X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=threads.h;h=248d948fe98c87863741d4ed94343ee22d9cef5e;hp=a97a04c704449963981fe443a711c64abc716fb3;hb=3c82af9a449b5cb3322809fd195a02e4a2ae37f4;hpb=ebab3e51073b1534ba5d9ce944568d933d16fb3d

diff --git a/threads.h b/threads.h
index a97a04c..248d948 100644
--- a/threads.h
+++ b/threads.h
@@ -6,6 +6,9 @@
 #define __THREADS_H__
 
 #include <ucontext.h>
+#include <stdint.h>
+#include <vector>
+
 #include "mymemory.h"
 #include "libthreads.h"
 
@@ -13,10 +16,20 @@ typedef int thread_id_t;
 
 #define THREAD_ID_T_NONE	-1
 
+/** @brief Represents the state of a user Thread */
 typedef enum thread_state {
+	/** Thread was just created and hasn't run yet */
 	THREAD_CREATED,
+	/** Thread is running */
 	THREAD_RUNNING,
+	/** Thread is not currently running but is ready to run */
 	THREAD_READY,
+	/**
+	 * Thread is waiting on another action (e.g., thread completion, lock
+	 * release, etc.)
+	 */
+	THREAD_BLOCKED,
+	/** Thread has completed its execution */
 	THREAD_COMPLETED
 } thread_state;
 
@@ -41,6 +54,46 @@ public:
 	void set_creation(ModelAction *act) { creation = act; }
 	ModelAction * get_creation() { return creation; }
 
+	/**
+	 * Set a return value for the last action in this thread (e.g., for an
+	 * atomic read).
+	 * @param value The value to return
+	 */
+	void set_return_value(uint64_t value) { last_action_val = value; }
+
+	/**
+	 * Retrieve a return value for the last action in this thread. Used,
+	 * for instance, for an atomic read to return the 'read' value. Should
+	 * be called from a user context.
+	 * @return The value 'returned' by the action
+	 */
+	uint64_t get_return_value() { return last_action_val; }
+
+	/** @return True if this thread is finished executing */
+	bool is_complete() { return state == THREAD_COMPLETED; }
+
+	/** @return True if this thread is blocked */
+	bool is_blocked() { return state == THREAD_BLOCKED; }
+
+	/** @return True if no threads are waiting on this Thread */
+	bool wait_list_empty() { return wait_list.empty(); }
+
+	/**
+	 * Add a thread to the waiting list for this thread.
+	 * @param t The Thread to add
+	 */
+	void push_wait_list(Thread *t) { wait_list.push_back(t); }
+
+	/**
+	 * Remove one Thread from the waiting list
+	 * @return The Thread that was removed from the waiting list
+	 */
+	Thread * pop_wait_list() {
+		Thread *ret = wait_list.front();
+		wait_list.pop_back();
+		return ret;
+	}
+
 	friend void thread_startup();
 
 	SNAPSHOTALLOC
@@ -56,6 +109,20 @@ private:
 	thrd_t *user_thread;
 	thread_id_t id;
 	thread_state state;
+
+	/**
+	 * A list of Threads waiting on this Thread. Particularly, this list is
+	 * used for thread joins, where another Thread waits for this Thread to
+	 * complete
+	 */
+	std::vector<Thread *> wait_list;
+
+	/**
+	 * The value returned by the last action in this thread
+	 * @see Thread::set_return_value()
+	 * @see Thread::get_return_value()
+	 */
+	uint64_t last_action_val;
 };
 
 Thread * thread_current();