openldap/servers/slapd/back-bdb/cache.c

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/* cache.c - routines to maintain an in-core cache of entries */
/* $OpenLDAP$ */
/*
2003-01-04 04:20:47 +08:00
* Copyright 1998-2003 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*/
#include "portable.h"
#include <stdio.h>
#include <ac/errno.h>
#include <ac/string.h>
#include <ac/socket.h>
#include "slap.h"
#include "back-bdb.h"
/* BDB backend specific entry info -- visible only to the cache */
typedef struct bdb_entry_info {
ldap_pvt_thread_rdwr_t bei_rdwr; /* reader/writer lock */
/*
* remaining fields require backend cache lock to access
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* These items are specific to the BDB backend and should
* be hidden.
*/
int bei_state; /* for the cache */
#define CACHE_ENTRY_UNDEFINED 0
#define CACHE_ENTRY_CREATING 1
#define CACHE_ENTRY_READY 2
#define CACHE_ENTRY_DELETED 3
#define CACHE_ENTRY_COMMITTED 4
int bei_refcnt; /* # threads ref'ing this entry */
Entry *bei_lrunext; /* for cache lru list */
Entry *bei_lruprev;
} EntryInfo;
#undef BEI
#define BEI(e) ((EntryInfo *) ((e)->e_private))
static int bdb_cache_delete_entry_internal(Cache *cache, Entry *e);
#ifdef LDAP_DEBUG
static void bdb_lru_print(Cache *cache);
#endif
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#if 0 /* unused */
static int
bdb_cache_entry_rdwr_lock(Entry *e, int rw)
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ENTRY,
"bdb_cache_entry_rdwr_lock: %s lock on ID %ld\n",
rw ? "w" : "r", e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%slock: ID: %ld\n",
rw ? "w" : "r", e->e_id, 0);
#endif
if (rw)
return ldap_pvt_thread_rdwr_wlock(&BEI(e)->bei_rdwr);
else
return ldap_pvt_thread_rdwr_rlock(&BEI(e)->bei_rdwr);
}
static int
bdb_cache_entry_rdwr_trylock(Entry *e, int rw)
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ENTRY,
"bdb_cache_entry_rdwr_trylock: try %s lock on ID: %ld.\n",
rw ? "w" : "r", e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%strylock: ID: %ld\n",
rw ? "w" : "r", e->e_id, 0);
#endif
if (rw)
return ldap_pvt_thread_rdwr_wtrylock(&BEI(e)->bei_rdwr);
else
return ldap_pvt_thread_rdwr_rtrylock(&BEI(e)->bei_rdwr);
}
static int
bdb_cache_entry_rdwr_unlock(Entry *e, int rw)
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ENTRY,
"bdb_cache_entry_rdwr_unlock: remove %s lock on ID %ld.\n",
rw ? "w" : "r", e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%sunlock: ID: %ld\n",
rw ? "w" : "r", e->e_id, 0);
#endif
if (rw)
return ldap_pvt_thread_rdwr_wunlock(&BEI(e)->bei_rdwr);
else
return ldap_pvt_thread_rdwr_runlock(&BEI(e)->bei_rdwr);
}
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#endif /* unused */
static int
bdb_cache_entry_rdwr_init(Entry *e)
{
return ldap_pvt_thread_rdwr_init( &BEI(e)->bei_rdwr );
}
static int
bdb_cache_entry_rdwr_destroy(Entry *e)
{
return ldap_pvt_thread_rdwr_destroy( &BEI(e)->bei_rdwr );
}
static int
bdb_cache_entry_private_init( Entry *e )
{
assert( e->e_private == NULL );
if( e->e_private != NULL ) {
/* this should never happen */
return 1;
}
e->e_private = ch_calloc(1, sizeof(struct bdb_entry_info));
if( bdb_cache_entry_rdwr_init( e ) != 0 ) {
free( BEI(e) );
e->e_private = NULL;
return 1;
}
return 0;
}
int
bdb_cache_entry_db_lock
( DB_ENV *env, u_int32_t locker, Entry *e, int rw, u_int32_t flags, DB_LOCK *lock )
{
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#ifdef NO_THREADS
return 0;
#else
int rc;
DBT lockobj;
int db_rw;
if (rw)
db_rw = DB_LOCK_WRITE;
else
db_rw = DB_LOCK_READ;
