diffu-lua-5.4.0-lua-5.4.1
Makefile
@@ -46,7 +46,7 @@
# Lua version and release.
V= 5.4
-R= $V.0
+R= $V.1
# Targets start here.
all: $(PLAT)
README
@@ -1,5 +1,5 @@
-This is Lua 5.4.0, released on 18 Jun 2020.
+This is Lua 5.4.1, released on 30 Sep 2020.
For installation instructions, license details, and
further information about Lua, see doc/readme.html.
doc/contents.html
@@ -95,6 +95,7 @@
<UL>
<LI><A HREF="manual.html#4.1.1">4.1.1 – Stack Size</A>
<LI><A HREF="manual.html#4.1.2">4.1.2 – Valid and Acceptable Indices</A>
+<LI><A HREF="manual.html#4.1.3">4.1.3 – Pointers to strings</A>
</UL>
<LI><A HREF="manual.html#4.2">4.2 – C Closures</A>
<LI><A HREF="manual.html#4.3">4.3 – Registry</A>
@@ -664,10 +665,10 @@
<P CLASS="footer">
Last update:
-Sat May 30 08:22:18 -03 2020
+Wed Sep 30 06:45:10 -03 2020
</P>
<!--
-Last change: revised for Lua 5.4.0 (final)
+Last change: revised for Lua 5.4.1
-->
</BODY>
doc/manual.html
@@ -2973,7 +2973,8 @@
<p>
Whenever Lua calls C,
it ensures that the stack has space for
-at least <a name="pdf-LUA_MINSTACK"><code>LUA_MINSTACK</code></a> extra slots.
+at least <a name="pdf-LUA_MINSTACK"><code>LUA_MINSTACK</code></a> extra elements;
+that is, you can safely push up to <code>LUA_MINSTACK</code> values into it.
<code>LUA_MINSTACK</code> is defined as 20,
so that usually you do not have to worry about stack space
unless your code has loops pushing elements onto the stack.
@@ -2984,7 +2985,7 @@
without a fixed number of results (see <a href="#lua_call"><code>lua_call</code></a>),
Lua ensures that the stack has enough space for all results,
but it does not ensure any extra space.
-So, before pushing anything in the stack after such a call
+So, before pushing anything on the stack after such a call
you should use <a href="#lua_checkstack"><code>lua_checkstack</code></a>.
@@ -3044,6 +3045,48 @@
+<h3>4.1.3 – <a name="4.1.3">Pointers to strings</a></h3>
+
+<p>
+Several functions in the API return pointers (<code>const char*</code>)
+to Lua strings in the stack.
+(See <a href="#lua_pushfstring"><code>lua_pushfstring</code></a>, <a href="#lua_pushlstring"><code>lua_pushlstring</code></a>,
+<a href="#lua_pushstring"><code>lua_pushstring</code></a>, and <a href="#lua_tolstring"><code>lua_tolstring</code></a>.
+See also <a href="#luaL_checklstring"><code>luaL_checklstring</code></a>, <a href="#luaL_checkstring"><code>luaL_checkstring</code></a>,
+and <a href="#luaL_tolstring"><code>luaL_tolstring</code></a> in the auxiliary library.)
+
+
+<p>
+In general,
+Lua's garbage collection can free or move internal memory
+and then invalidate pointers to internal strings.
+To allow a safe use of these pointers,
+The API guarantees that any pointer to a string in a stack index
+is valid while the value at that index is neither modified nor popped.
+When the index is a pseudo-index (referring to an upvalue),
+the pointer is valid while the corresponding call is active and
+the corresponding upvalue is not modified.
+
+
+<p>
+Some functions in the debug interface
+also return pointers to strings,
+namely <a href="#lua_getlocal"><code>lua_getlocal</code></a>, <a href="#lua_getupvalue"><code>lua_getupvalue</code></a>,
+<a href="#lua_setlocal"><code>lua_setlocal</code></a>, and <a href="#lua_setupvalue"><code>lua_setupvalue</code></a>.
+For these functions, the pointer is guaranteed to
+be valid while the caller function is active and
+the given closure (if one was given) is in the stack.
+
+
+<p>
+Except for these guarantees,
+the garbage collector is free to invalidate
+any pointer to internal strings.
+
+
+
+
+
<h2>4.2 – <a name="4.2">C Closures</a></h2>
@@ -3389,7 +3432,7 @@
an interrogation mark '<code>?</code>' means that
we cannot know how many elements the function pops/pushes
by looking only at its arguments.
-(For instance, they may depend on what is on the stack.)
+(For instance, they may depend on what is in the stack.)
The third field, <code>x</code>,
tells whether the function may raise errors:
'<code>-</code>' means the function never raises any error;
@@ -3678,7 +3721,7 @@
<pre>int lua_checkstack (lua_State *L, int n);</pre>
<p>
-Ensures that the stack has space for at least <code>n</code> extra slots,
+Ensures that the stack has space for at least <code>n</code> extra elements,
that is, that you can safely push up to <code>n</code> values into it.
It returns false if it cannot fulfill the request,
either because it would cause the stack
@@ -3686,7 +3729,7 @@
(typically at least several thousand elements) or
because it cannot allocate memory for the extra space.
This function never shrinks the stack;
-if the stack already has space for the extra slots,
+if the stack already has space for the extra elements,
it is left unchanged.
@@ -4443,6 +4486,10 @@
<p>
The function returns the address of the block of memory.
+Lua ensures that this address is valid as long as
+the corresponding userdata is alive (see <a href="#2.5">§2.5</a>).
+Moreover, if the userdata is marked for finalization (see <a href="#2.5.3">§2.5.3</a>),
+its address is valid at least until the call to its finalizer.
@@ -4688,7 +4735,7 @@
<p>
Pushes onto the stack a formatted string
-and returns a pointer to this string.
+and returns a pointer to this string (see <a href="#4.1.3">§4.1.3</a>).
It is similar to the ISO C function <code>sprintf</code>,
but has two important differences.
First,
@@ -4788,7 +4835,7 @@
<p>
-Returns a pointer to the internal copy of the string.
+Returns a pointer to the internal copy of the string (see <a href="#4.1.3">§4.1.3</a>).
@@ -4829,7 +4876,7 @@
<p>
-Returns a pointer to the internal copy of the string.
+Returns a pointer to the internal copy of the string (see <a href="#4.1.3">§4.1.3</a>).
<p>
@@ -5399,7 +5446,7 @@
<hr><h3><a name="lua_toclose"><code>lua_toclose</code></a></h3><p>
-<span class="apii">[-0, +0, <em>v</em>]</span>
+<span class="apii">[-0, +0, <em>m</em>]</span>
<pre>void lua_toclose (lua_State *L, int index);</pre>
<p>
@@ -5423,11 +5470,19 @@
<p>
-This function can raise an out-of-memory error.
-In that case, the value in the given index is immediately closed,
+In the case of an out-of-memory error,
+the value in the given index is immediately closed,
as if it was already marked.
+<p>
+Note that, both in case of errors and of a regular return,
+by the time the <code>__close</code> metamethod runs,
+the C stack was already unwound,
+so that any automatic C variable declared in the calling function
+will be out of scope.
+
+
@@ -5482,18 +5537,12 @@
<p>
<code>lua_tolstring</code> returns a pointer
-to a string inside the Lua state.
+to a string inside the Lua state (see <a href="#4.1.3">§4.1.3</a>).
This string always has a zero ('<code>\0</code>')
after its last character (as in C),
but can contain other zeros in its body.
-<p>
-Because Lua has garbage collection,
-there is no guarantee that the pointer returned by <code>lua_tolstring</code>
-will be valid after the corresponding Lua value is removed from the stack.
-
-
@@ -5944,7 +5993,7 @@
</li>
<li><b><code>ftransfer</code>: </b>
-the index on the stack of the first value being "transferred",
+the index in the stack of the first value being "transferred",
that is, parameters in a call or return values in a return.
(The other values are in consecutive indices.)
Using this index, you can access and modify these values
@@ -6141,7 +6190,7 @@
of the function executing at a given level.
Level 0 is the current running function,
whereas level <em>n+1</em> is the function that has called level <em>n</em>
-(except for tail calls, which do not count on the stack).
+(except for tail calls, which do not count in the stack).
