ngx_shmtx_trylock   43 src/core/ngx_shmtx.h ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx);
ngx_shmtx_trylock  369 src/event/ngx_event_accept.c     if (ngx_shmtx_trylock(&ngx_accept_mutex)) {