_MALLOC void * GC_CALL GC_gcj_malloc(size_t lb,
                                      void * ptr_to_struct_containing_descr)
#endif
{
    ptr_t op;
    DCL_LOCK_STATE;

    GC_DBG_COLLECT_AT_MALLOC(lb);
    if(SMALL_OBJ(lb)) {
        word lg = GC_size_map[lb];

        LOCK();
        op = GC_gcjobjfreelist[lg];
        if(EXPECT(0 == op, FALSE)) {
            maybe_finalize();
            op = (ptr_t)GENERAL_MALLOC_INNER((word)lb, GC_gcj_kind);
            if (0 == op) {
                GC_oom_func oom_fn = GC_oom_fn;
                UNLOCK();
                return((*oom_fn)(lb));
            }
        } else {
            GC_gcjobjfreelist[lg] = obj_link(op);
            GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
        }
        *(void **)op = ptr_to_struct_containing_descr;
        GC_ASSERT(((void **)op)[1] == 0);
        UNLOCK();
    } else {
        LOCK();
        maybe_finalize();
        op = (ptr_t)GENERAL_MALLOC_INNER((word)lb, GC_gcj_kind);
        if (0 == op) {
            GC_oom_func oom_fn = GC_oom_fn;
            UNLOCK();
            return((*oom_fn)(lb));
        }
        *(void **)op = ptr_to_struct_containing_descr;
        UNLOCK();
    }
    return((void *) op);
}

/* Similar to GC_gcj_malloc, but add debug info.  This is allocated     */
/* with GC_gcj_debug_kind.                                              */
GC_API GC_ATTR_MALLOC void * GC_CALL GC_debug_gcj_malloc(size_t lb,
                void * ptr_to_struct_containing_descr, GC_EXTRA_PARAMS)
{
    void * result;
    DCL_LOCK_STATE;

    /* We're careful to avoid extra calls, which could          */
    /* confuse the backtrace.                                   */
    LOCK();
    maybe_finalize();
    result = GC_generic_malloc_inner(SIZET_SAT_ADD(lb, DEBUG_BYTES),
                                     GC_gcj_debug_kind);
    if (result == 0) {
        GC_oom_func oom_fn = GC_oom_fn;
        UNLOCK();
        GC_err_printf("GC_debug_gcj_malloc(%lu, %p) returning NULL (%s:%d)\n",
                (unsigned long)lb, ptr_to_struct_containing_descr, s, i);
        return((*oom_fn)(lb));
    }
    *((void **)((ptr_t)result + sizeof(oh))) = ptr_to_struct_containing_descr;
    UNLOCK();
    if (!GC_debugging_started) {
        GC_start_debugging();
    }
    ADD_CALL_CHAIN(result, ra);
    return (GC_store_debug_info(result, (word)lb, s, i));
}

/* There is no THREAD_LOCAL_ALLOC for GC_gcj_malloc_ignore_off_page().  */
GC_API GC_ATTR_MALLOC void * GC_CALL GC_gcj_malloc_ignore_off_page(size_t lb,
                                     void * ptr_to_struct_containing_descr)
{
    ptr_t op;
    DCL_LOCK_STATE;

    GC_DBG_COLLECT_AT_MALLOC(lb);
    if(SMALL_OBJ(lb)) {
        word lg = GC_size_map[lb];

        LOCK();
        op = GC_gcjobjfreelist[lg];
        if (EXPECT(0 == op, FALSE)) {
            maybe_finalize();
            op = (ptr_t)GENERAL_MALLOC_INNER_IOP(lb, GC_gcj_kind);
            if (0 == op) {
                GC_oom_func oom_fn = GC_oom_fn;
                UNLOCK();
                return((*oom_fn)(lb));
            }
        } else {
            GC_gcjobjfreelist[lg] = obj_link(op);
            GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
        }
    } else {
        LOCK();
        maybe_finalize();
        op = (ptr_t)GENERAL_MALLOC_INNER_IOP(lb, GC_gcj_kind);
        if (0 == op) {
            GC_oom_func oom_fn = GC_oom_fn;
            UNLOCK();
            return((*oom_fn)(lb));
        }
    }
    *(void **)op = ptr_to_struct_containing_descr;
    UNLOCK();
    return((void *) op);
}

#endif  /* GC_GCJ_SUPPORT */