From: Oleg Babin via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: v.shpilevoy@tarantool.org, imun@tarantool.org Cc: tarantool-patches@dev.tarantool.org Subject: [Tarantool-patches] [PATCH v2 3/3] fiber: keep reference to userdata if fiber created once Date: Thu, 2 Sep 2021 21:13:31 +0300 [thread overview] Message-ID: <7ef7fcfec0d2c78721ea17376cbfe0d0f231798c.1630606077.git.babinoleg@mail.ru> (raw) In-Reply-To: <cover.1630606077.git.babinoleg@mail.ru> From: Oleg Babin <babinoleg@mail.ru> This patch reworks approach to fiber management in Lua. Before this patch each action that should return fiber led to new userdata creation that was quite slow and made GC suffer. This patch introduces new field in struct fiber to store a reference to userdata that was created once for a fiber. It allows speedup operations as fiber.self() and fiber.id(). Simple benchmark shows that access to fiber storage is faster in two times, fiber.find() - 2-3 times and fiber.new/create functions don't have any changes. --- src/lib/core/fiber.c | 5 ++ src/lib/core/fiber.h | 5 ++ src/lua/fiber.c | 113 +++++++++++++------------------------------ 3 files changed, 44 insertions(+), 79 deletions(-) diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c index 588b78504..39b67f940 100644 --- a/src/lib/core/fiber.c +++ b/src/lib/core/fiber.c @@ -32,6 +32,7 @@ #include <trivia/config.h> #include <trivia/util.h> +#include <lauxlib.h> #include <errno.h> #include <stdio.h> #include <stdlib.h> @@ -895,6 +896,8 @@ fiber_recycle(struct fiber *fiber) fiber->f = NULL; fiber->wait_pad = NULL; memset(&fiber->storage, 0, sizeof(fiber->storage)); + fiber->storage.lua.storage_ref = LUA_NOREF; + fiber->storage.lua.fid_ref = LUA_NOREF; unregister_fid(fiber); fiber->fid = 0; region_free(&fiber->gc); @@ -1236,6 +1239,8 @@ fiber_new_ex(const char *name, const struct fiber_attr *fiber_attr, return NULL; } memset(fiber, 0, sizeof(struct fiber)); + fiber->storage.lua.storage_ref = LUA_NOREF; + fiber->storage.lua.fid_ref = LUA_NOREF; if (fiber_stack_create(fiber, &cord()->slabc, fiber_attr->stack_size)) { diff --git a/src/lib/core/fiber.h b/src/lib/core/fiber.h index 593847df7..2d4443544 100644 --- a/src/lib/core/fiber.h +++ b/src/lib/core/fiber.h @@ -623,6 +623,11 @@ struct fiber { * Should not be used in other fibers. */ struct lua_State *stack; + /** + * Optional reference to userdata + * represented current fiber id in Lua. + */ + int fid_ref; /** * Optional fiber.storage Lua reference. */ diff --git a/src/lua/fiber.c b/src/lua/fiber.c index 5575f2079..ab0e895eb 100644 --- a/src/lua/fiber.c +++ b/src/lua/fiber.c @@ -87,27 +87,28 @@ luaL_testcancel(struct lua_State *L) static const char *fiberlib_name = "fiber"; /** - * @pre: stack top contains a table - * @post: sets table field specified by name of the table on top - * of the stack to a weak kv table and pops that weak table. + * Trigger invoked when the fiber has stopped execution of its + * current request. Only purpose - delete storage.lua.fid_ref and + * storage.lua.storage_ref keeping a reference of Lua + * fiber and fiber.storage objects. Unlike Lua stack, + * Lua fiber storage may be created not only for fibers born from + * Lua land. For example, an IProto request may execute a Lua + * function, which can create the storage. Trigger guarantees, + * that even for non-Lua fibers the Lua storage is destroyed. */ -static void -lbox_create_weak_table(struct lua_State *L, const char *name) +static int +lbox_fiber_on_stop(struct trigger *trigger, void *event) { - lua_newtable(L); - /* and a metatable */ - lua_newtable(L); - /* weak keys and values */ - lua_pushstring(L, "kv"); - /* pops 'kv' */ - lua_setfield(L, -2, "__mode"); - /* pops the metatable */ - lua_setmetatable(L, -2); - /* assigns and pops table */ - lua_setfield(L, -2, name); - /* gets memoize back. */ - lua_getfield(L, -1, name); - assert(! lua_isnil(L, -1)); + struct fiber *f = event; + int storage_ref = f->storage.lua.storage_ref; + luaL_unref(tarantool_L, LUA_REGISTRYINDEX, storage_ref); + f->storage.lua.storage_ref = LUA_NOREF; + int ref = f->storage.lua.fid_ref; + luaL_unref(tarantool_L, LUA_REGISTRYINDEX, ref); + f->storage.lua.fid_ref = LUA_NOREF; + trigger_clear(trigger); + free(trigger); + return 0; } /** @@ -116,42 +117,26 @@ lbox_create_weak_table(struct