When called with a level greater than the stack depth,
<a href="#lua_getstack"><code>lua_getstack</code></a> returns 0;
otherwise it returns 1.
@@ -6259,8 +6308,7 @@
<ul>
<li><b>The call hook: </b> is called when the interpreter calls a function.
-The hook is called just after Lua enters the new function,
-before the function gets its arguments.
+The hook is called just after Lua enters the new function.
</li>
<li><b>The return hook: </b> is called when the interpreter returns from a function.
@@ -7573,7 +7621,7 @@
Converts any Lua value at the given index to a C string
in a reasonable format.
The resulting string is pushed onto the stack and also
-returned by the function.
+returned by the function (see <a href="#4.1.3">§4.1.3</a>).
If <code>len</code> is not <code>NULL</code>,
the function also sets <code>*len</code> with the string length.
@@ -8001,9 +8049,11 @@
<p>
-Lua does not check the consistency of binary chunks.
-Maliciously crafted binary chunks can crash
-the interpreter.
+It is safe to load malformed binary chunks;
+<code>load</code> signals an appropriate error.
+However,
+Lua does not check the consistency of the code inside binary chunks;
+running maliciously crafted bytecode can crash the interpreter.
@@ -8665,6 +8715,18 @@
plus other Unix systems that support the <code>dlfcn</code> standard).
+<p>
+This function is inherently insecure,
+as it allows Lua to call any function in any readable dynamic
+library in the system.
+(Lua calls any function assuming the function
+has a proper prototype and respects a proper protocol
+(see <a href="#lua_CFunction"><code>lua_CFunction</code></a>).
+Therefore,
+calling an arbitrary function in an arbitrary dynamic library
+more often than not results in an access violation.)
+
+
<p>
@@ -11084,7 +11146,7 @@
of the given thread:
level 0 is the current function (<code>getinfo</code> itself);
level 1 is the function that called <code>getinfo</code>
-(except for tail calls, which do not count on the stack);
+(except for tail calls, which do not count in the stack);
and so on.
If <code>f</code> is a number greater than the number of active functions,
then <code>getinfo</code> returns <b>fail</b>.
@@ -11886,10 +11948,10 @@
<P CLASS="footer">
Last update:
-Thu Jun 18 16:10:16 UTC 2020
+Wed Sep 30 09:46:30 UTC 2020
</P>
<!--
-Last change: revised for Lua 5.4.0 (final)
+Last change: revised for Lua 5.4.1
-->
</body></html>
doc/readme.html
@@ -110,7 +110,7 @@
<OL>
<LI>
Open a terminal window and move to
-the top-level directory, which is named <TT>lua-5.4.0</TT>.
+the top-level directory, which is named <TT>lua-5.4.1</TT>.
The <TT>Makefile</TT> there controls both the build process and the installation process.
<P>
<LI>
@@ -330,10 +330,10 @@
<P CLASS="footer">
Last update:
-Fri May 1 19:33:31 UTC 2020
+Wed Sep 30 09:55:45 UTC 2020
</P>
<!--
-Last change: revised for Lua 5.4.0 (final)
+Last change: revised for Lua 5.4.1
-->
</BODY>
src/lapi.c
@@ -97,8 +97,9 @@
LUA_API int lua_checkstack (lua_State *L, int n) {
int res;
- CallInfo *ci = L->ci;
+ CallInfo *ci;
lua_lock(L);
+ ci = L->ci;
api_check(L, n >= 0, "negative 'n'");
if (L->stack_last - L->top > n) /* stack large enough? */
res = 1; /* yes; check is OK */
@@ -170,10 +171,12 @@
LUA_API void lua_settop (lua_State *L, int idx) {
- CallInfo *ci = L->ci;
- StkId func = ci->func;
+ CallInfo *ci;
+ StkId func;
ptrdiff_t diff; /* difference for new top */
lua_lock(L);
+ ci = L->ci;
+ func = ci->func;
if (idx >= 0) {
api_check(L, idx <= ci->top - (func + 1), "new top too large");
diff = ((func + 1) + idx) - L->top;
@@ -376,20 +379,22 @@
LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
- TValue *o = index2value(L, idx);
+ TValue *o;
+ lua_lock(L);
+ o = index2value(L, idx);
if (!ttisstring(o)) {
if (!cvt2str(o)) { /* not convertible? */
if (len != NULL) *len = 0;
+ lua_unlock(L);
return NULL;
}
- lua_lock(L); /* 'luaO_tostring' may create a new string */
luaO_tostring(L, o);
luaC_checkGC(L);
o = index2value(L, idx); /* previous call may reallocate the stack */
- lua_unlock(L);
}
if (len != NULL)
*len = vslen(o);
+ lua_unlock(L);
return svalue(o);
}
@@ -563,6 +568,7 @@
while (n--) {
setobj2n(L, &cl->upvalue[n], s2v(L->top + n));
/* does not need barrier because closure is white */
+ lua_assert(iswhite(cl));
}
setclCvalue(L, s2v(L->top), cl);
api_incr_top(L);
@@ -624,8 +630,9 @@
LUA_API int lua_getglobal (lua_State *L, const char *name) {
- Table *reg = hvalue(&G(L)->l_registry);
+ Table *reg;
lua_lock(L);
+ reg = hvalue(&G(L)->l_registry);
return auxgetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
}
@@ -804,8 +811,9 @@
LUA_API void lua_setglobal (lua_State *L, const char *name) {
- Table *reg = hvalue(&G(L)->l_registry);
+ Table *reg;
lua_lock(L); /* unlock done in 'auxsetstr' */
+ reg = hvalue(&G(L)->l_registry);
auxsetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
}
@@ -1093,8 +1101,9 @@
LUA_API int lua_gc (lua_State *L, int what, ...) {
va_list argp;
int res = 0;
- global_State *g = G(L);
+ global_State *g;
lua_lock(L);
+ g = G(L);
va_start(argp, what);
switch (what) {
case LUA_GCSTOP: {
@@ -1194,9 +1203,15 @@
LUA_API int lua_error (lua_State *L) {
+ TValue *errobj;
lua_lock(L);
+ errobj = s2v(L->top - 1);
api_checknelems(L, 1);
- luaG_errormsg(L);
+ /* error object is the memory error message? */
+ if (ttisshrstring(errobj) && eqshrstr(tsvalue(errobj), G(L)->memerrmsg))
+ luaM_error(L); /* raise a memory error */
+ else
+ luaG_errormsg(L); /* raise a regular error */
/* code unreachable; will unlock when control actually leaves the kernel */
return 0; /* to avoid warnings */
}
@@ -1238,14 +1253,12 @@
LUA_API void lua_concat (lua_State *L, int n) {
lua_lock(L);
api_checknelems(L, n);
- if (n >= 2) {
+ if (n > 0)
luaV_concat(L, n);
- }
- else if (n == 0) { /* push empty string */
- setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
+ else { /* nothing to concatenate */
+ setsvalue2s(L, L->top, luaS_newlstr(L, "", 0)); /* push empty string */
api_incr_top(L);
}
- /* else n == 1; nothing to do */
luaC_checkGC(L);
lua_unlock(L);
}
src/lauxlib.c
@@ -475,8 +475,10 @@
lua_Alloc allocf = lua_getallocf(L, &ud);
UBox *box = (UBox *)lua_touserdata(L, idx);
void *temp = allocf(ud, box->box, box->bsize, newsize);
- if (temp == NULL && newsize > 0) /* allocation error? */
- luaL_error(L, "not enough memory");
+ if (temp == NULL && newsize > 0) { /* allocation error? */
+ lua_pushliteral(L, "not enough memory");
+ lua_error(L); /* raise a memory error */
+ }
box->box = temp;
box->bsize = newsize;
return temp;
src/lcorolib.c
@@ -73,11 +73,12 @@
static int luaB_auxwrap (lua_State *L) {
lua_State *co = lua_tothread(L, lua_upvalueindex(1));
int r = auxresume(L, co, lua_gettop(L));
- if (r < 0) {
+ if (r < 0) { /* error? */
int stat = lua_status(co);
- if (stat != LUA_OK && stat != LUA_YIELD)
- lua_resetthread(co); /* close variables in case of errors */
- if (lua_type(L, -1) == LUA_TSTRING) { /* error object is a string? */
+ if (stat != LUA_OK && stat != LUA_YIELD) /* error in the coroutine? */
+ lua_resetthread(co); /* close its tbc variables */
+ if (stat != LUA_ERRMEM && /* not a memory error and ... */
+ lua_type(L, -1) == LUA_TSTRING) { /* ... error object is a string? */
luaL_where(L, 1); /* add extra info, if available */
lua_insert(L, -2);
lua_concat(L, 2);
src/lctype.h
@@ -13,7 +13,7 @@
/*
** WARNING: the functions defined here do not necessarily correspond
** to the similar functions in the standard C ctype.h. They are
-** optimized for the specific needs of Lua
+** optimized for the specific needs of Lua.
