X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=model.cc;h=078a1ce75849ebc48334958a7842b22dd6c958d1;hp=84a60a510456fbea7cd6f0e4e6df87499c40ee48;hb=829aac4055269992c26fed5530cfdaf59775b2a9;hpb=63b2c687570085f2a87b6a659d26608228af1ee0

diff --git a/model.cc b/model.cc
index 84a60a51..078a1ce7 100644
--- a/model.cc
+++ b/model.cc
@@ -7,7 +7,6 @@
 
 #include "model.h"
 #include "action.h"
-#include "nodestack.h"
 #include "schedule.h"
 #include "snapshot-interface.h"
 #include "common.h"
@@ -16,36 +15,58 @@
 #include "output.h"
 #include "traceanalysis.h"
 #include "execution.h"
+#include "history.h"
 #include "bugmessage.h"
+#include "params.h"
+#include "plugins.h"
 
-ModelChecker *model;
+ModelChecker *model = NULL;
+
+void placeholder(void *) {
+	ASSERT(0);
+}
 
 /** @brief Constructor */
 ModelChecker::ModelChecker() :
 	/* Initialize default scheduler */
 	params(),
-	restart_flag(false),
 	scheduler(new Scheduler()),
-	node_stack(new NodeStack()),
-	execution(new ModelExecution(this, scheduler, node_stack)),
+	history(new ModelHistory()),
+	execution(new ModelExecution(this, scheduler)),
 	execution_number(1),
 	trace_analyses(),
 	inspect_plugin(NULL)
 {
+	model_print("C11Tester\n"
+							"Copyright (c) 2013 and 2019 Regents of the University of California. All rights reserved.\n"
+							"Distributed under the GPLv2\n"
+							"Written by Weiyu Luo, Brian Norris, and Brian Demsky\n\n");
 	memset(&stats,0,sizeof(struct execution_stats));
+	init_thread = new Thread(execution->get_next_id(), (thrd_t *) model_malloc(sizeof(thrd_t)), &placeholder, NULL, NULL);
+#ifdef TLS
+	init_thread->setTLS((char *)get_tls_addr());
+#endif
+	execution->add_thread(init_thread);
+	scheduler->set_current_thread(init_thread);
+	register_plugins();
+	execution->setParams(&params);
+	param_defaults(&params);
+	parse_options(&params);
+	initRaceDetector();
+	/* Configure output redirection for the model-checker */
+	redirect_output();
+	install_trace_analyses(get_execution());
 }
 
 /** @brief Destructor */
 ModelChecker::~ModelChecker()
 {
-	delete node_stack;
 	delete scheduler;
 }
 
 /** Method to set parameters */
-void ModelChecker::setParams(struct model_params params) {
-	this->params = params;
-	execution->setParams(&params);
+model_params * ModelChecker::getParams() {
+	return &params;
 }
 
 /**
@@ -54,8 +75,6 @@ void ModelChecker::setParams(struct model_params params) {
  */
 void ModelChecker::reset_to_initial_state()
 {
-	DEBUG("+++ Resetting to initial state +++\n");
-	node_stack->reset_execution();
 
 	/**
 	 * FIXME: if we utilize partial rollback, we will need to free only
@@ -65,7 +84,7 @@ void ModelChecker::reset_to_initial_state()
 	for (unsigned int i = 0;i < get_num_threads();i++)
 		delete get_thread(int_to_id(i))->get_pending();
 
-	snapshot_backtrack_before(0);
+	snapshot_roll_back(snapshot);
 }
 
 /** @return the number of user threads created during this execution */
@@ -103,7 +122,7 @@ Thread * ModelChecker::get_next_thread()
 	 * Have we completed exploring the preselected path? Then let the
 	 * scheduler decide
 	 */
-	return scheduler->select_next_thread(node_stack->get_head());
+	return scheduler->select_next_thread();
 }
 
 /**
@@ -118,7 +137,7 @@ Thread * ModelChecker::get_next_thread()
  * @param msg Descriptive message for the bug (do not include newline char)
  * @return True if bug is immediately-feasible
  */
-bool ModelChecker::assert_bug(const char *msg, ...)
+void ModelChecker::assert_bug(const char *msg, ...)
 {
 	char str[800];
 
@@ -127,7 +146,7 @@ bool ModelChecker::assert_bug(const char *msg, ...)
 	vsnprintf(str, sizeof(str), msg, ap);
 	va_end(ap);
 
