openldap/servers/slapd/entry.c
Kurt Zeilenga 366701bdf7 Fix dbcache/entry lock deadlock. If dbcache lock is held, it's
okay to read and write LDBM specific fields (state, refcnt,
LRU.  The id field, though is read-only once set.
cache_find_entry_dn2id(), hence, does not require any entry locks.
cache_find_entry_id() must do a entry_rdwr_trylock() and back
off if busy.
Add new rdwr lock code with trylock() functionality.
Implement entry_rdwr_trylock().
1999-02-04 18:00:50 +00:00

312 lines
6.3 KiB
C

/* entry.c - routines for dealing with entries */
#include "portable.h"
#include <stdio.h>
#include <ac/ctype.h>
#include <ac/errno.h>
#include <ac/socket.h>
#include <ac/string.h>
#include "slap.h"
static unsigned char *ebuf; /* buf returned by entry2str */
static unsigned char *ecur; /* pointer to end of currently used ebuf */
static int emaxsize;/* max size of ebuf */
Entry *
str2entry( char *s )
{
int id = 0;
Entry *e;
Attribute **a;
char *type;
char *value;
char *next;
int vlen, nvals, maxvals;
struct berval bval;
struct berval *vals[2];
char ptype[64];
/*
* In string format, an entry looks like this:
*
* <id>\n
* dn: <dn>\n
* [<attr>:[:] <value>\n]
* [<tab><continuedvalue>\n]*
* ...
*
* If a double colon is used after a type, it means the
* following value is encoded as a base 64 string. This
* happens if the value contains a non-printing character
* or newline.
*/
Debug( LDAP_DEBUG_TRACE, "=> str2entry\n",
s ? s : "NULL", 0, 0 );
/* check to see if there's an id included */
next = s;
if ( isdigit( *s ) ) {
id = atoi( s );
if ( (s = ldif_getline( &next )) == NULL ) {
Debug( LDAP_DEBUG_TRACE,
"<= str2entry NULL (missing newline after id)\n",
0, 0, 0 );
return( NULL );
}
}
/* initialize reader/writer lock */
e = (Entry *) ch_calloc( 1, sizeof(Entry) );
if( e == NULL ) {
Debug( LDAP_DEBUG_TRACE,
"<= str2entry NULL (entry allocation failed)\n",
0, 0, 0 );
return( NULL );
}
e->e_id = id;
entry_rdwr_init(e);
/* dn + attributes */
e->e_attrs = NULL;
vals[0] = &bval;
vals[1] = NULL;
ptype[0] = '\0';
while ( (s = ldif_getline( &next )) != NULL ) {
if ( *s == '\n' || *s == '\0' ) {
break;
}
if ( ldif_parse_line( s, &type, &value, &vlen ) != 0 ) {
Debug( LDAP_DEBUG_TRACE,
"<= str2entry NULL (parse_line)\n", 0, 0, 0 );
continue;
}
if ( strcasecmp( type, ptype ) != 0 ) {
strncpy( ptype, type, sizeof(ptype) - 1 );
nvals = 0;
maxvals = 0;
a = NULL;
}
if ( strcasecmp( type, "dn" ) == 0 ) {
if ( e->e_dn != NULL ) {
Debug( LDAP_DEBUG_ANY,
"str2entry: entry %lu has multiple dns \"%s\" and \"%s\" (second ignored)\n",
e->e_id, e->e_dn, value );
continue;
}
e->e_dn = ch_strdup( value );
if ( e->e_ndn != NULL ) {
Debug( LDAP_DEBUG_ANY,
"str2entry: entry %lu already has a normalized dn \"%s\" for \"%s\" (first ignored)\n",
e->e_id, e->e_ndn, value );
free( e->e_ndn );
}
e->e_ndn = dn_normalize_case( ch_strdup( value ) );
continue;
}
bval.bv_val = value;
bval.bv_len = vlen;
if ( attr_merge_fast( e, type, vals, nvals, 1, &maxvals, &a )
!= 0 ) {
Debug( LDAP_DEBUG_TRACE,
"<= str2entry NULL (attr_merge)\n", 0, 0, 0 );
entry_free( e );
return( NULL );
}
nvals++;
}
/* check to make sure there was a dn: line */
if ( e->e_dn == NULL ) {
Debug( LDAP_DEBUG_ANY, "str2entry: entry %lu has no dn\n",
e->e_id, 0, 0 );
entry_free( e );
return( NULL );
