1 /*
2  * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
3  * Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P.
4  *
5  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
6  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
7  *
8  * Permission is hereby granted to use or copy this program
9  * for any purpose,  provided the above notices are retained on all copies.
10  * Permission to modify the code and to distribute modified code is granted,
11  * provided the above notices are retained, and a notice that the code was
12  * modified is included with the above copyright notice.
13  *
14  */
15 
16 #include "private/gc_pmark.h"  /* includes gc_priv.h */
17 
18 #ifdef GC_GCJ_SUPPORT
19 
20 /*
21  * This is an allocator interface tuned for gcj (the GNU static
22  * java compiler).
23  *
24  * Each allocated object has a pointer in its first word to a vtable,
25  * which for our purposes is simply a structure describing the type of
26  * the object.
27  * This descriptor structure contains a GC marking descriptor at offset
28  * MARK_DESCR_OFFSET.
29  *
30  * It is hoped that this interface may also be useful for other systems,
31  * possibly with some tuning of the constants.  But the immediate goal
32  * is to get better gcj performance.
33  *
34  * We assume:
35  *  1) Counting on explicit initialization of this interface is OK;
36  *  2) FASTLOCK is not a significant win.
37  */
38 
39 #include "gc_gcj.h"
40 #include "private/dbg_mlc.h"
41 
42 #ifdef GC_ASSERTIONS
43   GC_INNER /* variable is also used in thread_local_alloc.c */
44 #else
45   STATIC
46 #endif
47 GC_bool GC_gcj_malloc_initialized = FALSE;
48 
49 int GC_gcj_kind = 0;    /* Object kind for objects with descriptors     */
50                         /* in "vtable".                                 */
51 int GC_gcj_debug_kind = 0;
52                         /* The kind of objects that is always marked    */
53                         /* with a mark proc call.                       */
54 
55 GC_INNER ptr_t * GC_gcjobjfreelist = NULL;
56 
57 STATIC ptr_t * GC_gcjdebugobjfreelist = NULL;
58 
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)59 STATIC struct GC_ms_entry * GC_gcj_fake_mark_proc(word * addr GC_ATTR_UNUSED,
60                         struct GC_ms_entry *mark_stack_ptr,
61                         struct GC_ms_entry * mark_stack_limit GC_ATTR_UNUSED,
62                         word env GC_ATTR_UNUSED)
63 {
64     ABORT_RET("No client gcj mark proc is specified");
65     return mark_stack_ptr;
66 }
67 
68 /* Caller does not hold allocation lock. */
GC_init_gcj_malloc(int mp_index,void * mp)69 GC_API void GC_CALL GC_init_gcj_malloc(int mp_index,
70                                        void * /* really GC_mark_proc */mp)
71 {
72     GC_bool ignore_gcj_info;
73     DCL_LOCK_STATE;
74 
75     if (mp == 0)        /* In case GC_DS_PROC is unused.        */
76       mp = (void *)(word)GC_gcj_fake_mark_proc;
77 
78     GC_init();  /* In case it's not already done.       */
79     LOCK();
80     if (GC_gcj_malloc_initialized) {
81       UNLOCK();
82       return;
83     }
84     GC_gcj_malloc_initialized = TRUE;
85 #   ifdef GC_IGNORE_GCJ_INFO
86       /* This is useful for debugging on platforms with missing getenv(). */
87       ignore_gcj_info = 1;
88 #   else
89       ignore_gcj_info = (0 != GETENV("GC_IGNORE_GCJ_INFO"));
90 #   endif
91     if (ignore_gcj_info) {
92       GC_COND_LOG_PRINTF("Gcj-style type information is disabled!\n");
93     }
94     GC_ASSERT(GC_mark_procs[mp_index] == (GC_mark_proc)0); /* unused */
95     GC_mark_procs[mp_index] = (GC_mark_proc)(word)mp;
96     if ((unsigned)mp_index >= GC_n_mark_procs)
