From 0305199518f774307aebe04ca8abbc702a2f8ff4 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Sat, 3 Jul 2004 16:25:30 +0000
Subject: [PATCH] Additional debug tracking...

---
 libraries/libldap_r/rdwr.c | 42 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 40 insertions(+), 2 deletions(-)

diff --git a/libraries/libldap_r/rdwr.c b/libraries/libldap_r/rdwr.c
index dc9dcedc4b..b0613c0751 100644
--- a/libraries/libldap_r/rdwr.c
+++ b/libraries/libldap_r/rdwr.c
@@ -59,6 +59,12 @@ struct ldap_int_thread_rdwr_s {
 	int ltrw_w_active;
 	int ltrw_r_wait;
 	int ltrw_w_wait;
+#ifdef LDAP_RDWR_DEBUG
+	/* keep track of who has these locks */
+#define	MAX_READERS	32
+	ldap_pvt_thread_t ltrw_readers[MAX_READERS];
+	ldap_pvt_thread_t ltrw_writer;
+#endif
 };
 
 int 
@@ -162,8 +168,12 @@ int ldap_pvt_thread_rdwr_rlock( ldap_pvt_thread_rdwr_t *rwlock )
 		assert( rw->ltrw_r_wait >= 0 ); 
 	}
 
+#ifdef LDAP_RDWR_DEBUG
+	rw->ltrw_readers[rw->ltrw_r_active] = ldap_pvt_thread_self();
+#endif
 	rw->ltrw_r_active++;
 
+
 	ldap_pvt_thread_mutex_unlock( &rw->ltrw_mutex );
 
 	return 0;
@@ -194,6 +204,9 @@ int ldap_pvt_thread_rdwr_rtrylock( ldap_pvt_thread_rdwr_t *rwlock )
 		return LDAP_PVT_THREAD_EBUSY;
 	}
 
+#ifdef LDAP_RDWR_DEBUG
+	rw->ltrw_readers[rw->ltrw_r_active] = ldap_pvt_thread_self();
+#endif
 	rw->ltrw_r_active++;
 
 	ldap_pvt_thread_mutex_unlock( &rw->ltrw_mutex );
@@ -216,6 +229,22 @@ int ldap_pvt_thread_rdwr_runlock( ldap_pvt_thread_rdwr_t *rwlock )
 
 	ldap_pvt_thread_mutex_lock( &rw->ltrw_mutex );
 
+#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;
+		}
+	}
+	}
+#endif
 	rw->ltrw_r_active--;
 
 	assert( rw->ltrw_w_active >= 0 ); 
@@ -264,6 +293,9 @@ int ldap_pvt_thread_rdwr_wlock( ldap_pvt_thread_rdwr_t *rwlock )
 		assert( rw->ltrw_w_wait >= 0 ); 
 	}
 
+#ifdef LDAP_RDWR_DEBUG
+	rw->ltrw_writer = ldap_pvt_thread_self();
+#endif
 	rw->ltrw_w_active++;
 
 	ldap_pvt_thread_mutex_unlock( &rw->ltrw_mutex );
@@ -296,6 +328,9 @@ int ldap_pvt_thread_rdwr_wtrylock( ldap_pvt_thread_rdwr_t *rwlock )
 		return LDAP_PVT_THREAD_EBUSY;
 	}
 
+#ifdef LDAP_RDWR_DEBUG
+	rw->ltrw_writer = ldap_pvt_thread_self();
+#endif
 	rw->ltrw_w_active++;
 
 	ldap_pvt_thread_mutex_unlock( &rw->ltrw_mutex );
@@ -332,6 +367,9 @@ int ldap_pvt_thread_rdwr_wunlock( ldap_pvt_thread_rdwr_t *rwlock )
 		ldap_pvt_thread_cond_signal( &rw->ltrw_write );
 	}
 
+#ifdef LDAP_RDWR_DEBUG
+	rw->ltrw_writer = 0;
+#endif
 	ldap_pvt_thread_mutex_unlock( &rw->ltrw_mutex );
 
 	return 0;
@@ -397,8 +435,8 @@ int ldap_pvt_thread_rdwr_active(ldap_pvt_thread_rdwr_t *rwlock)
 	assert( rw->ltrw_r_active >= 0 ); 
 	assert( rw->ltrw_r_wait >= 0 ); 
 
-	return(ldap_pvt_thread_rdwr_readers(rw) +
-	       ldap_pvt_thread_rdwr_writers(rw));
+	return(ldap_pvt_thread_rdwr_readers(rwlock) +
+	       ldap_pvt_thread_rdwr_writers(rwlock));
 }
 
 #endif /* LDAP_DEBUG */
-- 
2.39.5