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

1 files changed, 6 insertions, 1 deletions

diff --git a/apps/plugins/lua/lstate.c b/apps/plugins/lua/lstate.c
index 4313b83a0c..67921d84a1 100644
--- a/apps/plugins/lua/lstate.c
+++ b/apps/plugins/lua/lstate.c
@@ -119,6 +119,8 @@ static void close_state (lua_State *L) {
 lua_State *luaE_newthread (lua_State *L) {
   lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));
   luaC_link(L, obj2gco(L1), LUA_TTHREAD);
+  setthvalue(L, L->top, L1); /* put thread on stack */
+  incr_top(L);
   preinit_state(L1, G(L));
   stack_init(L1, L);  /* init stack */
   setobj2n(L, gt(L1), gt(L));  /* share table of globals */
@@ -126,7 +128,8 @@ lua_State *luaE_newthread (lua_State *L) {
   L1->basehookcount = L->basehookcount;
   L1->hook = L->hook;
   resethookcount(L1);
-  lua_assert(iswhite(obj2gco(L1)));
+  lua_assert(!isdead(G(L), obj2gco(L1)));
+  L->top--; /* remove thread from stack */
   return L1;
 }
 
@@ -160,6 +163,7 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   g->uvhead.u.l.prev = &g->uvhead;
   g->uvhead.u.l.next = &g->uvhead;
   g->GCthreshold = 0;  /* mark it as unfinished state */
+  g->estimate = 0;
   g->strt.size = 0;
   g->strt.nuse = 0;
   g->strt.hash = NULL;
@@ -167,6 +171,7 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   luaZ_initbuffer(L, &g->buff);
   g->panic = NULL;
   g->gcstate = GCSpause;
+  g->gcflags = GCFlagsNone;
   g->rootgc = obj2gco(L);
   g->sweepstrgc = 0;
   g->sweepgc = &g->rootgc;