Fix snapshot code

[model-checker.git] / threads.cc

diff --git a/threads.cc b/threads.cc
index 87de32fb2452f0384016353306b0b0b43c3d4cea..a06af84636978f1bbd31f960c0c2368d79fc609a 100644 (file)
--- a/threads.cc
+++ b/threads.cc
@@ -5,8 +5,10 @@
 #include <string.h>
 
 #include <threads.h>
+#include <mutex>
 #include "common.h"
 #include "threads-model.h"
+#include "action.h"
 
 /* global "model" object */
 #include "model.h"
@@ -14,16 +16,22 @@
 /** Allocate a stack for a new thread. */
 static void * stack_allocate(size_t size)
 {
-       return snapshot_malloc(size);
+       return Thread_malloc(size);
 }
 
 /** Free a stack for a terminated thread. */
 static void stack_free(void *stack)
 {
-       snapshot_free(stack);
+       Thread_free(stack);
 }
 
-/** Return the currently executing thread. */
+/**
+ * @brief Get the current Thread
+ *
+ * Must be called from a user context
+ *
+ * @return The currently executing thread
+ */
 Thread * thread_current(void)
 {
        ASSERT(model);
@@ -84,7 +92,8 @@ int Thread::create_context()
  */
 int Thread::swap(Thread *t, ucontext_t *ctxt)
 {
-       return swapcontext(&t->context, ctxt);
+       t->set_state(THREAD_READY);
+       return model_swapcontext(&t->context, ctxt);
 }
 
 /**
@@ -97,19 +106,19 @@ int Thread::swap(Thread *t, ucontext_t *ctxt)
  */
 int Thread::swap(ucontext_t *ctxt, Thread *t)
 {
-       return swapcontext(ctxt, &t->context);
+       t->set_state(THREAD_RUNNING);
+       return model_swapcontext(ctxt, &t->context);
 }
 
 
 /** Terminate a thread and free its stack. */
 void Thread::complete()
 {
-       if (!is_complete()) {
-               DEBUG("completed thread %d\n", id_to_int(get_id()));
-               state = THREAD_COMPLETED;
-               if (stack)
-                       stack_free(stack);
-       }
+       ASSERT(!is_complete());
+       DEBUG("completed thread %d\n", id_to_int(get_id()));
+       state = THREAD_COMPLETED;
+       if (stack)
+               stack_free(stack);
 }
 
 /**
@@ -130,7 +139,6 @@ Thread::Thread(thread_id_t tid) :
        user_thread(NULL),
        id(tid),
        state(THREAD_READY), /* Thread is always ready? */
-       wait_list(),
        last_action_val(0),
        model_thread(true)
 {
@@ -143,14 +151,15 @@ Thread::Thread(thread_id_t tid) :
  * @param func The function that the thread will call.
  * @param a The parameter to pass to this function.
  */
-Thread::Thread(thrd_t *t, void (*func)(void *), void *a) :
+Thread::Thread(thread_id_t tid, thrd_t *t, void (*func)(void *), void *a, Thread *parent) :
+       parent(parent),
        creation(NULL),
        pending(NULL),
        start_routine(func),
        arg(a),
        user_thread(t),
+       id(tid),
        state(THREAD_CREATED),
-       wait_list(),
        last_action_val(VALUE_NONE),
        model_thread(false)
 {
@@ -161,16 +170,14 @@ Thread::Thread(thrd_t *t, void (*func)(void *), void *a) :
        if (ret)
                model_print("Error in create_context\n");
 
-       id = model->get_next_id();
-       *user_thread = id;
-       parent = thread_current();
+       user_thread->priv = this;
 }
 
 /** Destructor */
 Thread::~Thread()
 {
-       complete();
-       model->remove_thread(this);
+       if (!is_complete())
+               complete();
 }
 
 /** @return The thread_id_t corresponding to this Thread object. */
@@ -188,3 +195,35 @@ void Thread::set_state(thread_state s)
        ASSERT(s == THREAD_COMPLETED || state != THREAD_COMPLETED);
        state = s;
 }
+
+/**
+ * Get the Thread that this Thread is immediately waiting on
+ * @return The thread we are waiting on, if any; otherwise NULL
+ */
+Thread * Thread::waiting_on() const
+{
+       if (!pending)
+               return NULL;
+
+       if (pending->get_type() == THREAD_JOIN)
+               return pending->get_thread_operand();
+       else if (pending->is_lock())
+               return (Thread *)pending->get_mutex()->get_state()->locked;
+       return NULL;
+}
+
+/**
+ * Check if this Thread is waiting (blocking) on a given Thread, directly or
+ * indirectly (via a chain of waiting threads)
+ *
+ * @param t The Thread on which we may be waiting
+ * @return True if we are waiting on Thread t; false otherwise
+ */
+bool Thread::is_waiting_on(const Thread *t) const
+{
+       Thread *wait;
+       for (wait = waiting_on(); wait != NULL; wait = wait->waiting_on())
+               if (wait == t)
+                       return true;
+       return false;
+}