X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=model.cc;h=a1204d0ab852352600edb95063476bd6f2976fa7;hp=16d5db4ab280262d1c4439de6544a413f8ba794e;hb=c4f504bb8deb86c8e2b06cb8ddaec5d92ec17e9d;hpb=fb6d374952284313141eaee75ecd322209d152db

diff --git a/model.cc b/model.cc
index 16d5db4a..a1204d0a 100644
--- a/model.cc
+++ b/model.cc
@@ -2,10 +2,11 @@
 #include <algorithm>
 #include <new>
 #include <stdarg.h>
+#include <string.h>
+#include <cstdlib>
 
 #include "model.h"
 #include "action.h"
-#include "nodestack.h"
 #include "schedule.h"
 #include "snapshot-interface.h"
 #include "common.h"
@@ -14,49 +15,76 @@
 #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(struct model_params params) :
+ModelChecker::ModelChecker() :
 	/* Initialize default scheduler */
-	params(params),
+	params(),
 	scheduler(new Scheduler()),
-	node_stack(new NodeStack()),
-	execution(new ModelExecution(this, &this->params, scheduler, node_stack)),
+	history(new ModelHistory()),
+	execution(new ModelExecution(this, scheduler)),
 	execution_number(1),
-	diverge(NULL),
-	earliest_diverge(NULL),
-	trace_analyses()
+	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 */
+model_params * ModelChecker::getParams() {
+	return &params;
+}
+
 /**
  * Restores user program to initial state and resets all model-checker data
  * structures.
  */
 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
 	 * those pending actions which were NOT pending before the rollback
 	 * point
 	 */
-	for (unsigned int i = 0; i < get_num_threads(); i++)
+	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 */
@@ -89,73 +117,12 @@ Thread * ModelChecker::get_current_thread() const
  */
 Thread * ModelChecker::get_next_thread()
 {
-	thread_id_t tid;
 
 	/*
 	 * Have we completed exploring the preselected path? Then let the
 	 * scheduler decide
 	 */
-	if (diverge == NULL)
-		return scheduler->select_next_thread(node_stack->get_head());
-
-
-	/* Else, we are trying to replay an execution */
-	ModelAction *next = node_stack->get_next()->get_action();
-
-	if (next == diverge) {
-		if (earliest_diverge == NULL || *diverge < *earliest_diverge)
-			earliest_diverge = diverge;
-
-		Node *nextnode = next->get_node();
-		Node *prevnode = nextnode->get_parent();
-		scheduler->update_sleep_set(prevnode);
-
-		/* Reached divergence point */
-		if (nextnode->increment_behaviors()) {
-			/* Execute the same thread with a new behavior */
-			tid = next->get_tid();
-			node_stack->pop_restofstack(2);
-		} else {
-			ASSERT(prevnode);
-			/* Make a different thread execute for next step */
-			scheduler->add_sleep(get_thread(next->get_tid()));
-			tid = prevnode->get_next_backtrack();
-			/* Make sure the backtracked thread isn't sleeping. */
-			node_stack->pop_restofstack(1);
-			if (diverge == earliest_diverge) {
-				earliest_diverge = prevnode->get_action();
-			}
-		}
-		/* Start the round robin scheduler from this thread id */
-		scheduler->set_scheduler_thread(tid);
-		/* The correct sleep set is in the parent node. */
-		execute_sleep_set();
-
-		DEBUG("*** Divergence point ***\n");
-
-		diverge = NULL;
-	} else {
-		tid = next->get_tid();
-	}
-	DEBUG("*** ModelChecker chose next thread = %d ***\n", id_to_int(tid));
-	ASSERT(tid != THREAD_ID_T_NONE);
-	return get_thread(id_to_int(tid));
-}
-
-/**
- * We need to know what the next actions of all threads in the sleep
- * set will be.  This method computes them and stores the actions at
- * the corresponding thread object's pending action.
- */
-void ModelChecker::execute_sleep_set()
-{
-	for (unsigned int i = 0; i < get_num_threads(); i++) {
-		thread_id_t tid = int_to_id(i);
-		Thread *thr = get_thread(tid);
-		if (scheduler->is_sleep_set(thr) && thr->get_pending()) {
-			thr->get_pending()->set_sleep_flag();
-		}
-	}
+	return scheduler->select_next_thread();
 }
 
