view src/core/ngx_file.h @ 8045:aa28c802409f

Resolver: make TCP write timer event cancelable. Similar to 70e65bf8dfd7, the change is made to ensure that the ability to cancel resolver tasks is fully controlled by the caller. As mentioned in the referenced commit, it is safe to make this timer cancelable because resolve tasks can have their own timeouts that are not cancelable. The scenario where this may become a problem is a periodic background resolve task (not tied to a specific request or a client connection), which receives a response with short TTL, large enough to warrant fallback to a TCP query. With each event loop wakeup, we either have a previously set write timer instance or schedule a new one. The non-cancelable write timer can delay or block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable flag is set by the API user, and there are no other tasks or connections. We use the resolver API in this way to maintain the list of upstream server addresses specified with the 'resolve' parameter, and there could be third-party modules implementing similar logic.
author Aleksei Bavshin <a.bavshin@f5.com>
date Wed, 01 Jun 2022 20:17:23 -0700
parents 0c572ed91b36
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_FILE_H_INCLUDED_
#define _NGX_FILE_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


struct ngx_file_s {
    ngx_fd_t                   fd;
    ngx_str_t                  name;
    ngx_file_info_t            info;

    off_t                      offset;
    off_t                      sys_offset;

    ngx_log_t                 *log;

#if (NGX_THREADS || NGX_COMPAT)
    ngx_int_t                (*thread_handler)(ngx_thread_task_t *task,
                                               ngx_file_t *file);
    void                      *thread_ctx;
    ngx_thread_task_t         *thread_task;
#endif

#if (NGX_HAVE_FILE_AIO || NGX_COMPAT)
    ngx_event_aio_t           *aio;
#endif

    unsigned                   valid_info:1;
    unsigned                   directio:1;
};


#define NGX_MAX_PATH_LEVEL  3


typedef ngx_msec_t (*ngx_path_manager_pt) (void *data);
typedef ngx_msec_t (*ngx_path_purger_pt) (void *data);
typedef void (*ngx_path_loader_pt) (void *data);


typedef struct {
    ngx_str_t                  name;
    size_t                     len;
    size_t                     level[NGX_MAX_PATH_LEVEL];

    ngx_path_manager_pt        manager;
    ngx_path_purger_pt         purger;
    ngx_path_loader_pt         loader;
    void                      *data;

    u_char                    *conf_file;
    ngx_uint_t                 line;
} ngx_path_t;


typedef struct {
    ngx_str_t                  name;
    size_t                     level[NGX_MAX_PATH_LEVEL];
} ngx_path_init_t;


typedef struct {
    ngx_file_t                 file;
    off_t                      offset;
    ngx_path_t                *path;
    ngx_pool_t                *pool;
    char                      *warn;

    ngx_uint_t                 access;

    unsigned                   log_level:8;
    unsigned                   persistent:1;
    unsigned                   clean:1;
    unsigned                   thread_write:1;
} ngx_temp_file_t;


typedef struct {
    ngx_uint_t                 access;
    ngx_uint_t                 path_access;
    time_t                     time;
    ngx_fd_t                   fd;

    unsigned                   create_path:1;
    unsigned                   delete_file:1;

    ngx_log_t                 *log;
} ngx_ext_rename_file_t;


typedef struct {
    off_t                      size;
    size_t                     buf_size;

    ngx_uint_t                 access;
    time_t                     time;

    ngx_log_t                 *log;
} ngx_copy_file_t;


typedef struct ngx_tree_ctx_s  ngx_tree_ctx_t;

typedef ngx_int_t (*ngx_tree_init_handler_pt) (void *ctx, void *prev);
typedef ngx_int_t (*ngx_tree_handler_pt) (ngx_tree_ctx_t *ctx, ngx_str_t *name);

struct ngx_tree_ctx_s {
    off_t                      size;
    off_t                      fs_size;
    ngx_uint_t                 access;
    time_t                     mtime;

    ngx_tree_init_handler_pt   init_handler;
    ngx_tree_handler_pt        file_handler;
    ngx_tree_handler_pt        pre_tree_handler;
    ngx_tree_handler_pt        post_tree_handler;
    ngx_tree_handler_pt        spec_handler;

    void                      *data;
    size_t                     alloc;

    ngx_log_t                 *log;
};


ngx_int_t ngx_get_full_name(ngx_pool_t *pool, ngx_str_t *prefix,
    ngx_str_t *name);

ssize_t ngx_write_chain_to_temp_file(ngx_temp_file_t *tf, ngx_chain_t *chain);
ngx_int_t ngx_create_temp_file(ngx_file_t *file, ngx_path_t *path,
    ngx_pool_t *pool, ngx_uint_t persistent, ngx_uint_t clean,
    ngx_uint_t access);
void ngx_create_hashed_filename(ngx_path_t *path, u_char *file, size_t len);
ngx_int_t ngx_create_path(ngx_file_t *file, ngx_path_t *path);
ngx_err_t ngx_create_full_path(u_char *dir, ngx_uint_t access);
ngx_int_t ngx_add_path(ngx_conf_t *cf, ngx_path_t **slot);
ngx_int_t ngx_create_paths(ngx_cycle_t *cycle, ngx_uid_t user);
ngx_int_t ngx_ext_rename_file(ngx_str_t *src, ngx_str_t *to,
    ngx_ext_rename_file_t *ext);
ngx_int_t ngx_copy_file(u_char *from, u_char *to, ngx_copy_file_t *cf);
ngx_int_t ngx_walk_tree(ngx_tree_ctx_t *ctx, ngx_str_t *tree);

ngx_atomic_uint_t ngx_next_temp_number(ngx_uint_t collision);

char *ngx_conf_set_path_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
char *ngx_conf_merge_path_value(ngx_conf_t *cf, ngx_path_t **path,
    ngx_path_t *prev, ngx_path_init_t *init);
char *ngx_conf_set_access_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);


extern ngx_atomic_t      *ngx_temp_number;
extern ngx_atomic_int_t   ngx_random_number;


#endif /* _NGX_FILE_H_INCLUDED_ */