add support for sleep sets...

[model-checker.git] / schedule.cc

diff --git a/schedule.cc b/schedule.cc
index be4a92f739a1129bb2aa4bee50bb23ba0a3f8556..c5e58fe65cb50960db366bd39fb45177ec6fc7db 100644 (file)
--- a/schedule.cc
+++ b/schedule.cc
@@ -1,22 +1,77 @@
+#include <string.h>
+#include <stdlib.h>
+
 #include "threads.h"
 #include "schedule.h"
 #include "common.h"
 #include "model.h"
+#include "nodestack.h"
 
 /** Constructor */
 Scheduler::Scheduler() :
+       is_enabled(NULL),
+       enabled_len(0),
+       curr_thread_index(0),
        current(NULL)
 {
 }
 
+void Scheduler::set_enabled(Thread *t, enabled_type_t enabled_status) {
+       int threadid=id_to_int(t->get_id());
+       if (threadid>=enabled_len) {
+               enabled_type_t *new_enabled = (enabled_type_t *)snapshot_malloc(sizeof(enabled_type_t) * (threadid + 1));
+               memset(&new_enabled[enabled_len], 0, (threadid+1-enabled_len)*sizeof(enabled_type_t));
+               if (is_enabled != NULL) {
+                       memcpy(new_enabled, is_enabled, enabled_len*sizeof(enabled_type_t));
+                       snapshot_free(is_enabled);
+               }
+               is_enabled=new_enabled;
+               enabled_len=threadid+1;
+       }
+       is_enabled[threadid]=enabled_status;
+}
+
+enabled_type_t Scheduler::get_enabled(Thread *t) {
+       return is_enabled[id_to_int(t->get_id())];
+}
+
+void Scheduler::update_sleep_set(Node *n) {
+       enabled_type_t *enabled_array=n->get_enabled_array();
+       for(int i=0;i<enabled_len;i++) {
+               if (enabled_array[i]==THREAD_SLEEP_SET) {
+                       is_enabled[i]=THREAD_SLEEP_SET;
+               }
+       }
+}
+
+/**
+ * Add a Thread to the sleep set.
+ * @param t The Thread to add
+ */
+void Scheduler::add_sleep(Thread *t)
+{
+       DEBUG("thread %d\n", id_to_int(t->get_id()));
+       set_enabled(t, THREAD_SLEEP_SET);
+}
+
+/**
+ * Remove a Thread from the sleep set.
+ * @param t The Thread to remove
+ */
+void Scheduler::remove_sleep(Thread *t)
+{
+       DEBUG("thread %d\n", id_to_int(t->get_id()));
+       set_enabled(t, THREAD_ENABLED);
+}
+
 /**
  * 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);
+       DEBUG("thread %d\n", id_to_int(t->get_id()));
+       set_enabled(t, THREAD_ENABLED);
 }
 
 /**
@@ -27,22 +82,18 @@ void Scheduler::remove_thread(Thread *t)
 {
        if (current == t)
                current = NULL;
-       else
-               readyList.remove(t);
+       set_enabled(t, THREAD_DISABLED);
 }
 
 /**
- * Force one Thread to wait on another Thread. The "join" Thread should
- * eventually wake up the waiting Thread via Scheduler::wake.
- * @param wait The Thread that should wait
- * @param join The Thread on which we are waiting.
+ * 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::wait(Thread *wait, Thread *join)
+void Scheduler::sleep(Thread *t)
 {
-       ASSERT(!join->is_complete());
-       remove_thread(wait);
-       join->push_wait_list(wait);
-       wait->set_state(THREAD_BLOCKED);
+       set_enabled(t, THREAD_DISABLED);
+       t->set_state(THREAD_BLOCKED);
 }
 
 /**
@@ -51,13 +102,13 @@ void Scheduler::wait(Thread *wait, Thread *join)
  */
 void Scheduler::wake(Thread *t)
 {
-       add_thread(t);
+       set_enabled(t, THREAD_DISABLED);
        t->set_state(THREAD_READY);
 }
 
 /**
- * Remove one Thread from the scheduler. This implementation defaults to FIFO,
- * if a thread is not already provided.
+ * Select a Thread. This implementation defaults to round-robin, 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.
@@ -65,19 +116,25 @@ void Scheduler::wake(Thread *t)
  */
 Thread * Scheduler::next_thread(Thread *t)
 {
-       if (t != NULL) {
-               current = t;
-               readyList.remove(t);
-       } else if (readyList.empty()) {
-               t = NULL;
+       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]==THREAD_ENABLED) {
+                               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;
 }
 
@@ -96,12 +153,7 @@ Thread * Scheduler::get_current_thread() const
 void Scheduler::print() const
 {
        if (current)
-               DEBUG("Current thread: %d\n", current->get_id());
+               DEBUG("Current thread: %d\n", id_to_int(current->get_id()));
        else
                DEBUG("No current thread\n");
-       DEBUG("Num. threads in ready list: %zu\n", readyList.size());
-
-       std::list<Thread *, MyAlloc< Thread * > >::const_iterator it;
-       for (it = readyList.begin(); it != readyList.end(); it++)
-               DEBUG("In ready list: thread %d\n", (*it)->get_id());
 }