 /**
@@ -170,7 +137,7 @@ void ModelChecker::execute_sleep_set()
  * @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];
 
@@ -179,7 +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);
 }
 
 /**
@@ -190,8 +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) */
@@ -200,10 +167,10 @@ void ModelChecker::print_bugs() const
 	SnapVector<bug_message *> *bugs = execution->get_bugs();
 
 	model_print("Bug report: %zu bug%s detected\n",
-			bugs->size(),
-			bugs->size() > 1 ? "s" : "");
-	for (unsigned int i = 0; i < bugs->size(); i++)
-		(*bugs)[i]->print();
+							bugs->size(),
+							bugs->size() > 1 ? "s" : "");
+	for (unsigned int i = 0;i < bugs->size();i++)
+		(*bugs)[i] -> print();
 }
 
 /**
@@ -214,16 +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:
@@ -237,11 +201,8 @@ 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);
-	model_print("Total nodes created: %d\n", node_stack->get_total_nodes());
 }
 
 /**
@@ -251,17 +212,10 @@ void ModelChecker::print_stats() const
 void ModelChecker::print_execution(bool printbugs) const
 {
 	model_print("Program output from execution %d:\n",
-			get_execution_number());
+							get_execution_number());
 	print_program_output();
 
-	if (params.verbose >= 2) {
-		model_print("\nEarliest divergence point since last feasible execution:\n");
-		if (earliest_diverge)
-			earliest_diverge->print();
-		else
-			model_print("(Not set)\n");
-
-		model_print("\n");
+	if (params.verbose >= 3) {
 		print_stats();
 	}
 
@@ -282,52 +236,39 @@ 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() ||
-		 execution->have_bug_reports());
+	bool complete = (execution->is_complete_execution() ||
+									 execution->have_bug_reports());
 
 	/* End-of-execution bug checks */
 	if (complete) {
 		if (execution->is_deadlocked())
 			assert_bug("Deadlock detected");
 
-		checkDataRaces();
 		run_trace_analyses();
 	}
 
 	record_stats();
-
 	/* Output */
-	if (params.verbose || (complete && execution->have_bug_reports()))
+	if ( (complete && params.verbose) || params.verbose>1 || (complete && execution->have_bug_reports()))
 		print_execution(complete);
 	else
 		clear_program_output();
 
-	if (complete)
-		earliest_diverge = NULL;
-
-	if ((diverge = execution->get_next_backtrack()) == NULL)
-		return false;
-
-	if (DBG_ENABLED()) {
-		model_print("Next execution will diverge at:\n");
-		diverge->print();
-	}
-
-	execution_number++;
-
-	reset_to_initial_state();
-	return true;
+// test code
+	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());
 }
 
 /**
@@ -350,26 +291,6 @@ Thread * ModelChecker::get_thread(const ModelAction *act) const
 	return execution->get_thread(act);
 }
 
-/**
- * @brief Check if a Thread is currently enabled
- * @param t The Thread to check
- * @return True if the Thread is currently enabled
- */
-bool ModelChecker::is_enabled(Thread *t) const
-{
-	return scheduler->is_enabled(t);
-}
-
-/**
- * @brief Check if a Thread is currently enabled
- * @param tid The ID of the Thread to check
- * @return True if the Thread is currently enabled
- */
-bool ModelChecker::is_enabled(thread_id_t tid) const
-{
-	return scheduler->is_enabled(tid);
-}
-
 /**
  * Switch from a model-checker context to a user-thread context. This is the
  * complement of ModelChecker::switch_to_master and must be called from the
@@ -396,10 +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());
+
+	if (inspect_plugin != NULL) {
+		inspect_plugin->inspectModelAction(act);
+	}
+
 	old->set_pending(act);
 	if (Thread::swap(old, &system_context) < 0) {
 		perror("swap threads");
@@ -408,85 +344,267 @@ 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();
 	}
+	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);	
+}
 
