mcslock

diff --git a/benchmark/mcs-lock/mcs-lock.cc b/benchmark/mcs-lock/mcs-lock.cc
index 00817ee65f6ccc6a920527b60f3db4c89c15613b..d43689411a2855e3c1866177ab4393877303f8d7 100644 (file)
--- a/benchmark/mcs-lock/mcs-lock.cc
+++ b/benchmark/mcs-lock/mcs-lock.cc
@@ -12,25 +12,25 @@ static uint32_t shared;
 void threadA(void *arg)
 {
        mcs_mutex::guard g(mutex);
-       printf("store: %d\n", 17);
-       //store_32(&shared, 17);
-       shared = 17;
+       //printf("store: %d\n", 17);
+       store_32(&shared, 17);
+       //shared = 17;
        mutex->unlock(&g);
        mutex->lock(&g);
-       //printf("load: %u\n", load_32(&shared));
-       printf("load: %u\n", shared);
+       printf("load: %u\n", load_32(&shared));
+       //printf("load: %u\n", shared);
 }
 
 void threadB(void *arg)
 {
        mcs_mutex::guard g(mutex);
-       //printf("load: %u\n", load_32(&shared));
-       printf("load: %u\n", shared);
+       printf("load: %u\n", load_32(&shared));
+       //printf("load: %u\n", shared);
        mutex->unlock(&g);
        mutex->lock(&g);
        printf("store: %d\n", 17);
-       shared = 17;
-       //store_32(&shared, 17);
+       //shared = 17;
+       store_32(&shared, 17);
 }
 
 int user_main(int argc, char **argv)

diff --git a/benchmark/mcs-lock/mcs-lock.h b/benchmark/mcs-lock/mcs-lock.h
index af31894cfeaf626c0717be79c5429eb910c624ac..a27b37e0431d281934ed1ee9c3ae9d0176de7405 100644 (file)
--- a/benchmark/mcs-lock/mcs-lock.h
+++ b/benchmark/mcs-lock/mcs-lock.h
@@ -82,7 +82,6 @@ public:
                me->gate.store(1, std::mo_relaxed );
 
                // publish my node as the new tail :
-               // FIXME: Only weakening the mo_acq_rel cause the spec error
                mcs_node * pred = m_tail.exchange(me, std::mo_acq_rel);
                /**
                        @Begin
@@ -95,6 +94,7 @@ public:
                        // unlock of pred can see me in the tail before I fill next
 
                        // publish me to previous lock-holder :
+                       // FIXME: detection miss  
                        pred->next.store(me, std::mo_release );
 
                        // (*2) pred not touched any more       
@@ -105,6 +105,8 @@ public:
                        int my_gate = 1;
                        while (my_gate ) {
                                my_gate = me->gate.load(std::mo_acquire);
+                               if (my_gate == 0)
+                                       printf("lock at gate!\n");
                                /**
                                        @Begin
                                        @Commit_point_define_check: my_gate == 0
@@ -130,12 +132,12 @@ public:
        void unlock(guard * I) {
                mcs_node * me = &(I->m_node);
 
+               // FIXME: detection miss  
                mcs_node * next = me->next.load(std::mo_acquire);
                if ( next == NULL )
                {
                        mcs_node * tail_was_me = me;
                        bool success;
-                       // FIXME: Only weakening the mo_acq_rel cause the spec error
                        success = m_tail.compare_exchange_strong(
                                tail_was_me,NULL,std::mo_acq_rel);
                        /**
@@ -153,6 +155,7 @@ public:
                        // (*1) catch the race :
                        rl::linear_backoff bo;
                        for(;;) {
+                               // FIXME: detection miss  
                                next = me->next.load(std::mo_acquire);
                                if ( next != NULL )
                                        break;