MEDIUM: lua: make the functions hlua_gethlua() and hlua_sethlua() faster
Lua 5.3 provides an opaque space associated with each
coroutine stack. This patch uses this lot of memory to
store the "struct hlua *" associated pointer.
This patch makes the retrieval of the "struct hlua *"
associated struct faster because it replace a lookup in
a tree by an immediate access to the data.
diff --git a/src/hlua.c b/src/hlua.c
index c08c750..18c901c 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -64,12 +64,6 @@
/* List head of the function called at the initialisation time. */
struct list hlua_init_functions = LIST_HEAD_INIT(hlua_init_functions);
-/* Store the fast lua context for coroutines. This tree uses the
- * Lua stack pointer value as indexed entry, and store the associated
- * hlua context.
- */
-struct eb_root hlua_ctx = EB_ROOT_UNIQUE;
-
/* The following variables contains the reference of the different
* Lua classes. These references are useful for identify metadata
* associated with an object.
@@ -506,31 +500,19 @@
/*
* The following functions are used to make correspondance between the the
* executed lua pointer and the "struct hlua *" that contain the context.
- * They run with the tree head "hlua_ctx", they just perform lookup in the
- * tree.
*
* - hlua_gethlua : return the hlua context associated with an lua_State.
- * - hlua_delhlua : remove the association between hlua context and lua_state.
* - hlua_sethlua : create the association between hlua context and lua_state.
*/
static inline struct hlua *hlua_gethlua(lua_State *L)
{
- struct ebpt_node *node;
-
- node = ebpt_lookup(&hlua_ctx, L);
- if (!node)
- return NULL;
- return ebpt_entry(node, struct hlua, node);
-}
-static inline void hlua_delhlua(struct hlua *hlua)
-{
- if (hlua->node.key)
- ebpt_delete(&hlua->node);
+ struct hlua **hlua = lua_getextraspace(L);
+ return *hlua;
}
static inline void hlua_sethlua(struct hlua *hlua)
{
- hlua->node.key = hlua->T;
- ebpt_insert(&hlua_ctx, &hlua->node);
+ struct hlua **hlua_store = lua_getextraspace(hlua->T);
+ *hlua_store = hlua;
}
/* This function just ensure that the yield will be always
@@ -581,9 +563,6 @@
if (!lua->T)
return;
- /* Remove context. */
- hlua_delhlua(lua);
-
/* Purge all the pending signals. */
hlua_com_purge(lua);
@@ -608,9 +587,6 @@
if (lua == &gL)
return 0;
- /* Remove context. */
- hlua_delhlua(lua);
-
/* New Lua coroutine. */
T = lua_newthread(gL.T);
if (!T)