1 files changed, 0 insertions, 1728 deletions

diff --git a/src/lua/lgc.c b/src/lua/lgc.c
deleted file mode 100644
index b360eed..0000000
--- a/src/lua/lgc.c
+++ /dev/null
@@ -1,1728 +0,0 @@
-/*
-** $Id: lgc.c $
-** Garbage Collector
-** See Copyright Notice in lua.h
-*/
-
-#define lgc_c
-#define LUA_CORE
-
-#include "lprefix.h"
-
-#include <stdio.h>
-#include <string.h>
-
-
-#include "lua.h"
-
-#include "ldebug.h"
-#include "ldo.h"
-#include "lfunc.h"
-#include "lgc.h"
-#include "lmem.h"
-#include "lobject.h"
-#include "lstate.h"
-#include "lstring.h"
-#include "ltable.h"
-#include "ltm.h"
-
-
-/*
-** Maximum number of elements to sweep in each single step.
-** (Large enough to dissipate fixed overheads but small enough
-** to allow small steps for the collector.)
-*/
-#define GCSWEEPMAX      100
-
-/*
-** Maximum number of finalizers to call in each single step.
-*/
-#define GCFINMAX        10
-
-
-/*
-** Cost of calling one finalizer.
-*/
-#define GCFINALIZECOST  50
-
-
-/*
-** The equivalent, in bytes, of one unit of "work" (visiting a slot,
-** sweeping an object, etc.)
-*/
-#define WORK2MEM        sizeof(TValue)
-
-
-/*
-** macro to adjust 'pause': 'pause' is actually used like
-** 'pause / PAUSEADJ' (value chosen by tests)
-*/
-#define PAUSEADJ                100
-
-
-/* mask with all color bits */
-#define maskcolors      (bitmask(BLACKBIT) | WHITEBITS)
-
-/* mask with all GC bits */
-#define maskgcbits      (maskcolors | AGEBITS)
-
-
-/* macro to erase all color bits then set only the current white bit */
-#define makewhite(g,x)  \
-  (x->marked = cast_byte((x->marked & ~maskcolors) | luaC_white(g)))
-
-/* make an object gray (neither white nor black) */
-#define set2gray(x)     resetbits(x->marked, maskcolors)
-
-
-/* make an object black (coming from any color) */
-#define set2black(x)  \
-  (x->marked = cast_byte((x->marked & ~WHITEBITS) | bitmask(BLACKBIT)))
-
-
-#define valiswhite(x)   (iscollectable(x) && iswhite(gcvalue(x)))
-
-#define keyiswhite(n)   (keyiscollectable(n) && iswhite(gckey(n)))
-
-
-/*
-** Protected access to objects in values
-*/
-#define gcvalueN(o)     (iscollectable(o) ? gcvalue(o) : NULL)
-
-
-#define markvalue(g,o) { checkliveness(g->mainthread,o); \
-  if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); }
-
-#define markkey(g, n)   { if keyiswhite(n) reallymarkobject(g,gckey(n)); }
-
-#define markobject(g,t) { if (iswhite(t)) reallymarkobject(g, obj2gco(t)); }
-
-/*
-** mark an object that can be NULL (either because it is really optional,
-** or it was stripped as debug info, or inside an uncompleted structure)
-*/
-#define markobjectN(g,t)        { if (t) markobject(g,t); }
-
-static void reallymarkobject (global_State *g, GCObject *o);
-static lu_mem atomic (lua_State *L);
-static void entersweep (lua_State *L);
-
-
-/*
-** {======================================================
-** Generic functions
-** =======================================================
-*/
-
-
-/*
-** one after last element in a hash array
-*/
-#define gnodelast(h)    gnode(h, cast_sizet(sizenode(h)))
-
-
-static GCObject **getgclist (GCObject *o) {
-  switch (o->tt) {
-    case LUA_VTABLE: return &gco2t(o)->gclist;
-    case LUA_VLCL: return &gco2lcl(o)->gclist;
-    case LUA_VCCL: return &gco2ccl(o)->gclist;
-    case LUA_VTHREAD: return &gco2th(o)->gclist;
-    case LUA_VPROTO: return &gco2p(o)->gclist;
-    case LUA_VUSERDATA: {
-      Udata *u = gco2u(o);
-      lua_assert(u->nuvalue > 0);
-      return &u->gclist;
-    }
-    default: lua_assert(0); return 0;
-  }
-}
-
-
-/*
-** Link a collectable object 'o' with a known type into the list 'p'.
-** (Must be a macro to access the 'gclist' field in different types.)
-*/
-#define linkgclist(o,p) linkgclist_(obj2gco(o), &(o)->gclist, &(p))
-
-static void linkgclist_ (GCObject *o, GCObject **pnext, GCObject **list) {
-  lua_assert(!isgray(o));  /* cannot be in a gray list */
-  *pnext = *list;
-  *list = o;
-  set2gray(o);  /* now it is */
-}
-
-
-/*
-** Link a generic collectable object 'o' into the list 'p'.
-*/
-#define linkobjgclist(o,p) linkgclist_(obj2gco(o), getgclist(o), &(p))
-
-
-
-/*
-** Clear keys for empty entries in tables. If entry is empty, mark its
-** entry as dead. This allows the collection of the key, but keeps its
-** entry in the table: its removal could break a chain and could break
-** a table traversal.  Other places never manipulate dead keys, because
-** its associated empty value is enough to signal that the entry is
-** logically empty.
-*/
-static void clearkey (Node *n) {
-  lua_assert(isempty(gval(n)));
-  if (keyiscollectable(n))
-    setdeadkey(n);  /* unused key; remove it */
-}
-
-
-/*
-** tells whether a key or value can be cleared from a weak
-** table. Non-collectable objects are never removed from weak
-** tables. Strings behave as 'values', so are never removed too. for
-** other objects: if really collected, cannot keep them; for objects
-** being finalized, keep them in keys, but not in values
-*/
-static int iscleared (global_State *g, const GCObject *o) {
-  if (o == NULL) return 0;  /* non-collectable value */
-  else if (novariant(o->tt) == LUA_TSTRING) {
-    markobject(g, o);  /* strings are 'values', so are never weak */
-    return 0;
-  }
-  else return iswhite(o);
-}
-
-
-/*
-** Barrier that moves collector forward, that is, marks the white object
-** 'v' being pointed by the black object 'o'.  In the generational
-** mode, 'v' must also become old, if 'o' is old; however, it cannot
-** be changed directly to OLD, because it may still point to non-old
-** objects. So, it is marked as OLD0. In the next cycle it will become
-** OLD1, and in the next it will finally become OLD (regular old). By
-** then, any object it points to will also be old.  If called in the
-** incremental sweep phase, it clears the black object to white (sweep
-** it) to avoid other barrier calls for this same object. (That cannot
-** be done is generational mode, as its sweep does not distinguish
-** whites from deads.)
-*/
-void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
-  global_State *g = G(L);
-  lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
-  if (keepinvariant(g)) {  /* must keep invariant? */
-    reallymarkobject(g, v);  /* restore invariant */
-    if (isold(o)) {
-      lua_assert(!isold(v));  /* white object could not be old */
-      setage(v, G_OLD0);  /* restore generational invariant */
-    }
-  }
-  else {  /* sweep phase */
-    lua_assert(issweepphase(g));
-    if (g->gckind == KGC_INC)  /* incremental mode? */
-      makewhite(g, o);  /* mark 'o' as white to avoid other barriers */
-  }
-}
-
-
-/*
-** barrier that moves collector backward, that is, mark the black object
-** pointing to a white object as gray again.