*/
#if !defined(LUA_USE_CTYPE)
@@ -61,13 +61,19 @@
#define lisprint(c) testprop(c, MASK(PRINTBIT))
#define lisxdigit(c) testprop(c, MASK(XDIGITBIT))
+
/*
-** this 'ltolower' only works for alphabetic characters
+** In ASCII, this 'ltolower' is correct for alphabetic characters and
+** for '.'. That is enough for Lua needs. ('check_exp' ensures that
+** the character either is an upper-case letter or is unchanged by
+** the transformation, which holds for lower-case letters and '.'.)
*/
-#define ltolower(c) ((c) | ('A' ^ 'a'))
+#define ltolower(c) \
+ check_exp(('A' <= (c) && (c) <= 'Z') || (c) == ((c) | ('A' ^ 'a')), \
+ (c) | ('A' ^ 'a'))
-/* two more entries for 0 and -1 (EOZ) */
+/* one entry for each character and for -1 (EOZ) */
LUAI_DDEC(const lu_byte luai_ctype_[UCHAR_MAX + 2];)
src/ldebug.c
@@ -33,10 +33,8 @@
#define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_VCCL)
-
-/* Active Lua function (given call info) */
-#define ci_func(ci) (clLvalue(s2v((ci)->func)))
-
+/* inverse of 'pcRel' */
+#define invpcRel(pc, p) ((p)->code + (pc) + 1)
static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
const char **name);
@@ -127,20 +125,18 @@
/*
** This function can be called during a signal, under "reasonable"
** assumptions.
-** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
-** 'resethookcount') are for debug only, and it is no problem if they
-** get arbitrary values (causes at most one wrong hook call). 'hookmask'
-** is an atomic value. We assume that pointers are atomic too (e.g., gcc
-** ensures that for all platforms where it runs). Moreover, 'hook' is
-** always checked before being called (see 'luaD_hook').
+** Fields 'basehookcount' and 'hookcount' (set by 'resethookcount')
+** are for debug only, and it is no problem if they get arbitrary
+** values (causes at most one wrong hook call). 'hookmask' is an atomic
+** value. We assume that pointers are atomic too (e.g., gcc ensures that
+** for all platforms where it runs). Moreover, 'hook' is always checked
+** before being called (see 'luaD_hook').
*/
LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
if (func == NULL || mask == 0) { /* turn off hooks? */
mask = 0;
func = NULL;
}
- if (isLua(L->ci))
- L->oldpc = L->ci->u.l.savedpc;
L->hook = func;
L->basehookcount = count;
resethookcount(L);
@@ -192,8 +188,8 @@
static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
if (clLvalue(s2v(ci->func))->p->is_vararg) {
int nextra = ci->u.l.nextraargs;
- if (n <= nextra) {
- *pos = ci->func - nextra + (n - 1);
+ if (n >= -nextra) { /* 'n' is negative */
+ *pos = ci->func - nextra - (n + 1);
return "(vararg)"; /* generic name for any vararg */
}
}
@@ -206,7 +202,7 @@
const char *name = NULL;
if (isLua(ci)) {
if (n < 0) /* access to vararg values? */
- return findvararg(ci, -n, pos);
+ return findvararg(ci, n, pos);
else
name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
}
@@ -787,18 +783,34 @@
** previous instruction 'oldpc'.
*/
static int changedline (const Proto *p, int oldpc, int newpc) {
+ if (p->lineinfo == NULL) /* no debug information? */
+ return 0;
while (oldpc++ < newpc) {
if (p->lineinfo[oldpc] != 0)
return (luaG_getfuncline(p, oldpc - 1) != luaG_getfuncline(p, newpc));
}
- return 0; /* no line changes in the way */
+ return 0; /* no line changes between positions */
}
+/*
+** Traces the execution of a Lua function. Called before the execution
+** of each opcode, when debug is on. 'L->oldpc' stores the last
+** instruction traced, to detect line changes. When entering a new
+** function, 'npci' will be zero and will test as a new line without
+** the need for 'oldpc'; so, 'oldpc' does not need to be initialized
+** before. Some exceptional conditions may return to a function without
+** updating 'oldpc'. In that case, 'oldpc' may be invalid; if so, it is
+** reset to zero. (A wrong but valid 'oldpc' at most causes an extra
+** call to a line hook.)
+*/
int luaG_traceexec (lua_State *L, const Instruction *pc) {
CallInfo *ci = L->ci;
lu_byte mask = L->hookmask;
+ const Proto *p = ci_func(ci)->p;
int counthook;
+ /* 'L->oldpc' may be invalid; reset it in this case */
+ int oldpc = (L->oldpc < p->sizecode) ? L->oldpc : 0;
if (!(mask & (LUA_MASKLINE | LUA_MASKCOUNT))) { /* no hooks? */
ci->u.l.trap = 0; /* don't need to stop again */
return 0; /* turn off 'trap' */
@@ -819,15 +831,14 @@
if (counthook)
luaD_hook(L, LUA_HOOKCOUNT, -1, 0, 0); /* call count hook */
if (mask & LUA_MASKLINE) {
- const Proto *p = ci_func(ci)->p;
int npci = pcRel(pc, p);
if (npci == 0 || /* call linehook when enter a new function, */
- pc <= L->oldpc || /* when jump back (loop), or when */
- changedline(p, pcRel(L->oldpc, p), npci)) { /* enter new line */
+ pc <= invpcRel(oldpc, p) || /* when jump back (loop), or when */
+ changedline(p, oldpc, npci)) { /* enter new line */
int newline = luaG_getfuncline(p, npci);
luaD_hook(L, LUA_HOOKLINE, newline, 0, 0); /* call line hook */
}
- L->oldpc = pc; /* 'pc' of last call to line hook */
+ L->oldpc = npci; /* 'pc' of last call to line hook */
}
if (L->status == LUA_YIELD) { /* did hook yield? */
if (counthook)
src/ldebug.h
@@ -13,6 +13,11 @@
#define pcRel(pc, p) (cast_int((pc) - (p)->code) - 1)
+
+/* Active Lua function (given call info) */
+#define ci_func(ci) (clLvalue(s2v((ci)->func)))
+
+
#define resethookcount(L) (L->hookcount = L->basehookcount)
/*
src/ldo.c
@@ -245,13 +245,12 @@
void luaD_shrinkstack (lua_State *L) {
int inuse = stackinuse(L);
- int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
+ int goodsize = inuse + BASIC_STACK_SIZE;
if (goodsize > LUAI_MAXSTACK)
goodsize = LUAI_MAXSTACK; /* respect stack limit */
/* if thread is currently not handling a stack overflow and its
good size is smaller than current size, shrink its stack */
- if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) &&
- goodsize < L->stacksize)
+ if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) && goodsize < L->stacksize)
luaD_reallocstack(L, goodsize, 0); /* ok if that fails */
else /* don't change stack */
condmovestack(L,{},{}); /* (change only for debugging) */
@@ -328,7 +327,7 @@
ptrdiff_t oldtop = savestack(L, L->top); /* hook may change top */
int delta = 0;
if (isLuacode(ci)) {
- Proto *p = clLvalue(s2v(ci->func))->p;
+ Proto *p = ci_func(ci)->p;
if (p->is_vararg)
delta = ci->u.l.nextraargs + p->numparams + 1;
if (L->top < ci->top)
@@ -341,8 +340,8 @@
luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres); /* call it */
ci->func -= delta;
}
- if (isLua(ci->previous))
- L->oldpc = ci->previous->u.l.savedpc; /* update 'oldpc' */
+ if (isLua(ci = ci->previous))
+ L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p); /* update 'oldpc' */
return restorestack(L, oldtop);
}
@@ -466,13 +465,13 @@
f = fvalue(s2v(func));
Cfunc: {
int n; /* number of returns */
- CallInfo *ci = next_ci(L);
- checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
+ CallInfo *ci;
+ checkstackGCp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
+ L->ci = ci = next_ci(L);
ci->nresults = nresults;
ci->callstatus = CIST_C;
ci->top = L->top + LUA_MINSTACK;
ci->func = func;
- L->ci = ci;
lua_assert(ci->top <= L->stack_last);
if (L->hookmask & LUA_MASKCALL) {
int narg = cast_int(L->top - func) - 1;
@@ -486,12 +485,13 @@
break;
}
case LUA_VLCL: { /* Lua function */
- CallInfo *ci = next_ci(L);
+ CallInfo *ci;
Proto *p = clLvalue(s2v(func))->p;
int narg = cast_int(L->top - func) - 1; /* number of real arguments */
int nfixparams = p->numparams;
int fsize = p->maxstacksize; /* frame size */
- checkstackp(L, fsize, func);
+ checkstackGCp(L, fsize, func);
+ L->ci = ci = next_ci(L);
ci->nresults = nresults;
ci->u.l.savedpc = p->code; /* starting point */
ci->callstatus = 0;
@@ -505,7 +505,7 @@
break;
