1 /* -----------------------------------------------------------------------------
2 * $Id: Updates.h,v 1.24 2001/03/22 03:51:09 hwloidl Exp $
4 * (c) The GHC Team, 1998-1999
6 * Definitions related to updates.
8 * ---------------------------------------------------------------------------*/
13 /* -----------------------------------------------------------------------------
14 Update a closure with an indirection. This may also involve waking
15 up a queue of blocked threads waiting on the result of this
17 -------------------------------------------------------------------------- */
19 /* ToDo: overwrite slop words with something safe in case sanity checking
21 * (I think the fancy version of the GC is supposed to do this too.)
24 /* This expands to a fair chunk of code, what with waking up threads
25 * and checking whether we're updating something in a old generation.
26 * preferably don't use this macro inline in compiled code.
30 # define UPD_IND(updclosure, heapptr) UPD_PERM_IND(updclosure,heapptr)
32 # define UPD_IND(updclosure, heapptr) UPD_REAL_IND(updclosure,heapptr)
35 /* UPD_IND actually does a PERM_IND if TICKY_TICKY is on;
36 if you *really* need an IND use UPD_REAL_IND
39 #define UPD_REAL_IND(updclosure, heapptr) \
41 const StgInfoTable *info; \
42 if (Bdescr((P_)updclosure)->back != (bdescr *)BaseReg) { \
43 info = LOCK_CLOSURE(updclosure); \
45 info = updclosure->header.info; \
47 AWAKEN_BQ(info,updclosure); \
48 updateWithIndirection(info, \
49 (StgClosure *)updclosure, \
50 (StgClosure *)heapptr); \
53 #define UPD_REAL_IND(updclosure, heapptr) \
55 const StgInfoTable *info; \
56 info = ((StgClosure *)updclosure)->header.info; \
57 AWAKEN_BQ(info,updclosure); \
58 updateWithIndirection(info, \
59 (StgClosure *)updclosure, \
60 (StgClosure *)heapptr); \
64 #define UPD_STATIC_IND(updclosure, heapptr) \
66 const StgInfoTable *info; \
67 info = ((StgClosure *)updclosure)->header.info; \
68 AWAKEN_STATIC_BQ(info,updclosure); \
69 updateWithStaticIndirection(info, \
70 (StgClosure *)updclosure, \
71 (StgClosure *)heapptr); \
74 #if defined(PROFILING) || defined(TICKY_TICKY)
75 #define UPD_PERM_IND(updclosure, heapptr) \
77 const StgInfoTable *info; \
78 info = ((StgClosure *)updclosure)->header.info; \
79 AWAKEN_BQ(info,updclosure); \
80 updateWithPermIndirection(info, \
81 (StgClosure *)updclosure, \
82 (StgClosure *)heapptr); \
87 #define UPD_IND_NOLOCK(updclosure, heapptr) \
89 const StgInfoTable *info; \
90 info = updclosure->header.info; \
91 AWAKEN_BQ(info,updclosure); \
92 updateWithIndirection(info, \
93 (StgClosure *)updclosure, \
94 (StgClosure *)heapptr); \
97 #define UPD_IND_NOLOCK(updclosure,heapptr) UPD_IND(updclosure,heapptr)
100 /* -----------------------------------------------------------------------------
101 Awaken any threads waiting on this computation
102 -------------------------------------------------------------------------- */
107 In a parallel setup several types of closures might have a blocking queue:
108 BLACKHOLE_BQ ... same as in the default concurrent setup; it will be
109 reawakened via calling UPD_IND on that closure after
110 having finished the computation of the graph
111 FETCH_ME_BQ ... a global indirection (FETCH_ME) may be entered by a
112 local TSO, turning it into a FETCH_ME_BQ; it will be
113 reawakened via calling processResume
114 RBH ... a revertible black hole may be entered by another
115 local TSO, putting it onto its blocking queue; since
116 RBHs only exist while the corresponding closure is in
117 transit, they will be reawakened via calling
118 convertToFetchMe (upon processing an ACK message)
120 In a parallel setup a blocking queue may contain 3 types of closures:
121 TSO ... as in the default concurrent setup
122 BLOCKED_FETCH ... indicating that a TSO on another PE is waiting for
123 the result of the current computation
124 CONSTR ... an RBHSave closure (which contains data ripped out of
125 the closure to make room for a blocking queue; since
126 it only contains data we use the exisiting type of
127 a CONSTR closure); this closure is the end of a
128 blocking queue for an RBH closure; it only exists in
129 this kind of blocking queue and must be at the end
132 extern void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
133 #define DO_AWAKEN_BQ(bqe, node) STGCALL2(awakenBlockedQueue, bqe, node);
135 #define AWAKEN_BQ(info,closure) \
136 if (info == &stg_BLACKHOLE_BQ_info || \
137 info == &stg_FETCH_ME_BQ_info || \
138 get_itbl(closure)->type == RBH) { \
139 DO_AWAKEN_BQ(((StgBlockingQueue *)closure)->blocking_queue, closure); \
144 extern void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
145 #define DO_AWAKEN_BQ(bq, node) STGCALL2(awakenBlockedQueue, bq, node);
147 /* In GranSim we don't have FETCH_ME or FETCH_ME_BQ closures, so they are
148 not checked. The rest of the code is the same as for GUM.
