ngx threads: replace list with rbtree

Author: ZigzagAK

src/ngx_http_lua_common.h

@@ -440,6 +440,13 @@ typedef struct {
 } ngx_http_lua_vm_state_t;
 
 
+typedef struct ngx_http_user_co_ctx_s {
+    ngx_rbtree_t                  rbtree;
+    ngx_rbtree_node_t             sentinel;
+    ngx_pool_t                   *pool;
+} ngx_http_user_co_ctx_t;
+
+
 typedef struct ngx_http_lua_ctx_s {
     /* for lua_coce_cache off: */
     ngx_http_lua_vm_state_t  *vm_state;
@@ -449,8 +456,7 @@ typedef struct ngx_http_lua_ctx_s {
 
     ngx_http_lua_co_ctx_t   *cur_co_ctx; /* co ctx for the current coroutine */
 
-    /* FIXME: we should use rbtree here to prevent O(n) lookup overhead */
-    ngx_list_t              *user_co_ctx; /* coroutine contexts for user
+    ngx_http_user_co_ctx_t  *user_co_ctx; /* coroutine contexts for user
                                              coroutines */
 
     ngx_http_lua_co_ctx_t    entry_co_ctx; /* coroutine context for the

src/ngx_http_lua_coroutine.c

@@ -86,12 +86,15 @@ ngx_http_lua_coroutine_create_helper(lua_State *L, ngx_http_request_t *r,
      * to main Lua thread
      */
     co = lua_newthread(vm);
+    if (co == NULL) {
+        return luaL_error(L, "no memory");
+    }
 
     ngx_http_lua_probe_user_coroutine_create(r, L, co);
 
     coctx = ngx_http_lua_get_co_ctx(co, ctx);
     if (coctx == NULL) {
-        coctx = ngx_http_lua_create_co_ctx(r, ctx);
+        coctx = ngx_http_lua_create_co_ctx(r, ctx, co);
         if (coctx == NULL) {
             return luaL_error(L, "no memory");
         }