}
default: { /* not a function */
- checkstackp(L, 1, func); /* space for metamethod */
+ checkstackGCp(L, 1, func); /* space for metamethod */
luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */
goto retry; /* try again with metamethod */
}
@@ -515,14 +515,13 @@
/*
** Similar to 'luaD_call', but does not allow yields during the call.
-** If there is a stack overflow, freeing all CI structures will
-** force the subsequent call to invoke 'luaE_extendCI', which then
-** will raise any errors.
*/
void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
incXCcalls(L);
- if (getCcalls(L) <= CSTACKERR) /* possible stack overflow? */
- luaE_freeCI(L);
+ if (getCcalls(L) <= CSTACKERR) { /* possible C stack overflow? */
+ luaE_exitCcall(L); /* to compensate decrement in next call */
+ luaE_enterCcall(L); /* check properly */
+ }
luaD_call(L, func, nResults);
decXCcalls(L);
}
@@ -674,7 +673,7 @@
if (from == NULL)
L->nCcalls = CSTACKTHREAD;
else /* correct 'nCcalls' for this thread */
- L->nCcalls = getCcalls(from) + from->nci - L->nci - CSTACKCF;
+ L->nCcalls = getCcalls(from) - L->nci - CSTACKCF;
if (L->nCcalls <= CSTACKERR)
return resume_error(L, "C stack overflow", nargs);
luai_userstateresume(L, nargs);
@@ -706,9 +705,10 @@
LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
lua_KFunction k) {
- CallInfo *ci = L->ci;
+ CallInfo *ci;
luai_userstateyield(L, nresults);
lua_lock(L);
+ ci = L->ci;
api_checknelems(L, nresults);
if (unlikely(!yieldable(L))) {
if (L != G(L)->mainthread)
src/ldo.h
@@ -17,6 +17,8 @@
** Macro to check stack size and grow stack if needed. Parameters
** 'pre'/'pos' allow the macro to preserve a pointer into the
** stack across reallocations, doing the work only when needed.
+** It also allows the running of one GC step when the stack is
+** reallocated.
** 'condmovestack' is used in heavy tests to force a stack reallocation
** at every check.
*/
@@ -35,7 +37,7 @@
/* macro to check stack size, preserving 'p' */
-#define checkstackp(L,n,p) \
+#define checkstackGCp(L,n,p) \
luaD_checkstackaux(L, n, \
ptrdiff_t t__ = savestack(L, p); /* save 'p' */ \
luaC_checkGC(L), /* stack grow uses memory */ \
@@ -44,7 +46,7 @@
/* macro to check stack size and GC */
#define checkstackGC(L,fsize) \
- luaD_checkstackaux(L, (fsize), (void)0, luaC_checkGC(L))
+ luaD_checkstackaux(L, (fsize), luaC_checkGC(L), (void)0)
/* type of protected functions, to be ran by 'runprotected' */
src/lfunc.c
@@ -234,9 +234,10 @@
luaF_unlinkupval(uv);
setobj(L, slot, uv->v); /* move value to upvalue slot */
uv->v = slot; /* now current value lives here */
- if (!iswhite(uv))
- gray2black(uv); /* closed upvalues cannot be gray */
- luaC_barrier(L, uv, slot);
+ if (!iswhite(uv)) { /* neither white nor dead? */
+ nw2black(uv); /* closed upvalues cannot be gray */
+ luaC_barrier(L, uv, slot);
+ }
}
return status;
}
src/lgc.c
@@ -60,16 +60,24 @@
#define PAUSEADJ 100
-/* mask to erase all color bits (plus gen. related stuff) */
-#define maskcolors (~(bitmask(BLACKBIT) | WHITEBITS | AGEBITS))
+/* 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 sets only the current white bit */
+
+/* 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)))
+ (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)
-#define white2gray(x) resetbits(x->marked, WHITEBITS)
-#define black2gray(x) resetbit(x->marked, BLACKBIT)
+
+/* 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)))
@@ -77,16 +85,13 @@
#define keyiswhite(n) (keyiscollectable(n) && iswhite(gckey(n)))
-#define checkconsistency(obj) \
- lua_longassert(!iscollectable(obj) || righttt(obj))
-
/*
** Protected access to objects in values
*/
#define gcvalueN(o) (iscollectable(o) ? gcvalue(o) : NULL)
-#define markvalue(g,o) { checkconsistency(o); \
+#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)); }
@@ -135,15 +140,23 @@
/*
-** Link a collectable object 'o' with a known type into list pointed by 'p'.
+** 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) ((o)->gclist = (p), (p) = obj2gco(o))
+#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 list pointed by 'p'.
+** Link a generic collectable object 'o' into the list 'p'.
*/
-#define linkobjgclist(o,p) (*getgclist(o) = (p), (p) = obj2gco(o))
+#define linkobjgclist(o,p) linkgclist_(obj2gco(o), getgclist(o), &(p))
@@ -181,14 +194,17 @@
/*
-** barrier that moves collector forward, that is, mark the white object
-** 'v' being pointed by the black object 'o'. (If in sweep phase, clear
-** the black object to white [sweep it] to avoid other barrier calls for
-** this same object.) 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).
+** 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);
@@ -202,7 +218,8 @@
}
else { /* sweep phase */
lua_assert(issweepphase(g));
- makewhite(g, o); /* mark main obj. as white to avoid other barriers */
+ if (g->gckind == KGC_INC) /* incremental mode? */
+ makewhite(g, o); /* mark 'o' as white to avoid other barriers */
}
}
@@ -214,18 +231,20 @@
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) /* not already in gray list? */
- linkobjgclist(o, g->grayagain); /* link it in 'grayagain' */
- black2gray(o); /* make object gray (again) */
- setage(o, G_TOUCHED1); /* touched in current cycle */
+ 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! */
- white2gray(o); /* they will be gray forever */
+ 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 */
@@ -259,24 +278,30 @@
/*
-** Mark an object. Userdata, strings, and closed upvalues are visited
-** and turned black here. Other objects are marked gray and added
-** to appropriate list to be visited (and turned black) later. (Open
-** upvalues are already linked in 'headuv' list. They are kept gray
-** to avoid barriers, as their values will be revisited by the thread.)
+** 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) {
- white2gray(o);
switch (o->tt) {
case LUA_VSHRSTR:
case LUA_VLNGSTR: {
- gray2black(o);
+ set2black(o); /* nothing to visit */
break;
}
case LUA_VUPVAL: {
UpVal *uv = gco2upv(o);
- if (!upisopen(uv)) /* open upvalues are kept gray */
- gray2black(o);
+ if (upisopen(uv))
+ set2gray(uv); /* open upvalues are kept gray */
+ else
+ set2black(o); /* closed upvalues are visited here */
markvalue(g, uv->v); /* mark its content */
break;
}
@@ -284,14 +309,14 @@
Udata *u = gco2u(o);
if (u->nuvalue == 0) { /* no user values? */
markobjectN(g, u->metatable); /* mark its metatable */
- gray2black(o); /* nothing else to mark */
+ set2black(o); /* 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);
+ linkobjgclist(o, g->gray); /* to be visited later */
break;
}
default: lua_assert(0); break;
@@ -324,28 +349,36 @@
/*
-** Mark all values stored in marked open upvalues from non-marked threads.