-*/
-void luaC_barrierback_ (lua_State *L, GCObject *o) {
-  global_State *g = G(L);
-  lua_assert(isblack(o) && !isdead(g, o));
-  lua_assert((g->gckind == KGC_GEN) == (isold(o) && getage(o) != G_TOUCHED1));
-  if (getage(o) == G_TOUCHED2)  /* already in gray list? */
-    set2gray(o);  /* make it gray to become touched1 */
-  else  /* link it in 'grayagain' and paint it gray */
-    linkobjgclist(o, g->grayagain);
-  if (isold(o))  /* generational mode? */
-    setage(o, G_TOUCHED1);  /* touched in current cycle */
-}
-
-
-void luaC_fix (lua_State *L, GCObject *o) {
-  global_State *g = G(L);
-  lua_assert(g->allgc == o);  /* object must be 1st in 'allgc' list! */
-  set2gray(o);  /* they will be gray forever */
-  setage(o, G_OLD);  /* and old forever */
-  g->allgc = o->next;  /* remove object from 'allgc' list */
-  o->next = g->fixedgc;  /* link it to 'fixedgc' list */
-  g->fixedgc = o;
-}
-
-
-/*
-** create a new collectable object (with given type and size) and link
-** it to 'allgc' list.
-*/
-GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) {
-  global_State *g = G(L);
-  GCObject *o = cast(GCObject *, luaM_newobject(L, novariant(tt), sz));
-  o->marked = luaC_white(g);
-  o->tt = tt;
-  o->next = g->allgc;
-  g->allgc = o;
-  return o;
-}
-
-/* }====================================================== */
-
-
-
-/*
-** {======================================================
-** Mark functions
-** =======================================================
-*/
-
-
-/*
-** Mark an object.  Userdata with no user values, strings, and closed
-** upvalues are visited and turned black here.  Open upvalues are
-** already indirectly linked through their respective threads in the
-** 'twups' list, so they don't go to the gray list; nevertheless, they
-** are kept gray to avoid barriers, as their values will be revisited
-** by the thread or by 'remarkupvals'.  Other objects are added to the
-** gray list to be visited (and turned black) later.  Both userdata and
-** upvalues can call this function recursively, but this recursion goes
-** for at most two levels: An upvalue cannot refer to another upvalue
-** (only closures can), and a userdata's metatable must be a table.
-*/
-static void reallymarkobject (global_State *g, GCObject *o) {
-  switch (o->tt) {
-    case LUA_VSHRSTR:
-    case LUA_VLNGSTR: {
-      set2black(o);  /* nothing to visit */
-      break;
-    }
-    case LUA_VUPVAL: {
-      UpVal *uv = gco2upv(o);
-      if (upisopen(uv))
-        set2gray(uv);  /* open upvalues are kept gray */
-      else
-        set2black(uv);  /* closed upvalues are visited here */
-      markvalue(g, uv->v);  /* mark its content */
-      break;
-    }
-    case LUA_VUSERDATA: {
-      Udata *u = gco2u(o);
-      if (u->nuvalue == 0) {  /* no user values? */
-        markobjectN(g, u->metatable);  /* mark its metatable */
-        set2black(u);  /* nothing else to mark */
-        break;
-      }
-      /* else... */
-    }  /* FALLTHROUGH */
-    case LUA_VLCL: case LUA_VCCL: case LUA_VTABLE:
-    case LUA_VTHREAD: case LUA_VPROTO: {
-      linkobjgclist(o, g->gray);  /* to be visited later */
-      break;
-    }
-    default: lua_assert(0); break;
-  }
-}
-
-
-/*
-** mark metamethods for basic types
-*/
-static void markmt (global_State *g) {
-  int i;
-  for (i=0; i < LUA_NUMTAGS; i++)
-    markobjectN(g, g->mt[i]);
-}
-
-
-/*
-** mark all objects in list of being-finalized
-*/
-static lu_mem markbeingfnz (global_State *g) {
-  GCObject *o;
-  lu_mem count = 0;
-  for (o = g->tobefnz; o != NULL; o = o->next) {
-    count++;
-    markobject(g, o);
-  }
-  return count;
-}
-
-
-/*
-** For each non-marked thread, simulates a barrier between each open
-** upvalue and its value. (If the thread is collected, the value will be
-** assigned to the upvalue, but then it can be too late for the barrier
-** to act. The "barrier" does not need to check colors: A non-marked
-** thread must be young; upvalues cannot be older than their threads; so
-** any visited upvalue must be young too.) Also removes the thread from
-** the list, as it was already visited. Removes also threads with no
-** upvalues, as they have nothing to be checked. (If the thread gets an
-** upvalue later, it will be linked in the list again.)
-*/
-static int remarkupvals (global_State *g) {
-  lua_State *thread;
-  lua_State **p = &g->twups;
-  int work = 0;  /* estimate of how much work was done here */
-  while ((thread = *p) != NULL) {
-    work++;
-    if (!iswhite(thread) && thread->openupval != NULL)
-      p = &thread->twups;  /* keep marked thread with upvalues in the list */
-    else {  /* thread is not marked or without upvalues */
-      UpVal *uv;
-      lua_assert(!isold(thread) || thread->openupval == NULL);
-      *p = thread->twups;  /* remove thread from the list */
-      thread->twups = thread;  /* mark that it is out of list */
-      for (uv = thread->openupval; uv != NULL; uv = uv->u.open.next) {
-        lua_assert(getage(uv) <= getage(thread));
-        work++;
-        if (!iswhite(uv)) {  /* upvalue already visited? */
-          lua_assert(upisopen(uv) && isgray(uv));
-          markvalue(g, uv->v);  /* mark its value */
-        }
-      }
-    }
-  }
-  return work;
-}
-
-
-static void cleargraylists (global_State *g) {
-  g->gray = g->grayagain = NULL;
-  g->weak = g->allweak = g->ephemeron = NULL;
-}
-
-
-/*
-** mark root set and reset all gray lists, to start a new collection
-*/
-static void restartcollection (global_State *g) {
-  cleargraylists(g);
-  markobject(g, g->mainthread);
-  markvalue(g, &g->l_registry);
-  markmt(g);
-  markbeingfnz(g);  /* mark any finalizing object left from previous cycle */
-}
-
-/* }====================================================== */
-
-
-/*
-** {======================================================
-** Traverse functions
-** =======================================================
-*/
-
-
-/*
-** Check whether object 'o' should be kept in the 'grayagain' list for
-** post-processing by 'correctgraylist'. (It could put all old objects
-** in the list and leave all the work to 'correctgraylist', but it is
-** more efficient to avoid adding elements that will be removed.) Only
-** TOUCHED1 objects need to be in the list. TOUCHED2 doesn't need to go
-** back to a gray list, but then it must become OLD. (That is what
-** 'correctgraylist' does when it finds a TOUCHED2 object.)
-*/
-static void genlink (global_State *g, GCObject *o) {
-  lua_assert(isblack(o));
-  if (getage(o) == G_TOUCHED1) {  /* touched in this cycle? */
-    linkobjgclist(o, g->grayagain);  /* link it back in 'grayagain' */
-  }  /* everything else do not need to be linked back */
-  else if (getage(o) == G_TOUCHED2)
-    changeage(o, G_TOUCHED2, G_OLD);  /* advance age */
-}
-
-
-/*
-** Traverse a table with weak values and link it to proper list. During
-** propagate phase, keep it in 'grayagain' list, to be revisited in the
-** atomic phase. In the atomic phase, if table has any white value,
-** put it in 'weak' list, to be cleared.
-*/
-static void traverseweakvalue (global_State *g, Table *h) {
-  Node *n, *limit = gnodelast(h);
-  /* if there is array part, assume it may have white values (it is not
-     worth traversing it now just to check) */
-  int hasclears = (h->alimit > 0);
-  for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
-    if (isempty(gval(n)))  /* entry is empty? */
-      clearkey(n);  /* clear its key */
-    else {
-      lua_assert(!keyisnil(n));
-      markkey(g, n);
-      if (!hasclears && iscleared(g, gcvalueN(gval(n))))  /* a white value? */
-        hasclears = 1;  /* table will have to be cleared */
-    }
-  }
-  if (g->gcstate == GCSatomic && hasclears)
-    linkgclist(h, g->weak);  /* has to be cleared later */
-  else
-    linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
-}
-
-
-/*
-** Traverse an ephemeron table and link it to proper list. Returns true
-** iff any object was marked during this traversal (which implies that
-** convergence has to continue). During propagation phase, keep table
-** in 'grayagain' list, to be visited again in the atomic phase. In
-** the atomic phase, if table has any white->white entry, it has to
-** be revisited during ephemeron convergence (as that key may turn
-** black). Otherwise, if it has any white key, table has to be cleared
-** (in the atomic phase). In generational mode, some tables
-** must be kept in some gray list for post-processing; this is done
-** by 'genlink'.
