view src/core/ngx_file.h @ 6133:af7eba90645d

Win32: shared memory base addresses and remapping. Two mechanisms are implemented to make it possible to store pointers in shared memory on Windows, in particular on Windows Vista and later versions with ASLR: - The ngx_shm_remap() function added to allow remapping of a shared memory zone to the address originally used for it in the master process. While important, it doesn't solve the problem by itself as in many cases it's not possible to use the address because of conflicts with other allocations. - We now create mappings at the same address in all processes by starting mappings at predefined addresses normally unused by newborn processes. These two mechanisms combined allow to use shared memory on Windows almost without problems, including reloads. Based on the patch by Sergey Brester: http://mailman.nginx.org/pipermail/nginx-devel/2015-April/006836.html
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 27 Apr 2015 18:25:42 +0300
parents 1fdba317ee6d
children 9fd738b85fad
line wrap: on
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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_int_t                (*thread_handler)(ngx_thread_task_t *task,
                                               ngx_file_t *file);
    void                      *thread_ctx;
#endif

#if (NGX_HAVE_FILE_AIO)
    ngx_event_aio_t           *aio;
#endif

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


#define NGX_MAX_PATH_LEVEL  3


typedef time_t (*ngx_path_manager_pt) (void *data);
typedef void (*ngx_path_loader_pt) (void *data);


typedef struct {
    ngx_str_t                  name;
    size_t                     len;
    size_t                     level[3];

    ngx_path_manager_pt        manager;
    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[3];
} 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;
} 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_ */