-#include "threads.h"
+#include <string.h>
+#include <stdlib.h>
+
+#include "threads-model.h"
#include "schedule.h"
#include "common.h"
#include "model.h"
+#include "execution.h"
+#include "fuzzer.h"
+
+/**
+ * Format an "enabled_type_t" for printing
+ * @param e The type to format
+ * @param str The output character array
+ */
+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() :
+ execution(NULL),
+ enabled(NULL),
+ enabled_len(0),
+ curr_thread_index(0),
current(NULL)
{
}
+/**
+ * @brief Register the ModelExecution engine
+ * @param execution The ModelExecution which is controlling execution
+ */
+void Scheduler::register_engine(ModelExecution *execution)
+{
+ this->execution = execution;
+}
+
+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;
+}
+
+/**
+ * @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;
+}
+
+/**
+ * @brief Check if execution is stuck with no enabled threads and some sleeping
+ * thread
+ * @return True if no threads are enabled and some thread is in the sleep set;
+ * false otherwise
+ */
+bool Scheduler::all_threads_sleeping() const
+{
+ bool sleeping = false;
+ for (int i = 0;i < enabled_len;i++)
+ if (enabled[i] == THREAD_ENABLED)
+ return false;
+ else if (enabled[i] == THREAD_SLEEP_SET)
+ sleeping = true;
+ return sleeping;
+}
+
+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];
+}
+
+/**
+ * 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()));
+ ASSERT(!t->is_model_thread());
+ set_enabled(t, THREAD_ENABLED);
}
+/**
+ * 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, THREAD_DISABLED);
}
-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, THREAD_DISABLED);
+ 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)
+{
+ ASSERT(!t->is_model_thread());
+ set_enabled(t, THREAD_ENABLED);
+ t->set_state(THREAD_READY);
+}
+
+/**
+ * @brief Select a Thread to run via round-robin
+ *
+ *
+ * @return The next Thread to run
+ */
+Thread * Scheduler::select_next_thread()
+{
+ int avail_threads = 0;
+ int sleep_threads = 0;
+ int thread_list[enabled_len], sleep_list[enabled_len];
+ Thread * thread;
+
+ for (int i = 0; i < enabled_len; i++) {
+ if (enabled[i] == THREAD_ENABLED)
+ thread_list[avail_threads++] = i;
+ else if (enabled[i] == THREAD_SLEEP_SET)
+ sleep_list[sleep_threads++] = i;
+ }
+
+ if (avail_threads == 0 && !execution->getFuzzer()->has_paused_threads()) {
+ if (sleep_threads != 0) {
+ // No threads available, but some threads sleeping. Wake up one of them
+ thread = execution->getFuzzer()->selectThread(sleep_list, sleep_threads);
+ remove_sleep(thread);
+ thread->set_wakeup_state(true);
+ } else {
+ return NULL; // No threads available and no threads sleeping.
+ }
} else {
- t = readyList.front();
- current = t;
- readyList.pop_front();
+ // Some threads are available
+ thread = execution->getFuzzer()->selectThread(thread_list, avail_threads);
}
- print();
+ curr_thread_index = id_to_int(thread->get_id());
+ return thread;
+}
- return t;
+void Scheduler::set_scheduler_thread(thread_id_t tid) {
+ curr_thread_index=id_to_int(tid);
}
-Thread * Scheduler::get_current_thread(void)
+/**
+ * @brief Set the current "running" Thread
+ * @param t Thread to run
+ */
+void Scheduler::set_current_thread(Thread *t)
{
+ ASSERT(!t || !t->is_model_thread());
+
+ current = t;
+ if (DBG_ENABLED())
+ print();
+}
+
+/**
+ * @return The currently-running Thread
+ */
+Thread * Scheduler::get_current_thread() const
+{
+ ASSERT(!current || !current->is_model_thread());
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());
+ int curr_id = current ? id_to_int(current->get_id()) : -1;
- 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());
+ 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");
}
projects / c11tester.git / blobdiff