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authorWilliam Wilgus <me.theuser@yahoo.com>2019-07-12 05:23:52 -0500
committerWilliam Wilgus <me.theuser@yahoo.com>2019-07-28 15:17:48 +0200
commit45bd14b392622cb58e967a24e4652c510b3d43e4 (patch)
tree22bd2e5cafc2d82ecc4773f83de7f86515b4db43 /apps/plugins/lua/lgc.c
parent4beafe16fafc2e5c59734ef065a6f8d23766520d (diff)
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Lua Add Emergency Garbage Collector
Derivative of work by RobertGabrielJakabosky http://lua-users.org/wiki/EmergencyGarbageCollector I've only implemented the not enough memory part and expanded this idea to adding a mechanism to signal the OOM condition of the plugin buffer which allows us to only grab the playback buffer after garbage collection fails (SO THE MUSIC KEEPS PLAYING AS LONG AS POSSIBLE) Change-Id: I684fb98b540ffc01f7ba324ab5b761ceb59b9f9b
Diffstat (limited to 'apps/plugins/lua/lgc.c')
-rw-r--r--apps/plugins/lua/lgc.c60
1 files changed, 49 insertions, 11 deletions
diff --git a/apps/plugins/lua/lgc.c b/apps/plugins/lua/lgc.c
index 98194c1771..17b64a103b 100644
--- a/apps/plugins/lua/lgc.c
+++ b/apps/plugins/lua/lgc.c
@@ -58,6 +58,9 @@
#define setthreshold(g) (g->GCthreshold = (g->estimate/100) * g->gcpause)
+#ifndef yield
+ #define yield() {}
+#endif
static void removeentry (Node *n) {
lua_assert(ttisnil(gval(n)));
@@ -232,8 +235,10 @@ static void traverseclosure (global_State *g, Closure *cl) {
int i;
lua_assert(cl->l.nupvalues == cl->l.p->nups);
markobject(g, cl->l.p);
- for (i=0; i<cl->l.nupvalues; i++) /* mark its upvalues */
- markobject(g, cl->l.upvals[i]);
+ for (i=0; i<cl->l.nupvalues; i++) { /* mark its upvalues */
+ if(cl->l.upvals[i])
+ markobject(g, cl->l.upvals[i]);
+ }
}
}
@@ -258,6 +263,7 @@ static void traversestack (global_State *g, lua_State *l) {
CallInfo *ci;
markvalue(g, gt(l));
lim = l->top;
+ if(l->stack == NULL) return; /* no stack to traverse */
for (ci = l->base_ci; ci <= l->ci; ci++) {
lua_assert(ci->top <= l->stack_last);
if (lim < ci->top) lim = ci->top;
@@ -266,7 +272,8 @@ static void traversestack (global_State *g, lua_State *l) {
markvalue(g, o);
for (; o <= lim; o++)
setnilvalue(o);
- checkstacksizes(l, lim);
+ if (!isfixedstack(l)) /* if stack size is fixed, can't resize it. */
+ checkstacksizes(l, lim);
}
@@ -419,8 +426,6 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
else { /* must erase `curr' */
lua_assert(isdead(g, curr) || deadmask == bitmask(SFIXEDBIT));
*p = curr->gch.next;
- if (curr == g->rootgc) /* is the first element of the list? */
- g->rootgc = curr->gch.next; /* adjust first */
freeobj(L, curr);
}
}
@@ -434,6 +439,8 @@ static void checkSizes (lua_State *L) {
if (g->strt.nuse < cast(lu_int32, g->strt.size/4) &&
g->strt.size > MINSTRTABSIZE*2)
luaS_resize(L, g->strt.size/2); /* table is too big */
+ /* it is not safe to re-size the buffer if it is in use. */
+ if (luaZ_bufflen(&g->buff) > 0) return;
/* check size of buffer */
if (luaZ_sizebuffer(&g->buff) > LUA_MINBUFFER*2) { /* buffer too big? */
size_t newsize = luaZ_sizebuffer(&g->buff) / 2;
@@ -552,6 +559,15 @@ static void atomic (lua_State *L) {
g->estimate = g->totalbytes - udsize; /* first estimate */
}
+static void sweepstrstep (global_State *g, lua_State *L) {
+ lu_mem old = g->totalbytes;
+ sweepwholelist(L, &g->strt.hash[g->sweepstrgc++]);
+ if (g->sweepstrgc >= g->strt.size) /* nothing more to sweep? */
+ g->gcstate = GCSsweep; /* end sweep-string phase */
+ lua_assert(old >= g->totalbytes);
+ g->estimate -= old - g->totalbytes;
+}
+
static l_mem singlestep (lua_State *L) {
global_State *g = G(L);
@@ -570,12 +586,7 @@ static l_mem singlestep (lua_State *L) {
}
}
case GCSsweepstring: {
- lu_mem old = g->totalbytes;
- sweepwholelist(L, &g->strt.hash[g->sweepstrgc++]);
- if (g->sweepstrgc >= g->strt.size) /* nothing more to sweep? */
- g->gcstate = GCSsweep; /* end sweep-string phase */
- lua_assert(old >= g->totalbytes);
- g->estimate -= old - g->totalbytes;
+ sweepstrstep(g, L);
return GCSWEEPCOST;
}
case GCSsweep: {
@@ -609,10 +620,14 @@ static l_mem singlestep (lua_State *L) {
void luaC_step (lua_State *L) {
global_State *g = G(L);
+ if(is_block_gc(L)) return;
+ set_block_gc(L);
l_mem lim = (GCSTEPSIZE/100) * g->gcstepmul;
if (lim == 0)
lim = (MAX_LUMEM-1)/2; /* no limit */
g->gcdept += g->totalbytes - g->GCthreshold;
+ if (g->estimate > g->totalbytes)
+ g->estimate = g->totalbytes;
do {
lim -= singlestep(L);
if (g->gcstate == GCSpause)
@@ -629,11 +644,23 @@ void luaC_step (lua_State *L) {
else {
setthreshold(g);
}
+ unset_block_gc(L);
}
+int luaC_sweepstrgc (lua_State *L) {
+ global_State *g = G(L);
+ if (g->gcstate == GCSsweepstring) {
+ sweepstrstep(g, L);
+ return (g->gcstate == GCSsweepstring) ? 1 : 0;
+ }
+ return 0;
+}
+
void luaC_fullgc (lua_State *L) {
global_State *g = G(L);
+ if(is_block_gc(L)) return;
+ set_block_gc(L);
if (g->gcstate <= GCSpropagate) {
/* reset sweep marks to sweep all elements (returning them to white) */
g->sweepstrgc = 0;
@@ -649,12 +676,15 @@ void luaC_fullgc (lua_State *L) {
while (g->gcstate != GCSfinalize) {
lua_assert(g->gcstate == GCSsweepstring || g->gcstate == GCSsweep);
singlestep(L);
+ yield();
}
markroot(L);
while (g->gcstate != GCSpause) {
singlestep(L);
+ yield();
}
setthreshold(g);
+ unset_block_gc(L);
}
@@ -682,6 +712,14 @@ void luaC_barrierback (lua_State *L, Table *t) {
}
+void luaC_marknew (lua_State *L, GCObject *o) {
+ global_State *g = G(L);
+ o->gch.marked = luaC_white(g);
+ if (g->gcstate == GCSpropagate)
+ reallymarkobject(g, o); /* mark new objects as gray during propagate state. */
+}
+
+
void luaC_link (lua_State *L, GCObject *o, lu_byte tt) {
global_State *g = G(L);
o->gch.next = g->rootgc;