150 #define AWAKEN_BQ(info,closure) \
151 if (info == &stg_BLACKHOLE_BQ_info || \
152 get_itbl(closure)->type == RBH) { \
153 DO_AWAKEN_BQ(((StgBlockingQueue *)closure)->blocking_queue, closure); \
157 #else /* !GRAN && !PAR */
159 extern void awakenBlockedQueue(StgTSO *q);
160 #define DO_AWAKEN_BQ(closure) \
161 STGCALL1(awakenBlockedQueue, \
162 ((StgBlockingQueue *)closure)->blocking_queue);
164 #define AWAKEN_BQ(info,closure) \
165 if (info == &stg_BLACKHOLE_BQ_info) { \
166 DO_AWAKEN_BQ(closure); \
169 #define AWAKEN_STATIC_BQ(info,closure) \
170 if (info == &stg_BLACKHOLE_BQ_STATIC_info) { \
171 DO_AWAKEN_BQ(closure); \
174 #endif /* GRAN || PAR */
176 /* -------------------------------------------------------------------------
177 Push an update frame on the stack.
178 ------------------------------------------------------------------------- */
180 #if defined(PROFILING)
181 #define PUSH_STD_CCCS(frame) frame->header.prof.ccs = CCCS
183 #define PUSH_STD_CCCS(frame)
186 extern DLL_IMPORT_RTS const StgPolyInfoTable stg_upd_frame_info;
188 #define PUSH_UPD_FRAME(target, Sp_offset) \
190 StgUpdateFrame *__frame; \
191 TICK_UPDF_PUSHED(target, GET_INFO((StgClosure*)target)); \
192 __frame = (StgUpdateFrame *)(Sp + (Sp_offset)) - 1; \
193 SET_INFO(__frame, (StgInfoTable *)&stg_upd_frame_info); \
194 __frame->link = Su; \
195 __frame->updatee = (StgClosure *)(target); \
196 PUSH_STD_CCCS(__frame); \
200 /* -----------------------------------------------------------------------------
203 When a CAF is first entered, it creates a black hole in the heap,
204 and updates itself with an indirection to this new black hole.
206 We update the CAF with an indirection to a newly-allocated black
207 hole in the heap. We also set the blocking queue on the newly
208 allocated black hole to be empty.
210 Why do we make a black hole in the heap when we enter a CAF?
212 - for a generational garbage collector, which needs a fast
213 test for whether an updatee is in an old generation or not
215 - for the parallel system, which can implement updates more
216 easily if the updatee is always in the heap. (allegedly).
218 When debugging, we maintain a separate CAF list so we can tell when
219 a CAF has been garbage collected.
220 -------------------------------------------------------------------------- */
222 /* ToDo: only call newCAF when debugging. */
224 extern void newCAF(StgClosure*);
226 /* newCAF must be called before the itbl ptr is overwritten, since
227 newCAF records the old itbl ptr in order to do CAF reverting
228 (which Hugs needs to do in order that combined mode works right.)
230 #define UPD_CAF(cafptr, bhptr) \
232 LOCK_CLOSURE(cafptr); \
233 STGCALL1(newCAF,(StgClosure *)cafptr); \
234 ((StgInd *)cafptr)->indirectee = (StgClosure *)(bhptr); \
235 SET_INFO((StgInd *)cafptr,(const StgInfoTable*)&stg_IND_STATIC_info);\
238 /* -----------------------------------------------------------------------------
239 Update-related prototypes
240 -------------------------------------------------------------------------- */
242 DLL_IMPORT_RTS extern STGFUN(stg_upd_frame_entry);
244 extern DLL_IMPORT_RTS const StgInfoTable stg_PAP_info;
245 DLL_IMPORT_RTS STGFUN(stg_PAP_entry);
247 EXTFUN_RTS(stg_update_PAP);
249 extern DLL_IMPORT_RTS const StgInfoTable stg_AP_UPD_info;
250 DLL_IMPORT_RTS STGFUN(stg_AP_UPD_entry);
252 extern DLL_IMPORT_RTS const StgInfoTable stg_raise_info;
254 #endif /* UPDATES_H */