From: khizmax <libcds.dev@gmail.com>
Date: Mon, 15 May 2017 19:53:17 +0000 (+0300)
Subject: A magic code is found to fix CLang 3.6-3.7 mass test failures for FeldmanHashSet... 
X-Git-Tag: v2.3.0~27
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a94f24ba2b77d6cdfab38d86c346d05b3127c4f8;p=libcds.git

A magic code is found to fix CLang 3.6-3.7 mass test failures for FeldmanHashSet<RCU> even in single-threaded ubit tests
---

diff --git a/cds/urcu/details/gp.h b/cds/urcu/details/gp.h
index 512a0b2b..fa8cf8a6 100644
--- a/cds/urcu/details/gp.h
+++ b/cds/urcu/details/gp.h
@@ -87,6 +87,11 @@ namespace cds { namespace urcu { namespace details {
         uint32_t tmp = pRec->m_nAccessControl.load( atomics::memory_order_relaxed );
         assert( (tmp & rcu_class::c_nNestMask) > 0 );
 
+#if CDS_COMPILER == CDS_COMPILER_CLANG && CDS_COMPILER_VERSION < 30800
+        // CLang 3.6-3.7: some tests of intrusive::FeldmanHashSet based on general-purpose RCU 
+        // are failed even in single-threaded mode (unit tests) without magic compiler barrier below
+        CDS_COMPILER_RW_BARRIER;
+#endif
         pRec->m_nAccessControl.store( tmp - 1, atomics::memory_order_release );
     }