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A number of quite incremental refinements to struct inpcbinfo's definition:

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(1) Add a locking guide for inpcbinfo.
(2) Annotate inpcbinfo fields with synchronisation information; not all
    annotations are 100% satisfactory.
(3) Reorder inpcbinfo fields so that the lock is at the head of the
    structure, and close to fields it protects.
(4) Sort fields that will eventually be hashlock/pcbgroup-related together
    even though they remain locked by ipi_lock for now.

Reviewed by:	bz
Sponsored by:	Juniper Networks
X-MFC after:	KBI analysis required
This commit is contained in:
Robert Watson 2011-05-23 13:51:57 +00:00
parent fc26891004
commit 82a5be494a
1 changed files with 48 additions and 27 deletions
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75
sys/netinet/in_pcb.h
View File

@ -1,8 +1,12 @@
/*-
* Copyright (c) 1982, 1986, 1990, 1993
* The Regents of the University of California.
* Copyright (c) 2010-2011 Juniper Networks, Inc.
* All rights reserved.
*
* Portions of this software were developed by Robert N. M. Watson under
* contract to Juniper Networks, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
@ -260,53 +264,70 @@ struct inpcbport {
u_short phd_port;
};
/*
/*-
* Global data structure for each high-level protocol (UDP, TCP, ...) in both
* IPv4 and IPv6. Holds inpcb lists and information for managing them.
*
* Each pcbinfo is protected by ipi_lock, covering mutable global fields (such
* as the global pcb list) and hashed lookup tables. The lock order is:
*
* ipi_lock (before) inpcb locks
*
* Locking key:
*
* (c) Constant or nearly constant after initialisation
* (g) Locked by ipi_lock
* (h) Read using either ipi_lock or inpcb lock; write requires both.
* (x) Synchronisation properties poorly defined
*/
struct inpcbinfo {
/*
* Global lock protecting global inpcb list, inpcb count, hash tables,
* etc.
*/
struct rwlock ipi_lock;
/*
* Global list of inpcbs on the protocol.
*/
struct inpcbhead *ipi_listhead;
u_int ipi_count;
struct inpcbhead *ipi_listhead; /* (g) */
u_int ipi_count; /* (g) */
/*
* Generation count -- incremented each time a connection is allocated
* or freed.
*/
u_quad_t ipi_gencnt; /* (g) */
/*
* Fields associated with port lookup and allocation.
*/
u_short ipi_lastport; /* (x) */
u_short ipi_lastlow; /* (x) */
u_short ipi_lasthi; /* (x) */
/*
* UMA zone from which inpcbs are allocated for this protocol.
*/
struct uma_zone *ipi_zone; /* (c) */
/*
* Global hash of inpcbs, hashed by local and foreign addresses and
* port numbers.
*/
struct inpcbhead *ipi_hashbase;
u_long ipi_hashmask;
struct inpcbhead *ipi_hashbase; /* (g) */
u_long ipi_hashmask; /* (g) */
/*
* Global hash of inpcbs, hashed by only local port number.
*/
struct inpcbporthead *ipi_porthashbase;
u_long ipi_porthashmask;
/*
* Fields associated with port lookup and allocation.
*/
u_short ipi_lastport;
u_short ipi_lastlow;
u_short ipi_lasthi;
/*
* UMA zone from which inpcbs are allocated for this protocol.
*/
struct uma_zone *ipi_zone;
/*
* Generation count--incremented each time a connection is allocated
* or freed.
*/
u_quad_t ipi_gencnt;
struct rwlock ipi_lock;
struct inpcbporthead *ipi_porthashbase; /* (g) */
u_long ipi_porthashmask; /* (g) */
/*
* Pointer to network stack instance
*/
struct vnet *ipi_vnet;
struct vnet *ipi_vnet; /* (c) */
/*
* general use 2