-	return execution->assert_bug(str);
+	execution->assert_bug(str);
 }
 
 /**
@@ -138,8 +157,8 @@ bool ModelChecker::assert_bug(const char *msg, ...)
 void ModelChecker::assert_user_bug(const char *msg)
 {
 	/* If feasible bug, bail out now */
-	if (assert_bug(msg))
-		switch_to_master(NULL);
+	assert_bug(msg);
+	switch_to_master(NULL);
 }
 
 /** @brief Print bug report listing for this execution (if any bugs exist) */
@@ -151,7 +170,7 @@ void ModelChecker::print_bugs() const
 							bugs->size(),
 							bugs->size() > 1 ? "s" : "");
 	for (unsigned int i = 0;i < bugs->size();i++)
-		(*bugs)[i]->print();
+		(*bugs)[i] -> print();
 }
 
 /**
@@ -162,16 +181,13 @@ void ModelChecker::print_bugs() const
  */
 void ModelChecker::record_stats()
 {
-	stats.num_total++;
-	if (!execution->isfeasibleprefix())
-		stats.num_infeasible++;
-	else if (execution->have_bug_reports())
-		stats.num_buggy_executions++;
+	stats.num_total ++;
+	if (execution->have_bug_reports())
+		stats.num_buggy_executions ++;
 	else if (execution->is_complete_execution())
-		stats.num_complete++;
+		stats.num_complete ++;
 	else {
-		stats.num_redundant++;
-
+		//All threads are sleeping
 		/**
 		 * @todo We can violate this ASSERT() when fairness/sleep sets
 		 * conflict to cause an execution to terminate, e.g. with:
@@ -185,9 +201,7 @@ void ModelChecker::record_stats()
 void ModelChecker::print_stats() const
 {
 	model_print("Number of complete, bug-free executions: %d\n", stats.num_complete);
-	model_print("Number of redundant executions: %d\n", stats.num_redundant);
 	model_print("Number of buggy executions: %d\n", stats.num_buggy_executions);
-	model_print("Number of infeasible executions: %d\n", stats.num_infeasible);
 	model_print("Total executions: %d\n", stats.num_total);
 }
 
@@ -222,12 +236,11 @@ void ModelChecker::print_execution(bool printbugs) const
  * @return If there are more executions to explore, return true. Otherwise,
  * return false.
  */
-bool ModelChecker::next_execution()
+void ModelChecker::finish_execution(bool more_executions)
 {
 	DBG();
 	/* Is this execution a feasible execution that's worth bug-checking? */
-	bool complete = execution->isfeasibleprefix() &&
-									(execution->is_complete_execution() ||
+	bool complete = (execution->is_complete_execution() ||
 									 execution->have_bug_reports());
 
 	/* End-of-execution bug checks */
@@ -235,7 +248,6 @@ bool ModelChecker::next_execution()
 		if (execution->is_deadlocked())
 			assert_bug("Deadlock detected");
 
-		checkDataRaces();
 		run_trace_analyses();
 	}
 
@@ -246,21 +258,17 @@ bool ModelChecker::next_execution()
 	else
 		clear_program_output();
 
-	if (restart_flag) {
-		do_restart();
-		return true;
-	}
 // test code
-	execution_number++;
-	reset_to_initial_state();
-	node_stack->full_reset();
-	return false;
+	execution_number ++;
+	if (more_executions)
+		reset_to_initial_state();
+	history->set_new_exec_flag();
 }
 
 /** @brief Run trace analyses on complete trace */
 void ModelChecker::run_trace_analyses() {
-	for (unsigned int i = 0;i < trace_analyses.size();i++)
-		trace_analyses[i]->analyze(execution->get_action_trace());
+	for (unsigned int i = 0;i < trace_analyses.size();i ++)
+		trace_analyses[i] -> analyze(execution->get_action_trace());
 }
 
