lock mechanism

fallback.c

@@ -3,11 +3,13 @@
 ** TecCGraf - PUC-Rio
 */
  
-char *rcs_fallback="$Id: $";
+char *rcs_fallback="$Id: fallback.c,v 1.1 1994/11/07 15:20:56 roberto Exp roberto $";
 
 #include <stdio.h>
+#include <stdlib.h>
  
 #include "fallback.h"
+#include "opcode.h"
 #include "lua.h"
 
 
@@ -49,3 +51,66 @@ void luaI_orderFB (void)
   lua_error("unexpected type at comparison");
 }
 
+
+/*
+** Lock routines
+*/
+
+static Object *lockArray = NULL;
+static int lockSize = 0;
+
+int lua_lock (lua_Object object)
+{
+  int i;
+  int oldSize;
+  if (lua_isnil(object))
+    return -1;
+  for (i=0; i<lockSize; i++)
+    if (tag(&lockArray[i]) == LUA_T_NIL)
+    {
+      lockArray[i] = *luaI_Address(object);
+      return i;
+    }
+  /* no more empty spaces */
+  oldSize = lockSize;
+  if (lockArray == NULL)
+  {
+    lockSize = 10;
+    lockArray = (Object *)malloc(lockSize);
+  }
+  else
+  {
+    lockSize = 3*oldSize/2 + 5;
+    lockArray = (Object *)realloc(lockArray, lockSize);
+  }
+  if (lockArray == NULL)
+  {
+    lockSize = 0;
+    lua_error("lock - not enough memory");
+  }
+  for (i=oldSize; i<lockSize; i++)
+    tag(&lockArray[i]) = LUA_T_NIL;
+  lockArray[oldSize] = *luaI_Address(object);
+  return oldSize;
+}
+
+
+void lua_unlock (int ref)
+{
+  tag(&lockArray[ref]) = LUA_T_NIL;
+}
+
+
+Object *luaI_getlocked (int ref)
+{
+  return &lockArray[ref];
+}
+
+
+void luaI_travlock (void (*fn)(Object *))
+{
+  int i;
+  for (i=0; i<lockSize; i++)
+    fn(&lockArray[i]);
+}
+