diff options
-rw-r--r-- | lgc.c | 73 |
1 files changed, 40 insertions, 33 deletions
@@ -1,5 +1,5 @@ | |||
1 | /* | 1 | /* |
2 | ** $Id: lgc.c,v 1.154 2002/10/25 20:05:28 roberto Exp roberto $ | 2 | ** $Id: lgc.c,v 1.155 2002/11/07 15:37:10 roberto Exp roberto $ |
3 | ** Garbage Collector | 3 | ** Garbage Collector |
4 | ** See Copyright Notice in lua.h | 4 | ** See Copyright Notice in lua.h |
5 | */ | 5 | */ |
@@ -22,7 +22,9 @@ | |||
22 | 22 | ||
23 | typedef struct GCState { | 23 | typedef struct GCState { |
24 | Table *tmark; /* list of marked tables to be visited */ | 24 | Table *tmark; /* list of marked tables to be visited */ |
25 | Table *toclear; /* list of visited weak tables (to be cleared after GC) */ | 25 | Table *wk; /* list of visited key-weak tables (to be cleared after GC) */ |
26 | Table *wv; /* list of visited value-weak tables */ | ||
27 | Table *wkv; /* list of visited key-value weak tables */ | ||
26 | lua_State *L; | 28 | lua_State *L; |
27 | } GCState; | 29 | } GCState; |
28 | 30 | ||
@@ -198,10 +200,14 @@ static void traversetable (GCState *st, Table *h) { | |||
198 | marktable(st, h->metatable); | 200 | marktable(st, h->metatable); |
199 | lua_assert(h->lsizenode || h->node == G(st->L)->dummynode); | 201 | lua_assert(h->lsizenode || h->node == G(st->L)->dummynode); |
200 | if (h->mode & (WEAKKEY | WEAKVALUE)) { /* weak table? */ | 202 | if (h->mode & (WEAKKEY | WEAKVALUE)) { /* weak table? */ |
203 | Table **weaklist; | ||
201 | weakkey = h->mode & WEAKKEY; | 204 | weakkey = h->mode & WEAKKEY; |
202 | weakvalue = h->mode & WEAKVALUE; | 205 | weakvalue = h->mode & WEAKVALUE; |
203 | h->gclist = st->toclear; /* must be cleared after GC, ... */ | 206 | weaklist = (weakkey && weakvalue) ? &st->wkv : |
204 | st->toclear = h; /* ... so put in the appropriate list */ | 207 | (weakkey) ? &st->wk : |
208 | &st->wv; | ||
209 | h->gclist = *weaklist; /* must be cleared after GC, ... */ | ||
210 | *weaklist = h; /* ... so put in the appropriate list */ | ||
205 | } | 211 | } |
206 | if (!weakvalue) { | 212 | if (!weakvalue) { |
207 | i = sizearray(h); | 213 | i = sizearray(h); |
@@ -241,14 +247,12 @@ static int valismarked (const TObject *o) { | |||
241 | */ | 247 | */ |
242 | static void cleartablekeys (Table *h) { | 248 | static void cleartablekeys (Table *h) { |
243 | for (; h; h = h->gclist) { | 249 | for (; h; h = h->gclist) { |
244 | lua_assert(h->mode & (WEAKKEY | WEAKVALUE)); | 250 | int i = sizenode(h); |
245 | if ((h->mode & WEAKKEY)) { /* table may have collected keys? */ | 251 | lua_assert(h->mode & WEAKKEY); |
246 | int i = sizenode(h); | 252 | while (i--) { |
247 | while (i--) { | 253 | Node *n = node(h, i); |
248 | Node *n = node(h, i); | 254 | if (!valismarked(key(n))) /* key was collected? */ |
249 | if (!valismarked(key(n))) /* key was collected? */ | 255 | removekey(n); /* remove entry from table */ |
250 | removekey(n); /* remove entry from table */ | ||
251 | } | ||
252 | } | 256 | } |
253 | } | 257 | } |
254 | } | 258 | } |
@@ -259,19 +263,18 @@ static void cleartablekeys (Table *h) { | |||
259 | */ | 263 | */ |
260 | static void cleartablevalues (Table *h) { | 264 | static void cleartablevalues (Table *h) { |
261 | for (; h; h = h->gclist) { | 265 | for (; h; h = h->gclist) { |
262 | if ((h->mode & WEAKVALUE)) { /* table may have collected values? */ | 266 | int i = sizearray(h); |
263 | int i = sizearray(h); | 267 | lua_assert(h->mode & WEAKVALUE); |
264 | while (i--) { | 268 | while (i--) { |
265 | TObject *o = &h->array[i]; | 269 | TObject *o = &h->array[i]; |
266 | if (!valismarked(o)) /* value was collected? */ | 270 | if (!valismarked(o)) /* value was collected? */ |
267 | setnilvalue(o); /* remove value */ | 271 | setnilvalue(o); /* remove value */ |
268 | } | 272 | } |
269 | i = sizenode(h); | 273 | i = sizenode(h); |
270 | while (i--) { | 274 | while (i--) { |
271 | Node *n = node(h, i); | 275 | Node *n = node(h, i); |
272 | if (!valismarked(val(n))) /* value was collected? */ | 276 | if (!valismarked(val(n))) /* value was collected? */ |
273 | removekey(n); /* remove entry from table */ | 277 | removekey(n); /* remove entry from table */ |
274 | } | ||
275 | } | 278 | } |
276 | } | 279 | } |
277 | } | 280 | } |
@@ -398,22 +401,26 @@ static void markroot (GCState *st) { | |||
398 | 401 | ||
399 | static void mark (lua_State *L) { | 402 | static void mark (lua_State *L) { |
400 | GCState st; | 403 | GCState st; |
401 | Table *toclear; | 404 | Table *wkv; |
402 | st.L = L; | 405 | st.L = L; |
403 | st.tmark = NULL; | 406 | st.tmark = NULL; |
404 | st.toclear = NULL; | 407 | st.wkv = st.wk = st.wv = NULL; |
405 | markroot(&st); | 408 | markroot(&st); |
406 | propagatemarks(&st); /* mark all reachable objects */ | 409 | propagatemarks(&st); /* mark all reachable objects */ |
407 | toclear = st.toclear; /* weak tables; to be cleared */ | 410 | cleartablevalues(st.wkv); |
408 | st.toclear = NULL; | 411 | cleartablevalues(st.wv); |
409 | cleartablevalues(toclear); | 412 | wkv = st.wkv; /* keys must be cleared after preserving udata */ |
413 | st.wkv = NULL; | ||
414 | st.wv = NULL; | ||
410 | separateudata(L); /* separate userdata to be preserved */ | 415 | separateudata(L); /* separate userdata to be preserved */ |
411 | marktmu(&st); /* mark `preserved' userdata */ | 416 | marktmu(&st); /* mark `preserved' userdata */ |
412 | propagatemarks(&st); /* remark, to propagate `preserveness' */ | 417 | propagatemarks(&st); /* remark, to propagate `preserveness' */ |
413 | cleartablekeys(toclear); | 418 | cleartablekeys(wkv); |
414 | /* `propagatemarks' may reborne some weak tables; clear them too */ | 419 | /* `propagatemarks' may reborne some weak tables; clear them too */ |
415 | cleartablekeys(st.toclear); | 420 | cleartablekeys(st.wk); |
416 | cleartablevalues(st.toclear); | 421 | cleartablevalues(st.wv); |
422 | cleartablekeys(st.wkv); | ||
423 | cleartablevalues(st.wkv); | ||
417 | } | 424 | } |
418 | 425 | ||
419 | 426 | ||