+/** @file threads.h
+ * @brief Model Checker Thread class.
+ */
+
#ifndef __THREADS_H__
#define __THREADS_H__
#include <ucontext.h>
+#include <stdint.h>
+#include <vector>
+
#include "mymemory.h"
#include "libthreads.h"
#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;
class ModelAction;
+/** @brief A Thread is created for each user-space thread */
class Thread {
public:
Thread(thrd_t *t, void (*func)(void *), void *a);
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 ModelAction to the waiting list for this thread.
+ * @param t The ModelAction to add. Must be a JOIN.
+ */
+ void push_wait_list(ModelAction *act) { wait_list.push_back(act); }
+
+ ModelAction * get_pending() { return pending; }
+ void set_pending(ModelAction *act) { pending = act; }
+ /**
+ * Remove one ModelAction from the waiting list
+ * @return The ModelAction that was removed from the waiting list
+ */
+ ModelAction * pop_wait_list() {
+ ModelAction *ret = wait_list.front();
+ wait_list.pop_back();
+ return ret;
+ }
+
friend void thread_startup();
SNAPSHOTALLOC
Thread *parent;
ModelAction *creation;
+ ModelAction *pending;
void (*start_routine)(void *);
void *arg;
ucontext_t context;
thrd_t *user_thread;
thread_id_t id;
thread_state state;
+
+ /**
+ * A list of ModelActions waiting on this Thread. Particularly, this
+ * list is used for thread joins, where another Thread waits for this
+ * Thread to complete
+ */
+ std::vector<ModelAction *> 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();