97         ABORT("GC_init_gcj_malloc: bad index");
98     /* Set up object kind gcj-style indirect descriptor. */
99       GC_gcjobjfreelist = (ptr_t *)GC_new_free_list_inner();
100       if (ignore_gcj_info) {
101         /* Use a simple length-based descriptor, thus forcing a fully   */
102         /* conservative scan.                                           */
103         GC_gcj_kind = GC_new_kind_inner((void **)GC_gcjobjfreelist,
104                                         /* 0 | */ GC_DS_LENGTH,
105                                         TRUE, TRUE);
106       } else {
107         GC_gcj_kind = GC_new_kind_inner(
108                         (void **)GC_gcjobjfreelist,
109                         (((word)(-(signed_word)MARK_DESCR_OFFSET
110                                  - GC_INDIR_PER_OBJ_BIAS))
111                          | GC_DS_PER_OBJECT),
112                         FALSE, TRUE);
113       }
114     /* Set up object kind for objects that require mark proc call.      */
115       if (ignore_gcj_info) {
116         GC_gcj_debug_kind = GC_gcj_kind;
117         GC_gcjdebugobjfreelist = GC_gcjobjfreelist;
118       } else {
119         GC_gcjdebugobjfreelist = (ptr_t *)GC_new_free_list_inner();
120         GC_gcj_debug_kind = GC_new_kind_inner(
121                                 (void **)GC_gcjdebugobjfreelist,
122                                 GC_MAKE_PROC(mp_index,
123                                              1 /* allocated with debug info */),
124                                 FALSE, TRUE);
125       }
126     UNLOCK();
127 }
128 
129 #define GENERAL_MALLOC_INNER(lb,k) \
130     GC_clear_stack(GC_generic_malloc_inner(lb, k))
131 
132 #define GENERAL_MALLOC_INNER_IOP(lb,k) \
133     GC_clear_stack(GC_generic_malloc_inner_ignore_off_page(lb, k))
134 
135 /* We need a mechanism to release the lock and invoke finalizers.       */
136 /* We don't really have an opportunity to do this on a rarely executed  */
137 /* path on which the lock is not held.  Thus we check at a              */
138 /* rarely executed point at which it is safe to release the lock.       */
139 /* We do this even where we could just call GC_INVOKE_FINALIZERS,       */
140 /* since it's probably cheaper and certainly more uniform.              */
141 /* FIXME - Consider doing the same elsewhere?                           */
maybe_finalize(void)142 static void maybe_finalize(void)
143 {
144    static word last_finalized_no = 0;
145    DCL_LOCK_STATE;
146 
147    if (GC_gc_no == last_finalized_no ||
148        !EXPECT(GC_is_initialized, TRUE)) return;
149    UNLOCK();
150    GC_INVOKE_FINALIZERS();
151    LOCK();
152    last_finalized_no = GC_gc_no;
153 }
154 
155 /* Allocate an object, clear it, and store the pointer to the   */
156 /* type structure (vtable in gcj).                              */
157 /* This adds a byte at the end of the object if GC_malloc would.*/
158 #ifdef THREAD_LOCAL_ALLOC
GC_core_gcj_malloc(size_t lb,void * ptr_to_struct_containing_descr)159   GC_INNER void * GC_core_gcj_malloc(size_t lb,
160                                      void * ptr_to_struct_containing_descr)
161 #else
162   GC_API GC_ATTR_MALLOC void * GC_CALL GC_gcj_malloc(size_t lb,
163                                       void * ptr_to_struct_containing_descr)
164 #endif
165 {
166     ptr_t op;
167     ptr_t * opp;
168     word lg;
169     DCL_LOCK_STATE;
170 
171     GC_DBG_COLLECT_AT_MALLOC(lb);
172     if(SMALL_OBJ(lb)) {
173         lg = GC_size_map[lb];
174         opp = &(GC_gcjobjfreelist[lg]);
175         LOCK();
176         op = *opp;
177         if(EXPECT(op == 0, FALSE)) {
178             maybe_finalize();