-** (Values from marked threads were already marked when traversing the
-** thread.) Remove from the list threads that no longer have upvalues and
-** not-marked threads.
+** 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;
+ int work = 0; /* estimate of how much work was done here */
while ((thread = *p) != NULL) {
work++;
- lua_assert(!isblack(thread)); /* threads are never black */
- if (isgray(thread) && thread->openupval != NULL)
+ 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? */
+ if (!iswhite(uv)) { /* upvalue already visited? */
+ lua_assert(upisopen(uv) && isgray(uv));
markvalue(g, uv->v); /* mark its value */
+ }
}
}
}
@@ -353,12 +386,17 @@
}
+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) {
- g->gray = g->grayagain = NULL;
- g->weak = g->allweak = g->ephemeron = NULL;
+ cleargraylists(g);
markobject(g, g->mainthread);
markvalue(g, &g->l_registry);
markmt(g);
@@ -374,6 +412,26 @@
** =======================================================
*/
+
+/*
+** 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
@@ -410,8 +468,9 @@
** 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, it (like all visited
-** tables) must be kept in some gray list for post-processing.
+** (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 */
@@ -450,10 +509,8 @@
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 if (g->gckind == KGC_GEN)
- linkgclist(h, g->grayagain); /* keep it in some list */
else
- gray2black(h);
+ genlink(g, obj2gco(h)); /* check whether collector still needs to see it */
return marked;
}
@@ -473,10 +530,7 @@
markvalue(g, gval(n));
}
}
- if (g->gckind == KGC_GEN) {
- linkgclist(h, g->grayagain); /* keep it in some gray list */
- black2gray(h);
- }
+ genlink(g, obj2gco(h));
}
@@ -488,7 +542,6 @@
(cast_void(weakkey = strchr(svalue(mode), 'k')),
cast_void(weakvalue = strchr(svalue(mode), 'v')),
(weakkey || weakvalue))) { /* is really weak? */
- black2gray(h); /* keep table gray */
if (!weakkey) /* strong keys? */
traverseweakvalue(g, h);
else if (!weakvalue) /* strong values? */
@@ -507,10 +560,7 @@
markobjectN(g, u->metatable); /* mark its metatable */
for (i = 0; i < u->nuvalue; i++)
markvalue(g, &u->uv[i].uv);
- if (g->gckind == KGC_GEN) {
- linkgclist(u, g->grayagain); /* keep it in some gray list */
- black2gray(u);
- }
+ genlink(g, obj2gco(u));
return 1 + u->nuvalue;
}
@@ -559,12 +609,21 @@
/*
** 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.
+** 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 ||
@@ -590,12 +649,11 @@
/*
-** traverse one gray object, turning it to black (except for threads,
-** which are always gray).
+** traverse one gray object, turning it to black.
*/
static lu_mem propagatemark (global_State *g) {
GCObject *o = g->gray;
- gray2black(o);
+ nw2black(o);
g->gray = *getgclist(o); /* remove from 'gray' list */
switch (o->tt) {
case LUA_VTABLE: return traversetable(g, gco2t(o));
@@ -603,12 +661,7 @@
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: {
- lua_State *th = gco2th(o);
- linkgclist(th, g->grayagain); /* insert into 'grayagain' list */
- black2gray(o);
- return traversethread(g, th);
- }
+ case LUA_VTHREAD: return traversethread(g, gco2th(o));
default: lua_assert(0); return 0;
}
}
@@ -638,8 +691,10 @@
g->ephemeron = NULL; /* tables may return to this list when traversed */
changed = 0;
while ((w = next) != NULL) { /* for each ephemeron table */
- next = gco2t(w)->gclist; /* list is rebuilt during loop */
- if (traverseephemeron(g, gco2t(w), dir)) { /* marked some value? */
+ 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 */
}
@@ -766,7 +821,7 @@
freeobj(L, curr); /* erase 'curr' */
}
else { /* change mark to 'white' */
- curr->marked = cast_byte((marked & maskcolors) | white);
+ curr->marked = cast_byte((marked & ~maskgcbits) | white);
p = &curr->next; /* go to next element */
}
}
@@ -823,6 +878,8 @@
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;
}
@@ -896,15 +953,15 @@
/*
** Move all unreachable objects (or 'all' objects) that need
** finalization from list 'finobj' to list 'tobefnz' (to be finalized).
-** (Note that objects after 'finobjold' cannot be white, so they
-** don't need to be traversed. In incremental mode, 'finobjold' is NULL,
+** (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->finobjold) { /* traverse all finalizable objects */
+ 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 */
@@ -921,6 +978,27 @@
/*
+** 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.
*/
@@ -936,14 +1014,8 @@
if (g->sweepgc == &o->next) /* should not remove 'sweepgc' object */
g->sweepgc = sweeptolive(L, g->sweepgc); /* change 'sweepgc' */
}
- else { /* correct pointers into 'allgc' list, if needed */
- if (o == g->survival)
- g->survival = o->next;
- if (o == g->old)
- g->old = o->next;
- if (o == g->reallyold)
- g->reallyold = o->next;
- }
+ 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 */
@@ -965,24 +1037,31 @@
static void setpause (global_State *g);
-/* mask to erase all color bits, not changing gen-related stuff */
-#define maskgencolors (~(bitmask(BLACKBIT) | WHITEBITS))
-
-
/*
-** Sweep a list of objects, deleting dead ones and turning
-** the non dead to old (without changing their colors).
+** 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(L), curr));
+ 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 */
}
}
@@ -995,9 +1074,13 @@
** 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 *limit, GCObject **pfirstold1) {
static const lu_byte nextage[] = {
G_SURVIVAL, /* from G_NEW */
G_OLD1, /* from G_SURVIVAL */
@@ -1016,9 +1099,15 @@
freeobj(L, curr); /* erase 'curr' */
}
else { /* correct mark and age */
- if (getage(curr) == G_NEW)
- curr->marked = cast_byte((curr->marked & maskgencolors) | white);
- setage(curr, nextage[getage(curr)]);
+ 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 */
}
}
@@ -1028,58 +1117,50 @@
/*
** Traverse a list making all its elements white and clearing their
-** age.
+** 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 & maskcolors) | white);
+ p->marked = cast_byte((p->marked & ~maskgcbits) | white);
}
/*
-** Correct a list of gray objects.
+** 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.
-** For tables and userdata, advance 'touched1' to 'touched2'; 'touched2'
-** objects become regular old and are removed from the list.
-** For threads, just remove white ones from the list.
+** '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) {
- switch (curr->tt) {
- case LUA_VTABLE: case LUA_VUSERDATA: {
- GCObject **next = getgclist(curr);
- if (getage(curr) == G_TOUCHED1) { /* touched in this cycle? */
- lua_assert(isgray(curr));
- gray2black(curr); /* make it black, for next barrier */
- changeage(curr, G_TOUCHED1, G_TOUCHED2);
- p = next; /* go to next element */
- }
- else { /* not touched in this cycle */
- if (!iswhite(curr)) { /* not white? */
- lua_assert(isold(curr));
- if (getage(curr) == G_TOUCHED2) /* advance from G_TOUCHED2... */
- changeage(curr, G_TOUCHED2, G_OLD); /* ... to G_OLD */
- gray2black(curr); /* make it black */
- }
- /* else, object is white: just remove it from this list */
- *p = *next; /* remove 'curr' from gray list */
- }
- break;
- }
- case LUA_VTHREAD: {
- lua_State *th = gco2th(curr);
- lua_assert(!isblack(th));
- if (iswhite(th)) /* new object? */
- *p = th->gclist; /* remove from gray list */
- else /* old threads remain gray */
- p = &th->gclist; /* go to next element */
- break;
- }
- default: lua_assert(0); /* nothing more could be gray here */
+ 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;
}
@@ -1100,7 +1181,7 @@
/*
-** Mark 'OLD1' objects when starting a new young collection.
+** 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.
