Mercurial > hg > nginx
view src/core/ngx_shmtx.c @ 6778:5e95b9fb33b7
HTTP/2: graceful shutdown of active connections (closes #1106).
Previously, while shutting down gracefully, the HTTP/2 connections were
closed in transition to idle state after all active streams have been
processed. That might never happen if the client continued opening new
streams.
Now, nginx sends GOAWAY to all HTTP/2 connections and ignores further
attempts to open new streams. A worker process will quit as soon as
processing of already opened streams is finished.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Thu, 20 Oct 2016 16:15:03 +0300 |
parents | 860a1c37f3b2 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_HAVE_ATOMIC_OPS) static void ngx_shmtx_wakeup(ngx_shmtx_t *mtx); ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr, u_char *name) { mtx->lock = &addr->lock; if (mtx->spin == (ngx_uint_t) -1) { return NGX_OK; } mtx->spin = 2048; #if (NGX_HAVE_POSIX_SEM) mtx->wait = &addr->wait; if (sem_init(&mtx->sem, 1, 0) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, "sem_init() failed"); } else { mtx->semaphore = 1; } #endif return NGX_OK; } void ngx_shmtx_destroy(ngx_shmtx_t *mtx) { #if (NGX_HAVE_POSIX_SEM) if (mtx->semaphore) { if (sem_destroy(&mtx->sem) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, "sem_destroy() failed"); } } #endif } ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx) { return (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)); } void ngx_shmtx_lock(ngx_shmtx_t *mtx) { ngx_uint_t i, n; ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx lock"); for ( ;; ) { if (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)) { return; } if (ngx_ncpu > 1) { for (n = 1; n < mtx->spin; n <<= 1) { for (i = 0; i < n; i++) { ngx_cpu_pause(); } if (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)) { return; } } } #if (NGX_HAVE_POSIX_SEM) if (mtx->semaphore) { (void) ngx_atomic_fetch_add(mtx->wait, 1); if (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)) { (void) ngx_atomic_fetch_add(mtx->wait, -1); return; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx wait %uA", *mtx->wait); while (sem_wait(&mtx->sem) == -1) { ngx_err_t err; err = ngx_errno; if (err != NGX_EINTR) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, err, "sem_wait() failed while waiting on shmtx"); break; } } ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx awoke"); continue; } #endif ngx_sched_yield(); } } void ngx_shmtx_unlock(ngx_shmtx_t *mtx) { if (mtx->spin != (ngx_uint_t) -1) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx unlock"); } if (ngx_atomic_cmp_set(mtx->lock, ngx_pid, 0)) { ngx_shmtx_wakeup(mtx); } } ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx forced unlock"); if (ngx_atomic_cmp_set(mtx->lock, pid, 0)) { ngx_shmtx_wakeup(mtx); return 1; } return 0; } static void ngx_shmtx_wakeup(ngx_shmtx_t *mtx) { #if (NGX_HAVE_POSIX_SEM) ngx_atomic_uint_t wait; if (!mtx->semaphore) { return; } for ( ;; ) { wait = *mtx->wait; if ((ngx_atomic_int_t) wait <= 0) { return; } if (ngx_atomic_cmp_set(mtx->wait, wait, wait - 1)) { break; } } ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx wake %uA", wait); if (sem_post(&mtx->sem) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, "sem_post() failed while wake shmtx"); } #endif } #else ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr, u_char *name) { if (mtx->name) { if (ngx_strcmp(name, mtx->name) == 0) { mtx->name = name; return NGX_OK; } ngx_shmtx_destroy(mtx); } mtx->fd = ngx_open_file(name, NGX_FILE_RDWR, NGX_FILE_CREATE_OR_OPEN, NGX_FILE_DEFAULT_ACCESS); if (mtx->fd == NGX_INVALID_FILE) { ngx_log_error(NGX_LOG_EMERG, ngx_cycle->log, ngx_errno, ngx_open_file_n " \"%s\" failed", name); return NGX_ERROR; } if (ngx_delete_file(name) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, ngx_delete_file_n " \"%s\" failed", name); } mtx->name = name; return NGX_OK; } void ngx_shmtx_destroy(ngx_shmtx_t *mtx) { if (ngx_close_file(mtx->fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, ngx_close_file_n " \"%s\" failed", mtx->name); } } ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx) { ngx_err_t err; err = ngx_trylock_fd(mtx->fd); if (err == 0) { return 1; } if (err == NGX_EAGAIN) { return 0; } #if __osf__ /* Tru64 UNIX */ if (err == NGX_EACCES) { return 0; } #endif ngx_log_abort(err, ngx_trylock_fd_n " %s failed", mtx->name); return 0; } void ngx_shmtx_lock(ngx_shmtx_t *mtx) { ngx_err_t err; err = ngx_lock_fd(mtx->fd); if (err == 0) { return; } ngx_log_abort(err, ngx_lock_fd_n " %s failed", mtx->name); } void ngx_shmtx_unlock(ngx_shmtx_t *mtx) { ngx_err_t err; err = ngx_unlock_fd(mtx->fd); if (err == 0) { return; } ngx_log_abort(err, ngx_unlock_fd_n " %s failed", mtx->name); } ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid) { return 0; } #endif