threads: remove wait_list

We can glean the "thread waiting" information without recording it
directly in a list for each thread.

diff --git a/model.cc b/model.cc
index 4d62361197dd5c416a15ab6754186e60d679857e..557d103bae5f1e2c998abf09fd89d7faaf96d689 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -1219,9 +1219,12 @@ bool ModelChecker::process_thread_action(ModelAction *curr)
        }
        case THREAD_FINISH: {
                Thread *th = get_thread(curr);
-               while (!th->wait_list_empty()) {
-                       ModelAction *act = th->pop_wait_list();
-                       scheduler->wake(get_thread(act));
+               /* Wake up any joining threads */
+               for (unsigned int i = 0; i < get_num_threads(); i++) {
+                       Thread *waiting = get_thread(int_to_id(i));
+                       if (waiting->waiting_on() == th &&
+                                       waiting->get_pending()->is_thread_join())
+                               scheduler->wake(waiting);
                }
                th->complete();
                /* Completed thread can't satisfy promises */
@@ -1464,7 +1467,6 @@ bool ModelChecker::check_action_enabled(ModelAction *curr) {
        } else if (curr->is_thread_join()) {
                Thread *blocking = curr->get_thread_operand();
                if (!blocking->is_complete()) {
-                       blocking->push_wait_list(curr);
                        thread_blocking_check_promises(blocking, get_thread(curr));
                        return false;
                }

diff --git a/threads-model.h b/threads-model.h
index eed11cbb0ce827bc4f3eea1ca5ba515ca36df874..ef2c9e10433559c519d1d6062963e2dd6b342f91 100644 (file)
--- a/threads-model.h
+++ b/threads-model.h
@@ -78,23 +78,6 @@ public:
        /** @return True if this thread is blocked */
        bool is_blocked() const { return state == THREAD_BLOCKED; }
 
-       /** @return True if no threads are waiting on this Thread */
-       bool wait_list_empty() const { 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); }
-
-       unsigned int num_wait_list() const {
-               return wait_list.size();
-       }
-
-       ModelAction * get_waiter(unsigned int i) const {
-               return wait_list[i];
-       }
-
        /** @return The pending (next) ModelAction for this Thread
         *  @see Thread::pending */
        ModelAction * get_pending() const { return pending; }
@@ -107,16 +90,6 @@ public:
        Thread * waiting_on() const;
        bool is_waiting_on(const Thread *t) const;
 
-       /**
-        * 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;
-       }
-
        bool is_model_thread() const { return model_thread; }
 
        friend void thread_startup();
@@ -165,13 +138,6 @@ private:
        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
-        */
-       SnapVector<ModelAction *> wait_list;
-
        /**
         * The value returned by the last action in this thread
         * @see Thread::set_return_value()

diff --git a/threads.cc b/threads.cc
index e4b46561a0e7be13016661a541f09146b9726f28..5bfd028746aa99f314263d90d4f7234df629b63b 100644 (file)
--- a/threads.cc
+++ b/threads.cc
@@ -139,7 +139,6 @@ Thread::Thread(thread_id_t tid) :
        user_thread(NULL),
        id(tid),
        state(THREAD_READY), /* Thread is always ready? */
-       wait_list(),
        last_action_val(0),
        model_thread(true)
 {
@@ -160,7 +159,6 @@ Thread::Thread(thrd_t *t, void (*func)(void *), void *a, Thread *parent) :
        arg(a),
        user_thread(t),
        state(THREAD_CREATED),
-       wait_list(),
        last_action_val(VALUE_NONE),
        model_thread(false)
 {