179             op = (ptr_t)GENERAL_MALLOC_INNER((word)lb, GC_gcj_kind);
180             if (0 == op) {
181                 GC_oom_func oom_fn = GC_oom_fn;
182                 UNLOCK();
183                 return((*oom_fn)(lb));
184             }
185         } else {
186             *opp = obj_link(op);
187             GC_bytes_allocd += GRANULES_TO_BYTES(lg);
188         }
189         *(void **)op = ptr_to_struct_containing_descr;
190         GC_ASSERT(((void **)op)[1] == 0);
191         UNLOCK();
192     } else {
193         LOCK();
194         maybe_finalize();
195         op = (ptr_t)GENERAL_MALLOC_INNER((word)lb, GC_gcj_kind);
196         if (0 == op) {
197             GC_oom_func oom_fn = GC_oom_fn;
198             UNLOCK();
199             return((*oom_fn)(lb));
200         }
201         *(void **)op = ptr_to_struct_containing_descr;
202         UNLOCK();
203     }
204     return((void *) op);
205 }
206 
207 /* Similar to GC_gcj_malloc, but add debug info.  This is allocated     */
208 /* with GC_gcj_debug_kind.                                              */
GC_debug_gcj_malloc(size_t lb,void * ptr_to_struct_containing_descr,GC_EXTRA_PARAMS)209 GC_API GC_ATTR_MALLOC void * GC_CALL GC_debug_gcj_malloc(size_t lb,
210                 void * ptr_to_struct_containing_descr, GC_EXTRA_PARAMS)
211 {
212     void * result;
213     DCL_LOCK_STATE;
214 
215     /* We're careful to avoid extra calls, which could          */
216     /* confuse the backtrace.                                   */
217     LOCK();
218     maybe_finalize();
219     result = GC_generic_malloc_inner(lb + DEBUG_BYTES, GC_gcj_debug_kind);
220     if (result == 0) {
221         GC_oom_func oom_fn = GC_oom_fn;
222         UNLOCK();
223         GC_err_printf("GC_debug_gcj_malloc(%lu, %p) returning NULL (%s:%d)\n",
224                 (unsigned long)lb, ptr_to_struct_containing_descr, s, i);
225         return((*oom_fn)(lb));
226     }
227     *((void **)((ptr_t)result + sizeof(oh))) = ptr_to_struct_containing_descr;
228     UNLOCK();
229     if (!GC_debugging_started) {
230         GC_start_debugging();
231     }
232     ADD_CALL_CHAIN(result, ra);
233     return (GC_store_debug_info(result, (word)lb, s, i));
234 }
235 
236 /* There is no THREAD_LOCAL_ALLOC for GC_gcj_malloc_ignore_off_page().  */
GC_gcj_malloc_ignore_off_page(size_t lb,void * ptr_to_struct_containing_descr)237 GC_API GC_ATTR_MALLOC void * GC_CALL GC_gcj_malloc_ignore_off_page(size_t lb,
238                                      void * ptr_to_struct_containing_descr)
239 {
240     ptr_t op;
241     ptr_t * opp;
242     word lg;
243     DCL_LOCK_STATE;
244 
245     GC_DBG_COLLECT_AT_MALLOC(lb);
246     if(SMALL_OBJ(lb)) {
247         lg = GC_size_map[lb];
248         opp = &(GC_gcjobjfreelist[lg]);
249         LOCK();
250         op = *opp;
251         if (EXPECT(0 == op, FALSE)) {
252             maybe_finalize();
253             op = (ptr_t)GENERAL_MALLOC_INNER_IOP(lb, GC_gcj_kind);
254             if (0 == op) {
255                 GC_oom_func oom_fn = GC_oom_fn;
256                 UNLOCK();
257                 return((*oom_fn)(lb));
258             }
259         } else {
260             *opp = obj_link(op);
261             GC_bytes_allocd += GRANULES_TO_BYTES(lg);
262         }
263     } else {
264         LOCK();
265         maybe_finalize();
266         op = (ptr_t)GENERAL_MALLOC_INNER_IOP(lb, GC_gcj_kind);
267         if (0 == op) {
268             GC_oom_func oom_fn = GC_oom_fn;
269             UNLOCK();
270             return((*oom_fn)(lb));
271         }
272     }
273     *(void **)op = ptr_to_struct_containing_descr;
274     UNLOCK();
275     return((void *) op);
276 }
277 
278 #endif  /* GC_GCJ_SUPPORT */
279