Commit b70d6dd8 authored by Hallvard Furuseth's avatar Hallvard Furuseth
Browse files

LDAP_RDWR_DEBUG update:

- Avoid buffer overrun when too many readers.
- When remoinv reader ID, move one ID instead of all later IDs in array.
- assert(correct lock owner) before unlocking a write lock.
parent ca4a4456
......@@ -64,6 +64,7 @@ struct ldap_int_thread_rdwr_s {
#ifdef LDAP_RDWR_DEBUG
/* keep track of who has these locks */
#define MAX_READERS 32
int ltrw_more_readers; /* Set if ltrw_readers[] is incomplete */
ldap_pvt_thread_t ltrw_readers[MAX_READERS];
ldap_pvt_thread_t ltrw_writer;
#endif
......@@ -173,7 +174,10 @@ int ldap_pvt_thread_rdwr_rlock( ldap_pvt_thread_rdwr_t *rwlock )
}
#ifdef LDAP_RDWR_DEBUG
rw->ltrw_readers[rw->ltrw_r_active] = ldap_pvt_thread_self();
if( rw->ltrw_r_active < MAX_READERS )
rw->ltrw_readers[rw->ltrw_r_active] = ldap_pvt_thread_self();
else
rw->ltrw_more_readers = 1;
#endif
rw->ltrw_r_active++;
......@@ -209,7 +213,10 @@ int ldap_pvt_thread_rdwr_rtrylock( ldap_pvt_thread_rdwr_t *rwlock )
}
#ifdef LDAP_RDWR_DEBUG
rw->ltrw_readers[rw->ltrw_r_active] = ldap_pvt_thread_self();
if( rw->ltrw_r_active < MAX_READERS )
rw->ltrw_readers[rw->ltrw_r_active] = ldap_pvt_thread_self();
else
rw->ltrw_more_readers = 1;
#endif
rw->ltrw_r_active++;
......@@ -233,23 +240,25 @@ int ldap_pvt_thread_rdwr_runlock( ldap_pvt_thread_rdwr_t *rwlock )
ldap_pvt_thread_mutex_lock( &rw->ltrw_mutex );
rw->ltrw_r_active--;
#ifdef LDAP_RDWR_DEBUG
/* Remove us from the list of readers */
{ int i, j;
ldap_pvt_thread_t self = ldap_pvt_thread_self();
for (i=0; i<rw->ltrw_r_active;i++)
{
if (rw->ltrw_readers[i] == self) {
for (j=i; j<rw->ltrw_r_active-1; j++)
rw->ltrw_readers[j] = rw->ltrw_readers[j+1];
rw->ltrw_readers[j] = 0;
break;
ldap_pvt_thread_t self = ldap_pvt_thread_self();
int i, j;
for( i = j = rw->ltrw_r_active; i >= 0; i--) {
if (rw->ltrw_readers[i] == self) {
rw->ltrw_readers[i] = rw->ltrw_readers[j];
rw->ltrw_readers[j] = 0;
break;
}
}
}
if( !rw->ltrw_more_readers )
assert( i >= 0 );
else if( j == 0 )
rw->ltrw_more_readers = 0;
}
#endif
rw->ltrw_r_active--;
assert( rw->ltrw_w_active >= 0 );
assert( rw->ltrw_w_wait >= 0 );
......@@ -372,6 +381,7 @@ int ldap_pvt_thread_rdwr_wunlock( ldap_pvt_thread_rdwr_t *rwlock )
}
#ifdef LDAP_RDWR_DEBUG
assert( rw->ltrw_writer == ldap_pvt_thread_self() );
rw->ltrw_writer = 0;
#endif
ldap_pvt_thread_mutex_unlock( &rw->ltrw_mutex );
......
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