*/
@@ -1109,10 +1190,9 @@
for (p = from; p != to; p = p->next) {
if (getage(p) == G_OLD1) {
lua_assert(!iswhite(p));
- if (isblack(p)) {
- black2gray(p); /* should be '2white', but gray works too */
+ changeage(p, G_OLD1, G_OLD); /* now they are old */
+ if (isblack(p))
reallymarkobject(g, p);
- }
}
}
}
@@ -1131,50 +1211,63 @@
/*
-** Does a young collection. First, mark 'OLD1' objects. (Only survival
-** and "recent old" lists can contain 'OLD1' objects. New lists cannot
-** contain 'OLD1' objects, at most 'OLD0' objects that were already
-** visited when marked old.) Then does the atomic step. Then,
-** sweep all lists and advance pointers. Finally, finish the collection.
+** 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);
- markold(g, g->survival, g->reallyold);
+ 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 */
- psurvival = sweepgen(L, g, &g->allgc, g->survival);
- /* sweep 'survival' and 'old' */
- sweepgen(L, g, psurvival, g->reallyold);
- g->reallyold = g->old;
- g->old = *psurvival; /* 'survival' survivals are old now */
+ 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 */
- psurvival = sweepgen(L, g, &g->finobj, g->finobjsur);
- /* sweep 'survival' and 'old' */
- sweepgen(L, g, psurvival, g->finobjrold);
- g->finobjrold = g->finobjold;
- g->finobjold = *psurvival; /* 'survival' survivals are old now */
+ 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);
-
+ 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->old = g->survival = g->allgc;
+ 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->finobjold = g->finobjsur = g->finobj;
+ g->finobjrold = g->finobjold1 = g->finobjsur = g->finobj;
sweep2old(L, &g->tobefnz);
@@ -1187,8 +1280,9 @@
/*
** Enter generational mode. Must go until the end of an atomic cycle
-** to ensure that all threads and weak tables are in the gray lists.
-** Then, turn all objects into old and finishes the collection.
+** 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;
@@ -1207,10 +1301,10 @@
*/
static void enterinc (global_State *g) {
whitelist(g, g->allgc);
- g->reallyold = g->old = g->survival = NULL;
+ g->reallyold = g->old1 = g->survival = NULL;
whitelist(g, g->finobj);
whitelist(g, g->tobefnz);
- g->finobjrold = g->finobjold = g->finobjsur = NULL;
+ g->finobjrold = g->finobjold1 = g->finobjsur = NULL;
g->gcstate = GCSpause;
g->gckind = KGC_INC;
g->lastatomic = 0;
src/lgc.h
@@ -12,16 +12,16 @@
#include "lstate.h"
/*
-** Collectable objects may have one of three colors: white, which
-** means the object is not marked; gray, which means the
-** object is marked, but its references may be not marked; and
-** black, which means that the object and all its references are marked.
-** The main invariant of the garbage collector, while marking objects,
-** is that a black object can never point to a white one. Moreover,
-** any gray object must be in a "gray list" (gray, grayagain, weak,
-** allweak, ephemeron) so that it can be visited again before finishing
-** the collection cycle. These lists have no meaning when the invariant
-** is not being enforced (e.g., sweep phase).
+** Collectable objects may have one of three colors: white, which means
+** the object is not marked; gray, which means the object is marked, but
+** its references may be not marked; and black, which means that the
+** object and all its references are marked. The main invariant of the
+** garbage collector, while marking objects, is that a black object can
+** never point to a white one. Moreover, any gray object must be in a
+** "gray list" (gray, grayagain, weak, allweak, ephemeron) so that it
+** can be visited again before finishing the collection cycle. (Open
+** upvalues are an exception to this rule.) These lists have no meaning
+** when the invariant is not being enforced (e.g., sweep phase).
*/
@@ -69,14 +69,16 @@
/*
** Layout for bit use in 'marked' field. First three bits are
-** used for object "age" in generational mode. Last bit is free
-** to be used by respective objects.
+** used for object "age" in generational mode. Last bit is used
+** by tests.
*/
#define WHITE0BIT 3 /* object is white (type 0) */
#define WHITE1BIT 4 /* object is white (type 1) */
#define BLACKBIT 5 /* object is black */
#define FINALIZEDBIT 6 /* object has been marked for finalization */
+#define TESTBIT 7
+
#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT)
@@ -94,7 +96,8 @@
#define isdead(g,v) isdeadm(otherwhite(g), (v)->marked)
#define changewhite(x) ((x)->marked ^= WHITEBITS)
-#define gray2black(x) l_setbit((x)->marked, BLACKBIT)
+#define nw2black(x) \
+ check_exp(!iswhite(x), l_setbit((x)->marked, BLACKBIT))
#define luaC_white(g) cast_byte((g)->currentwhite & WHITEBITS)
src/liolib.c
@@ -52,6 +52,12 @@
** =======================================================
*/
+#if !defined(l_checkmodep)
+/* By default, Lua accepts only "r" or "w" as mode */
+#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0')
+#endif
+
+
#if !defined(l_popen) /* { */
#if defined(LUA_USE_POSIX) /* { */
@@ -279,6 +285,7 @@
const char *filename = luaL_checkstring(L, 1);
const char *mode = luaL_optstring(L, 2, "r");
LStream *p = newprefile(L);
+ luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode");
p->f = l_popen(L, filename, mode);
p->closef = &io_pclose;
return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
src/llex.c
@@ -81,7 +81,6 @@
const char *luaX_token2str (LexState *ls, int token) {
if (token < FIRST_RESERVED) { /* single-byte symbols? */
- lua_assert(token == cast_uchar(token));
if (lisprint(token))
return luaO_pushfstring(ls->L, "'%c'", token);
else /* control character */
src/llex.h
@@ -7,11 +7,17 @@
#ifndef llex_h
#define llex_h
+#include <limits.h>
+
#include "lobject.h"
#include "lzio.h"
-#define FIRST_RESERVED 257
+/*
+** Single-char tokens (terminal symbols) are represented by their own
+** numeric code. Other tokens start at the following value.
+*/
+#define FIRST_RESERVED (UCHAR_MAX + 1)
#if !defined(LUA_ENV)
src/llimits.h
@@ -84,7 +84,15 @@
typedef LUAI_UACINT l_uacInt;
-/* internal assertions for in-house debugging */
+/*
+** Internal assertions for in-house debugging
+*/
+#if defined LUAI_ASSERT
+#undef NDEBUG
+#include <assert.h>
+#define lua_assert(c) assert(c)
+#endif
+
#if defined(lua_assert)
#define check_exp(c,e) (lua_assert(c), (e))
/* to avoid problems with conditions too long */
src/lmem.c
@@ -22,7 +22,7 @@
#include "lstate.h"
-#if defined(HARDMEMTESTS)
+#if defined(EMERGENCYGCTESTS)
/*
** First allocation will fail whenever not building initial state
** and not shrinking a block. (This fail will trigger 'tryagain' and
src/lobject.c
@@ -215,37 +215,42 @@
/* }====================================================== */
-/* maximum length of a numeral */
+/* maximum length of a numeral to be converted to a number */
#if !defined (L_MAXLENNUM)
#define L_MAXLENNUM 200
#endif
+/*
+** Convert string 's' to a Lua number (put in 'result'). Return NULL on
+** fail or the address of the ending '\0' on success. ('mode' == 'x')
+** means a hexadecimal numeral.
+*/
static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
char *endptr;
*result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */
: lua_str2number(s, &endptr);
if (endptr == s) return NULL; /* nothing recognized? */
while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */
- return (*endptr == '\0') ? endptr : NULL; /* OK if no trailing characters */
+ return (*endptr == '\0') ? endptr : NULL; /* OK iff no trailing chars */
}
/*
-** Convert string 's' to a Lua number (put in 'result'). Return NULL
-** on fail or the address of the ending '\0' on success.
-** 'pmode' points to (and 'mode' contains) special things in the string:
-** - 'x'/'X' means a hexadecimal numeral
-** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
-** - '.' just optimizes the search for the common case (nothing special)
+** Convert string 's' to a Lua number (put in 'result') handling the
+** current locale.
