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view src/core/ngx_palloc.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 | d620f497c50f |
children | ef935cd7ed8d |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_PALLOC_H_INCLUDED_ #define _NGX_PALLOC_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> /* * NGX_MAX_ALLOC_FROM_POOL should be (ngx_pagesize - 1), i.e. 4095 on x86. * On Windows NT it decreases a number of locked pages in a kernel. */ #define NGX_MAX_ALLOC_FROM_POOL (ngx_pagesize - 1) #define NGX_DEFAULT_POOL_SIZE (16 * 1024) #define NGX_POOL_ALIGNMENT 16 #define NGX_MIN_POOL_SIZE \ ngx_align((sizeof(ngx_pool_t) + 2 * sizeof(ngx_pool_large_t)), \ NGX_POOL_ALIGNMENT) typedef void (*ngx_pool_cleanup_pt)(void *data); typedef struct ngx_pool_cleanup_s ngx_pool_cleanup_t; struct ngx_pool_cleanup_s { ngx_pool_cleanup_pt handler; void *data; ngx_pool_cleanup_t *next; }; typedef struct ngx_pool_large_s ngx_pool_large_t; struct ngx_pool_large_s { ngx_pool_large_t *next; void *alloc; }; typedef struct { u_char *last; u_char *end; ngx_pool_t *next; ngx_uint_t failed; } ngx_pool_data_t; struct ngx_pool_s { ngx_pool_data_t d; size_t max; ngx_pool_t *current; ngx_chain_t *chain; ngx_pool_large_t *large; ngx_pool_cleanup_t *cleanup; ngx_log_t *log; }; typedef struct { ngx_fd_t fd; u_char *name; ngx_log_t *log; } ngx_pool_cleanup_file_t; void *ngx_alloc(size_t size, ngx_log_t *log); void *ngx_calloc(size_t size, ngx_log_t *log); ngx_pool_t *ngx_create_pool(size_t size, ngx_log_t *log); void ngx_destroy_pool(ngx_pool_t *pool); void ngx_reset_pool(ngx_pool_t *pool); void *ngx_palloc(ngx_pool_t *pool, size_t size); void *ngx_pnalloc(ngx_pool_t *pool, size_t size); void *ngx_pcalloc(ngx_pool_t *pool, size_t size); void *ngx_pmemalign(ngx_pool_t *pool, size_t size, size_t alignment); ngx_int_t ngx_pfree(ngx_pool_t *pool, void *p); ngx_pool_cleanup_t *ngx_pool_cleanup_add(ngx_pool_t *p, size_t size); void ngx_pool_run_cleanup_file(ngx_pool_t *p, ngx_fd_t fd); void ngx_pool_cleanup_file(void *data); void ngx_pool_delete_file(void *data); #endif /* _NGX_PALLOC_H_INCLUDED_ */