lockobj.data = e->e_nname.bv_val;
lockobj.size = e->e_nname.bv_len;
rc = LOCK_GET(env, locker, flags | DB_LOCK_NOWAIT,
&lockobj, db_rw, lock);
if (rc) {
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_entry_db_lock: entry %s, rw %d, rc %d\n",
e->e_nname.bv_val, rw, rc );
#else
Debug( LDAP_DEBUG_TRACE,
"bdb_cache_entry_db_lock: entry %s, rw %d, rc %d\n",
e->e_nname.bv_val, rw, rc );
#endif
}
return rc;
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#endif /* NO_THREADS */
}
int
bdb_cache_entry_db_unlock
( DB_ENV *env, DB_LOCK *lock )
{
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#ifdef NO_THREADS
return 0;
#else
int rc;
rc = LOCK_PUT ( env, lock );
return rc;
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#endif
}
/*
* marks an entry in CREATING state as committed, so it is really returned
* to the cache. Otherwise an entry in CREATING state is removed.
* Makes e_private be destroyed at the following cache_return_entry_w,
* but lets the entry untouched (owned by someone else)
*/
void
bdb_cache_entry_commit( Entry *e )
{
assert( e );
assert( e->e_private );
assert( BEI(e)->bei_state == CACHE_ENTRY_CREATING );
/* assert( BEI(e)->bei_refcnt == 1 ); */
BEI(e)->bei_state = CACHE_ENTRY_COMMITTED;
}
static int
bdb_cache_entry_private_destroy( Entry *e )
{
assert( e->e_private );
bdb_cache_entry_rdwr_destroy( e );
free( e->e_private );
e->e_private = NULL;
return 0;
}
void
bdb_unlocked_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
{
ID id;
int refcnt, freeit = 1;
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
assert( e->e_private );
#if 0
bdb_cache_entry_rdwr_unlock(e, rw);
#endif
id = e->e_id;
refcnt = --BEI(e)->bei_refcnt;
/*
* if the entry is returned when in CREATING state, it is deleted
* but not freed because it may belong to someone else (do_add,
* for instance)
*/
if ( BEI(e)->bei_state == CACHE_ENTRY_CREATING ) {
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
bdb_cache_delete_entry_internal( cache, e );
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
freeit = 0;
/* now the entry is in DELETED state */
}
if ( BEI(e)->bei_state == CACHE_ENTRY_COMMITTED ) {
BEI(e)->bei_state = CACHE_ENTRY_READY;
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_unlocked_cache_return_entry_rw: return (%ld):%s, refcnt=%d\n",
id, rw ? "w" : "r", refcnt );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_unlocked_cache_return_entry_%s( %ld ): created (%d)\n",
rw ? "w" : "r", id, refcnt );
#endif
} else if ( BEI(e)->bei_state == CACHE_ENTRY_DELETED ) {
if( refcnt > 0 ) {
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_unlocked_cache_return_entry_rw: %ld, delete pending (%d).\n",
id, refcnt, 0 );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_unlocked_cache_return_entry_%s( %ld ): delete pending (%d)\n",
rw ? "w" : "r", id, refcnt );
#endif
} else {
bdb_cache_entry_private_destroy( e );
if ( freeit ) {
bdb_entry_return( e );
}
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_unlocked_cache_return_entry_rw: (%ld): deleted (%d)\n",
id, refcnt, 0 );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_unlocked_cache_return_entry_%s( %ld ): deleted (%d)\n",
rw ? "w" : "r", id, refcnt );
#endif
}
} else {
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_unlocked_cache_return_entry_rw: ID %ld:%s returned (%d)\n",
id, rw ? "w": "r", refcnt );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_unlocked_cache_return_entry_%s( %ld ): returned (%d)\n",
rw ? "w" : "r", id, refcnt);
#endif
}
}
void
bdb_cache_return_entry_rw
