Handout

thread/dispatcher.h

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+// vim: set noet ts=4 sw=4:
+
+/*! \file
+ *  \brief \ref Dispatcher for \ref Thread threads
+ */
+#pragma once
+#include "../thread/thread.h"
+#include "../types.h"
+
+/*! \brief The dispatcher dispatches threads and puts the scheduler's
+ *  decisions into action.
+ *  \ingroup thread
+ *
+ *  The dispatcher manages the life pointer that refers to the currently
+ *  active thread and performs the actual switching of processes.
+ *  For single-core systems, a single life pointer is sufficient, as only a
+ *  single thread can be active at any one time. On multi-core systems,
+ *  every CPU core needs its own life pointer.
+ */
+class Dispatcher {
+  /*! \brief set the currently active thread
+   *  \param thread active Thread
+   */
+  void setActive(Thread* thread) { (void)thread; }
+
+ public:
+  /*! \brief constructor
+   *
+   *	\todo(14) Implement Method
+   */
+  Dispatcher();
+
+  /*! \brief Returns the thread currently running on the CPU core calling
+   *  this method
+   *
+   *  \todo(14) Implement Method
+   */
+  Thread* active();
+
+  /*! \brief Check if thread is currently active
+   *  \param thread Pointer to the thread in question
+   *  \param cpu will receive the core number if `cpu` pointer is not `nullptr`
+   *             and the thread is currently active
+   *  \return `true` if currently running, false otherwise
+   *
+   *  \todo(15) Implement method for kill IPI (in \MPStuBS only)
+   */
+  bool isActive(const Thread* thread, unsigned* cpu = nullptr);
+
+  /*! \brief This method stores first as life pointer for this CPU core and
+   *  triggers the execution of first. Only to be used for the first thread
+   *  running on a CPU.
+   *  \param first First thread to be executed on this CPU core.
+   *
+   *  \todo(14) Implement Method
+   */
+  void go(Thread* first);
+
+  /*! \brief Updates the life pointer to next and issues a thread change from
+   *  the old to the new life pointer.
+   *  \param next Next thread to be executed.
+   *
+   *  \todo(14) Implement Method
+   */
+  void dispatch(Thread* next);
+};