X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=threads.cc;h=dc2db2d9bfefcab57458035f3f4bc815b75b5fc5;hb=6b87c110fbda87ccec4f58b1e292d5f9434c8691;hp=ad88ad3602188e3fdb4d2089347ae004b03cadda;hpb=0cb167b8fb332e4d9726badd0aa58e943bb4b459;p=model-checker.git

diff --git a/threads.cc b/threads.cc
index ad88ad3..dc2db2d 100644
--- a/threads.cc
+++ b/threads.cc
@@ -2,9 +2,11 @@
  *  @brief Thread functions.
  */
 
-#include "libthreads.h"
+#include <string.h>
+
+#include <threads.h>
 #include "common.h"
-#include "threads.h"
+#include "threads-model.h"
 
 /* global "model" object */
 #include "model.h"
@@ -12,17 +14,16 @@
 /** Allocate a stack for a new thread. */
 static void * stack_allocate(size_t size)
 {
-	return malloc(size);
+	return snapshot_malloc(size);
 }
 
 /** Free a stack for a terminated thread. */
 static void stack_free(void *stack)
 {
-	free(stack);
+	snapshot_free(stack);
 }
 
 /** Return the currently executing thread. */
-
 Thread * thread_current(void)
 {
 	ASSERT(model);
@@ -45,13 +46,16 @@ void thread_startup()
 
 	/* Call the actual thread function */
 	curr_thread->start_routine(curr_thread->arg);
+
+	/* Finish thread properly */
+	model->switch_to_master(new ModelAction(THREAD_FINISH, std::memory_order_seq_cst, curr_thread));
 }
 
-/** Create a thread context for a new thread so we can use
- *  setcontext/getcontext/swapcontext to swap it out.
- *  @return 0 on success.
+/**
+ * Create a thread context for a new thread so we can use
+ * setcontext/getcontext/swapcontext to swap it out.
+ * @return 0 on success; otherwise, non-zero error condition
  */
-
 int Thread::create_context()
 {
 	int ret;
@@ -74,8 +78,9 @@ int Thread::create_context()
 /**
  * Swaps the current context to another thread of execution. This form switches
  * from a user Thread to a system context.
- * @param t Thread representing the current context
- * @param ctxt Context to switch to
+ * @param t Thread representing the currently-running thread. The current
+ * context is saved here.
+ * @param ctxt Context to which we will swap. Must hold a valid system context.
  * @return Does not return, unless we return to Thread t's context. See
  * swapcontext(3) (returns 0 for success, -1 for failure).
  */
@@ -87,9 +92,9 @@ int Thread::swap(Thread *t, ucontext_t *ctxt)
 /**
  * Swaps the current context to another thread of execution. This form switches
  * from a system context to a user Thread.
- * @param t Thread representing the current context
- * @param ctxt Context to switch to
- * @return Does not return, unless we return to Thread t's context. See
+ * @param ctxt System context variable to which to save the current context.
+ * @param t Thread to which we will swap. Must hold a valid user context.
+ * @return Does not return, unless we return to the system context (ctxt). See
  * swapcontext(3) (returns 0 for success, -1 for failure).
  */
 int Thread::swap(ucontext_t *ctxt, Thread *t)
@@ -101,26 +106,55 @@ int Thread::swap(ucontext_t *ctxt, Thread *t)
 /** Terminate a thread and free its stack. */
 void Thread::complete()
 {
-	if (state != THREAD_COMPLETED) {
-		DEBUG("completed thread %d\n", get_id());
+	if (!is_complete()) {
+		DEBUG("completed thread %d\n", id_to_int(get_id()));
 		state = THREAD_COMPLETED;
 		if (stack)
 			stack_free(stack);
 	}
 }
 
-/** Create a new thread.
- *  Takes the following parameters:
- *  @param t The thread identifier of the newly created thread.
- *  @param func  The function that the thread will call.
- *  @param a The parameter to pass to this function. */
+/**
+ * @brief Construct a new model-checker Thread
+ *
+ * A model-checker Thread is used for accounting purposes only. It will never
+ * have its own stack, and it should never be inserted into the Scheduler.
+ *
+ * @param tid The thread ID to assign
+ */
+Thread::Thread(thread_id_t tid) :
+	parent(NULL),
+	creation(NULL),
+	pending(NULL),
+	start_routine(NULL),
+	arg(NULL),
+	stack(NULL),
+	user_thread(NULL),
+	id(tid),
+	state(THREAD_READY), /* Thread is always ready? */
+	wait_list(),
+	last_action_val(0),
+	model_thread(true)
+{
+	memset(&context, 0, sizeof(context));
+}
 
+/**
+ * Construct a new thread.
+ * @param t The thread identifier of the newly created thread.
+ * @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) :
+	creation(NULL),
+	pending(NULL),
 	start_routine(func),
 	arg(a),
 	user_thread(t),
 	state(THREAD_CREATED),
-	last_action_val(VALUE_NONE)
+	wait_list(),
+	last_action_val(VALUE_NONE),
+	model_thread(false)
 {
 	int ret;
 
@@ -134,14 +168,14 @@ Thread::Thread(thrd_t *t, void (*func)(void *), void *a) :
 	parent = thread_current();
 }
 
+/** Destructor */
 Thread::~Thread()
 {
 	complete();
 	model->remove_thread(this);
 }
 
-/** Return the thread_id_t corresponding to this Thread object. */
-
+/** @return The thread_id_t corresponding to this Thread object. */
 thread_id_t Thread::get_id()
 {
 	return id;