-*/
-static int traverseephemeron (global_State *g, Table *h, int inv) {
-  int marked = 0;  /* true if an object is marked in this traversal */
-  int hasclears = 0;  /* true if table has white keys */
-  int hasww = 0;  /* true if table has entry "white-key -> white-value" */
-  unsigned int i;
-  unsigned int asize = luaH_realasize(h);
-  unsigned int nsize = sizenode(h);
-  /* traverse array part */
-  for (i = 0; i < asize; i++) {
-    if (valiswhite(&h->array[i])) {
-      marked = 1;
-      reallymarkobject(g, gcvalue(&h->array[i]));
-    }
-  }
-  /* traverse hash part; if 'inv', traverse descending
-     (see 'convergeephemerons') */
-  for (i = 0; i < nsize; i++) {
-    Node *n = inv ? gnode(h, nsize - 1 - i) : gnode(h, i);
-    if (isempty(gval(n)))  /* entry is empty? */
-      clearkey(n);  /* clear its key */
-    else if (iscleared(g, gckeyN(n))) {  /* key is not marked (yet)? */
-      hasclears = 1;  /* table must be cleared */
-      if (valiswhite(gval(n)))  /* value not marked yet? */
-        hasww = 1;  /* white-white entry */
-    }
-    else if (valiswhite(gval(n))) {  /* value not marked yet? */
-      marked = 1;
-      reallymarkobject(g, gcvalue(gval(n)));  /* mark it now */
-    }
-  }
-  /* link table into proper list */
-  if (g->gcstate == GCSpropagate)
-    linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
-  else if (hasww)  /* table has white->white entries? */
-    linkgclist(h, g->ephemeron);  /* have to propagate again */
-  else if (hasclears)  /* table has white keys? */
-    linkgclist(h, g->allweak);  /* may have to clean white keys */
-  else
-    genlink(g, obj2gco(h));  /* check whether collector still needs to see it */
-  return marked;
-}
-
-
-static void traversestrongtable (global_State *g, Table *h) {
-  Node *n, *limit = gnodelast(h);
-  unsigned int i;
-  unsigned int asize = luaH_realasize(h);
-  for (i = 0; i < asize; i++)  /* traverse array part */
-    markvalue(g, &h->array[i]);
-  for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
-    if (isempty(gval(n)))  /* entry is empty? */
-      clearkey(n);  /* clear its key */
-    else {
-      lua_assert(!keyisnil(n));
-      markkey(g, n);
-      markvalue(g, gval(n));
-    }
-  }
-  genlink(g, obj2gco(h));
-}
-
-
-static lu_mem traversetable (global_State *g, Table *h) {
-  const char *weakkey, *weakvalue;
-  const TValue *mode = gfasttm(g, h->metatable, TM_MODE);
-  markobjectN(g, h->metatable);
-  if (mode && ttisstring(mode) &&  /* is there a weak mode? */
-      (cast_void(weakkey = strchr(svalue(mode), 'k')),
-       cast_void(weakvalue = strchr(svalue(mode), 'v')),
-       (weakkey || weakvalue))) {  /* is really weak? */
-    if (!weakkey)  /* strong keys? */
-      traverseweakvalue(g, h);
-    else if (!weakvalue)  /* strong values? */
-      traverseephemeron(g, h, 0);
-    else  /* all weak */
-      linkgclist(h, g->allweak);  /* nothing to traverse now */
-  }
-  else  /* not weak */
-    traversestrongtable(g, h);
-  return 1 + h->alimit + 2 * allocsizenode(h);
-}
-
-
-static int traverseudata (global_State *g, Udata *u) {
-  int i;
-  markobjectN(g, u->metatable);  /* mark its metatable */
-  for (i = 0; i < u->nuvalue; i++)
-    markvalue(g, &u->uv[i].uv);
-  genlink(g, obj2gco(u));
-  return 1 + u->nuvalue;
-}
-
-
-/*
-** Traverse a prototype. (While a prototype is being build, its
-** arrays can be larger than needed; the extra slots are filled with
-** NULL, so the use of 'markobjectN')
-*/
-static int traverseproto (global_State *g, Proto *f) {
-  int i;
-  markobjectN(g, f->source);
-  for (i = 0; i < f->sizek; i++)  /* mark literals */
-    markvalue(g, &f->k[i]);
-  for (i = 0; i < f->sizeupvalues; i++)  /* mark upvalue names */
-    markobjectN(g, f->upvalues[i].name);
-  for (i = 0; i < f->sizep; i++)  /* mark nested protos */
-    markobjectN(g, f->p[i]);
-  for (i = 0; i < f->sizelocvars; i++)  /* mark local-variable names */
-    markobjectN(g, f->locvars[i].varname);
-  return 1 + f->sizek + f->sizeupvalues + f->sizep + f->sizelocvars;
-}
-
-
-static int traverseCclosure (global_State *g, CClosure *cl) {
-  int i;
-  for (i = 0; i < cl->nupvalues; i++)  /* mark its upvalues */
-    markvalue(g, &cl->upvalue[i]);
-  return 1 + cl->nupvalues;
-}
-
-/*
-** Traverse a Lua closure, marking its prototype and its upvalues.
-** (Both can be NULL while closure is being created.)
-*/
-static int traverseLclosure (global_State *g, LClosure *cl) {
-  int i;
-  markobjectN(g, cl->p);  /* mark its prototype */
-  for (i = 0; i < cl->nupvalues; i++) {  /* visit its upvalues */
-    UpVal *uv = cl->upvals[i];
-    markobjectN(g, uv);  /* mark upvalue */
-  }
-  return 1 + cl->nupvalues;
-}
-
-
-/*
-** Traverse a thread, marking the elements in the stack up to its top
-** and cleaning the rest of the stack in the final traversal. That
-** ensures that the entire stack have valid (non-dead) objects.
-** Threads have no barriers. In gen. mode, old threads must be visited
-** at every cycle, because they might point to young objects.  In inc.
-** mode, the thread can still be modified before the end of the cycle,
-** and therefore it must be visited again in the atomic phase. To ensure
-** these visits, threads must return to a gray list if they are not new
-** (which can only happen in generational mode) or if the traverse is in
-** the propagate phase (which can only happen in incremental mode).
-*/
-static int traversethread (global_State *g, lua_State *th) {
-  UpVal *uv;
-  StkId o = th->stack;
-  if (isold(th) || g->gcstate == GCSpropagate)
-    linkgclist(th, g->grayagain);  /* insert into 'grayagain' list */
-  if (o == NULL)
-    return 1;  /* stack not completely built yet */
-  lua_assert(g->gcstate == GCSatomic ||
-             th->openupval == NULL || isintwups(th));
-  for (; o < th->top; o++)  /* mark live elements in the stack */
-    markvalue(g, s2v(o));
-  for (uv = th->openupval; uv != NULL; uv = uv->u.open.next)
-    markobject(g, uv);  /* open upvalues cannot be collected */
-  if (g->gcstate == GCSatomic) {  /* final traversal? */
-    for (; o < th->stack_last + EXTRA_STACK; o++)
-      setnilvalue(s2v(o));  /* clear dead stack slice */
-    /* 'remarkupvals' may have removed thread from 'twups' list */
-    if (!isintwups(th) && th->openupval != NULL) {
-      th->twups = g->twups;  /* link it back to the list */
-      g->twups = th;
-    }
-  }
-  else if (!g->gcemergency)
-    luaD_shrinkstack(th); /* do not change stack in emergency cycle */
-  return 1 + stacksize(th);
-}
-
-
-/*
-** traverse one gray object, turning it to black.
