changes with lines of spec counted

[cdsspec-compiler.git] / benchmark / mcs-lock / mcs-lock.h

diff --git a/benchmark/mcs-lock/mcs-lock.h b/benchmark/mcs-lock/mcs-lock.h
index 27db46981f3d165823ce3a3372cc6ecc1a7e0e96..bf496318f1107cfb709f25ec04c34cc70da39f24 100644 (file)
--- a/benchmark/mcs-lock/mcs-lock.h
+++ b/benchmark/mcs-lock/mcs-lock.h
@@ -54,12 +54,9 @@ public:
                        LANG = CPP;
                        CLASS = mcs_mutex;
                @Global_define:
-                       @DeclareVar:
-                               bool _lock_acquired;
-                       @InitVar:
-                               _lock_acquired = false;
-               @Happens_before:
-                       Unlock -> Lock
+                       @DeclareVar: bool _lock_acquired;
+                       @InitVar: _lock_acquired = false;
+               @Happens_before: Unlock -> Lock
                @End
        */
 
@@ -67,10 +64,8 @@ public:
                @Begin
                @Interface: Lock
                @Commit_point_set: Lock_Enqueue_Point1 | Lock_Enqueue_Point2
-               @Check:
-                       _lock_acquired == false;
-               @Action:
-                       _lock_acquired = true;
+               @Check: _lock_acquired == false;
+               @Action: _lock_acquired = true;
                @End
        */
        void lock(guard * I) {
@@ -81,9 +76,9 @@ public:
                me->next.store(NULL, std::mo_relaxed );
                me->gate.store(1, std::mo_relaxed );
 
+               /** Run this in the -Y mode to expose the HB bug */
                // publish my node as the new tail :
                mcs_node * pred = m_tail.exchange(me, std::mo_acq_rel);
-               // FIXME: Only weakening the mo_acq_rel cause the spec error
                /**
                        @Begin
                        @Commit_point_define_check: pred == NULL
@@ -95,7 +90,11 @@ public:
                        // unlock of pred can see me in the tail before I fill next
 
                        // publish me to previous lock-holder :
+                       // FIXME: detection miss, execution never ends
+                       // If this is relaxed, the store 0 to gate will be read before and
+                       // that lock will never ends.
                        pred->next.store(me, std::mo_release );
+                       //printf("lock_miss1\n");
 
                        // (*2) pred not touched any more       
 
@@ -105,6 +104,8 @@ 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
@@ -119,25 +120,23 @@ public:
        /**
                @Begin
                @Interface: Unlock
-               @Commit_point_set:
-                       Unlock_Point_Success_1 | Unlock_Point_Success_2
-               @Check:
-                       _lock_acquired == true
-               @Action:
-                       _lock_acquired = false;
+               @Commit_point_set: Unlock_Point_Success_1 | Unlock_Point_Success_2
+               @Check: _lock_acquired == true
+               @Action: _lock_acquired = false;
                @End
        */
        void unlock(guard * I) {
                mcs_node * me = &(I->m_node);
 
+               // FIXME: detection miss, execution never ends
                mcs_node * next = me->next.load(std::mo_acquire);
+               //printf("unlock_miss2\n");
                if ( next == NULL )
                {
                        mcs_node * tail_was_me = me;
                        bool success;
                        success = m_tail.compare_exchange_strong(
                                tail_was_me,NULL,std::mo_acq_rel);
-                       // FIXME: Only weakening the mo_acq_rel cause the spec error
                        /**
                                @Begin
                                @Commit_point_define_check: success == true
@@ -153,7 +152,9 @@ public:
                        // (*1) catch the race :
                        rl::linear_backoff bo;
                        for(;;) {
+                               // FIXME: detection miss, execution never ends
                                next = me->next.load(std::mo_acquire);
+                               //printf("unlock_miss3\n");
                                if ( next != NULL )
                                        break;
                                thrd_yield();