X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=threads.cc;h=e4b46561a0e7be13016661a541f09146b9726f28;hp=87de32fb2452f0384016353306b0b0b43c3d4cea;hb=73ba97016012e678ba1ad7d45970265470501b61;hpb=a330eb33b1b62dfa71f3f0cb055367a30090c180

diff --git a/threads.cc b/threads.cc
index 87de32f..e4b4656 100644
--- 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"
@@ -23,7 +25,13 @@ static void stack_free(void *stack)
 	snapshot_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);
@@ -84,6 +92,7 @@ int Thread::create_context()
  */
 int Thread::swap(Thread *t, ucontext_t *ctxt)
 {
+	t->set_state(THREAD_READY);
 	return swapcontext(&t->context, ctxt);
 }
 
@@ -97,6 +106,7 @@ int Thread::swap(Thread *t, ucontext_t *ctxt)
  */
 int Thread::swap(ucontext_t *ctxt, Thread *t)
 {
+	t->set_state(THREAD_RUNNING);
 	return swapcontext(ctxt, &t->context);
 }
 
@@ -104,12 +114,11 @@ int Thread::swap(ucontext_t *ctxt, Thread *t)
 /** 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);
 }
 
 /**
@@ -143,7 +152,8 @@ 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(thrd_t *t, void (*func)(void *), void *a, Thread *parent) :
+	parent(parent),
 	creation(NULL),
 	pending(NULL),
 	start_routine(func),
@@ -162,15 +172,14 @@ Thread::Thread(thrd_t *t, void (*func)(void *), void *a) :
 		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 +197,35 @@ 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;
+}