}
if ( e->e_ndn == NULL ) {
Debug( LDAP_DEBUG_ANY,
"str2entry: entry %lu (\"%s\") has no normalized dn\n",
e->e_id, e->e_dn, 0 );
entry_free( e );
return( NULL );
}
Debug(LDAP_DEBUG_TRACE, "<= str2entry 0x%lx\n", (unsigned long)e, 0,0);
return( e );
}
#define GRABSIZE BUFSIZ
#define MAKE_SPACE( n ) { \
while ( ecur + (n) > ebuf + emaxsize ) { \
int offset; \
offset = (int) (ecur - ebuf); \
ebuf = (unsigned char *) ch_realloc( (char *) ebuf, \
emaxsize + GRABSIZE ); \
emaxsize += GRABSIZE; \
ecur = ebuf + offset; \
} \
}
char *
entry2str(
Entry *e,
int *len,
int printid
)
{
Attribute *a;
struct berval *bv;
int i, tmplen;
/*
* In string format, an entry looks like this:
* <id>\n
* dn: <dn>\n
* [<attr>: <value>\n]*
*/
ecur = ebuf;
if ( printid ) {
/* id + newline */
MAKE_SPACE( 10 );
sprintf( (char *) ecur, "%ld\n", e->e_id );
ecur = (unsigned char *) strchr( (char *) ecur, '\0' );
}
/* put the dn */
if ( e->e_dn != NULL ) {
/* put "dn: <dn>" */
tmplen = strlen( e->e_dn );
MAKE_SPACE( LDIF_SIZE_NEEDED( 2, tmplen ));
ldif_put_type_and_value( (char **) &ecur, "dn", e->e_dn, tmplen );
}
/* put the attributes */
for ( a = e->e_attrs; a != NULL; a = a->a_next ) {
/* put "<type>:[:] <value>" line for each value */
for ( i = 0; a->a_vals[i] != NULL; i++ ) {
bv = a->a_vals[i];
tmplen = strlen( a->a_type );
MAKE_SPACE( LDIF_SIZE_NEEDED( tmplen, bv->bv_len ));
ldif_put_type_and_value( (char **) &ecur, a->a_type,
bv->bv_val, bv->bv_len );
}
}
MAKE_SPACE( 1 );
*ecur = '\0';
*len = ecur - ebuf;
return( (char *) ebuf );
}
void
entry_free( Entry *e )
{
int i;
Attribute *a, *next;
/* check that no reader/writer locks exist */
if ( ldap_pvt_thread_rdwr_wtrylock( &e->e_rdwr ) ==
LDAP_PVT_THREAD_EBUSY )
{
Debug( LDAP_DEBUG_ANY, "entry_free(%ld): active (%d, %d)\n",
e->e_id,
ldap_pvt_thread_rdwr_readers( &e->e_rdwr ),
ldap_pvt_thread_rdwr_writers( &e->e_rdwr ));
#ifdef LDAP_DEBUG
assert(!ldap_pvt_thread_rdwr_active( &e->e_rdwr ));
#endif
}
if ( e->e_dn != NULL ) {
free( e->e_dn );
}
if ( e->e_ndn != NULL ) {
free( e->e_ndn );
}
for ( a = e->e_attrs; a != NULL; a = next ) {
next = a->a_next;
attr_free( a );
}
free( e );
}
int
entry_rdwr_lock(Entry *e, int rw)
{
Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%slock: ID: %ld\n",
rw ? "w" : "r", e->e_id, 0);
if (rw)
return ldap_pvt_thread_rdwr_wlock(&e->e_rdwr);
else
return ldap_pvt_thread_rdwr_rlock(&e->e_rdwr);
}
int
entry_rdwr_rlock(Entry *e)
{
return entry_rdwr_lock( e, 0 );
}
int
entry_rdwr_wlock(Entry *e)
{
return entry_rdwr_lock( e, 1 );
}
int
entry_rdwr_trylock(Entry *e, int rw)
{
Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%strylock: ID: %ld\n",
rw ? "w" : "r", e->e_id, 0);
if (rw)
return ldap_pvt_thread_rdwr_wtrylock(&e->e_rdwr);
else
return ldap_pvt_thread_rdwr_rtrylock(&e->e_rdwr);
}
int
entry_rdwr_unlock(Entry *e, int rw)
{
Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%sunlock: ID: %ld\n",
rw ? "w" : "r", e->e_id, 0);
if (rw)
return ldap_pvt_thread_rdwr_wunlock(&e->e_rdwr);
else
return ldap_pvt_thread_rdwr_runlock(&e->e_rdwr);
}
int
entry_rdwr_runlock(Entry *e)
{
return entry_rdwr_unlock( e, 0 );
}
int
entry_rdwr_wunlock(Entry *e)
{
return entry_rdwr_unlock( e, 1 );
}
int
entry_rdwr_init(Entry *e)
{
return ldap_pvt_thread_rdwr_init( &e->e_rdwr );
}