** This function accepts both the current locale or a dot as the radix
** mark. If the conversion fails, it may mean number has a dot but
** locale accepts something else. In that case, the code copies 's'
** to a buffer (because 's' is read-only), changes the dot to the
** current locale radix mark, and tries to convert again.
+** The variable 'mode' checks for special characters in the string:
+** - 'n' means 'inf' or 'nan' (which should be rejected)
+** - 'x' means a hexadecimal numeral
+** - '.' just optimizes the search for the common case (no special chars)
*/
static const char *l_str2d (const char *s, lua_Number *result) {
const char *endptr;
- const char *pmode = strpbrk(s, ".xXnN");
+ const char *pmode = strpbrk(s, ".xXnN"); /* look for special chars */
int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
if (mode == 'n') /* reject 'inf' and 'nan' */
return NULL;
@@ -333,8 +338,15 @@
}
-/* maximum length of the conversion of a number to a string */
-#define MAXNUMBER2STR 50
+/*
+** Maximum length of the conversion of a number to a string. Must be
+** enough to accommodate both LUA_INTEGER_FMT and LUA_NUMBER_FMT.
+** (For a long long int, this is 19 digits plus a sign and a final '\0',
+** adding to 21. For a long double, it can go to a sign, 33 digits,
+** the dot, an exponent letter, an exponent sign, 5 exponent digits,
+** and a final '\0', adding to 43.)
+*/
+#define MAXNUMBER2STR 44
/*
@@ -375,7 +387,7 @@
*/
/* size for buffer space used by 'luaO_pushvfstring' */
-#define BUFVFS 400
+#define BUFVFS 200
/* buffer used by 'luaO_pushvfstring' */
typedef struct BuffFS {
@@ -387,18 +399,16 @@
/*
-** Push given string to the stack, as part of the buffer. If the stack
-** is almost full, join all partial strings in the stack into one.
+** Push given string to the stack, as part of the buffer, and
+** join the partial strings in the stack into one.
*/
static void pushstr (BuffFS *buff, const char *str, size_t l) {
lua_State *L = buff->L;
setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
L->top++; /* may use one extra slot */
buff->pushed++;
- if (buff->pushed > 1 && L->top + 1 >= L->stack_last) {
- luaV_concat(L, buff->pushed); /* join all partial results into one */
- buff->pushed = 1;
- }
+ luaV_concat(L, buff->pushed); /* join partial results into one */
+ buff->pushed = 1;
}
@@ -521,8 +531,7 @@
}
addstr2buff(&buff, fmt, strlen(fmt)); /* rest of 'fmt' */
clearbuff(&buff); /* empty buffer into the stack */
- if (buff.pushed > 1)
- luaV_concat(L, buff.pushed); /* join all partial results */
+ lua_assert(buff.pushed == 1);
return svalue(s2v(L->top - 1));
}
src/lobject.h
@@ -96,7 +96,8 @@
/*
** Any value being manipulated by the program either is non
** collectable, or the collectable object has the right tag
-** and it is not dead.
+** and it is not dead. The option 'L == NULL' allows other
+** macros using this one to be used where L is not available.
*/
#define checkliveness(L,obj) \
((void)L, lua_longassert(!iscollectable(obj) || \
@@ -703,9 +704,9 @@
*/
#define BITRAS (1 << 7)
-#define isrealasize(t) (!((t)->marked & BITRAS))
-#define setrealasize(t) ((t)->marked &= cast_byte(~BITRAS))
-#define setnorealasize(t) ((t)->marked |= BITRAS)
+#define isrealasize(t) (!((t)->flags & BITRAS))
+#define setrealasize(t) ((t)->flags &= cast_byte(~BITRAS))
+#define setnorealasize(t) ((t)->flags |= BITRAS)
typedef struct Table {
src/lstate.c
@@ -301,6 +301,7 @@
L->openupval = NULL;
L->status = LUA_OK;
L->errfunc = 0;
+ L->oldpc = 0;
}
@@ -318,9 +319,10 @@
LUA_API lua_State *lua_newthread (lua_State *L) {
- global_State *g = G(L);
+ global_State *g;
lua_State *L1;
lua_lock(L);
+ g = G(L);
luaC_checkGC(L);
/* create new thread */
L1 = &cast(LX *, luaM_newobject(L, LUA_TTHREAD, sizeof(LX)))->l;
@@ -395,6 +397,7 @@
g->allgc = obj2gco(L); /* by now, only object is the main thread */
L->next = NULL;
g->Cstacklimit = L->nCcalls = LUAI_MAXCSTACK + CSTACKERR;
+ incnny(L); /* main thread is always non yieldable */
g->frealloc = f;
g->ud = ud;
g->warnf = NULL;
@@ -410,8 +413,8 @@
g->gckind = KGC_INC;
g->gcemergency = 0;
g->finobj = g->tobefnz = g->fixedgc = NULL;
- g->survival = g->old = g->reallyold = NULL;
- g->finobjsur = g->finobjold = g->finobjrold = NULL;
+ g->firstold1 = g->survival = g->old1 = g->reallyold = NULL;
+ g->finobjsur = g->finobjold1 = g->finobjrold = NULL;
g->sweepgc = NULL;
g->gray = g->grayagain = NULL;
g->weak = g->ephemeron = g->allweak = NULL;
@@ -436,8 +439,8 @@
LUA_API void lua_close (lua_State *L) {
- L = G(L)->mainthread; /* only the main thread can be closed */
lua_lock(L);
+ L = G(L)->mainthread; /* only the main thread can be closed */
close_state(L);
}
src/lstate.h
@@ -32,13 +32,29 @@
**
** 'allgc' -> 'survival': new objects;
** 'survival' -> 'old': objects that survived one collection;
-** 'old' -> 'reallyold': objects that became old in last collection;
+** 'old1' -> 'reallyold': objects that became old in last collection;
** 'reallyold' -> NULL: objects old for more than one cycle.
**
** 'finobj' -> 'finobjsur': new objects marked for finalization;
-** 'finobjsur' -> 'finobjold': survived """";
-** 'finobjold' -> 'finobjrold': just old """";
+** 'finobjsur' -> 'finobjold1': survived """";
+** 'finobjold1' -> 'finobjrold': just old """";
** 'finobjrold' -> NULL: really old """".
+**
+** All lists can contain elements older than their main ages, due
+** to 'luaC_checkfinalizer' and 'udata2finalize', which move
+** objects between the normal lists and the "marked for finalization"
+** lists. Moreover, barriers can age young objects in young lists as
+** OLD0, which then become OLD1. However, a list never contains
+** elements younger than their main ages.
+**
+** The generational collector also uses a pointer 'firstold1', which
+** points to the first OLD1 object in the list. It is used to optimize
+** 'markold'. (Potentially OLD1 objects can be anywhere between 'allgc'
+** and 'reallyold', but often the list has no OLD1 objects or they are
+** after 'old1'.) Note the difference between it and 'old1':
+** 'firstold1': no OLD1 objects before this point; there can be all
+** ages after it.
+** 'old1': no objects younger than OLD1 after this point.
*/
/*
@@ -47,7 +63,7 @@
** can become gray have such a field. The field is not the same
** in all objects, but it always has this name.) Any gray object
** must belong to one of these lists, and all objects in these lists
-** must be gray:
+** must be gray (with two exceptions explained below):
**
** 'gray': regular gray objects, still waiting to be visited.
** 'grayagain': objects that must be revisited at the atomic phase.
@@ -58,6 +74,14 @@
** 'weak': tables with weak values to be cleared;
** 'ephemeron': ephemeron tables with white->white entries;
** 'allweak': tables with weak keys and/or weak values to be cleared.
+**
+** The exceptions to that "gray rule" are:
+** - TOUCHED2 objects in generational mode stay in a gray list (because
+** they must be visited again at the end of the cycle), but they are
+** marked black because assignments to them must activate barriers (to
+** move them back to TOUCHED1).
+** - Open upvales are kept gray to avoid barriers, but they stay out
+** of gray lists. (They don't even have a 'gclist' field.)
