HTTP/2: limit the number of idle state switches. An attack that continuously switches HTTP/2 connection between idle and active states can result in excessive CPU usage. This is because when a connection switches to the idle state, all of its memory pool caches are freed. This change limits the maximum allowed number of idle state switches to 10 * http2_max_requests (i.e., 10000 by default). This limits possible CPU usage in one connection, and also imposes a limit on the maximum lifetime of a connection. Initially reported by Gal Goldshtein from F5 Networks.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_DARWIN_H_INCLUDED_
#define _NGX_DARWIN_H_INCLUDED_


void ngx_debug_init(void);
ngx_chain_t *ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in,
    off_t limit);

extern int       ngx_darwin_kern_osreldate;
extern int       ngx_darwin_hw_ncpu;
extern u_long    ngx_darwin_net_inet_tcp_sendspace;

extern ngx_uint_t  ngx_debug_malloc;


#endif /* _NGX_DARWIN_H_INCLUDED_ */