bugfix: coroutines might incorrectly enter the "dead" state even right after creation with coroutine.create(). thanks James Hurst for the report.

Author: agentzh

src/ngx_http_lua_coroutine.c

@@ -81,9 +81,16 @@ ngx_http_lua_coroutine_create_helper(lua_State *L, ngx_http_request_t *r,
 
     ngx_http_lua_probe_user_coroutine_create(r, L, co);
 
-    coctx = ngx_http_lua_create_co_ctx(r, ctx);
+    coctx = ngx_http_lua_get_co_ctx(co, ctx);
     if (coctx == NULL) {
-        return luaL_error(L, "out of memory");
+        coctx = ngx_http_lua_create_co_ctx(r, ctx);
+        if (coctx == NULL) {
+            return luaL_error(L, "out of memory");
+        }
+
+    } else {
+        ngx_memzero(coctx, sizeof(ngx_http_lua_co_ctx_t));
+        coctx->co_ref = LUA_NOREF;
     }
 
     coctx->co = co;

t/091-coroutine.t

@@ -1158,3 +1158,35 @@ data
 --- no_error_log
 [error]
 
+
+
+=== TEST 28: coroutine context collicisions
+--- config
+    location /lua {
+        content_by_lua '
+            local cc, cr, cy = coroutine.create, coroutine.resume, coroutine.yield
+
+            function f()
+                return 3
+            end
+
+            for i = 1, 10 do
+                collectgarbage()
+                local c = cc(f)
+                if coroutine.status(c) == "dead" then
+                    ngx.say("found a dead coroutine")
+                    return
+                end
+                cr(c)
+            end
+            ngx.say("ok")
+        ';
+    }
+--- request
+GET /lua
+--- stap2 eval: $::StapScript
+--- response_body
+ok
+--- no_error_log
+[error]
+