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FFI: Add ffi.gc() function for finalization of cdata objects.

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This commit is contained in:
Mike Pall
2011-02-28 16:48:13 +01:00
parent cead25f928
commit 83a37aeca7
9 changed files with 191 additions and 57 deletions
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103
src/lj_gc.c
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@@ -20,6 +20,7 @@
#include "lj_state.h"
#include "lj_frame.h"
#if LJ_HASFFI
#include "lj_ctype.h"
#include "lj_cdata.h"
#endif
#include "lj_trace.h"
@@ -170,8 +171,9 @@ static int gc_traverse_tab(global_State *g, GCtab *t)
while ((c = *modestr++)) {
if (c == 'k') weak |= LJ_GC_WEAKKEY;
else if (c == 'v') weak |= LJ_GC_WEAKVAL;
else if (c == 'K') weak = (int)(~0u & ~LJ_GC_WEAKVAL);
}
if (weak) { /* Weak tables are cleared in the atomic phase. */
if (weak > 0) { /* Weak tables are cleared in the atomic phase. */
t->marked = cast_byte((t->marked & ~LJ_GC_WEAK) | weak);
setgcrefr(t->gclist, g->gc.weak);
setgcref(g->gc.weak, obj2gco(t));
@@ -458,53 +460,98 @@ static void gc_clearweak(GCobj *o)
}
}
/* Finalize one userdata object from mmudata list. */
/* Call a userdata or cdata finalizer. */
static void gc_call_finalizer(global_State *g, lua_State *L,
cTValue *mo, GCobj *o)
{
/* Save and restore lots of state around the __gc callback. */
uint8_t oldh = hook_save(g);
MSize oldt = g->gc.threshold;
int errcode;
TValue *top;
lj_trace_abort(g);
top = L->top;
L->top = top+2;
hook_entergc(g); /* Disable hooks and new traces during __gc. */
g->gc.threshold = LJ_MAX_MEM; /* Prevent GC steps. */
copyTV(L, top, mo);
setgcV(L, top+1, o, ~o->gch.gct);
errcode = lj_vm_pcall(L, top+1, 1+0, -1); /* Stack: |mo|o| -> | */
hook_restore(g, oldh);
g->gc.threshold = oldt; /* Restore GC threshold. */
if (errcode)
lj_err_throw(L, errcode); /* Propagate errors. */
}
/* Finalize one userdata or cdata object from the mmudata list. */
static void gc_finalize(lua_State *L)
{
global_State *g = G(L);
GCobj *o = gcnext(gcref(g->gc.mmudata));
GCudata *ud = gco2ud(o);
cTValue *mo;
lua_assert(gcref(g->jit_L) == NULL); /* Must not be called on trace. */
/* Unchain from list of userdata to be finalized. */
if (o == gcref(g->gc.mmudata))
setgcrefnull(g->gc.mmudata);
else
setgcrefr(gcref(g->gc.mmudata)->gch.nextgc, ud->nextgc);
/* Add it back to the main userdata list and make it white. */
setgcrefr(ud->nextgc, mainthread(g)->nextgc);
setgcref(mainthread(g)->nextgc, o);
setgcrefr(gcref(g->gc.mmudata)->gch.nextgc, o->gch.nextgc);
makewhite(g, o);
/* Resolve the __gc metamethod. */
mo = lj_meta_fastg(g, tabref(ud->metatable), MM_gc);
if (mo) {
/* Save and restore lots of state around the __gc callback. */
uint8_t oldh = hook_save(g);
MSize oldt = g->gc.threshold;
int errcode;
TValue *top;
lj_trace_abort(g);
top = L->top;
L->top = top+2;
hook_entergc(g); /* Disable hooks and new traces during __gc. */
g->gc.threshold = LJ_MAX_MEM; /* Prevent GC steps. */
copyTV(L, top, mo);
setudataV(L, top+1, ud);
errcode = lj_vm_pcall(L, top+1, 1+0, -1); /* Stack: |mo|ud| -> | */
hook_restore(g, oldh);
g->gc.threshold = oldt; /* Restore GC threshold. */
if (errcode)
lj_err_throw(L, errcode); /* Propagate errors. */
#if LJ_HASFFI
if (o->gch.gct == ~LJ_TCDATA) {
TValue tmp, *tv;
setgcrefr(o->gch.nextgc, g->gc.root); /* Add cdata back to the gc list. */
setgcref(g->gc.root, o);
/* Resolve finalizer. */
setcdataV(L, &tmp, gco2cd(o));
tv = lj_tab_set(L, ctype_ctsG(g)->finalizer, &tmp);
if (!tvisnil(tv)) {
copyTV(L, &tmp, tv);
setnilV(tv); /* Clear entry in finalizer table. */
gc_call_finalizer(g, L, &tmp, o);
}
return;
}
#endif
/* Add userdata back to the main userdata list. */
setgcrefr(o->gch.nextgc, mainthread(g)->nextgc);
setgcref(mainthread(g)->nextgc, o);
/* Resolve the __gc metamethod. */
mo = lj_meta_fastg(g, tabref(gco2ud(o)->metatable), MM_gc);
if (mo)
gc_call_finalizer(g, L, mo, o);
}
/* Finalize all userdata objects from mmudata list. */
void lj_gc_finalizeudata(lua_State *L)
void lj_gc_finalize_udata(lua_State *L)
{
while (gcref(G(L)->gc.mmudata) != NULL)
gc_finalize(L);
}
#if LJ_HASFFI
/* Finalize all cdata objects from finalizer table. */
void lj_gc_finalize_cdata(lua_State *L)
{
global_State *g = G(L);
CTState *cts = ctype_ctsG(g);
if (cts) {
GCtab *t = cts->finalizer;
Node *node = noderef(t->node);
ptrdiff_t i;
setgcrefnull(t->metatable); /* Mark finalizer table as disabled. */
for (i = (ptrdiff_t)t->hmask; i >= 0; i--)
if (!tvisnil(&node[i].val) && tviscdata(&node[i].key)) {
GCobj *o = gcV(&node[i].key);
TValue tmp;
o->gch.marked &= ~LJ_GC_CDATA_FIN;
copyTV(L, &tmp, &node[i].val);
setnilV(&node[i].val);
gc_call_finalizer(g, L, &tmp, o);
}
}
}
#endif
/* Free all remaining GC objects. */
void lj_gc_freeall(global_State *g)
{