( DB_ENV *env, Cache *cache, Entry *e, int rw, DB_LOCK *lock )
{
ID id;
int refcnt, freeit = 1;
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
assert( e->e_private );
bdb_cache_entry_db_unlock( env, lock );
#if 0
bdb_cache_entry_rdwr_unlock(e, rw);
#endif
id = e->e_id;
refcnt = --BEI(e)->bei_refcnt;
/*
* if the entry is returned when in CREATING state, it is deleted
* but not freed because it may belong to someone else (do_add,
* for instance)
*/
if ( BEI(e)->bei_state == CACHE_ENTRY_CREATING ) {
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
bdb_cache_delete_entry_internal( cache, e );
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
freeit = 0;
/* now the entry is in DELETED state */
}
if ( BEI(e)->bei_state == CACHE_ENTRY_COMMITTED ) {
BEI(e)->bei_state = CACHE_ENTRY_READY;
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_return_entry_rw: return (%ld):%s, refcnt=%d\n",
id, rw ? "w" : "r", refcnt );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_cache_return_entry_%s( %ld ): created (%d)\n",
rw ? "w" : "r", id, refcnt );
#endif
} else if ( BEI(e)->bei_state == CACHE_ENTRY_DELETED ) {
if( refcnt > 0 ) {
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_return_entry_rw: %ld, delete pending (%d).\n",
id, refcnt, 0 );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_cache_return_entry_%s( %ld ): delete pending (%d)\n",
rw ? "w" : "r", id, refcnt );
#endif
} else {
bdb_cache_entry_private_destroy( e );
if ( freeit ) {
bdb_entry_return( e );
}
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_return_entry_rw: (%ld): deleted (%d)\n",
id, refcnt, 0 );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_cache_return_entry_%s( %ld ): deleted (%d)\n",
rw ? "w" : "r", id, refcnt );
#endif
}
} else {
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_return_entry_rw: ID %ld:%s returned (%d)\n",
id, rw ? "w": "r", refcnt );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_cache_return_entry_%s( %ld ): returned (%d)\n",
rw ? "w" : "r", id, refcnt);
#endif
}
}
#define LRU_DELETE( cache, e ) do { \
if ( BEI(e)->bei_lruprev != NULL ) { \
BEI(BEI(e)->bei_lruprev)->bei_lrunext = BEI(e)->bei_lrunext; \
} else { \
(cache)->c_lruhead = BEI(e)->bei_lrunext; \
} \
if ( BEI(e)->bei_lrunext != NULL ) { \
BEI(BEI(e)->bei_lrunext)->bei_lruprev = BEI(e)->bei_lruprev; \
} else { \
(cache)->c_lrutail = BEI(e)->bei_lruprev; \
} \
} while(0)
#define LRU_ADD( cache, e ) do { \
BEI(e)->bei_lrunext = (cache)->c_lruhead; \
if ( BEI(e)->bei_lrunext != NULL ) { \
BEI(BEI(e)->bei_lrunext)->bei_lruprev = (e); \
} \
(cache)->c_lruhead = (e); \
BEI(e)->bei_lruprev = NULL; \
if ( (cache)->c_lrutail == NULL ) { \
(cache)->c_lrutail = (e); \
} \
} while(0)
/*
* cache_add_entry_rw - create and lock an entry in the cache
* returns: 0 entry has been created and locked
* 1 entry already existed
* -1 something bad happened
* other Berkeley DB locking error code
*/
int
bdb_cache_add_entry_rw(
DB_ENV *env,
Cache *cache,
Entry *e,
int rw,
u_int32_t locker,
DB_LOCK *lock
)
{
int i, rc;
Entry *ee;
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ENTRY,
"bdb_cache_add_entry_rw: add (%s):%s to cache\n",
e->e_dn, rw ? "w" : "r", 0 );
#endif
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
assert( e->e_private == NULL );
if( bdb_cache_entry_private_init(e) != 0 ) {
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ERR,
"bdb_cache_add_entry_rw: add (%s):%ld private init failed!\n",
e->e_dn, e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ANY,
"====> bdb_cache_add_entry( %ld ): \"%s\": private init failed!\n",