-*/
-static lu_mem propagatemark (global_State *g) {
-  GCObject *o = g->gray;
-  nw2black(o);
-  g->gray = *getgclist(o);  /* remove from 'gray' list */
-  switch (o->tt) {
-    case LUA_VTABLE: return traversetable(g, gco2t(o));
-    case LUA_VUSERDATA: return traverseudata(g, gco2u(o));
-    case LUA_VLCL: return traverseLclosure(g, gco2lcl(o));
-    case LUA_VCCL: return traverseCclosure(g, gco2ccl(o));
-    case LUA_VPROTO: return traverseproto(g, gco2p(o));
-    case LUA_VTHREAD: return traversethread(g, gco2th(o));
-    default: lua_assert(0); return 0;
-  }
-}
-
-
-static lu_mem propagateall (global_State *g) {
-  lu_mem tot = 0;
-  while (g->gray)
-    tot += propagatemark(g);
-  return tot;
-}
-
-
-/*
-** Traverse all ephemeron tables propagating marks from keys to values.
-** Repeat until it converges, that is, nothing new is marked. 'dir'
-** inverts the direction of the traversals, trying to speed up
-** convergence on chains in the same table.
-**
-*/
-static void convergeephemerons (global_State *g) {
-  int changed;
-  int dir = 0;
-  do {
-    GCObject *w;
-    GCObject *next = g->ephemeron;  /* get ephemeron list */
-    g->ephemeron = NULL;  /* tables may return to this list when traversed */
-    changed = 0;
-    while ((w = next) != NULL) {  /* for each ephemeron table */
-      Table *h = gco2t(w);
-      next = h->gclist;  /* list is rebuilt during loop */
-      nw2black(h);  /* out of the list (for now) */
-      if (traverseephemeron(g, h, dir)) {  /* marked some value? */
-        propagateall(g);  /* propagate changes */
-        changed = 1;  /* will have to revisit all ephemeron tables */
-      }
-    }
-    dir = !dir;  /* invert direction next time */
-  } while (changed);  /* repeat until no more changes */
-}
-
-/* }====================================================== */
-
-
-/*
-** {======================================================
-** Sweep Functions
-** =======================================================
-*/
-
-
-/*
-** clear entries with unmarked keys from all weaktables in list 'l'
-*/
-static void clearbykeys (global_State *g, GCObject *l) {
-  for (; l; l = gco2t(l)->gclist) {
-    Table *h = gco2t(l);
-    Node *limit = gnodelast(h);
-    Node *n;
-    for (n = gnode(h, 0); n < limit; n++) {
-      if (iscleared(g, gckeyN(n)))  /* unmarked key? */
-        setempty(gval(n));  /* remove entry */
-      if (isempty(gval(n)))  /* is entry empty? */
-        clearkey(n);  /* clear its key */
-    }
-  }
-}
-
-
-/*
-** clear entries with unmarked values from all weaktables in list 'l' up
-** to element 'f'
-*/
-static void clearbyvalues (global_State *g, GCObject *l, GCObject *f) {
-  for (; l != f; l = gco2t(l)->gclist) {
-    Table *h = gco2t(l);
-    Node *n, *limit = gnodelast(h);
-    unsigned int i;
-    unsigned int asize = luaH_realasize(h);
-    for (i = 0; i < asize; i++) {
-      TValue *o = &h->array[i];
-      if (iscleared(g, gcvalueN(o)))  /* value was collected? */
-        setempty(o);  /* remove entry */
-    }
-    for (n = gnode(h, 0); n < limit; n++) {
-      if (iscleared(g, gcvalueN(gval(n))))  /* unmarked value? */
-        setempty(gval(n));  /* remove entry */
-      if (isempty(gval(n)))  /* is entry empty? */
-        clearkey(n);  /* clear its key */
-    }
-  }
-}
-
-
-static void freeupval (lua_State *L, UpVal *uv) {
-  if (upisopen(uv))
-    luaF_unlinkupval(uv);
-  luaM_free(L, uv);
-}
-
-
-static void freeobj (lua_State *L, GCObject *o) {
-  switch (o->tt) {
-    case LUA_VPROTO:
-      luaF_freeproto(L, gco2p(o));
-      break;
-    case LUA_VUPVAL:
-      freeupval(L, gco2upv(o));
-      break;
-    case LUA_VLCL: {
-      LClosure *cl = gco2lcl(o);
-      luaM_freemem(L, cl, sizeLclosure(cl->nupvalues));
-      break;
-    }
-    case LUA_VCCL: {
-      CClosure *cl = gco2ccl(o);
-      luaM_freemem(L, cl, sizeCclosure(cl->nupvalues));
-      break;
-    }
-    case LUA_VTABLE:
-      luaH_free(L, gco2t(o));
-      break;
-    case LUA_VTHREAD:
-      luaE_freethread(L, gco2th(o));
-      break;
-    case LUA_VUSERDATA: {
-      Udata *u = gco2u(o);
-      luaM_freemem(L, o, sizeudata(u->nuvalue, u->len));
-      break;
-    }
-    case LUA_VSHRSTR: {
-      TString *ts = gco2ts(o);
-      luaS_remove(L, ts);  /* remove it from hash table */
-      luaM_freemem(L, ts, sizelstring(ts->shrlen));
-      break;
-    }
-    case LUA_VLNGSTR: {
-      TString *ts = gco2ts(o);
-      luaM_freemem(L, ts, sizelstring(ts->u.lnglen));
-      break;
-    }
-    default: lua_assert(0);
-  }
-}
-
-
-/*
-** sweep at most 'countin' elements from a list of GCObjects erasing dead
-** objects, where a dead object is one marked with the old (non current)
-** white; change all non-dead objects back to white, preparing for next
-** collection cycle. Return where to continue the traversal or NULL if
-** list is finished. ('*countout' gets the number of elements traversed.)
-*/
-static GCObject **sweeplist (lua_State *L, GCObject **p, int countin,
-                             int *countout) {
-  global_State *g = G(L);
-  int ow = otherwhite(g);
-  int i;
-  int white = luaC_white(g);  /* current white */
-  for (i = 0; *p != NULL && i < countin; i++) {
-    GCObject *curr = *p;
-    int marked = curr->marked;
-    if (isdeadm(ow, marked)) {  /* is 'curr' dead? */
-      *p = curr->next;  /* remove 'curr' from list */
-      freeobj(L, curr);  /* erase 'curr' */
-    }
-    else {  /* change mark to 'white' */
-      curr->marked = cast_byte((marked & ~maskgcbits) | white);
-      p = &curr->next;  /* go to next element */
-    }
-  }
-  if (countout)
-    *countout = i;  /* number of elements traversed */
-  return (*p == NULL) ? NULL : p;
-}
-
-
-/*
-** sweep a list until a live object (or end of list)
-*/
-static GCObject **sweeptolive (lua_State *L, GCObject **p) {
-  GCObject **old = p;
-  do {
-    p = sweeplist(L, p, 1, NULL);
-  } while (p == old);
-  return p;
-}
-
-/* }====================================================== */
-
-
-/*
-** {======================================================
-** Finalization
-** =======================================================
-*/
-
-/*
-** If possible, shrink string table.
-*/
-static void checkSizes (lua_State *L, global_State *g) {
-  if (!g->gcemergency) {
-    if (g->strt.nuse < g->strt.size / 4) {  /* string table too big? */
-      l_mem olddebt = g->GCdebt;
-      luaS_resize(L, g->strt.size / 2);
-      g->GCestimate += g->GCdebt - olddebt;  /* correct estimate */
-    }
-  }
-}
-
-
-/*
-** Get the next udata to be finalized from the 'tobefnz' list, and
-** link it back into the 'allgc' list.
