--- tbb-2020.2/oneTBB-2020.2/src/rml/test/test_thread_monitor.cpp	2020-03-30 13:38:06.000000000 +0200

+++ oneTBB-2020.2/src/rml/test/test_thread_monitor.cpp	2020-04-27 15:43:34.209452298 +0200

@@ -23,6 +23,7 @@

 #include "thread_monitor.h"

 #include "harness_memory.h"

 #include "tbb/semaphore.cpp"

+#include <atomic>

 class ThreadState {

     void loop();

@@ -33,21 +34,21 @@

     }

     typedef rml::internal::thread_monitor thread_monitor;

     thread_monitor monitor;

-    volatile int request;

-    volatile int ack;

-    volatile unsigned clock;

-    volatile unsigned stamp;

+    std::atomic<int> request;

+    std::atomic<int> ack;

+    std::atomic<unsigned> clock;

+    unsigned stamp;

     ThreadState() : request(-1), ack(-1), clock(0) {}

 };

 void ThreadState::loop() {

     for(;;) {

-        ++clock;

         if( ack==request ) {

             thread_monitor::cookie c;

             monitor.prepare_wait(c);

             if( ack==request ) {

-                REMARK("%p: request=%d ack=%d\n", this, request, ack );

+                REMARK("%p: request=%d ack=%d\n", this, request.load(), ack.load() );

+                ++clock;

                 monitor.commit_wait(c);

             } else

                 monitor.cancel_wait();

@@ -60,7 +61,7 @@

                     rml::internal::thread_monitor::yield();

             }

             int r = request;

-            ack = request;

+            ack = r;

             if( !r ) return;

         }

     }

@@ -89,7 +90,7 @@

                                 REPORT("Warning: thread %d not waiting\n",i);

                                 break;

                             }

-                        } while( t[i].stamp!=t[i].clock );

+                        } while( t[i].stamp==0 || t[i].stamp!=t[i].clock );

                     }

                 }

                 REMARK("notifying threads\n");