 /**
@@ -309,14 +317,25 @@ void ModelChecker::switch_from_master(Thread *thread)
  */
 uint64_t ModelChecker::switch_to_master(ModelAction *act)
 {
+	if (modellock) {
+		static bool fork_message_printed = false;
+
+		if (!fork_message_printed) {
+			model_print("Fork handler or dead thread trying to call into model checker...\n");
+			fork_message_printed = true;
+		}
+		delete act;
+		return 0;
+	}
 	DBG();
 	Thread *old = thread_current();
 	scheduler->set_current_thread(NULL);
 	ASSERT(!old->get_pending());
-/* W: No plugin
-        if (inspect_plugin != NULL) {
-                inspect_plugin->inspectModelAction(act);
-        }*/
+
+	if (inspect_plugin != NULL) {
+		inspect_plugin->inspectModelAction(act);
+	}
+
 	old->set_pending(act);
 	if (Thread::swap(old, &system_context) < 0) {
 		perror("swap threads");
@@ -325,116 +344,273 @@ uint64_t ModelChecker::switch_to_master(ModelAction *act)
 	return old->get_return_value();
 }
 
-/** Wrapper to run the user's main function, with appropriate arguments */
-void user_main_wrapper(void *)
+void ModelChecker::continueRunExecution(Thread *old) 
 {
-	user_main(model->params.argc, model->params.argv);
+
+	if (params.traceminsize != 0 &&
+			execution->get_curr_seq_num() > checkfree) {
+		checkfree += params.checkthreshold;
+		execution->collectActions();
+	}
+
+	thread_chosen = false;
+	curr_thread_num = 1;
+	Thread *thr = getNextThread();
+	if (thr != nullptr) {
+		scheduler->set_current_thread(thr);
+		if (Thread::swap(old, thr) < 0) {
+			perror("swap threads");
+			exit(EXIT_FAILURE);
+		}
+	} else
+		handleChosenThread(old);	
 }
 
-bool ModelChecker::should_terminate_execution()
+void ModelChecker::startRunExecution(ucontext_t *old) 
 {
-	/* Infeasible -> don't take any more steps */
-	if (execution->is_infeasible())
-		return true;
-	else if (execution->isfeasibleprefix() && execution->have_bug_reports()) {
-		execution->set_assert();
-		return true;
+
+	if (params.traceminsize != 0 &&
+			execution->get_curr_seq_num() > checkfree) {
+		checkfree += params.checkthreshold;
+		execution->collectActions();
 	}
-	return false;
+
+	thread_chosen = false;
+	curr_thread_num = 1;
+	Thread *thr = getNextThread();
+	if (thr != nullptr) {
+		scheduler->set_current_thread(thr);
+		if (Thread::swap(old, thr) < 0) {
+			perror("swap threads");
+			exit(EXIT_FAILURE);
+		}
+	} else
+		handleChosenThread(old);	
 }
 
-/** @brief Restart ModelChecker upon returning to the run loop of the
- *	model checker. */
-void ModelChecker::restart()
+Thread* ModelChecker::getNextThread()
 {
-	restart_flag = true;
+	Thread *nextThread = nullptr;
+	for (unsigned int i = curr_thread_num; i < get_num_threads(); i++) {
+		thread_id_t tid = int_to_id(i);
+		Thread *thr = get_thread(tid);
+		
+		if (!thr->is_complete() && !thr->get_pending()) {
+			curr_thread_num = i;
+			nextThread = thr;
+			break;
+		}
+		ModelAction *act = thr->get_pending();
+		
+		if (act && execution->is_enabled(thr) && !execution->check_action_enabled(act)) {
+			scheduler->sleep(thr);
+		}
+
+	chooseThread(act, thr);
+	}
+	return nextThread;
 }
 
-void ModelChecker::do_restart()
+void ModelChecker::finishRunExecution(Thread *old) 
 {
-	restart_flag = false;
-	reset_to_initial_state();
-	node_stack->full_reset();
-	memset(&stats,0,sizeof(struct execution_stats));
-	execution_number = 1;
+	scheduler->set_current_thread(NULL);
+	if (Thread::swap(old, &system_context) < 0) {
+		perror("swap threads");
+		exit(EXIT_FAILURE);
+	}
 }
 
-/** @brief Run ModelChecker for the user program */
-void ModelChecker::run()
+void ModelChecker::finishRunExecution(ucontext_t *old) 
 {
-	//Need to initial random number generator state to avoid resets on rollback
-	char random_state[256];
-	initstate(423121, random_state, sizeof(random_state));
+	scheduler->set_current_thread(NULL);
+}
 