e->e_id, e->e_dn, 0 );
#endif
return( -1 );
}
if ( avl_insert( &cache->c_dntree, (caddr_t) e,
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entry_dn_cmp, avl_dup_error ) != 0 )
{
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_add_entry: (%s):%ld already in cache.\n",
e->e_dn, e->e_id, 0 );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_cache_add_entry( %ld ): \"%s\": already in dn cache\n",
e->e_id, e->e_dn, 0 );
#endif
bdb_cache_entry_private_destroy(e);
return( 1 );
}
/* id tree */
if ( avl_insert( &cache->c_idtree, (caddr_t) e,
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entry_id_cmp, avl_dup_error ) != 0 )
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_add_entry: (%s):%ls already in cache.\n",
e->e_dn, e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ANY,
"====> bdb_cache_add_entry( %ld ): \"%s\": already in id cache\n",
e->e_id, e->e_dn, 0 );
#endif
/* delete from dn tree inserted above */
if ( avl_delete( &cache->c_dntree, (caddr_t) e,
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entry_dn_cmp ) == NULL )
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_add_entry: can't delete (%s) from cache.\n",
e->e_dn, 0, 0 );
#else
Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
0, 0, 0 );
#endif
}
bdb_cache_entry_private_destroy(e);
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return( -1 );
}
rc = bdb_cache_entry_db_lock( env, locker, e, rw, 0, lock );
switch ( rc ) {
case 0 :
break;
case DB_LOCK_DEADLOCK :
case DB_LOCK_NOTGRANTED :
/* undo avl changes immediately */
if ( avl_delete( &cache->c_idtree, (caddr_t) e,
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entry_id_cmp ) == NULL ) {
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_add_entry: can't delete (%s) from cache.\n",
e->e_dn, 0, 0 );
#else
Debug( LDAP_DEBUG_ANY, "====> can't delete from id cache\n", 0, 0, 0 );
#endif
}
if ( avl_delete( &cache->c_dntree, (caddr_t) e,
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entry_dn_cmp ) == NULL ) {
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_add_entry: can't delete (%s) from cache.\n",
e->e_dn, 0, 0 );
#else
Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n", 0, 0, 0 );
#endif
}
/* fall through */
default :
bdb_cache_entry_private_destroy(e);
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return rc;
}
/* put the entry into 'CREATING' state */
/* will be marked after when entry is returned */
BEI(e)->bei_state = CACHE_ENTRY_CREATING;
BEI(e)->bei_refcnt = 1;
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
/* lru */
LRU_ADD( cache, e );
if ( ++cache->c_cursize > cache->c_maxsize ) {
/*
* find the lru entry not currently in use and delete it.
* in case a lot of entries are in use, only look at the
* first 10 on the tail of the list.
*/
i = 0;
while ( cache->c_lrutail != NULL &&
BEI(cache->c_lrutail)->bei_refcnt != 0 &&
i < 10 )
{
/* move this in-use entry to the front of the q */
ee = cache->c_lrutail;
LRU_DELETE( cache, ee );
LRU_ADD( cache, ee );
i++;
}
/*
* found at least one to delete - try to get back under
* the max cache size.
*/
while ( cache->c_lrutail != NULL &&
BEI(cache->c_lrutail)->bei_refcnt == 0 &&
cache->c_cursize > cache->c_maxsize )
{
e = cache->c_lrutail;
/* delete from cache and lru q */
/* XXX do we need rc ? */
rc = bdb_cache_delete_entry_internal( cache, e );
bdb_cache_entry_private_destroy( e );
bdb_entry_return( e );
}
}
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return( 0 );
}
/*
* cache_update_entry - update a LOCKED entry which has been deleted.
