Mercurial > hg > nginx
view src/core/ngx_hash.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 | f8f6b9fee66a |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_HASH_H_INCLUDED_ #define _NGX_HASH_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct { void *value; u_short len; u_char name[1]; } ngx_hash_elt_t; typedef struct { ngx_hash_elt_t **buckets; ngx_uint_t size; } ngx_hash_t; typedef struct { ngx_hash_t hash; void *value; } ngx_hash_wildcard_t; typedef struct { ngx_str_t key; ngx_uint_t key_hash; void *value; } ngx_hash_key_t; typedef ngx_uint_t (*ngx_hash_key_pt) (u_char *data, size_t len); typedef struct { ngx_hash_t hash; ngx_hash_wildcard_t *wc_head; ngx_hash_wildcard_t *wc_tail; } ngx_hash_combined_t; typedef struct { ngx_hash_t *hash; ngx_hash_key_pt key; ngx_uint_t max_size; ngx_uint_t bucket_size; char *name; ngx_pool_t *pool; ngx_pool_t *temp_pool; } ngx_hash_init_t; #define NGX_HASH_SMALL 1 #define NGX_HASH_LARGE 2 #define NGX_HASH_LARGE_ASIZE 16384 #define NGX_HASH_LARGE_HSIZE 10007 #define NGX_HASH_WILDCARD_KEY 1 #define NGX_HASH_READONLY_KEY 2 typedef struct { ngx_uint_t hsize; ngx_pool_t *pool; ngx_pool_t *temp_pool; ngx_array_t keys; ngx_array_t *keys_hash; ngx_array_t dns_wc_head; ngx_array_t *dns_wc_head_hash; ngx_array_t dns_wc_tail; ngx_array_t *dns_wc_tail_hash; } ngx_hash_keys_arrays_t; typedef struct ngx_table_elt_s ngx_table_elt_t; struct ngx_table_elt_s { ngx_uint_t hash; ngx_str_t key; ngx_str_t value; u_char *lowcase_key; ngx_table_elt_t *next; }; void *ngx_hash_find(ngx_hash_t *hash, ngx_uint_t key, u_char *name, size_t len); void *ngx_hash_find_wc_head(ngx_hash_wildcard_t *hwc, u_char *name, size_t len); void *ngx_hash_find_wc_tail(ngx_hash_wildcard_t *hwc, u_char *name, size_t len); void *ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key, u_char *name, size_t len); ngx_int_t ngx_hash_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts); ngx_int_t ngx_hash_wildcard_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts); #define ngx_hash(key, c) ((ngx_uint_t) key * 31 + c) ngx_uint_t ngx_hash_key(u_char *data, size_t len); ngx_uint_t ngx_hash_key_lc(u_char *data, size_t len); ngx_uint_t ngx_hash_strlow(u_char *dst, u_char *src, size_t n); ngx_int_t ngx_hash_keys_array_init(ngx_hash_keys_arrays_t *ha, ngx_uint_t type); ngx_int_t ngx_hash_add_key(ngx_hash_keys_arrays_t *ha, ngx_str_t *key, void *value, ngx_uint_t flags); #endif /* _NGX_HASH_H_INCLUDED_ */