model: schedule appropriate fence backtracking points
[c11tester.git] / schedule.cc
index 7a703abab8cc7e229f7218c85add8580c7f3ad53..e87490313cf4836e1f11dab9528ef7ad00b6bf26 100644 (file)
 #include <string.h>
 #include <stdlib.h>
 
-#include "threads.h"
+#include "threads-model.h"
 #include "schedule.h"
 #include "common.h"
 #include "model.h"
+#include "nodestack.h"
+
+/**
+ * Format an "enabled_type_t" for printing
+ * @param e The type to format
+ * @param str The output character array
+ */
+static void enabled_type_to_string(enabled_type_t e, char *str)
+{
+       const char *res;
+       switch (e) {
+       case THREAD_DISABLED:
+               res = "disabled";
+               break;
+       case THREAD_ENABLED:
+               res = "enabled";
+               break;
+       case THREAD_SLEEP_SET:
+               res = "sleep";
+               break;
+       default:
+               ASSERT(0);
+               res = NULL;
+               break;
+       }
+       strcpy(str, res);
+}
 
 /** Constructor */
 Scheduler::Scheduler() :
-       is_enabled(NULL),
+       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);
+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 (enabled != NULL) {
+                       memcpy(new_enabled, enabled, enabled_len * sizeof(enabled_type_t));
+                       snapshot_free(enabled);
+               }
+               enabled = new_enabled;
+               enabled_len = threadid + 1;
+       }
+       enabled[threadid] = enabled_status;
+       if (enabled_status == THREAD_DISABLED)
+               model->check_promises_thread_disabled();
+}
+
+/**
+ * @brief Check if a Thread is currently enabled
+ *
+ * Check if a Thread is currently enabled. "Enabled" includes both
+ * THREAD_ENABLED and THREAD_SLEEP_SET.
+ * @param t The Thread to check
+ * @return True if the Thread is currently enabled
+ */
+bool Scheduler::is_enabled(const Thread *t) const
+{
+       return is_enabled(t->get_id());
+}
+
+/**
+ * @brief Check if a Thread is currently enabled
+ *
+ * Check if a Thread is currently enabled. "Enabled" includes both
+ * THREAD_ENABLED and THREAD_SLEEP_SET.
+ * @param tid The ID of the Thread to check
+ * @return True if the Thread is currently enabled
+ */
+bool Scheduler::is_enabled(thread_id_t tid) const
+{
+       int i = id_to_int(tid);
+       return (i >= enabled_len) ? false : (enabled[i] != THREAD_DISABLED);
+}
+
+/**
+ * @brief Check if a Thread is currently in the sleep set
+ * @param t The Thread to check
+ * @return True if the Thread is currently enabled
+ */
+bool Scheduler::is_sleep_set(const Thread *t) const
+{
+       return get_enabled(t) == THREAD_SLEEP_SET;
+}
+
+enabled_type_t Scheduler::get_enabled(const Thread *t) const
+{
+       int id = id_to_int(t->get_id());
+       ASSERT(id < enabled_len);
+       return enabled[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) {
+                       enabled[i] = THREAD_SLEEP_SET;
                }
-               is_enabled=new_enabled;
-               enabled_len=threadid+1;
        }
-       is_enabled[threadid]=enabled_status;
+}
+
+/**
+ * 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);
 }
 
 /**
@@ -36,8 +138,9 @@ void Scheduler::set_enabled(Thread *t, bool enabled_status) {
  */
 void Scheduler::add_thread(Thread *t)
 {
-       DEBUG("thread %d\n", t->get_id());
-       set_enabled(t, true);
+       DEBUG("thread %d\n", id_to_int(t->get_id()));
+       ASSERT(!t->is_model_thread());
+       set_enabled(t, THREAD_ENABLED);
 }
 
 /**
@@ -48,7 +151,7 @@ void Scheduler::remove_thread(Thread *t)
 {
        if (current == t)
                current = NULL;
-       set_enabled(t, false);
+       set_enabled(t, THREAD_DISABLED);
 }
 
 /**
@@ -58,7 +161,7 @@ void Scheduler::remove_thread(Thread *t)
  */
 void Scheduler::sleep(Thread *t)
 {
-       set_enabled(t, false);
+       set_enabled(t, THREAD_DISABLED);
        t->set_state(THREAD_BLOCKED);
 }
 
@@ -68,40 +171,55 @@ void Scheduler::sleep(Thread *t)
  */
 void Scheduler::wake(Thread *t)
 {
-       set_enabled(t, true);
+       ASSERT(!t->is_model_thread());
+       set_enabled(t, THREAD_ENABLED);
        t->set_state(THREAD_READY);
 }
 
 /**
- * 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.
+ * @brief Select a Thread to run via round-robin
  * @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;
-                       }
+Thread * Scheduler::select_next_thread()
+{
+       int old_curr_thread = curr_thread_index;
+       bool have_enabled_thread_with_priority = false;
+       Node *n = model->get_curr_node();
+
+       for (int i = 0; i < enabled_len; i++) {
+               thread_id_t tid = int_to_id(i);
+               if (n->has_priority(tid)) {
+                       DEBUG("Node (tid %d) has priority\n", i);
+                       if (enabled[i] != THREAD_DISABLED)
+                               have_enabled_thread_with_priority = true;
                }
-       } else {
-               curr_thread_index = id_to_int(t->get_id());
        }
 
+       for (int i = 0; i < enabled_len; i++) {
+               curr_thread_index = (old_curr_thread + i + 1) % enabled_len;
+               thread_id_t curr_tid = int_to_id(curr_thread_index);
+               if (enabled[curr_thread_index] == THREAD_ENABLED &&
+                               (!have_enabled_thread_with_priority || n->has_priority(curr_tid))) {
+                       return model->get_thread(curr_tid);
+               }
+       }
+       /* No thread was enabled */
+       return NULL;
+}
+
+/**
+ * @brief Set the current "running" Thread
+ * @param t Thread to run
+ */
+void Scheduler::set_current_thread(Thread *t)
+{
+       ASSERT(t && !t->is_model_thread());
+
+       curr_thread_index = id_to_int(t->get_id());
+
        current = t;
-       print();
-       return t;
+       if (DBG_ENABLED())
+               print();
 }
 
 /**
@@ -109,6 +227,7 @@ Thread * Scheduler::next_thread(Thread *t)
  */
 Thread * Scheduler::get_current_thread() const
 {
+       ASSERT(!current || !current->is_model_thread());
        return current;
 }
 
@@ -118,8 +237,13 @@ Thread * Scheduler::get_current_thread() const
  */
 void Scheduler::print() const
 {
-       if (current)
-               DEBUG("Current thread: %d\n", current->get_id());
-       else
-               DEBUG("No current thread\n");
+       int curr_id = current ? id_to_int(current->get_id()) : -1;
+
+       model_print("Scheduler: ");
+       for (int i = 0; i < enabled_len; i++) {
+               char str[20];
+               enabled_type_to_string(enabled[i], str);
+               model_print("[%i: %s%s]", i, i == curr_id ? "current, " : "", str);
+       }
+       model_print("\n");
 }