lua_State *L, const char *name) static void lbox_pushfiber(struct lua_State *L, struct fiber *f) { - /* - * Use 'memoize' pattern and keep a single userdata for - * the given fiber. This is important to not run __gc - * twice for a copy of an attached fiber -- __gc should - * not remove attached fiber's coro prematurely. - */ - luaL_getmetatable(L, fiberlib_name); - lua_getfield(L, -1, "memoize"); - if (lua_isnil(L, -1)) { - /* first access - instantiate memoize */ - /* pop the nil */ - lua_pop(L, 1); - /* create memoize table */ - lbox_create_weak_table(L, "memoize"); - } - /* Find out whether the fiber is already in the memoize table. */ - uint64_t fid = f->fid; - luaL_pushuint64(L, fid); - lua_gettable(L, -2); - if (lua_isnil(L, -1)) { - /* no userdata for fiber created so far */ - /* pop the nil */ - lua_pop(L, 1); - /* push the key back */ - luaL_pushuint64(L, fid); + int ref = f->storage.lua.fid_ref; + if (ref == LUA_NOREF) { + struct trigger *t = malloc(sizeof(*t)); + if (t == NULL) { + diag_set(OutOfMemory, sizeof(*t), "malloc", "t"); + luaT_error(L); + } + trigger_create(t, lbox_fiber_on_stop, NULL, (trigger_f0)free); + trigger_add(&f->on_stop, t); + + uint64_t fid = f->fid; /* create a new userdata */ uint64_t *ptr = lua_newuserdata(L, sizeof(*ptr)); *ptr = fid; luaL_getmetatable(L, fiberlib_name); lua_setmetatable(L, -2); - /* memoize it */ - lua_settable(L, -3); - luaL_pushuint64(L, fid); - /* get it back */ - lua_gettable(L, -2); + ref = luaL_ref(L, LUA_REGISTRYINDEX); + f->storage.lua.fid_ref = ref; } + lua_rawgeti(L, LUA_REGISTRYINDEX, ref); } static struct fiber * @@ -669,42 +654,12 @@ lbox_fiber_name(struct lua_State *L) } } -/** - * Trigger invoked when the fiber has stopped execution of its - * current request. Only purpose - delete storage.lua.storage_ref keeping - * a reference of Lua fiber.storage object. Unlike Lua stack, - * Lua fiber storage may be created not only for fibers born from - * Lua land. For example, an IProto request may execute a Lua - * function, which can create the storage. Trigger guarantees, - * that even for non-Lua fibers the Lua storage is destroyed. - */ -static int -lbox_fiber_on_stop(struct trigger *trigger, void *event) -{ - struct fiber *f = (struct fiber *) event; - int storage_ref = f->storage.lua.storage_ref; - assert(storage_ref > 0); - luaL_unref(tarantool_L, LUA_REGISTRYINDEX, storage_ref); - f->storage.lua.storage_ref = LUA_NOREF; - trigger_clear(trigger); - free(trigger); - return 0; -} - static int lbox_fiber_storage(struct lua_State *L) { struct fiber *f = lbox_checkfiber(L, 1); int storage_ref = f->storage.lua.storage_ref; if (storage_ref <= 0) { - struct trigger *t = (struct trigger *) - malloc(sizeof(*t)); - if (t == NULL) { - diag_set(OutOfMemory, sizeof(*t), "malloc", "t"); - return luaT_error(L); - } - trigger_create(t, lbox_fiber_on_stop, NULL, (trigger_f0) free); - trigger_add(&f->on_stop, t); lua_newtable(L); /* create local storage on demand */ storage_ref = luaL_ref(L, LUA_REGISTRYINDEX); f->storage.lua.storage_ref = storage_ref; -- 2.32.0
next prev parent reply other threads:[~2021-09-02 18:15 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-02 18:13 [Tarantool-patches] [PATCH v2 0/3] " Oleg Babin via Tarantool-patches 2021-09-02 18:13 ` [Tarantool-patches] [PATCH v2 1/3] fiber: rename ref to storage_ref Oleg Babin via Tarantool-patches 2021-09-02 18:13 ` [Tarantool-patches] [PATCH v2 2/3] fiber: pass struct fiber into lbox_pushfiber instead of id Oleg Babin via Tarantool-patches 2021-09-02 18:13 ` Oleg Babin via Tarantool-patches [this message] 2021-09-02 19:47 ` [Tarantool-patches] [PATCH v2 3/3] fiber: keep reference to userdata if fiber created once Oleg Babin via Tarantool-patches 2021-09-03 12:23 ` Igor Munkin via Tarantool-patches 2021-09-03 20:48 ` Oleg Babin via Tarantool-patches 2021-09-05 15:07 ` Vladislav Shpilevoy via Tarantool-patches
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=7ef7fcfec0d2c78721ea17376cbfe0d0f231798c.1630606077.git.babinoleg@mail.ru \ --to=tarantool-patches@dev.tarantool.org \ --cc=imun@tarantool.org \ --cc=olegrok@tarantool.org \ --cc=v.shpilevoy@tarantool.org \ --subject='Re: [Tarantool-patches] [PATCH v2 3/3] fiber: keep reference to userdata if fiber created once' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox