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| author | dormando <dormando@rydia.net> | 2023-01-20 16:02:53 -0800 |
|---|---|---|
| committer | dormando <dormando@rydia.net> | 2023-01-20 16:02:53 -0800 |
| commit | 3b9f7300b012805beaa6e0f01fcfde2ddcfe6b01 (patch) | |
| tree | 12a2ba6e4a58a0a77d306da4a1bb1b522c936c92 /proxy_await.c | |
| parent | 6537cfe41ead9c81dd3e9c9f5d3929a050692cbd (diff) | |
| download | memcached-3b9f7300b012805beaa6e0f01fcfde2ddcfe6b01.tar.gz | |
proxy: fix stats deadlock caused by await code
- specifically the WSTAT_DECR in proxy_await.c's return code could
potentially use the wrong thread's lock
This is why I've been swapping c with thread as lock/function arguments
all over the code lately; it's very accident prone.
Am reasonably sure this causes the deadlock but need to attempt to
verify more.
Diffstat (limited to 'proxy_await.c')
| -rw-r--r-- | proxy_await.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/proxy_await.c b/proxy_await.c index 3dfd16b..4192900 100644 --- a/proxy_await.c +++ b/proxy_await.c @@ -132,7 +132,7 @@ static void mcp_queue_await_io(conn *c, lua_State *Lc, mcp_request_t *rq, int aw io_pending_proxy_t *p = do_cache_alloc(c->thread->io_cache); if (p == NULL) { - WSTAT_INCR(c, proxy_conn_oom, 1); + WSTAT_INCR(c->thread, proxy_conn_oom, 1); proxy_lua_error(Lc, "out of memory allocating from IO cache"); return; } @@ -186,7 +186,7 @@ static void mcp_queue_await_dummy_io(conn *c, lua_State *Lc, int await_ref) { io_pending_proxy_t *p = do_cache_alloc(c->thread->io_cache); if (p == NULL) { - WSTAT_INCR(c, proxy_conn_oom, 1); + WSTAT_INCR(c->thread, proxy_conn_oom, 1); proxy_lua_error(Lc, "out of memory allocating from IO cache"); return; } @@ -223,7 +223,7 @@ static void mcp_queue_await_dummy_io(conn *c, lua_State *Lc, int await_ref) { // places. Else these errors currently crash the daemon. int mcplib_await_run(conn *c, mc_resp *resp, lua_State *L, int coro_ref) { P_DEBUG("%s: start\n", __func__); - WSTAT_INCR(c, proxy_await_active, 1); + WSTAT_INCR(c->thread, proxy_await_active, 1); mcp_await_t *aw = lua_touserdata(L, -1); int await_ref = luaL_ref(L, LUA_REGISTRYINDEX); // await is popped. assert(aw != NULL); @@ -430,7 +430,7 @@ int mcplib_await_return(io_pending_proxy_t *p) { luaL_unref(L, LUA_REGISTRYINDEX, aw->argtable_ref); luaL_unref(L, LUA_REGISTRYINDEX, aw->req_ref); luaL_unref(L, LUA_REGISTRYINDEX, p->await_ref); - WSTAT_DECR(p->c, proxy_await_active, 1); + WSTAT_DECR(p->thread, proxy_await_active, 1); } // Just remove anything we could have left on the primary VM stack |