-*/
-static GCObject *udata2finalize (global_State *g) {
-  GCObject *o = g->tobefnz;  /* get first element */
-  lua_assert(tofinalize(o));
-  g->tobefnz = o->next;  /* remove it from 'tobefnz' list */
-  o->next = g->allgc;  /* return it to 'allgc' list */
-  g->allgc = o;
-  resetbit(o->marked, FINALIZEDBIT);  /* object is "normal" again */
-  if (issweepphase(g))
-    makewhite(g, o);  /* "sweep" object */
-  else if (getage(o) == G_OLD1)
-    g->firstold1 = o;  /* it is the first OLD1 object in the list */
-  return o;
-}
-
-
-static void dothecall (lua_State *L, void *ud) {
-  UNUSED(ud);
-  luaD_callnoyield(L, L->top - 2, 0);
-}
-
-
-static void GCTM (lua_State *L) {
-  global_State *g = G(L);
-  const TValue *tm;
-  TValue v;
-  lua_assert(!g->gcemergency);
-  setgcovalue(L, &v, udata2finalize(g));
-  tm = luaT_gettmbyobj(L, &v, TM_GC);
-  if (!notm(tm)) {  /* is there a finalizer? */
-    int status;
-    lu_byte oldah = L->allowhook;
-    int running  = g->gcrunning;
-    L->allowhook = 0;  /* stop debug hooks during GC metamethod */
-    g->gcrunning = 0;  /* avoid GC steps */
-    setobj2s(L, L->top++, tm);  /* push finalizer... */
-    setobj2s(L, L->top++, &v);  /* ... and its argument */
-    L->ci->callstatus |= CIST_FIN;  /* will run a finalizer */
-    status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
-    L->ci->callstatus &= ~CIST_FIN;  /* not running a finalizer anymore */
-    L->allowhook = oldah;  /* restore hooks */
-    g->gcrunning = running;  /* restore state */
-    if (l_unlikely(status != LUA_OK)) {  /* error while running __gc? */
-      luaE_warnerror(L, "__gc metamethod");
-      L->top--;  /* pops error object */
-    }
-  }
-}
-
-
-/*
-** Call a few finalizers
-*/
-static int runafewfinalizers (lua_State *L, int n) {
-  global_State *g = G(L);
-  int i;
-  for (i = 0; i < n && g->tobefnz; i++)
-    GCTM(L);  /* call one finalizer */
-  return i;
-}
-
-
-/*
-** call all pending finalizers
-*/
-static void callallpendingfinalizers (lua_State *L) {
-  global_State *g = G(L);
-  while (g->tobefnz)
-    GCTM(L);
-}
-
-
-/*
-** find last 'next' field in list 'p' list (to add elements in its end)
-*/
-static GCObject **findlast (GCObject **p) {
-  while (*p != NULL)
-    p = &(*p)->next;
-  return p;
-}
-
-
-/*
-** Move all unreachable objects (or 'all' objects) that need
-** finalization from list 'finobj' to list 'tobefnz' (to be finalized).
-** (Note that objects after 'finobjold1' cannot be white, so they
-** don't need to be traversed. In incremental mode, 'finobjold1' is NULL,
-** so the whole list is traversed.)
-*/
-static void separatetobefnz (global_State *g, int all) {
-  GCObject *curr;
-  GCObject **p = &g->finobj;
-  GCObject **lastnext = findlast(&g->tobefnz);
-  while ((curr = *p) != g->finobjold1) {  /* traverse all finalizable objects */
-    lua_assert(tofinalize(curr));
-    if (!(iswhite(curr) || all))  /* not being collected? */
-      p = &curr->next;  /* don't bother with it */
-    else {
-      if (curr == g->finobjsur)  /* removing 'finobjsur'? */
-        g->finobjsur = curr->next;  /* correct it */
-      *p = curr->next;  /* remove 'curr' from 'finobj' list */
-      curr->next = *lastnext;  /* link at the end of 'tobefnz' list */
-      *lastnext = curr;
-      lastnext = &curr->next;
-    }
-  }
-}
-
-
-/*
-** If pointer 'p' points to 'o', move it to the next element.
-*/
-static void checkpointer (GCObject **p, GCObject *o) {
-  if (o == *p)
-    *p = o->next;
-}
-
-
-/*
-** Correct pointers to objects inside 'allgc' list when
-** object 'o' is being removed from the list.
-*/
-static void correctpointers (global_State *g, GCObject *o) {
-  checkpointer(&g->survival, o);
-  checkpointer(&g->old1, o);
-  checkpointer(&g->reallyold, o);
-  checkpointer(&g->firstold1, o);
-}
-
-
-/*
-** if object 'o' has a finalizer, remove it from 'allgc' list (must
-** search the list to find it) and link it in 'finobj' list.
-*/
-void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
-  global_State *g = G(L);
-  if (tofinalize(o) ||                 /* obj. is already marked... */
-      gfasttm(g, mt, TM_GC) == NULL)   /* or has no finalizer? */
-    return;  /* nothing to be done */
-  else {  /* move 'o' to 'finobj' list */
-    GCObject **p;
-    if (issweepphase(g)) {
-      makewhite(g, o);  /* "sweep" object 'o' */
-      if (g->sweepgc == &o->next)  /* should not remove 'sweepgc' object */
-        g->sweepgc = sweeptolive(L, g->sweepgc);  /* change 'sweepgc' */
-    }
-    else
-      correctpointers(g, o);
-    /* search for pointer pointing to 'o' */
-    for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ }
-    *p = o->next;  /* remove 'o' from 'allgc' list */
-    o->next = g->finobj;  /* link it in 'finobj' list */
-    g->finobj = o;
-    l_setbit(o->marked, FINALIZEDBIT);  /* mark it as such */
-  }
-}
-
-/* }====================================================== */
-
-
-/*
-** {======================================================
-** Generational Collector
-** =======================================================
-*/
-
-static void setpause (global_State *g);
-
-
-/*
-** Sweep a list of objects to enter generational mode.  Deletes dead
-** objects and turns the non dead to old. All non-dead threads---which
-** are now old---must be in a gray list. Everything else is not in a
-** gray list. Open upvalues are also kept gray.
-*/
-static void sweep2old (lua_State *L, GCObject **p) {
-  GCObject *curr;
-  global_State *g = G(L);
-  while ((curr = *p) != NULL) {
-    if (iswhite(curr)) {  /* is 'curr' dead? */
-      lua_assert(isdead(g, curr));
-      *p = curr->next;  /* remove 'curr' from list */
-      freeobj(L, curr);  /* erase 'curr' */
-    }
-    else {  /* all surviving objects become old */
-      setage(curr, G_OLD);
-      if (curr->tt == LUA_VTHREAD) {  /* threads must be watched */
-        lua_State *th = gco2th(curr);
-        linkgclist(th, g->grayagain);  /* insert into 'grayagain' list */
-      }
-      else if (curr->tt == LUA_VUPVAL && upisopen(gco2upv(curr)))
-        set2gray(curr);  /* open upvalues are always gray */
-      else  /* everything else is black */
-        nw2black(curr);
-      p = &curr->next;  /* go to next element */
-    }
-  }
-}
-
-
-/*
-** Sweep for generational mode. Delete dead objects. (Because the
-** collection is not incremental, there are no "new white" objects
-** during the sweep. So, any white object must be dead.) For
-** non-dead objects, advance their ages and clear the color of
-** new objects. (Old objects keep their colors.)
-** The ages of G_TOUCHED1 and G_TOUCHED2 objects cannot be advanced
-** here, because these old-generation objects are usually not swept
-** here.  They will all be advanced in 'correctgraylist'. That function
-** will also remove objects turned white here from any gray list.