* returns: 0 entry has been created and locked
* 1 entry already existed
* -1 something bad happened
*/
int
bdb_cache_update_entry(
Cache *cache,
Entry *e
)
{
int i, rc;
Entry *ee;
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
assert( e->e_private );
if ( avl_insert( &cache->c_dntree, (caddr_t) e,
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entry_dn_cmp, avl_dup_error ) != 0 )
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_update_entry: (%s):%ld already in dn cache\n",
e->e_dn, e->e_id, 0 );
#else
Debug( LDAP_DEBUG_TRACE,
"====> bdb_cache_update_entry( %ld ): \"%s\": already in dn cache\n",
e->e_id, e->e_dn, 0 );
#endif
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return( 1 );
}
/* id tree */
if ( avl_insert( &cache->c_idtree, (caddr_t) e,
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entry_id_cmp, avl_dup_error ) != 0 )
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_update_entry: (%s)%ld already in id cache\n",
e->e_dn, e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ANY,
"====> bdb_cache_update_entry( %ld ): \"%s\": already in id cache\n",
e->e_id, e->e_dn, 0 );
#endif
/* delete from dn tree inserted above */
if ( avl_delete( &cache->c_dntree, (caddr_t) e,
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entry_dn_cmp ) == NULL )
{
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_update_entry: can't delete (%s)%ld from dn cache.\n",
e->e_dn, e->e_id, 0 );
#else
Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
0, 0, 0 );
#endif
}
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return( -1 );
}
/* put the entry into 'CREATING' state */
/* will be marked after when entry is returned */
BEI(e)->bei_state = CACHE_ENTRY_CREATING;
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
/* lru */
LRU_ADD( cache, e );
if ( ++cache->c_cursize > cache->c_maxsize ) {
/*
* find the lru entry not currently in use and delete it.
* in case a lot of entries are in use, only look at the
* first 10 on the tail of the list.
*/
i = 0;
while ( cache->c_lrutail != NULL &&
BEI(cache->c_lrutail)->bei_refcnt != 0 &&
i < 10 )
{
/* move this in-use entry to the front of the q */
ee = cache->c_lrutail;
LRU_DELETE( cache, ee );
LRU_ADD( cache, ee );
i++;
}
/*
* found at least one to delete - try to get back under
* the max cache size.
*/
while ( cache->c_lrutail != NULL &&
BEI(cache->c_lrutail)->bei_refcnt == 0 &&
cache->c_cursize > cache->c_maxsize )
{
e = cache->c_lrutail;
/* delete from cache and lru q */
/* XXX do we need rc ? */
rc = bdb_cache_delete_entry_internal( cache, e );
bdb_cache_entry_private_destroy( e );
bdb_entry_return( e );
}
}
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return( 0 );
}
ID
bdb_cache_find_entry_ndn2id(
Backend *be,
Cache *cache,
struct berval *ndn
)
{
Entry e, *ep;
ID id;
int count = 0;
/* this function is always called with normalized DN */
e.e_nname = *ndn;
try_again:
/* set cache read lock */
ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
if ( (ep = (Entry *) avl_find( cache->c_dntree, (caddr_t) &e,
2002-12-15 06:25:52 +08:00
entry_dn_cmp )) != NULL )
{
int state;
count++;
/*
* ep now points to an unlocked entry
* we do not need to lock the entry if we only
* check the state, refcnt, LRU, and id.
