more bugs

[model-checker.git] / schedule.cc

diff --git a/schedule.cc b/schedule.cc
index 1791605b7c38842c37d11553c37f663c9dc88c38..8883d2a9b82cccc78a47b62a14d05e0e64ee52a5 100644 (file)
--- a/schedule.cc
+++ b/schedule.cc
@@ -3,59 +3,120 @@
 #include "common.h"
 #include "model.h"
 
+/** Constructor */
 Scheduler::Scheduler() :
+       is_enabled(NULL),
+       enabled_len(0),
+       curr_thread_index(0),
        current(NULL)
 {
 }
 
+void Scheduler::set_enabled(Thread *t, bool enabled_status) {
+       int threadid=id_to_int(t->get_id());
+       if (threadid>=enabled_len) {
+               bool * new_enabled=(bool *)malloc(sizeof(bool)*(threadid+1));
+               memset(&new_enabled[enabled_len], 0, (threadid+1-enabled_len)*sizeof(bool));
+               if (is_enabled != NULL) {
+                       memcpy(new_enabled, is_enabled, enabled_len*sizeof(bool));
+                       free(is_enabled);
+               }
+               is_enabled=new_enabled;
+               enabled_len=threadid+1;
+       }
+       is_enabled[threadid]=enabled_status;
+}
+
+/**
+ * Add a Thread to the scheduler's ready list.
+ * @param t The Thread to add
+ */
 void Scheduler::add_thread(Thread *t)
 {
        DEBUG("thread %d\n", t->get_id());
-       readyList.push_back(t);
+       set_enabled(t, true);
 }
 
+/**
+ * Remove a given Thread from the scheduler.
+ * @param t The Thread to remove
+ */
 void Scheduler::remove_thread(Thread *t)
 {
        if (current == t)
                current = NULL;
-       else
-               readyList.remove(t);
+       set_enabled(t, false);
 }
 
-Thread * Scheduler::next_thread(void)
+/**
+ * Prevent a Thread from being scheduled. The sleeping Thread should be
+ * re-awoken via Scheduler::wake.
+ * @param thread The Thread that should sleep
+ */
+void Scheduler::sleep(Thread *t)
 {
-       Thread *t = model->schedule_next_thread();
+       set_enabled(t, false);
+       t->set_state(THREAD_BLOCKED);
+}
 
-       if (t != NULL) {
-               current = t;
-               readyList.remove(t);
-       } else if (readyList.empty()) {
-               t = NULL;
+/**
+ * Wake a Thread up that was previously waiting (see Scheduler::wait)
+ * @param t The Thread to wake up
+ */
+void Scheduler::wake(Thread *t)
+{
+       set_enabled(t, true);
+       t->set_state(THREAD_READY);
+}
+
+/**
+ * Remove one Thread from the scheduler. This implementation defaults to FIFO,
+ * if a thread is not already provided.
+ *
+ * @param t Thread to run, if chosen by an external entity (e.g.,
+ * ModelChecker). May be NULL to indicate no external choice.
+ * @return The next Thread to run
+ */
+Thread * Scheduler::next_thread(Thread *t)
+{
+       if ( t == NULL ) {
+               int old_curr_thread = curr_thread_index;
+               while(true) {
+                       curr_thread_index = (curr_thread_index+1) % enabled_len;
+                       if (is_enabled[curr_thread_index]) {
+                               t = model->get_thread(int_to_id(curr_thread_index));
+                               break;
+                       }
+                       if (curr_thread_index == old_curr_thread) {
+                               print();
+                               return NULL;
+                       }
+               }
        } else {
-               t = readyList.front();
-               current = t;
-               readyList.pop_front();
+               curr_thread_index = id_to_int(t->get_id());
        }
 
+       current = t;
        print();
-
        return t;
 }
 
-Thread * Scheduler::get_current_thread(void)
+/**
+ * @return The currently-running Thread
+ */
+Thread * Scheduler::get_current_thread() const
 {
        return current;
 }
 
-void Scheduler::print()
+/**
+ * Print debugging information about the current state of the scheduler. Only
+ * prints something if debugging is enabled.
+ */
+void Scheduler::print() const
 {
        if (current)
                DEBUG("Current thread: %d\n", current->get_id());
        else
                DEBUG("No current thread\n");
-       DEBUG("Num. threads in ready list: %zu\n", readyList.size());
-
-       std::list<Thread *, MyAlloc< Thread * > >::iterator it;
-       for (it = readyList.begin(); it != readyList.end(); it++)
-               DEBUG("In ready list: thread %d\n", (*it)->get_id());
 }