-	for(int exec = 0;exec < params.maxexecutions;exec++) {
-		thrd_t user_thread;
-		Thread *t = new Thread(execution->get_next_id(), &user_thread, &user_main_wrapper, NULL, NULL);	// L: user_main_wrapper passes the user program
-		execution->add_thread(t);
-		//Need to seed random number generator, otherwise its state gets reset
-		do {
-			/*
-			 * Stash next pending action(s) for thread(s). There
-			 * should only need to stash one thread's action--the
-			 * thread which just took a step--plus the first step
-			 * for any newly-created thread
-			 */
-
-			for (unsigned int i = 0;i < get_num_threads();i++) {
-				thread_id_t tid = int_to_id(i);
-				Thread *thr = get_thread(tid);
-				if (!thr->is_model_thread() && !thr->is_complete() && !thr->get_pending()) {
-					switch_from_master(thr);	// L: context swapped, and action type of thr changed.
-					if (thr->is_waiting_on(thr))
-						assert_bug("Deadlock detected (thread %u)", i);
-				}
-			}
+void ModelChecker::consumeAction()
+{
+	ModelAction *curr = chosen_thread->get_pending();
+	Thread * th = thread_current();
+	if (curr->get_type() == THREAD_FINISH && th != NULL)  {
+		// Thread finish must be consumed in the master context
+		scheduler->set_current_thread(NULL);
+		if (Thread::swap(th, &system_context) < 0) {
+			perror("swap threads");
+			exit(EXIT_FAILURE);
+		}
+	} else {
+		chosen_thread->set_pending(NULL);
+		chosen_thread = execution->take_step(curr);
+	}
+}
 
-			/* Don't schedule threads which should be disabled */
-			for (unsigned int i = 0;i < get_num_threads();i++) {
-				Thread *th = get_thread(int_to_id(i));
-				ModelAction *act = th->get_pending();
-				if (act && execution->is_enabled(th) && !execution->check_action_enabled(act)) {
-					scheduler->sleep(th);
-				}
+void ModelChecker::chooseThread(ModelAction *act, Thread *thr)
+{
+	if (!thread_chosen && act && execution->is_enabled(thr) && (thr->get_state() != THREAD_BLOCKED) ) {
+		if (act->is_write()) {
+			std::memory_order order = act->get_mo();
+			if (order == std::memory_order_relaxed || \
+					order == std::memory_order_release) {
+				chosen_thread = thr;
+				thread_chosen = true;
 			}
+		} else if (act->get_type() == THREAD_CREATE || \
+							act->get_type() == PTHREAD_CREATE || \
+							act->get_type() == THREAD_START || \
+							act->get_type() == THREAD_FINISH) {
+			chosen_thread = thr;
+			thread_chosen = true;
+		}
+	}	
+}
 
-			for (unsigned int i = 1;i < get_num_threads();i++) {
-				Thread *th = get_thread(int_to_id(i));
-				ModelAction *act = th->get_pending();
-				if (act && execution->is_enabled(th) && (th->get_state() != THREAD_BLOCKED) ) {
-					if (act->is_write()) {
-						std::memory_order order = act->get_mo();
-						if (order == std::memory_order_relaxed || \
-								order == std::memory_order_release) {
-							t = th;
-							break;
-						}
-					} else if (act->get_type() == THREAD_CREATE || \
-										 act->get_type() == PTHREAD_CREATE || \
-										 act->get_type() == THREAD_START || \
-										 act->get_type() == THREAD_FINISH) {
-						t = th;
-						break;
-					}
-				}
-			}
+uint64_t ModelChecker::switch_thread(ModelAction *act)
+{
+	if (modellock) {
+		static bool fork_message_printed = false;
+
+		if (!fork_message_printed) {
+			model_print("Fork handler or dead thread trying to call into model checker...\n");
+			fork_message_printed = true;
+		}
+		delete act;
+		return 0;
+	}
+	DBG();
+	Thread *old = thread_current();
+	ASSERT(!old->get_pending());
+
+	if (inspect_plugin != NULL) {
+		inspect_plugin->inspectModelAction(act);
+	}
 
-			/* Catch assertions from prior take_step or from
-			* between-ModelAction bugs (e.g., data races) */
+	old->set_pending(act);
+	
+	if (old->is_waiting_on(old))
+		assert_bug("Deadlock detected (thread %u)", curr_thread_num);
 