*/
assert( ep->e_private );
/* save id */
id = ep->e_id;
state = BEI(ep)->bei_state;
/*
* entry is deleted or not fully created yet
*/
if ( state != CACHE_ENTRY_READY && state != CACHE_ENTRY_COMMITTED ) {
assert(state != CACHE_ENTRY_UNDEFINED);
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_find_entry_dn2id: (%s) %ld not ready: %d\n",
ndn->bv_val, id, state );
#else
Debug(LDAP_DEBUG_TRACE,
"====> bdb_cache_find_entry_dn2id(\"%s\"): %ld (not ready) %d\n",
ndn->bv_val, id, state);
#endif
ldap_pvt_thread_yield();
goto try_again;
}
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
/* lru */
LRU_DELETE( cache, ep );
LRU_ADD( cache, ep );
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_find_entry_dn2id: (%s): %ld %d tries\n",
ndn->bv_val, id, count );
#else
Debug(LDAP_DEBUG_TRACE,
"====> bdb_cache_find_entry_dn2id(\"%s\"): %ld (%d tries)\n",
ndn->bv_val, id, count);
#endif
} else {
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
id = NOID;
}
return( id );
}
/*
* cache_find_entry_id - find an entry in the cache, given id
*/
Entry *
bdb_cache_find_entry_id(
DB_ENV *env,
Cache *cache,
ID id,
int rw,
u_int32_t locker,
DB_LOCK *lock
)
{
Entry e;
Entry *ep;
int count = 0;
int rc;
e.e_id = id;
try_again:
/* set cache read lock */
ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
if ( (ep = (Entry *) avl_find( cache->c_idtree, (caddr_t) &e,
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entry_id_cmp )) != NULL )
{
int state;
ID ep_id;
count++;
assert( ep->e_private );
ep_id = ep->e_id;
state = BEI(ep)->bei_state;
/*
* entry is deleted or not fully created yet
*/
if ( state != CACHE_ENTRY_READY && state != CACHE_ENTRY_COMMITTED ) {
assert(state != CACHE_ENTRY_UNDEFINED);
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_find_entry_id: (%ld)->%ld not ready (%d).\n",
id, ep_id, state );
#else
Debug(LDAP_DEBUG_TRACE,
"====> bdb_cache_find_entry_id( %ld ): %ld (not ready) %d\n",
id, ep_id, state);
#endif
ldap_pvt_thread_yield();
goto try_again;
}
/* acquire reader lock */
rc = bdb_cache_entry_db_lock ( env, locker, ep, rw, 0, lock );
#if 0
if ( bdb_cache_entry_rdwr_trylock(ep, rw) == LDAP_PVT_THREAD_EBUSY ) {
#endif
if ( rc ) { /* will be changed to retry beyond threshold */
/* could not acquire entry lock...
* owner cannot free as we have the cache locked.
* so, unlock the cache, yield, and try again.
*/
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_find_entry_id: %ld -> %ld (busy) %d.\n",
id, ep_id, state );
#else
Debug(LDAP_DEBUG_TRACE,
"====> bdb_cache_find_entry_id( %ld ): %ld (busy) %d\n",
id, ep_id, state);
Debug(LDAP_DEBUG_TRACE,
"locker = %d\n",
locker, 0, 0);
#endif
ldap_pvt_thread_yield();
goto try_again;
}
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
/* lru */
LRU_DELETE( cache, ep );
LRU_ADD( cache, ep );
BEI(ep)->bei_refcnt++;
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, DETAIL1,
"bdb_cache_find_entry_id: %ld -> %s found %d tries.\n",
ep_id, ep->e_dn, count );
#else
Debug(LDAP_DEBUG_TRACE,
"====> bdb_cache_find_entry_id( %ld ) \"%s\" (found) (%d tries)\n",
ep_id, ep->e_dn, count);
#endif
return( ep );
}
/* free cache read lock */
ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
return( NULL );
}
/*
* cache_delete_entry - delete the entry e from the cache. the caller
* should have obtained e (increasing its ref count) via a call to one
* of the cache_find_* routines. the caller should *not* call the
* cache_return_entry() routine prior to calling cache_delete_entry().
* it performs this function.
