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view src/core/ngx_shmtx.h @ 8078:5244d3b165ff
SSL: single allocation in session cache on 32-bit platforms.
Given the present typical SSL session sizes, on 32-bit platforms it is
now beneficial to store all data in a single allocation, since rbtree
node + session id + ASN1 representation of a session takes 256 bytes of
shared memory (36 + 32 + 150 = about 218 bytes plus SNI server name).
Storing all data in a single allocation is beneficial for SNI names up to
about 40 characters long and makes it possible to store about 4000 sessions
in one megabyte (instead of about 3000 sessions now). This also slightly
simplifies the code.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 12 Oct 2022 20:14:40 +0300 |
parents | 512c741fa841 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_SHMTX_H_INCLUDED_ #define _NGX_SHMTX_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct { ngx_atomic_t lock; #if (NGX_HAVE_POSIX_SEM) ngx_atomic_t wait; #endif } ngx_shmtx_sh_t; typedef struct { #if (NGX_HAVE_ATOMIC_OPS) ngx_atomic_t *lock; #if (NGX_HAVE_POSIX_SEM) ngx_atomic_t *wait; ngx_uint_t semaphore; sem_t sem; #endif #else ngx_fd_t fd; u_char *name; #endif ngx_uint_t spin; } ngx_shmtx_t; ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr, u_char *name); void ngx_shmtx_destroy(ngx_shmtx_t *mtx); ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx); void ngx_shmtx_lock(ngx_shmtx_t *mtx); void ngx_shmtx_unlock(ngx_shmtx_t *mtx); ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid); #endif /* _NGX_SHMTX_H_INCLUDED_ */