1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 2001
6 * Lag/Drag/Void profiling.
8 * ---------------------------------------------------------------------------*/
12 #include "PosixSource.h"
15 #include "Profiling.h"
20 /* --------------------------------------------------------------------------
21 * Fills in the slop when a *dynamic* closure changes its type.
22 * First calls LDV_recordDead() to declare the closure is dead, and then
26 * 1) blackholing, UPD_BH_UPDATABLE() and UPD_BH_SINGLE_ENTRY (in
27 * includes/StgMacros.h), threadLazyBlackHole() and
28 * threadSqueezeStack() (in GC.c).
29 * 2) updating with indirection closures, updateWithIndirection()
30 * and updateWithPermIndirection() (in Storage.h).
32 * LDV_recordDead_FILL_SLOP_DYNAMIC() is not called on 'inherently used'
33 * closures such as TSO. It is not called on PAP because PAP is not updatable.
34 * ----------------------------------------------------------------------- */
36 LDV_recordDead_FILL_SLOP_DYNAMIC( StgClosure *p )
40 #if defined(__GNUC__) && __GNUC__ < 3 && defined(DEBUG)
41 #error Please use gcc 3.0+ to compile this file with DEBUG; gcc < 3.0 miscompiles it
45 // very like FILL_SLOP(), except that we call LDV_recordDead().
46 size = closure_sizeW(p);
48 LDV_recordDead((StgClosure *)(p), size);
50 if (size > sizeofW(StgThunkHeader)) {
51 for (i = 0; i < size - sizeofW(StgThunkHeader); i++) {
52 ((StgThunk *)(p))->payload[i] = 0;
58 /* --------------------------------------------------------------------------
59 * This function is called eventually on every object destroyed during
60 * a garbage collection, whether it is a major garbage collection or
61 * not. If c is an 'inherently used' closure, nothing happens. If c
62 * is an ordinary closure, LDV_recordDead() is called on c with its
63 * proper size which excludes the profiling header portion in the
64 * closure. Returns the size of the closure, including the profiling
65 * header portion, so that the caller can find the next closure.
66 * ----------------------------------------------------------------------- */
68 processHeapClosureForDead( StgClosure *c )
71 const StgInfoTable *info;
75 info = c->header.info;
76 if (IS_FORWARDING_PTR(info)) {
77 // The size of the evacuated closure is currently stored in
78 // the LDV field. See SET_EVACUAEE_FOR_LDV() in
79 // includes/StgLdvProf.h.
82 info = INFO_PTR_TO_STRUCT(info);
84 ASSERT(((LDVW(c) & LDV_CREATE_MASK) >> LDV_SHIFT) <= era &&
85 ((LDVW(c) & LDV_CREATE_MASK) >> LDV_SHIFT) > 0);
86 ASSERT(((LDVW(c) & LDV_STATE_MASK) == LDV_STATE_CREATE) ||
88 (LDVW(c) & LDV_LAST_MASK) <= era &&
89 (LDVW(c) & LDV_LAST_MASK) > 0
93 size = closure_sizeW(c);
97 'inherently used' cases: do nothing.
102 case MUT_ARR_PTRS_CLEAN:
103 case MUT_ARR_PTRS_DIRTY:
104 case MUT_ARR_PTRS_FROZEN:
105 case MUT_ARR_PTRS_FROZEN0:
112 case TVAR_WATCH_QUEUE:
116 case INVARIANT_CHECK_QUEUE:
117 case ATOMIC_INVARIANT:
121 ordinary cases: call LDV_recordDead().
148 case IND_OLDGEN_PERM:
152 // Why can we ignore IND/IND_OLDGEN closures? We assume that
153 // any census is preceded by a major garbage collection, which
154 // IND/IND_OLDGEN closures cannot survive. Therefore, it is no
155 // use considering IND/IND_OLDGEN closures in the meanwhile
156 // because they will perish before the next census at any
160 // Found a dead closure: record its size
161 LDV_recordDead(c, size);
172 case CONSTR_NOCAF_STATIC:
189 barf("Invalid object in processHeapClosureForDead(): %d", info->type);
194 /* --------------------------------------------------------------------------
195 * Calls processHeapClosureForDead() on every *dead* closures in the
196 * heap blocks starting at bd.
197 * ----------------------------------------------------------------------- */
199 processHeapForDead( bdescr *bd )
205 while (p < bd->free) {
206 p += processHeapClosureForDead((StgClosure *)p);
207 while (p < bd->free && !*p) // skip slop
210 ASSERT(p == bd->free);
215 /* --------------------------------------------------------------------------
216 * Calls processHeapClosureForDead() on every *dead* closures in the nursery.
217 * ----------------------------------------------------------------------- */
219 processNurseryForDead( void )
224 bd = MainCapability.r.rNursery->blocks;
225 while (bd->start < bd->free) {
227 bdLimit = bd->start + BLOCK_SIZE_W;
228 while (p < bd->free && p < bdLimit) {
229 p += processHeapClosureForDead((StgClosure *)p);
230 while (p < bd->free && p < bdLimit && !*p) // skip slop
239 /* --------------------------------------------------------------------------
240 * Calls processHeapClosureForDead() on every *dead* closures in the
242 * ----------------------------------------------------------------------- */
244 processSmallObjectPoolForDead( void )
249 for (bd = g0s0->blocks; bd != NULL; bd = bd->link) {
251 while (p < bd->free) {
252 p += processHeapClosureForDead((StgClosure *)p);
253 while (p < bd->free && !*p) // skip slop
256 ASSERT(p == bd->free);
260 /* --------------------------------------------------------------------------
261 * Calls processHeapClosureForDead() on every *dead* closures in the closure
263 * ----------------------------------------------------------------------- */
265 processChainForDead( bdescr *bd )
267 // Any object still in the chain is dead!
269 if (!(bd->flags & BF_PINNED)) {
270 processHeapClosureForDead((StgClosure *)bd->start);
276 /* --------------------------------------------------------------------------
277 * Start a census for *dead* closures, and calls
278 * processHeapClosureForDead() on every closure which died in the
279 * current garbage collection. This function is called from a garbage
280 * collector right before tidying up, when all dead closures are still
281 * stored in the heap and easy to identify. Generations 0 through N
282 * have just beed garbage collected.
283 * ----------------------------------------------------------------------- */
285 LdvCensusForDead( nat N )
289 // ldvTime == 0 means that LDV profiling is currently turned off.
293 if (RtsFlags.GcFlags.generations == 1) {
295 // Todo: support LDV for two-space garbage collection.
297 barf("Lag/Drag/Void profiling not supported with -G1");
299 for (g = 0; g <= N; g++)
300 for (s = 0; s < generations[g].n_steps; s++) {
301 if (g == 0 && s == 0) {
302 processSmallObjectPoolForDead();
303 processNurseryForDead();
304 processChainForDead(generations[g].steps[s].large_objects);
306 processHeapForDead(generations[g].steps[s].old_blocks);
307 processChainForDead(generations[g].steps[s].large_objects);
313 /* --------------------------------------------------------------------------
314 * Regard any closure in the current heap as dead or moribund and update
315 * LDV statistics accordingly.
316 * Called from shutdownHaskell() in RtsStartup.c.
317 * Also, stops LDV profiling by resetting ldvTime to 0.
318 * ----------------------------------------------------------------------- */
320 LdvCensusKillAll( void )
322 LdvCensusForDead(RtsFlags.GcFlags.generations - 1);
325 #endif /* PROFILING */