-*/
-static GCObject **sweepgen (lua_State *L, global_State *g, GCObject **p,
-                            GCObject *limit, GCObject **pfirstold1) {
-  static const lu_byte nextage[] = {
-    G_SURVIVAL,  /* from G_NEW */
-    G_OLD1,      /* from G_SURVIVAL */
-    G_OLD1,      /* from G_OLD0 */
-    G_OLD,       /* from G_OLD1 */
-    G_OLD,       /* from G_OLD (do not change) */
-    G_TOUCHED1,  /* from G_TOUCHED1 (do not change) */
-    G_TOUCHED2   /* from G_TOUCHED2 (do not change) */
-  };
-  int white = luaC_white(g);
-  GCObject *curr;
-  while ((curr = *p) != limit) {
-    if (iswhite(curr)) {  /* is 'curr' dead? */
-      lua_assert(!isold(curr) && isdead(g, curr));
-      *p = curr->next;  /* remove 'curr' from list */
-      freeobj(L, curr);  /* erase 'curr' */
-    }
-    else {  /* correct mark and age */
-      if (getage(curr) == G_NEW) {  /* new objects go back to white */
-        int marked = curr->marked & ~maskgcbits;  /* erase GC bits */
-        curr->marked = cast_byte(marked | G_SURVIVAL | white);
-      }
-      else {  /* all other objects will be old, and so keep their color */
-        setage(curr, nextage[getage(curr)]);
-        if (getage(curr) == G_OLD1 && *pfirstold1 == NULL)
-          *pfirstold1 = curr;  /* first OLD1 object in the list */
-      }
-      p = &curr->next;  /* go to next element */
-    }
-  }
-  return p;
-}
-
-
-/*
-** Traverse a list making all its elements white and clearing their
-** age. In incremental mode, all objects are 'new' all the time,
-** except for fixed strings (which are always old).
-*/
-static void whitelist (global_State *g, GCObject *p) {
-  int white = luaC_white(g);
-  for (; p != NULL; p = p->next)
-    p->marked = cast_byte((p->marked & ~maskgcbits) | white);
-}
-
-
-/*
-** Correct a list of gray objects. Return pointer to where rest of the
-** list should be linked.
-** Because this correction is done after sweeping, young objects might
-** be turned white and still be in the list. They are only removed.
-** 'TOUCHED1' objects are advanced to 'TOUCHED2' and remain on the list;
-** Non-white threads also remain on the list; 'TOUCHED2' objects become
-** regular old; they and anything else are removed from the list.
-*/
-static GCObject **correctgraylist (GCObject **p) {
-  GCObject *curr;
-  while ((curr = *p) != NULL) {
-    GCObject **next = getgclist(curr);
-    if (iswhite(curr))
-      goto remove;  /* remove all white objects */
-    else if (getage(curr) == G_TOUCHED1) {  /* touched in this cycle? */
-      lua_assert(isgray(curr));
-      nw2black(curr);  /* make it black, for next barrier */
-      changeage(curr, G_TOUCHED1, G_TOUCHED2);
-      goto remain;  /* keep it in the list and go to next element */
-    }
-    else if (curr->tt == LUA_VTHREAD) {
-      lua_assert(isgray(curr));
-      goto remain;  /* keep non-white threads on the list */
-    }
-    else {  /* everything else is removed */
-      lua_assert(isold(curr));  /* young objects should be white here */
-      if (getage(curr) == G_TOUCHED2)  /* advance from TOUCHED2... */
-        changeage(curr, G_TOUCHED2, G_OLD);  /* ... to OLD */
-      nw2black(curr);  /* make object black (to be removed) */
-      goto remove;
-    }
-    remove: *p = *next; continue;
-    remain: p = next; continue;
-  }
-  return p;
-}
-
-
-/*
-** Correct all gray lists, coalescing them into 'grayagain'.
-*/
-static void correctgraylists (global_State *g) {
-  GCObject **list = correctgraylist(&g->grayagain);
-  *list = g->weak; g->weak = NULL;
-  list = correctgraylist(list);
-  *list = g->allweak; g->allweak = NULL;
-  list = correctgraylist(list);
-  *list = g->ephemeron; g->ephemeron = NULL;
-  correctgraylist(list);
-}
-
-
-/*
-** Mark black 'OLD1' objects when starting a new young collection.
-** Gray objects are already in some gray list, and so will be visited
-** in the atomic step.
-*/
-static void markold (global_State *g, GCObject *from, GCObject *to) {
-  GCObject *p;
-  for (p = from; p != to; p = p->next) {
-    if (getage(p) == G_OLD1) {
-      lua_assert(!iswhite(p));
-      changeage(p, G_OLD1, G_OLD);  /* now they are old */
-      if (isblack(p))
-        reallymarkobject(g, p);
-    }
-  }
-}
-
-
-/*
-** Finish a young-generation collection.
-*/
-static void finishgencycle (lua_State *L, global_State *g) {
-  correctgraylists(g);
-  checkSizes(L, g);
-  g->gcstate = GCSpropagate;  /* skip restart */
-  if (!g->gcemergency)
-    callallpendingfinalizers(L);
-}
-
-
-/*
-** Does a young collection. First, mark 'OLD1' objects. Then does the
-** atomic step. Then, sweep all lists and advance pointers. Finally,
-** finish the collection.
-*/
-static void youngcollection (lua_State *L, global_State *g) {
-  GCObject **psurvival;  /* to point to first non-dead survival object */
-  GCObject *dummy;  /* dummy out parameter to 'sweepgen' */
-  lua_assert(g->gcstate == GCSpropagate);
-  if (g->firstold1) {  /* are there regular OLD1 objects? */
-    markold(g, g->firstold1, g->reallyold);  /* mark them */
-    g->firstold1 = NULL;  /* no more OLD1 objects (for now) */
-  }
-  markold(g, g->finobj, g->finobjrold);
-  markold(g, g->tobefnz, NULL);
-  atomic(L);
-
-  /* sweep nursery and get a pointer to its last live element */
-  g->gcstate = GCSswpallgc;
-  psurvival = sweepgen(L, g, &g->allgc, g->survival, &g->firstold1);
-  /* sweep 'survival' */
-  sweepgen(L, g, psurvival, g->old1, &g->firstold1);
-  g->reallyold = g->old1;
-  g->old1 = *psurvival;  /* 'survival' survivals are old now */
-  g->survival = g->allgc;  /* all news are survivals */
-
-  /* repeat for 'finobj' lists */
-  dummy = NULL;  /* no 'firstold1' optimization for 'finobj' lists */
-  psurvival = sweepgen(L, g, &g->finobj, g->finobjsur, &dummy);
-  /* sweep 'survival' */
-  sweepgen(L, g, psurvival, g->finobjold1, &dummy);
-  g->finobjrold = g->finobjold1;
-  g->finobjold1 = *psurvival;  /* 'survival' survivals are old now */
-  g->finobjsur = g->finobj;  /* all news are survivals */
-
-  sweepgen(L, g, &g->tobefnz, NULL, &dummy);
-  finishgencycle(L, g);
-}
-
-
-/*
-** Clears all gray lists, sweeps objects, and prepare sublists to enter
-** generational mode. The sweeps remove dead objects and turn all
-** surviving objects to old. Threads go back to 'grayagain'; everything
-** else is turned black (not in any gray list).
-*/
-static void atomic2gen (lua_State *L, global_State *g) {
-  cleargraylists(g);
-  /* sweep all elements making them old */
-  g->gcstate = GCSswpallgc;
-  sweep2old(L, &g->allgc);
-  /* everything alive now is old */
-  g->reallyold = g->old1 = g->survival = g->allgc;
-  g->firstold1 = NULL;  /* there are no OLD1 objects anywhere */
-
-  /* repeat for 'finobj' lists */
-  sweep2old(L, &g->finobj);
-  g->finobjrold = g->finobjold1 = g->finobjsur = g->finobj;
-
-  sweep2old(L, &g->tobefnz);
-
-  g->gckind = KGC_GEN;
-  g->lastatomic = 0;
-  g->GCestimate = gettotalbytes(g);  /* base for memory control */
-  finishgencycle(L, g);
-}
-
-
-/*
-** Enter generational mode. Must go until the end of an atomic cycle
-** to ensure that all objects are correctly marked and weak tables
-** are cleared. Then, turn all objects into old and finishes the
-** collection.
-*/
-static lu_mem entergen (lua_State *L, global_State *g) {
-  lu_mem numobjs;
-  luaC_runtilstate(L, bitmask(GCSpause));  /* prepare to start a new cycle */
-  luaC_runtilstate(L, bitmask(GCSpropagate));  /* start new cycle */
-  numobjs = atomic(L);  /* propagates all and then do the atomic stuff */
-  atomic2gen(L, g);
-  return numobjs;
-}
-
-
-/*
-** Enter incremental mode. Turn all objects white, make all
-** intermediate lists point to NULL (to avoid invalid pointers),
-** and go to the pause state.
