+#include <string.h>
#include <stdlib.h>
-#include "libthreads.h"
+#include "threads-model.h"
#include "schedule.h"
#include "common.h"
#include "model.h"
+#include "nodestack.h"
-struct thread_list_node {
- struct thread *t;
- struct thread_list_node *next;
- int live;
-};
-
-#define NUM_LIST_NODES 32
+/** Constructor */
+Scheduler::Scheduler() :
+ enabled(NULL),
+ enabled_len(0),
+ curr_thread_index(0),
+ current(NULL)
+{
+}
-struct thread_list_node *head, *tail;
-struct thread_list_node nodes[NUM_LIST_NODES];
-struct thread *current;
+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;
+}
-static void enqueue_thread(struct thread *t)
+/**
+ * @brief Check if a Thread is currently enabled
+ * @param t The Thread to check
+ * @return True if the Thread is currently enabled
+ */
+bool Scheduler::is_enabled(Thread *t) const
{
- int i;
- struct thread_list_node *node;
+ int id = id_to_int(t->get_id());
+ return (id >= enabled_len) ? false : (enabled[id] != THREAD_DISABLED);
+}
- for (node = nodes, i = 0; node->live && i < NUM_LIST_NODES; i++, node++);
- if (i >= NUM_LIST_NODES) {
- printf("ran out of nodes\n");
- exit(1);
- }
- node->t = t;
- node->next = NULL;
- node->live = 1;
+enabled_type_t Scheduler::get_enabled(Thread *t) {
+ return enabled[id_to_int(t->get_id())];
+}
- if (tail)
- tail->next = node;
- else
- head = node;
- tail = node;
+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;
+ }
+ }
}
-static struct thread *dequeue_thread(void)
+/**
+ * Add a Thread to the sleep set.
+ * @param t The Thread to add
+ */
+void Scheduler::add_sleep(Thread *t)
{
- struct thread *pop;
+ DEBUG("thread %d\n", id_to_int(t->get_id()));
+ set_enabled(t, THREAD_SLEEP_SET);
+}
- if (!head)
- return NULL;
+/**
+ * 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);
+}
- pop = head->t;
- head->live = 0;
- if (head == tail)
- tail = NULL;
- head = head->next;
+/**
+ * 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", id_to_int(t->get_id()));
+ ASSERT(!t->is_model_thread());
+ set_enabled(t, THREAD_ENABLED);
+}
- /* Set new current thread */
- current = pop;
+/**
+ * Remove a given Thread from the scheduler.
+ * @param t The Thread to remove
+ */
+void Scheduler::remove_thread(Thread *t)
+{
+ if (current == t)
+ current = NULL;
+ set_enabled(t, THREAD_DISABLED);
+}
- return pop;
+/**
+ * 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)
+{
+ set_enabled(t, THREAD_DISABLED);
+ t->set_state(THREAD_BLOCKED);
}
-void DefaultScheduler::add_thread(struct thread *t)
+/**
+ * Wake a Thread up that was previously waiting (see Scheduler::wait)
+ * @param t The Thread to wake up
+ */
+void Scheduler::wake(Thread *t)
{
- DEBUG("thread %d\n", t->id);
- enqueue_thread(t);
+ ASSERT(!t->is_model_thread());
+ set_enabled(t, THREAD_ENABLED);
+ t->set_state(THREAD_READY);
}
-struct thread *DefaultScheduler::next_thread(void)
+/**
+ * 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.
+ * @return The next Thread to run
+ */
+Thread * Scheduler::next_thread(Thread *t)
{
- return dequeue_thread();
+ if ( t == NULL ) {
+ 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)) {
+ //Have a thread with priority
+ if (enabled[i]!=THREAD_DISABLED)
+ have_enabled_thread_with_priority=true;
+ }
+ }
+
+ while(true) {
+ curr_thread_index = (curr_thread_index+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))) {
+ t = model->get_thread(int_to_id(curr_tid));
+ break;
+ }
+ if (curr_thread_index == old_curr_thread) {
+ print();
+ return NULL;
+ }
+ }
+ } else if (t->is_model_thread()) {
+ /* model-checker threads never run */
+ t = NULL;
+ } else {
+ curr_thread_index = id_to_int(t->get_id());
+ }
+
+ current = t;
+ print();
+ return t;
}
-struct thread *DefaultScheduler::get_current_thread(void)
+/**
+ * @return The currently-running Thread
+ */
+Thread * Scheduler::get_current_thread() const
{
+ ASSERT(!current || !current->is_model_thread());
return current;
}
+
+/**
+ * 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", id_to_int(current->get_id()));
+ else
+ DEBUG("No current thread\n");
+}
projects / model-checker.git / blobdiff