Fix the symbol visibility pragmas
[ghc.git] / rts / Updates.h
1 /* -----------------------------------------------------------------------------
2 *
3 * (c) The GHC Team, 1998-2004
4 *
5 * Performing updates.
6 *
7 * ---------------------------------------------------------------------------*/
8
9 #ifndef UPDATES_H
10 #define UPDATES_H
11
12 #ifndef CMINUSMINUS
13 #include "BeginPrivate.h"
14 #endif
15
16 /* -----------------------------------------------------------------------------
17 Updates
18 -------------------------------------------------------------------------- */
19
20 /* LDV profiling:
21 * We call LDV_recordDead_FILL_SLOP_DYNAMIC(p1) regardless of the generation in
22 * which p1 resides.
23 *
24 * Note:
25 * After all, we do *NOT* need to call LDV_RECORD_CREATE() for IND
26 * closures because they are inherently used. But, it corrupts
27 * the invariants that every closure keeps its creation time in the profiling
28 * field. So, we call LDV_RECORD_CREATE().
29 */
30
31 /* In the DEBUG case, we also zero out the slop of the old closure,
32 * so that the sanity checker can tell where the next closure is.
33 *
34 * Two important invariants: we should never try to update a closure
35 * to point to itself, and the closure being updated should not
36 * already have been updated (the mutable list will get messed up
37 * otherwise).
38 *
39 * NB. We do *not* do this in THREADED_RTS mode, because when we have the
40 * possibility of multiple threads entering the same closure, zeroing
41 * the slop in one of the threads would have a disastrous effect on
42 * the other (seen in the wild!).
43 */
44 #ifdef CMINUSMINUS
45
46 #define FILL_SLOP(p) \
47 W_ inf; \
48 W_ sz; \
49 W_ i; \
50 inf = %GET_STD_INFO(p); \
51 if (%INFO_TYPE(inf) != HALF_W_(BLACKHOLE)) { \
52 if (%INFO_TYPE(inf) == HALF_W_(THUNK_SELECTOR)) { \
53 sz = BYTES_TO_WDS(SIZEOF_StgSelector_NoThunkHdr); \
54 } else { \
55 if (%INFO_TYPE(inf) == HALF_W_(AP_STACK)) { \
56 sz = StgAP_STACK_size(p) + BYTES_TO_WDS(SIZEOF_StgAP_STACK_NoThunkHdr); \
57 } else { \
58 if (%INFO_TYPE(inf) == HALF_W_(AP)) { \
59 sz = TO_W_(StgAP_n_args(p)) + BYTES_TO_WDS(SIZEOF_StgAP_NoThunkHdr); \
60 } else { \
61 sz = TO_W_(%INFO_PTRS(inf)) + TO_W_(%INFO_NPTRS(inf)); \
62 } \
63 } \
64 } \
65 i = 0; \
66 for: \
67 if (i < sz) { \
68 StgThunk_payload(p,i) = 0; \
69 i = i + 1; \
70 goto for; \
71 } \
72 }
73
74 #else /* !CMINUSMINUS */
75
76 INLINE_HEADER void
77 FILL_SLOP(StgClosure *p)
78 {
79 StgInfoTable *inf = get_itbl(p);
80 nat i, sz;
81
82 switch (inf->type) {
83 case BLACKHOLE:
84 goto no_slop;
85 // we already filled in the slop when we overwrote the thunk
86 // with BLACKHOLE, and also an evacuated BLACKHOLE is only the
87 // size of an IND.
88 case THUNK_SELECTOR:
89 sz = sizeofW(StgSelector) - sizeofW(StgThunkHeader);
90 break;
91 case AP:
92 sz = ((StgAP *)p)->n_args + sizeofW(StgAP) - sizeofW(StgThunkHeader);
93 break;
94 case AP_STACK:
95 sz = ((StgAP_STACK *)p)->size + sizeofW(StgAP_STACK) - sizeofW(StgThunkHeader);
96 break;
97 default:
98 sz = inf->layout.payload.ptrs + inf->layout.payload.nptrs;
99 break;
100 }
101 for (i = 0; i < sz; i++) {
102 ((StgThunk *)p)->payload[i] = 0;
103 }
104 no_slop:
105 ;
106 }
107
108 #endif /* CMINUSMINUS */
109
110 #if !defined(DEBUG) || defined(THREADED_RTS)
111 #define DEBUG_FILL_SLOP(p) /* do nothing */
112 #else
113 #define DEBUG_FILL_SLOP(p) FILL_SLOP(p)
114 #endif
115
116 /* We have two versions of this macro (sadly), one for use in C-- code,
117 * and the other for C.
118 *
119 * The and_then argument is a performance hack so that we can paste in
120 * the continuation code directly. It helps shave a couple of
121 * instructions off the common case in the update code, which is
122 * worthwhile (the update code is often part of the inner loop).
123 * (except that gcc now appears to common up this code again and
124 * invert the optimisation. Grrrr --SDM).
125 */
126 #ifdef CMINUSMINUS
127
128 #define updateWithIndirection(p1, p2, and_then) \
129 W_ bd; \
130 \
131 DEBUG_FILL_SLOP(p1); \
132 LDV_RECORD_DEAD_FILL_SLOP_DYNAMIC(p1); \
133 StgInd_indirectee(p1) = p2; \
134 prim %write_barrier() []; \
135 SET_INFO(p1, stg_BLACKHOLE_info); \
136 LDV_RECORD_CREATE(p1); \
137 bd = Bdescr(p1); \
138 if (bdescr_gen_no(bd) != 0 :: bits16) { \
139 recordMutableCap(p1, TO_W_(bdescr_gen_no(bd)), R1); \
140 TICK_UPD_OLD_IND(); \
141 and_then; \
142 } else { \
143 TICK_UPD_NEW_IND(); \
144 and_then; \
145 }
146
147 #else /* !CMINUSMINUS */
148
149 INLINE_HEADER void updateWithIndirection (Capability *cap,
150 StgClosure *p1,
151 StgClosure *p2)
152 {
153 bdescr *bd;
154
155 ASSERT( (P_)p1 != (P_)p2 );
156 /* not necessarily true: ASSERT( !closure_IND(p1) ); */
157 /* occurs in RaiseAsync.c:raiseAsync() */
158 DEBUG_FILL_SLOP(p1);
159 LDV_RECORD_DEAD_FILL_SLOP_DYNAMIC(p1);
160 ((StgInd *)p1)->indirectee = p2;
161 write_barrier();
162 SET_INFO(p1, &stg_BLACKHOLE_info);
163 LDV_RECORD_CREATE(p1);
164 bd = Bdescr((StgPtr)p1);
165 if (bd->gen_no != 0) {
166 recordMutableCap(p1, cap, bd->gen_no);
167 TICK_UPD_OLD_IND();
168 } else {
169 TICK_UPD_NEW_IND();
170 }
171 }
172
173 #endif /* CMINUSMINUS */
174
175 #ifndef CMINUSMINUS
176 #include "EndPrivate.h"
177 #endif
178
179 #endif /* UPDATES_H */