-*/
-static void enterinc (global_State *g) {
-  whitelist(g, g->allgc);
-  g->reallyold = g->old1 = g->survival = NULL;
-  whitelist(g, g->finobj);
-  whitelist(g, g->tobefnz);
-  g->finobjrold = g->finobjold1 = g->finobjsur = NULL;
-  g->gcstate = GCSpause;
-  g->gckind = KGC_INC;
-  g->lastatomic = 0;
-}
-
-
-/*
-** Change collector mode to 'newmode'.
-*/
-void luaC_changemode (lua_State *L, int newmode) {
-  global_State *g = G(L);
-  if (newmode != g->gckind) {
-    if (newmode == KGC_GEN)  /* entering generational mode? */
-      entergen(L, g);
-    else
-      enterinc(g);  /* entering incremental mode */
-  }
-  g->lastatomic = 0;
-}
-
-
-/*
-** Does a full collection in generational mode.
-*/
-static lu_mem fullgen (lua_State *L, global_State *g) {
-  enterinc(g);
-  return entergen(L, g);
-}
-
-
-/*
-** Set debt for the next minor collection, which will happen when
-** memory grows 'genminormul'%.
-*/
-static void setminordebt (global_State *g) {
-  luaE_setdebt(g, -(cast(l_mem, (gettotalbytes(g) / 100)) * g->genminormul));
-}
-
-
-/*
-** Does a major collection after last collection was a "bad collection".
-**
-** When the program is building a big structure, it allocates lots of
-** memory but generates very little garbage. In those scenarios,
-** the generational mode just wastes time doing small collections, and
-** major collections are frequently what we call a "bad collection", a
-** collection that frees too few objects. To avoid the cost of switching
-** between generational mode and the incremental mode needed for full
-** (major) collections, the collector tries to stay in incremental mode
-** after a bad collection, and to switch back to generational mode only
-** after a "good" collection (one that traverses less than 9/8 objects
-** of the previous one).
-** The collector must choose whether to stay in incremental mode or to
-** switch back to generational mode before sweeping. At this point, it
-** does not know the real memory in use, so it cannot use memory to
-** decide whether to return to generational mode. Instead, it uses the
-** number of objects traversed (returned by 'atomic') as a proxy. The
-** field 'g->lastatomic' keeps this count from the last collection.
-** ('g->lastatomic != 0' also means that the last collection was bad.)
-*/
-static void stepgenfull (lua_State *L, global_State *g) {
-  lu_mem newatomic;  /* count of traversed objects */
-  lu_mem lastatomic = g->lastatomic;  /* count from last collection */
-  if (g->gckind == KGC_GEN)  /* still in generational mode? */
-    enterinc(g);  /* enter incremental mode */
-  luaC_runtilstate(L, bitmask(GCSpropagate));  /* start new cycle */
-  newatomic = atomic(L);  /* mark everybody */
-  if (newatomic < lastatomic + (lastatomic >> 3)) {  /* good collection? */
-    atomic2gen(L, g);  /* return to generational mode */
-    setminordebt(g);
-  }
-  else {  /* another bad collection; stay in incremental mode */
-    g->GCestimate = gettotalbytes(g);  /* first estimate */;
-    entersweep(L);
-    luaC_runtilstate(L, bitmask(GCSpause));  /* finish collection */
-    setpause(g);
-    g->lastatomic = newatomic;
-  }
-}
-
-
-/*
-** Does a generational "step".
-** Usually, this means doing a minor collection and setting the debt to
-** make another collection when memory grows 'genminormul'% larger.
-**
-** However, there are exceptions.  If memory grows 'genmajormul'%
-** larger than it was at the end of the last major collection (kept
-** in 'g->GCestimate'), the function does a major collection. At the
-** end, it checks whether the major collection was able to free a
-** decent amount of memory (at least half the growth in memory since
-** previous major collection). If so, the collector keeps its state,
-** and the next collection will probably be minor again. Otherwise,
-** we have what we call a "bad collection". In that case, set the field
-** 'g->lastatomic' to signal that fact, so that the next collection will
-** go to 'stepgenfull'.
-**
-** 'GCdebt <= 0' means an explicit call to GC step with "size" zero;
-** in that case, do a minor collection.
-*/
-static void genstep (lua_State *L, global_State *g) {
-  if (g->lastatomic != 0)  /* last collection was a bad one? */
-    stepgenfull(L, g);  /* do a full step */
-  else {
-    lu_mem majorbase = g->GCestimate;  /* memory after last major collection */
-    lu_mem majorinc = (majorbase / 100) * getgcparam(g->genmajormul);
-    if (g->GCdebt > 0 && gettotalbytes(g) > majorbase + majorinc) {
-      lu_mem numobjs = fullgen(L, g);  /* do a major collection */
-      if (gettotalbytes(g) < majorbase + (majorinc / 2)) {
-        /* collected at least half of memory growth since last major
-           collection; keep doing minor collections */
-        setminordebt(g);
-      }
-      else {  /* bad collection */
-        g->lastatomic = numobjs;  /* signal that last collection was bad */
-        setpause(g);  /* do a long wait for next (major) collection */
-      }
-    }
-    else {  /* regular case; do a minor collection */
-      youngcollection(L, g);
-      setminordebt(g);
-      g->GCestimate = majorbase;  /* preserve base value */
-    }
-  }
-  lua_assert(isdecGCmodegen(g));
-}
-
-/* }====================================================== */
-
-
-/*
-** {======================================================
-** GC control
-** =======================================================
-*/
-
-
-/*
-** Set the "time" to wait before starting a new GC cycle; cycle will
-** start when memory use hits the threshold of ('estimate' * pause /
-** PAUSEADJ). (Division by 'estimate' should be OK: it cannot be zero,
-** because Lua cannot even start with less than PAUSEADJ bytes).
-*/
-static void setpause (global_State *g) {
-  l_mem threshold, debt;
-  int pause = getgcparam(g->gcpause);
-  l_mem estimate = g->GCestimate / PAUSEADJ;  /* adjust 'estimate' */
-  lua_assert(estimate > 0);
-  threshold = (pause < MAX_LMEM / estimate)  /* overflow? */
-            ? estimate * pause  /* no overflow */
-            : MAX_LMEM;  /* overflow; truncate to maximum */
-  debt = gettotalbytes(g) - threshold;
-  if (debt > 0) debt = 0;
-  luaE_setdebt(g, debt);
-}
-
-
-/*
-** Enter first sweep phase.
-** The call to 'sweeptolive' makes the pointer point to an object
-** inside the list (instead of to the header), so that the real sweep do
-** not need to skip objects created between "now" and the start of the
-** real sweep.
-*/
-static void entersweep (lua_State *L) {
-  global_State *g = G(L);
-  g->gcstate = GCSswpallgc;
-  lua_assert(g->sweepgc == NULL);
-  g->sweepgc = sweeptolive(L, &g->allgc);
-}
-
-
-/*
-** Delete all objects in list 'p' until (but not including) object
-** 'limit'.
-*/
-static void deletelist (lua_State *L, GCObject *p, GCObject *limit) {
-  while (p != limit) {
-    GCObject *next = p->next;
-    freeobj(L, p);
-    p = next;
-  }
-}
-
-
-/*
-** Call all finalizers of the objects in the given Lua state, and
-** then free all objects, except for the main thread.