*/
@@ -257,10 +281,11 @@
GCObject *fixedgc; /* list of objects not to be collected */
/* fields for generational collector */
GCObject *survival; /* start of objects that survived one GC cycle */
- GCObject *old; /* start of old objects */
- GCObject *reallyold; /* old objects with more than one cycle */
+ GCObject *old1; /* start of old1 objects */
+ GCObject *reallyold; /* objects more than one cycle old ("really old") */
+ GCObject *firstold1; /* first OLD1 object in the list (if any) */
GCObject *finobjsur; /* list of survival objects with finalizers */
- GCObject *finobjold; /* list of old objects with finalizers */
+ GCObject *finobjold1; /* list of old1 objects with finalizers */
GCObject *finobjrold; /* list of really old objects with finalizers */
struct lua_State *twups; /* list of threads with open upvalues */
lua_CFunction panic; /* to be called in unprotected errors */
@@ -286,7 +311,6 @@
StkId top; /* first free slot in the stack */
global_State *l_G;
CallInfo *ci; /* call info for current function */
- const Instruction *oldpc; /* last pc traced */
StkId stack_last; /* last free slot in the stack */
StkId stack; /* stack base */
UpVal *openupval; /* list of open upvalues in this stack */
@@ -297,6 +321,7 @@
volatile lua_Hook hook;
ptrdiff_t errfunc; /* current error handling function (stack index) */
l_uint32 nCcalls; /* number of allowed nested C calls - 'nci' */
+ int oldpc; /* last pc traced */
int stacksize;
int basehookcount;
int hookcount;
@@ -309,6 +334,12 @@
/*
** Union of all collectable objects (only for conversions)
+** ISO C99, 6.5.2.3 p.5:
+** "if a union contains several structures that share a common initial
+** sequence [...], and if the union object currently contains one
+** of these structures, it is permitted to inspect the common initial
+** part of any of them anywhere that a declaration of the complete type
+** of the union is visible."
*/
union GCUnion {
GCObject gc; /* common header */
@@ -322,6 +353,11 @@
};
+/*
+** ISO C99, 6.7.2.1 p.14:
+** "A pointer to a union object, suitably converted, points to each of
+** its members [...], and vice versa."
+*/
#define cast_u(o) cast(union GCUnion *, (o))
/* macros to convert a GCObject into a specific value */
src/ltable.c
@@ -583,7 +583,7 @@
GCObject *o = luaC_newobj(L, LUA_VTABLE, sizeof(Table));
Table *t = gco2t(o);
t->metatable = NULL;
- t->flags = cast_byte(~0);
+ t->flags = cast_byte(maskflags); /* table has no metamethod fields */
t->array = NULL;
t->alimit = 0;
setnodevector(L, t, 0);
src/ltable.h
@@ -15,7 +15,12 @@
#define gnext(n) ((n)->u.next)
-#define invalidateTMcache(t) ((t)->flags = 0)
+/*
+** Clear all bits of fast-access metamethods, which means that the table
+** may have any of these metamethods. (First access that fails after the
+** clearing will set the bit again.)
+*/
+#define invalidateTMcache(t) ((t)->flags &= ~maskflags)
/* true when 't' is using 'dummynode' as its hash part */
src/ltm.c
@@ -240,7 +240,7 @@
int actual = cast_int(L->top - ci->func) - 1; /* number of arguments */
int nextra = actual - nfixparams; /* number of extra arguments */
ci->u.l.nextraargs = nextra;
- checkstackGC(L, p->maxstacksize + 1);
+ luaD_checkstack(L, p->maxstacksize + 1);
/* copy function to the top of the stack */
setobjs2s(L, L->top++, ci->func);
/* move fixed parameters to the top of the stack */
@@ -259,7 +259,7 @@
int nextra = ci->u.l.nextraargs;
if (wanted < 0) {
wanted = nextra; /* get all extra arguments available */
- checkstackp(L, nextra, where); /* ensure stack space */
+ checkstackGCp(L, nextra, where); /* ensure stack space */
L->top = where + nextra; /* next instruction will need top */
}
for (i = 0; i < wanted && i < nextra; i++)
src/ltm.h
@@ -46,6 +46,15 @@
/*
+** Mask with 1 in all fast-access methods. A 1 in any of these bits
+** in the flag of a (meta)table means the metatable does not have the
+** corresponding metamethod field. (Bit 7 of the flag is used for
+** 'isrealasize'.)
+*/
+#define maskflags (~(~0u << (TM_EQ + 1)))
+
+
+/*
** Test whether there is no tagmethod.
** (Because tagmethods use raw accesses, the result may be an "empty" nil.)
*/
src/lua.h
@@ -18,7 +18,7 @@
#define LUA_VERSION_MAJOR "5"
#define LUA_VERSION_MINOR "4"
-#define LUA_VERSION_RELEASE "0"
+#define LUA_VERSION_RELEASE "1"
#define LUA_VERSION_NUM 504
#define LUA_VERSION_RELEASE_NUM (LUA_VERSION_NUM * 100 + 0)
src/lundump.c
@@ -120,7 +120,10 @@
}
else { /* long string */
ts = luaS_createlngstrobj(L, size); /* create string */
+ setsvalue2s(L, L->top, ts); /* anchor it ('loadVector' can GC) */
+ luaD_inctop(L);
loadVector(S, getstr(ts), size); /* load directly in final place */
+ L->top--; /* pop string */
}
luaC_objbarrier(L, p, ts);
return ts;
@@ -200,13 +203,20 @@
}
+/*
+** Load the upvalues for a function. The names must be filled first,
+** because the filling of the other fields can raise read errors and
+** the creation of the error message can call an emergency collection;
+** in that case all prototypes must be consistent for the GC.
+*/
static void loadUpvalues (LoadState *S, Proto *f) {
int i, n;
n = loadInt(S);
f->upvalues = luaM_newvectorchecked(S->L, n, Upvaldesc);
f->sizeupvalues = n;
- for (i = 0; i < n; i++) {
+ for (i = 0; i < n; i++) /* make array valid for GC */
f->upvalues[i].name = NULL;
+ for (i = 0; i < n; i++) { /* following calls can raise errors */
f->upvalues[i].instack = loadByte(S);
f->upvalues[i].idx = loadByte(S);
f->upvalues[i].kind = loadByte(S);
src/lvm.c
@@ -634,7 +634,8 @@
** from 'L->top - total' up to 'L->top - 1'.
*/
void luaV_concat (lua_State *L, int total) {
- lua_assert(total >= 2);
+ if (total == 1)
+ return; /* "all" values already concatenated */
do {
StkId top = L->top;
int n = 2; /* number of elements handled in this pass (at least 2) */
@@ -840,10 +841,8 @@
int a = GETARG_A(inst); /* first element to concatenate */
int total = cast_int(top - 1 - (base + a)); /* yet to concatenate */
setobjs2s(L, top - 2, top); /* put TM result in proper position */
- if (total > 1) { /* are there elements to concat? */
- L->top = top - 1; /* top is one after last element (at top-2) */
- luaV_concat(L, total); /* concat them (may yield again) */
- }
+ L->top = top - 1; /* top is one after last element (at top-2) */
+ luaV_concat(L, total); /* concat them (may yield again) */
break;
}
default: {
@@ -1102,9 +1101,9 @@
/* idem, but without changing the stack */
#define halfProtectNT(exp) (savepc(L), (exp))
-
+/* 'c' is the limit of live values in the stack */
#define checkGC(L,c) \
- { luaC_condGC(L, L->top = (c), /* limit of live values */ \
+ { luaC_condGC(L, (savepc(L), L->top = (c)), \
updatetrap(ci)); \
luai_threadyield(L); }
@@ -1635,7 +1634,7 @@
while (!ttisfunction(s2v(ra))) { /* not a function? */
luaD_tryfuncTM(L, ra); /* try '__call' metamethod */
b++; /* there is now one extra argument */
- checkstackp(L, 1, ra);
+ checkstackGCp(L, 1, ra);
}
if (!ttisLclosure(s2v(ra))) { /* C function? */
luaD_call(L, ra, LUA_MULTRET); /* call it */
@@ -1792,11 +1791,10 @@
vmbreak;
}
vmcase(OP_VARARGPREP) {
- luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p);
- updatetrap(ci);
+ ProtectNT(luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p));
if (trap) {
luaD_hookcall(L, ci);
- L->oldpc = pc + 1; /* next opcode will be seen as a "new" line */
+ L->oldpc = 1; /* next opcode will be seen as a "new" line */
}
updatebase(ci); /* function has new base after adjustment */
vmbreak;