ticketlock foo

sync/ticketlock.cc

@@ -0,0 +1,12 @@
+#include "sync/ticketlock.h"
+
+void Ticketlock::lock() {
+    uint64_t ticket = __atomic_fetch_add(&ticket_count, 1, __ATOMIC_SEQ_CST);
+    while (ticket != ticket_current) {
+        Core::pause();
+    }
+}
+
+void Ticketlock::unlock() {
+    __atomic_fetch_add(&ticket_current, 1, __ATOMIC_SEQ_CST);
+}

sync/ticketlock.h

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include "arch/core.h"
+#include "arch/cache.h"
 /*! \brief Using Ticketlocks, it is possible to serialize blocks of code
  *  that might otherwise run in parallel on multiple CPU cores,
  *  or be interleaved due to interrupts or scheduling.
@@ -29,12 +31,17 @@ class Ticketlock {
   Ticketlock(const Ticketlock& copy) = delete;
   Ticketlock& operator=(const Ticketlock&) = delete;
 
+  
+ private:
+	volatile uint64_t ticket_current;
+	volatile uint64_t ticket_count;
+
  public:
   /*! \brief Constructor
    *
    * \todo(12) Complete Constructor (for \MPStuBS)
    */
-  consteval Ticketlock() {}
+  consteval Ticketlock() : ticket_current(0), ticket_count(0) {}
 
   /*! \brief Enters the critical area. In case the area is already locked,
    *  \ref lock() will actively wait until the area can be entered.
@@ -42,11 +49,11 @@ class Ticketlock {
    * \see \ref Core::pause()
    * \todo(12) Implement Method (for \MPStuBS)
    */
-  void lock() {}
+  void lock();
 
   /*! \brief Unblocks the critical area.
    *
    * \todo(12) Implement Method (for \MPStuBS)
    */
-  void unlock() {}
+  void unlock();
 };