From 62d2b0026e895448b9dff76f2565012340afdfcd Mon Sep 17 00:00:00 2001
From: Noriko Hosoi <nhosoi@redhat.com>
Date: Wed, 18 Nov 2015 11:44:35 -0800
Subject: [PATCH] Ticket #48338 - SimplePagedResults -- abandon could happen
between the abandon check and sending results
Description: commit 390b8bd9076e8976facc0858e60985d6b4fac05c introduced
a self deadlock (see also bz1282607: 389-ds-base-1.2.11.15-67.el6_7 hang)
First phase of the following approach:
Fix design by Ludwig Krispenz and Rich Megginson (Thanks!)
Investigate the connection params used in the pblock access one by one and.
- for fields not used, either remove the access or just leave it as is
- With a big ASSERT to flag cases if the field is ever used, and a plan to
deprecate and remove the field.
- for fields with atomic access, like c_isreplication_session remove the mutex
- for filelds requiring copying, define them directly in the pblock and when
the pblock is created, populate them from the connection, the pblock access
would no longer need the c_mutex.
Removing PR_Lock(c_mutex) from slapi_pblock_get(SLAPI_CONN_CLIENTNETADDR) since
acquiring the lock is not necessary for the atomic reads. This change solves
the self deadlock.
https://fedorahosted.org/389/ticket/48338#comment:11
Reviewed by nkinder@redhat.com and mreynolds@redhat.com (Thank you, Nathan and Mark!)
(cherry picked from commit 79ca67d1fc5d50d8a9ae6b686b9564f3960f8592)
(cherry picked from commit 36245abd78f7abfed8219a5ac4a4cf50c1c0237c)
---
ldap/servers/slapd/pblock.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/ldap/servers/slapd/pblock.c b/ldap/servers/slapd/pblock.c
index bf57a33..f2017be 100644
--- a/ldap/servers/slapd/pblock.c
+++ b/ldap/servers/slapd/pblock.c
@@ -223,14 +223,12 @@ slapi_pblock_get( Slapi_PBlock *pblock, int arg, void *value )
memset( value, 0, sizeof( PRNetAddr ));
break;
}
- PR_Lock( pblock->pb_conn->c_mutex );
+ /* For fields with atomic access, remove the PR_Lock(c_mutex) */
if ( pblock->pb_conn->cin_addr == NULL ) {
memset( value, 0, sizeof( PRNetAddr ));
} else {
- (*(PRNetAddr *)value) =
- *(pblock->pb_conn->cin_addr);
+ (*(PRNetAddr *)value) = *(pblock->pb_conn->cin_addr);
}
- PR_Unlock( pblock->pb_conn->c_mutex );
break;
case SLAPI_CONN_SERVERNETADDR:
if (pblock->pb_conn == NULL)
--
2.4.3