-	if (execution->too_many_steps())
-		return true;
-	return false;
+Thread* ModelChecker::getNextThread()
+{
+	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;
 }
 
-/** @brief Run ModelChecker for the user program */
-void ModelChecker::run()
+void ModelChecker::finishRunExecution(Thread *old) 
 {
-	do {
-		thrd_t user_thread;
-		Thread *t = new Thread(execution->get_next_id(), &user_thread, &user_main_wrapper, NULL, NULL);
-		execution->add_thread(t);
-
-		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);
-					if (thr->is_waiting_on(thr))
-						assert_bug("Deadlock detected (thread %u)", i);
-				}
-			}
+	scheduler->set_current_thread(NULL);
+	if (Thread::swap(old, &system_context) < 0) {
+		perror("swap threads");
+		exit(EXIT_FAILURE);
+	}
+}
 
-			/* 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 && is_enabled(th) && !execution->check_action_enabled(act)) {
-					scheduler->sleep(th);
-				}
+void ModelChecker::finishRunExecution(ucontext_t *old) 
+{
+	scheduler->set_current_thread(NULL);
+}
+
+void ModelChecker::consumeAction()
+{
+	ModelAction *curr = chosen_thread->get_pending();
+	chosen_thread->set_pending(NULL);
+	chosen_thread = execution->take_step(curr);
+}
+
+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;
+		}
+	}	
+}
+
+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);
+	}
+
+	old->set_pending(act);
+	
+	if (old->is_waiting_on(old))
+		assert_bug("Deadlock detected (thread %u)", curr_thread_num);
+
+	ModelAction *act2 = old->get_pending();
+		
+	if (act2 && execution->is_enabled(old) && !execution->check_action_enabled(act2)) {
+		scheduler->sleep(old);
+	}
+	chooseThread(act2, old);
+
+	curr_thread_num++;
+	Thread* next = getNextThread();
+	if (next != nullptr) 
+		handleNewValidThread(old, next);
+	else
+		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);		
+	}
+}
 
-			/* Catch assertions from prior take_step or from
-			 * between-ModelAction bugs (e.g., data races) */
-			if (execution->has_asserted())
-				break;
 
-			if (!t)
-				t = get_next_thread();
-			if (!t || t->is_model_thread())
-				break;
+static void runChecker() {
+	model->run();
+	delete model;
+}
 
-			/* Consume the next action for a Thread */
-			ModelAction *curr = t->get_pending();
-			t->set_pending(NULL);
-			t = execution->take_step(curr);
-		} while (!should_terminate_execution());
+void ModelChecker::startChecker() {
+	startExecution(get_system_context(), runChecker);
+	snapshot = take_snapshot();
+	initMainThread();
+}
 
-	} while (next_execution());
+bool ModelChecker::should_terminate_execution()
+{
+	if (execution->have_bug_reports()) {
+		execution->set_assert();
+		return true;
+	} else if (execution->isFinished()) {
+		return true;
+	}
+	return false;
+}
 
-	execution->fixup_release_sequences();
+/** @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;
+		thread_chosen = false;
+		curr_thread_num = 1;
+		startRunExecution(&system_context);
+		finish_execution((exec+1) < params.maxexecutions);
+		//restore random number generator state after rollback
+		setstate(random_state);
+	}
 
 	model_print("******* Model-checking complete: *******\n");
 	print_stats();
 
 	/* Have the trace analyses dump their output. */
-	for (unsigned int i = 0; i < trace_analyses.size(); i++)
+	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);
 }