X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=threads.cc;h=3b793cff0c443f6f70f6d156e6ec456f40fdbe67;hp=1e2af8cbba16343349b91a90e2f87d5bd335631b;hb=7966c737f2a88e5e1a56817eb9f6fdaead3eca92;hpb=50f263af6b0ea0148dfaa1e527951c6b9022ff7f

diff --git a/threads.cc b/threads.cc
index 1e2af8cb..3b793cff 100644
--- a/threads.cc
+++ b/threads.cc
@@ -1,27 +1,59 @@
-#include "libthreads.h"
+/** @file threads.cc
+ *  @brief Thread functions.
+ */
+
+#include <string.h>
+
+#include <threads.h>
 #include "common.h"
-#include "threads.h"
+#include "threads-model.h"
 
 /* global "model" object */
 #include "model.h"
 
-#define STACK_SIZE (1024 * 1024)
-
+/** Allocate a stack for a new thread. */
 static void * stack_allocate(size_t size)
 {
-	return userMalloc(size);
+	return snapshot_malloc(size);
 }
 
+/** Free a stack for a terminated thread. */
 static void stack_free(void *stack)
 {
-	userFree(stack);
+	snapshot_free(stack);
 }
 
+/** Return the currently executing thread. */
 Thread * thread_current(void)
 {
-	return model->scheduler->get_current_thread();
+	ASSERT(model);
+	return model->get_current_thread();
 }
 
+/**
+ * Provides a startup wrapper for each thread, allowing some initial
+ * model-checking data to be recorded. This method also gets around makecontext
+ * not being 64-bit clean
+ */
+void thread_startup()
+{
+	Thread * curr_thread = thread_current();
+
+	/* Add dummy "start" action, just to create a first clock vector */
+	model->switch_to_master(new ModelAction(THREAD_START, std::memory_order_seq_cst, curr_thread));
+
+	/* 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; otherwise, non-zero error condition
+ */
 int Thread::create_context()
 {
 	int ret;
@@ -36,63 +68,112 @@ int Thread::create_context()
 	context.uc_stack.ss_size = STACK_SIZE;
 	context.uc_stack.ss_flags = 0;
 	context.uc_link = model->get_system_context();
-	makecontext(&context, start_routine, 1, arg);
+	makecontext(&context, thread_startup, 0);
 
 	return 0;
 }
 
+/**
+ * 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 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).
+ */
 int Thread::swap(Thread *t, ucontext_t *ctxt)
 {
 	return swapcontext(&t->context, ctxt);
 }
 
+/**
+ * Swaps the current context to another thread of execution. This form switches
+ * from a system context to a user Thread.
+ * @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)
 {
 	return swapcontext(ctxt, &t->context);
 }
 
+
+/** 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);
 	}
 }
 
-void * Thread::operator new(size_t size) {
-	return userMalloc(size);
-}
-
-void Thread::operator delete(void *ptr) {
-	userFree(ptr);
+/**
+ * @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));
 }
 
-Thread::Thread(thrd_t *t, void (*func)(), void *a) {
+/**
+ * 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),
+	wait_list(),
+	last_action_val(VALUE_NONE),
+	model_thread(false)
+{
 	int ret;
 
-	user_thread = t;
-	start_routine = func;
-	arg = a;
-
 	/* Initialize state */
 	ret = create_context();
 	if (ret)
-		printf("Error in create_context\n");
+		model_print("Error in create_context\n");
 
-	state = THREAD_CREATED;
 	id = model->get_next_id();
 	*user_thread = id;
 	parent = thread_current();
 }
 
+/** Destructor */
 Thread::~Thread()
 {
 	complete();
 	model->remove_thread(this);
 }
 
+/** @return The thread_id_t corresponding to this Thread object. */
 thread_id_t Thread::get_id()
 {
 	return id;