2 * @brief Stack of operations for use in backtracking.
5 #ifndef __NODESTACK_H__
6 #define __NODESTACK_H__
13 #include "clockvector.h"
18 * A flag used for the promise counting/combination problem within a node,
19 * denoting whether a particular Promise is
20 * <ol><li>@b applicable: can be satisfied by this Node's ModelAction and</li>
21 * <li>@b fulfilled: satisfied by this Node's ModelAction under the current
22 * configuration.</li></ol>
25 PROMISE_IGNORE = 0, /**< This promise is inapplicable; ignore it */
26 PROMISE_UNFULFILLED, /**< This promise is applicable but unfulfilled */
27 PROMISE_FULFILLED /**< This promise is applicable and fulfilled */
32 modelclock_t expiration;
37 * @brief A single node in a NodeStack
39 * Represents a single node in the NodeStack. Each Node is associated with up
40 * to one action and up to one parent node. A node holds information
41 * regarding the last action performed (the "associated action"), the thread
42 * choices that have been explored (explored_children) and should be explored
43 * (backtrack), and the actions that the last action may read from.
47 Node(ModelAction *act = NULL, Node *par = NULL, int nthreads = 1);
49 /* return true = thread choice has already been explored */
50 bool has_been_explored(thread_id_t tid);
51 /* return true = backtrack set is empty */
52 bool backtrack_empty();
54 void explore_child(ModelAction *act);
55 /* return false = thread was already in backtrack */
56 bool set_backtrack(thread_id_t id);
57 thread_id_t get_next_backtrack();
58 bool is_enabled(Thread *t);
59 ModelAction * get_action() { return action; }
61 /** @return the parent Node to this Node; that is, the action that
62 * occurred previously in the stack. */
63 Node * get_parent() const { return parent; }
65 bool add_future_value(uint64_t value, modelclock_t expiration);
66 uint64_t get_future_value();
67 modelclock_t get_future_value_expiration();
68 bool increment_future_value();
69 bool future_value_empty();
71 void add_read_from(const ModelAction *act);
72 const ModelAction * get_read_from();
73 bool increment_read_from();
74 bool read_from_empty();
75 int get_read_from_size();
76 const ModelAction * get_read_from_at(int i);
78 void set_promise(unsigned int i);
79 bool get_promise(unsigned int i);
80 bool increment_promise();
84 void print_may_read_from();
88 void explore(thread_id_t tid);
93 std::vector< bool, MyAlloc<bool> > explored_children;
94 std::vector< bool, MyAlloc<bool> > backtrack;
97 /** The set of ModelActions that this the action at this Node may read
98 * from. Only meaningful if this Node represents a 'read' action. */
99 std::vector< const ModelAction *, MyAlloc< const ModelAction * > > may_read_from;
101 unsigned int read_from_index;
103 std::vector< struct future_value, MyAlloc<struct future_value> > future_values;
104 std::vector< promise_t, MyAlloc<promise_t> > promises;
105 unsigned int future_index;
108 typedef std::list< Node *, MyAlloc< Node * > > node_list_t;
111 * @brief A stack of nodes
113 * Holds a Node linked-list that can be used for holding backtracking,
114 * may-read-from, and replay information. It is used primarily as a
115 * stack-like structure, in that backtracking points and replay nodes are
116 * only removed from the top (most recent).
122 ModelAction * explore_action(ModelAction *act);
125 void reset_execution();
126 void pop_restofstack(int numAhead);
127 int get_total_nodes() { return total_nodes; }
133 node_list_t node_list;
134 node_list_t::iterator iter;
139 #endif /* __NODESTACK_H__ */