*
* returns: 0 e was deleted ok
* 1 e was not in the cache
* -1 something bad happened
*/
int
bdb_cache_delete_entry(
Cache *cache,
Entry *e
)
{
int rc;
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
assert( e->e_private );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ENTRY,
"bdb_cache_delete_entry: delete %ld.\n", e->e_id, 0, 0 );
#else
Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_delete_entry( %ld )\n",
e->e_id, 0, 0 );
#endif
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
rc = bdb_cache_delete_entry_internal( cache, e );
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
return( rc );
}
static int
bdb_cache_delete_entry_internal(
Cache *cache,
Entry *e
)
{
int rc = 0; /* return code */
/* dn tree */
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if ( avl_delete( &cache->c_dntree, (caddr_t) e, entry_dn_cmp ) == NULL )
{
rc = -1;
}
/* id tree */
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if ( avl_delete( &cache->c_idtree, (caddr_t) e, entry_id_cmp ) == NULL )
{
rc = -1;
}
if (rc != 0) {
return rc;
}
/* lru */
LRU_DELETE( cache, e );
cache->c_cursize--;
/*
* flag entry to be freed later by a call to cache_return_entry()
*/
BEI(e)->bei_state = CACHE_ENTRY_DELETED;
return( 0 );
}
void
bdb_cache_release_all( Cache *cache )
{
Entry *e;
int rc;
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, ENTRY, "bdb_cache_release_all: enter\n", 0, 0, 0 );
#else
Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_release_all\n", 0, 0, 0 );
#endif
while ( (e = cache->c_lrutail) != NULL && BEI(e)->bei_refcnt == 0 ) {
#ifdef LDAP_RDWR_DEBUG
assert(!ldap_pvt_thread_rdwr_active(&BEI(e)->bei_rdwr));
#endif
/* delete from cache and lru q */
/* XXX do we need rc ? */
rc = bdb_cache_delete_entry_internal( cache, e );
bdb_cache_entry_private_destroy( e );
bdb_entry_return( e );
}
if ( cache->c_cursize ) {
#ifdef NEW_LOGGING
LDAP_LOG( CACHE, INFO,
"bdb_cache_release_all: Entry cache could not be emptied.\n", 0, 0, 0 );
#else
Debug( LDAP_DEBUG_TRACE, "Entry-cache could not be emptied\n", 0, 0, 0 );
#endif
}
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
}
#ifdef LDAP_DEBUG
static void
bdb_lru_print( Cache *cache )
{
Entry *e;
fprintf( stderr, "LRU queue (head to tail):\n" );
for ( e = cache->c_lruhead; e != NULL; e = BEI(e)->bei_lrunext ) {
fprintf( stderr, "\tdn \"%20s\" id %ld refcnt %d\n",
e->e_dn, e->e_id, BEI(e)->bei_refcnt );
}
fprintf( stderr, "LRU queue (tail to head):\n" );
for ( e = cache->c_lrutail; e != NULL; e = BEI(e)->bei_lruprev ) {
fprintf( stderr, "\tdn \"%20s\" id %ld refcnt %d\n",
e->e_dn, e->e_id, BEI(e)->bei_refcnt );
}
}
#endif
#ifdef BDB_REUSE_LOCKERS
void
bdb_locker_id_free( void *key, void *data )
{
DB_ENV *env = key;
int lockid = (int) data;
XLOCK_ID_FREE( env, lockid );
}
int
2002-09-19 14:34:53 +08:00
bdb_locker_id( Operation *op, DB_ENV *env, int *locker )
{
int i, rc, lockid;
void *data;
2002-09-19 14:34:53 +08:00
if ( !env || !op || !locker ) return -1;
2002-09-19 14:34:53 +08:00
/* Shouldn't happen unless we're single-threaded */
if ( !op->o_threadctx ) {
*locker = 0;
2002-09-19 14:34:53 +08:00
return 0;
}
if ( ldap_pvt_thread_pool_getkey( op->o_threadctx, env, &data, NULL ) ) {
for ( i=0, rc=1; rc != 0 && i<4; i++ ) {
rc = XLOCK_ID( env, &lockid );
if (rc) ldap_pvt_thread_yield();
}
if ( rc != 0) {
return rc;
}
data = (void *)lockid;
if ( ( rc = ldap_pvt_thread_pool_setkey( op->o_threadctx, env,
data, bdb_locker_id_free ) ) ) {
XLOCK_ID_FREE( env, lockid );
#ifdef NEW_LOGGING
LDAP_LOG( BACK_BDB, ERR, "bdb_locker_id: err %s(%d)\n",
db_strerror(rc), rc, 0 );
#else
Debug( LDAP_DEBUG_ANY, "bdb_locker_id: err %s(%d)\n",
db_strerror(rc), rc, 0 );
#endif
return rc;
}
} else {
lockid = (int)data;
}
*locker = lockid;
return 0;
}
#endif