commit 1f7103e05d01a6a4c300a73bcfc8d9b17b2c20a4
parent dcc10accea47fa1475c627de6f7c3e3f7eeec27b
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 4 Oct 1999 15:50:02 -0200
implementation of lua_ref (previously in module `lmem').
Diffstat:
A | lref.c | | | 78 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
A | lref.h | | | 17 | +++++++++++++++++ |
2 files changed, 95 insertions(+), 0 deletions(-)
diff --git a/lref.c b/lref.c
@@ -0,0 +1,78 @@
+/*
+** $Id: $
+** REF mechanism
+** See Copyright Notice in lua.h
+*/
+
+
+#include "lmem.h"
+#include "lref.h"
+#include "lstate.h"
+#include "lua.h"
+
+
+int luaR_ref (const TObject *o, int lock) {
+ int ref;
+ if (ttype(o) == LUA_T_NIL)
+ ref = LUA_REFNIL;
+ else {
+ for (ref=0; ref<L->refSize; ref++)
+ if (L->refArray[ref].status == FREE)
+ break;
+ if (ref == L->refSize) { /* no more empty spaces? */
+ luaM_growvector(L->refArray, L->refSize, 1, struct ref, refEM, MAX_INT);
+ L->refSize++;
+ }
+ L->refArray[ref].o = *o;
+ L->refArray[ref].status = lock ? LOCK : HOLD;
+ }
+ return ref;
+}
+
+
+void lua_unref (int ref) {
+ if (ref >= 0 && ref < L->refSize)
+ L->refArray[ref].status = FREE;
+}
+
+
+const TObject *luaR_getref (int ref) {
+ if (ref == LUA_REFNIL)
+ return &luaO_nilobject;
+ if (ref >= 0 && ref < L->refSize &&
+ (L->refArray[ref].status == LOCK || L->refArray[ref].status == HOLD))
+ return &L->refArray[ref].o;
+ else
+ return NULL;
+}
+
+
+static int ismarked (const TObject *o) {
+ /* valid only for locked objects */
+ switch (o->ttype) {
+ case LUA_T_STRING: case LUA_T_USERDATA:
+ return o->value.ts->marked;
+ case LUA_T_ARRAY:
+ return o->value.a->marked;
+ case LUA_T_CLOSURE:
+ return o->value.cl->marked;
+ case LUA_T_PROTO:
+ return o->value.tf->marked;
+#ifdef DEBUG
+ case LUA_T_LINE: case LUA_T_CLMARK:
+ case LUA_T_CMARK: case LUA_T_PMARK:
+ LUA_INTERNALERROR("invalid type");
+#endif
+ default: /* nil, number or cproto */
+ return 1;
+ }
+}
+
+
+void luaR_invalidaterefs (void) {
+ int i;
+ for (i=0; i<L->refSize; i++)
+ if (L->refArray[i].status == HOLD && !ismarked(&L->refArray[i].o))
+ L->refArray[i].status = COLLECTED;
+}
+
diff --git a/lref.h b/lref.h
@@ -0,0 +1,17 @@
+/*
+** $Id: $
+** REF mechanism
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lref_h
+#define lref_h
+
+#include "lobject.h"
+
+int luaR_ref (const TObject *o, int lock);
+const TObject *luaR_getref (int ref);
+void luaR_invalidaterefs (void);
+
+
+#endif