New option "setparms" for 'collectgarbage'

The generational mode also uses the parameters for the incremental
mode in its major collections, so it should be easy to change those
parameters without having to change the GC mode.

1 files changed, 17 insertions, 7 deletions

diff --git a/lapi.c b/lapi.c
index 3ea3d0aa..aa2ee735 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1186,27 +1186,37 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
       break;
     }
     case LUA_GCGEN: {
+#if defined(LUA_COMPAT_GCPARAMS)
       int minormul = va_arg(argp, int);
       int minormajor = va_arg(argp, int);
-      int majorminor = va_arg(argp, int);
+      if (minormul > 0) setgcparam(g, MINORMUL, minormul);
+      if (minormajor > 0) setgcparam(g, MINORMAJOR, minormajor);
+#endif
       res = (g->gckind == KGC_INC) ? LUA_GCINC : LUA_GCGEN;
-      setgcparam(g, gcpgenminormul, minormul);
-      setgcparam(g, gcpminormajor, minormajor);
-      setgcparam(g, gcpmajorminor, majorminor);
       luaC_changemode(L, KGC_GENMINOR);
       break;
     }
     case LUA_GCINC: {
+#if defined(LUA_COMPAT_GCPARAMS)
       int pause = va_arg(argp, int);
       int stepmul = va_arg(argp, int);
       int stepsize = va_arg(argp, int);
+      if (pause > 0) setgcparam(g, PAUSE, pause);
+      if (stepmul > 0) setgcparam(g, STEPMUL, stepmul);
+      if (stepsize > 0) setgcparam(g, STEPSIZE, 1u << stepsize);
+#endif
       res = (g->gckind == KGC_INC) ? LUA_GCINC : LUA_GCGEN;
-      setgcparam(g, gcppause, pause);
-      setgcparam(g, gcpstepmul, stepmul);
-      setgcparam(g, gcpstepsize, stepsize);
       luaC_changemode(L, KGC_INC);
       break;
     }
+    case LUA_GCSETPARAM: {
+      int param = va_arg(argp, int);
+      int value = va_arg(argp, int);
+      api_check(L, 0 <= param && param < LUA_GCPN, "invalid parameter");
+      res = luaO_applyparam(g->gcparams[param], 100);
+      g->gcparams[param] = luaO_codeparam(value);
+      break;
+    }
     default: res = -1;  /* invalid option */
   }
   va_end(argp);