-			if (execution->has_asserted())
-				break;
-			if (!t)
-				t = get_next_thread();
-			if (!t || t->is_model_thread())
-				break;
+	if (act && execution->is_enabled(old) && !execution->check_action_enabled(act)) {
+		scheduler->sleep(old);
+	}
+	chooseThread(act, old);
+
+	curr_thread_num++;
+	Thread* next = getNextThread();
+	if (next != nullptr) 
+		handleNewValidThread(old, next);
+	else {
+		old->set_state(THREAD_READY);	// Just to avoid the first ASSERT in ModelExecution::take_step 
+		handleChosenThread(old);
+	}
+
+	return old->get_return_value();
+}
+
+void ModelChecker::handleNewValidThread(Thread *old, Thread *next)
+{
+	scheduler->set_current_thread(next);	
+
+	if (Thread::swap(old, next) < 0) {
+		perror("swap threads");
+		exit(EXIT_FAILURE);
+	}		
+}
+
+void ModelChecker::handleChosenThread(Thread *old)
+{
+	if (execution->has_asserted())
+		finishRunExecution(old);
+	if (!chosen_thread)
+		chosen_thread = get_next_thread();
+	if (!chosen_thread || chosen_thread->is_model_thread())
+		finishRunExecution(old);
+	if (chosen_thread->just_woken_up()) {
+		chosen_thread->set_wakeup_state(false);
+		chosen_thread->set_pending(NULL);
+		chosen_thread = NULL;
+		// Allow this thread to stash the next pending action
+		if (should_terminate_execution())
+			finishRunExecution(old);
+		else
+			continueRunExecution(old);	
+	} else {
+		/* Consume the next action for a Thread */
+		consumeAction();
+
+		if (should_terminate_execution())
+			finishRunExecution(old);
+		else
+			continueRunExecution(old);		
+	}
+}
+
+void ModelChecker::handleChosenThread(ucontext_t *old)
+{
+	if (execution->has_asserted())
+		finishRunExecution(old);
+	if (!chosen_thread)
+		chosen_thread = get_next_thread();
+	if (!chosen_thread || chosen_thread->is_model_thread())
+		finishRunExecution(old);
+	if (chosen_thread->just_woken_up()) {
+		chosen_thread->set_wakeup_state(false);
+		chosen_thread->set_pending(NULL);
+		chosen_thread = NULL;
+		// Allow this thread to stash the next pending action
+		if (should_terminate_execution())
+			finishRunExecution(old);
+		else
+			startRunExecution(old);	
+	} else
+
+	{
+		/* Consume the next action for a Thread */
+		consumeAction();
+
+		if (should_terminate_execution())
+			finishRunExecution(old);
+		else
+			startRunExecution(old);		
+	}
+}
 
-			/* Consume the next action for a Thread */
-			ModelAction *curr = t->get_pending();
-			t->set_pending(NULL);
-			t = execution->take_step(curr);
+
+static void runChecker() {
+	model->run();
+	delete model;
+}
+
+void ModelChecker::startChecker() {
+	startExecution(get_system_context(), runChecker);
+	snapshot = take_snapshot();
+	initMainThread();
+}
+
+bool ModelChecker::should_terminate_execution()
+{
+	if (execution->have_bug_reports()) {
+		execution->set_assert();
+		return true;
+	} else if (execution->isFinished()) {
+		return true;
+	}
+	return false;
+}
+
+/** @brief Run ModelChecker for the user program */
+void ModelChecker::run()
+{
+	//Need to initial random number generator state to avoid resets on rollback
+	char random_state[256];
+	initstate(423121, random_state, sizeof(random_state));
+	checkfree = params.checkthreshold;
+	for(int exec = 0;exec < params.maxexecutions;exec++) {
+		chosen_thread = init_thread;
+		do {
+			thread_chosen = false;
+			curr_thread_num = 1;
+			startRunExecution(&system_context);
 		} while (!should_terminate_execution());
-		next_execution();
+
+		finish_execution((exec+1) < params.maxexecutions);
 		//restore random number generator state after rollback
 		setstate(random_state);
 	}
@@ -445,4 +621,9 @@ void ModelChecker::run()
 	/* Have the trace analyses dump their output. */
 	for (unsigned int i = 0;i < trace_analyses.size();i++)
 		trace_analyses[i]->finish();
+
+	/* unlink tmp file created by last child process */
+	char filename[256];
+	snprintf_(filename, sizeof(filename), "C11FuzzerTmp%d", getpid());
+	unlink(filename);
 }