-*/
-void luaC_freeallobjects (lua_State *L) {
-  global_State *g = G(L);
-  luaC_changemode(L, KGC_INC);
-  separatetobefnz(g, 1);  /* separate all objects with finalizers */
-  lua_assert(g->finobj == NULL);
-  callallpendingfinalizers(L);
-  deletelist(L, g->allgc, obj2gco(g->mainthread));
-  deletelist(L, g->finobj, NULL);
-  deletelist(L, g->fixedgc, NULL);  /* collect fixed objects */
-  lua_assert(g->strt.nuse == 0);
-}
-
-
-static lu_mem atomic (lua_State *L) {
-  global_State *g = G(L);
-  lu_mem work = 0;
-  GCObject *origweak, *origall;
-  GCObject *grayagain = g->grayagain;  /* save original list */
-  g->grayagain = NULL;
-  lua_assert(g->ephemeron == NULL && g->weak == NULL);
-  lua_assert(!iswhite(g->mainthread));
-  g->gcstate = GCSatomic;
-  markobject(g, L);  /* mark running thread */
-  /* registry and global metatables may be changed by API */
-  markvalue(g, &g->l_registry);
-  markmt(g);  /* mark global metatables */
-  work += propagateall(g);  /* empties 'gray' list */
-  /* remark occasional upvalues of (maybe) dead threads */
-  work += remarkupvals(g);
-  work += propagateall(g);  /* propagate changes */
-  g->gray = grayagain;
-  work += propagateall(g);  /* traverse 'grayagain' list */
-  convergeephemerons(g);
-  /* at this point, all strongly accessible objects are marked. */
-  /* Clear values from weak tables, before checking finalizers */
-  clearbyvalues(g, g->weak, NULL);
-  clearbyvalues(g, g->allweak, NULL);
-  origweak = g->weak; origall = g->allweak;
-  separatetobefnz(g, 0);  /* separate objects to be finalized */
-  work += markbeingfnz(g);  /* mark objects that will be finalized */
-  work += propagateall(g);  /* remark, to propagate 'resurrection' */
-  convergeephemerons(g);
-  /* at this point, all resurrected objects are marked. */
-  /* remove dead objects from weak tables */
-  clearbykeys(g, g->ephemeron);  /* clear keys from all ephemeron tables */
-  clearbykeys(g, g->allweak);  /* clear keys from all 'allweak' tables */
-  /* clear values from resurrected weak tables */
-  clearbyvalues(g, g->weak, origweak);
-  clearbyvalues(g, g->allweak, origall);
-  luaS_clearcache(g);
-  g->currentwhite = cast_byte(otherwhite(g));  /* flip current white */
-  lua_assert(g->gray == NULL);
-  return work;  /* estimate of slots marked by 'atomic' */
-}
-
-
-static int sweepstep (lua_State *L, global_State *g,
-                      int nextstate, GCObject **nextlist) {
-  if (g->sweepgc) {
-    l_mem olddebt = g->GCdebt;
-    int count;
-    g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX, &count);
-    g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
-    return count;
-  }
-  else {  /* enter next state */
-    g->gcstate = nextstate;
-    g->sweepgc = nextlist;
-    return 0;  /* no work done */
-  }
-}
-
-
-static lu_mem singlestep (lua_State *L) {
-  global_State *g = G(L);
-  lu_mem work;
-  lua_assert(!g->gcstopem);  /* collector is not reentrant */
-  g->gcstopem = 1;  /* no emergency collections while collecting */
-  switch (g->gcstate) {
-    case GCSpause: {
-      restartcollection(g);
-      g->gcstate = GCSpropagate;
-      work = 1;
-      break;
-    }
-    case GCSpropagate: {
-      if (g->gray == NULL) {  /* no more gray objects? */
-        g->gcstate = GCSenteratomic;  /* finish propagate phase */
-        work = 0;
-      }
-      else
-        work = propagatemark(g);  /* traverse one gray object */
-      break;
-    }
-    case GCSenteratomic: {
-      work = atomic(L);  /* work is what was traversed by 'atomic' */
-      entersweep(L);
-      g->GCestimate = gettotalbytes(g);  /* first estimate */;
-      break;
-    }
-    case GCSswpallgc: {  /* sweep "regular" objects */
-      work = sweepstep(L, g, GCSswpfinobj, &g->finobj);
-      break;
-    }
-    case GCSswpfinobj: {  /* sweep objects with finalizers */
-      work = sweepstep(L, g, GCSswptobefnz, &g->tobefnz);
-      break;
-    }
-    case GCSswptobefnz: {  /* sweep objects to be finalized */
-      work = sweepstep(L, g, GCSswpend, NULL);
-      break;
-    }
-    case GCSswpend: {  /* finish sweeps */
-      checkSizes(L, g);
-      g->gcstate = GCScallfin;
-      work = 0;
-      break;
-    }
-    case GCScallfin: {  /* call remaining finalizers */
-      if (g->tobefnz && !g->gcemergency) {
-        g->gcstopem = 0;  /* ok collections during finalizers */
-        work = runafewfinalizers(L, GCFINMAX) * GCFINALIZECOST;
-      }
-      else {  /* emergency mode or no more finalizers */
-        g->gcstate = GCSpause;  /* finish collection */
-        work = 0;
-      }
-      break;
-    }
-    default: lua_assert(0); return 0;
-  }
-  g->gcstopem = 0;
-  return work;
-}
-
-
-/*
-** advances the garbage collector until it reaches a state allowed
-** by 'statemask'
-*/
-void luaC_runtilstate (lua_State *L, int statesmask) {
-  global_State *g = G(L);
-  while (!testbit(statesmask, g->gcstate))
-    singlestep(L);
-}
-
-
-/*
-** Performs a basic incremental step. The debt and step size are
-** converted from bytes to "units of work"; then the function loops
-** running single steps until adding that many units of work or
-** finishing a cycle (pause state). Finally, it sets the debt that
-** controls when next step will be performed.
-*/
-static void incstep (lua_State *L, global_State *g) {
-  int stepmul = (getgcparam(g->gcstepmul) | 1);  /* avoid division by 0 */
-  l_mem debt = (g->GCdebt / WORK2MEM) * stepmul;
-  l_mem stepsize = (g->gcstepsize <= log2maxs(l_mem))
-                 ? ((cast(l_mem, 1) << g->gcstepsize) / WORK2MEM) * stepmul
-                 : MAX_LMEM;  /* overflow; keep maximum value */
-  do {  /* repeat until pause or enough "credit" (negative debt) */
-    lu_mem work = singlestep(L);  /* perform one single step */
-    debt -= work;
-  } while (debt > -stepsize && g->gcstate != GCSpause);
-  if (g->gcstate == GCSpause)
-    setpause(g);  /* pause until next cycle */
-  else {
-    debt = (debt / stepmul) * WORK2MEM;  /* convert 'work units' to bytes */
-    luaE_setdebt(g, debt);
-  }
-}
-
-/*
-** performs a basic GC step if collector is running
-*/
-void luaC_step (lua_State *L) {
-  global_State *g = G(L);
-  lua_assert(!g->gcemergency);
-  if (g->gcrunning) {  /* running? */
-    if(isdecGCmodegen(g))
-      genstep(L, g);
-    else
-      incstep(L, g);
-  }
-}
-
-
-/*
-** Perform a full collection in incremental mode.
-** Before running the collection, check 'keepinvariant'; if it is true,
-** there may be some objects marked as black, so the collector has
-** to sweep all objects to turn them back to white (as white has not
-** changed, nothing will be collected).
-*/
-static void fullinc (lua_State *L, global_State *g) {
-  if (keepinvariant(g))  /* black objects? */
-    entersweep(L); /* sweep everything to turn them back to white */
-  /* finish any pending sweep phase to start a new cycle */
-  luaC_runtilstate(L, bitmask(GCSpause));
-  luaC_runtilstate(L, bitmask(GCScallfin));  /* run up to finalizers */
-  /* estimate must be correct after a full GC cycle */
-  lua_assert(g->GCestimate == gettotalbytes(g));
-  luaC_runtilstate(L, bitmask(GCSpause));  /* finish collection */
-  setpause(g);
-}
-
-
-/*
-** Performs a full GC cycle; if 'isemergency', set a flag to avoid
-** some operations which could change the interpreter state in some
-** unexpected ways (running finalizers and shrinking some structures).
-*/
-void luaC_fullgc (lua_State *L, int isemergency) {
-  global_State *g = G(L);
-  lua_assert(!g->gcemergency);
-  g->gcemergency = isemergency;  /* set flag */
-  if (g->gckind == KGC_INC)
-    fullinc(L, g);
-  else
-    fullgen(L, g);
-  g->gcemergency = 0;
-}
-
-/* }====================================================== */
-
-