From f5e6c695a7881c572a66bb5f62e5e9b641b6b542 Mon Sep 17 00:00:00 2001
From: krangelov <kr.angelov@gmail.com>
Date: Tue, 16 Nov 2021 08:53:22 +0100
Subject: [PATCH] make r/w lock shared only if there is a shared file as well

---
 src/runtime/c/pgf/db.cxx | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/runtime/c/pgf/db.cxx b/src/runtime/c/pgf/db.cxx
index 377765bbd..e76ceaed9 100644
--- a/src/runtime/c/pgf/db.cxx
+++ b/src/runtime/c/pgf/db.cxx
@@ -690,9 +690,11 @@ void PgfDB::init_state(size_t size)
     if ((code = pthread_rwlockattr_init(&attr)) != 0) {
         throw pgf_systemerror(code);
     }
-    if ((code = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED)) != 0) {
-        pthread_rwlockattr_destroy(&attr);
-        throw pgf_systemerror(code);
+    if (fd > 0) {
+        if ((code = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED)) != 0) {
+            pthread_rwlockattr_destroy(&attr);
+            throw pgf_systemerror(code);
+        }
     }
     if ((code = pthread_rwlock_init(&ms->rwlock, &attr)) != 0) {
         pthread_rwlockattr_destroy(&attr);