From: Howard Chu <hyc@symas.com>
Date: Fri, 19 Jul 2013 16:57:33 +0000 (-0700)
Subject: Tweak reader_pid check
X-Git-Tag: OPENLDAP_REL_ENG_2_4_36~32^2
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=de72c08660fca1597be0bb0b6536c122ae324645;p=openldap

Tweak reader_pid check

Check again after acquiring rmutex. Avoids potential issue with
a duplicate pid coming in between initial check and rmutex.
---

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 1e26d16ed4..4d686007ba 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -8092,11 +8092,13 @@ int mdb_reader_check(MDB_env *env, int *dead)
 			if (mdb_pid_insert(pids, pid) == 0) {
 				if (mdb_reader_pid(env, Pidcheck, pid)) {
 					LOCK_MUTEX_R(env);
-					for (j=i; j<rdrs; j++)
-						if (mr[j].mr_pid == pid) {
-							mr[j].mr_pid = 0;
-							count++;
-						}
+					if (mdb_reader_pid(env, Pidcheck, pid)) {
+						for (j=i; j<rdrs; j++)
+							if (mr[j].mr_pid == pid) {
+								mr[j].mr_pid = 0;
+								count++;
+							}
+					}
 					UNLOCK_MUTEX_R(env);
 				}
 			}