X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=5b5ccf701c1798f9627c352f6ae50be4159fc929;hb=fbed9b2aaf6ac4f928a59dd0dd885348dcb0eb4c;hp=bfb6d22f85009e61e0d4fbad5926764328a4a8fd;hpb=76308d1cc00abc4ab775977e9332c4992af2bef5;p=c11tester.git

diff --git a/model.cc b/model.cc
index bfb6d22f..5b5ccf70 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"
@@ -16,53 +15,108 @@
 #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);
+}
+
+#include <signal.h>
+
+#define SIGSTACKSIZE 65536
+static void mprot_handle_pf(int sig, siginfo_t *si, void *unused)
+{
+	model_print("Segmentation fault at %p\n", si->si_addr);
+	model_print("For debugging, place breakpoint at: %s:%d\n",
+							__FILE__, __LINE__);
+	print_trace();	// Trace printing may cause dynamic memory allocation
+	while(1)
+		;
+}
+
+void install_handler() {
+	stack_t ss;
+	ss.ss_sp = model_malloc(SIGSTACKSIZE);
+	ss.ss_size = SIGSTACKSIZE;
+	ss.ss_flags = 0;
+	sigaltstack(&ss, NULL);
+	struct sigaction sa;
+	sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART | SA_ONSTACK;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_sigaction = mprot_handle_pf;
+
+	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+		perror("sigaction(SIGSEGV)");
+		exit(EXIT_FAILURE);
+	}
+
+}
 
 /** @brief Constructor */
-ModelChecker::ModelChecker(struct model_params params) :
+ModelChecker::ModelChecker() :
 	/* Initialize default scheduler */
-	params(params),
-	restart_flag(false),
-	exit_flag(false),
+	params(),
 	scheduler(new Scheduler()),
-	node_stack(new NodeStack()),
-	execution(new ModelExecution(this, &this->params, scheduler, node_stack)),	// L: Model thread is created inside
+	history(new ModelHistory()),
+	execution(new ModelExecution(this, scheduler)),
 	execution_number(1),
-	diverge(NULL),
-	earliest_diverge(NULL),
 	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());
+	install_handler();
 }
 
 /** @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 */
@@ -95,72 +149,12 @@ 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)	// W: diverge is set to NULL permanently
-		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();
 }
 
 /**
@@ -175,7 +169,7 @@ 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];
 
@@ -184,7 +178,7 @@ 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);
 }
 
 /**
@@ -195,8 +189,8 @@ 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) */
@@ -205,10 +199,10 @@ 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();
 }
 
 /**
@@ -219,16 +213,13 @@ 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:
@@ -242,12 +233,8 @@ 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);
-	if (params.verbose)
-		model_print("Total nodes created: %d\n", node_stack->get_total_nodes());
 }
 
 /**
@@ -257,17 +244,10 @@ 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 >= 3) {
-		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");
 		print_stats();
 	}
 
@@ -288,22 +268,20 @@ 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 */
@@ -312,52 +290,17 @@ 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->pop_restofstack(2);
-//	node_stack->full_reset();
-	diverge = NULL;
-	return false;
-/* test
-	if (complete)
-		earliest_diverge = NULL;
-
-	if (exit_flag)
-		return false;
-
-//	diverge = execution->get_next_backtrack();
-	if (diverge == NULL) {
-		execution_number++;
+	execution_number ++;
+	if (more_executions)
 		reset_to_initial_state();
-		model_print("Does not diverge\n");
-		return false;
-	} 
-
-	if (DBG_ENABLED()) {
-		model_print("Next execution will diverge at:\n");
-		diverge->print();
-	}
-
-	execution_number++;
-
-	if (params.maxexecutions != 0 && stats.num_complete >= params.maxexecutions)
-		return false;
-
-	reset_to_initial_state();
-	return true;
-*/
-
+	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());
 }
 
 /**
@@ -406,14 +349,25 @@ 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); 
-	}*/
+		inspect_plugin->inspectModelAction(act);
+	}
+
 	old->set_pending(act);
 	if (Thread::swap(old, &system_context) < 0) {
 		perror("swap threads");
@@ -422,131 +376,128 @@ 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 *)
-{
-	user_main(model->params.argc, model->params.argv);
+static void runChecker() {
+	model->run();
+	delete model;
+}
+
+void ModelChecker::startChecker() {
+	startExecution(get_system_context(), runChecker);
+	snapshot = take_snapshot();
+	initMainThread();
 }
 
 bool ModelChecker::should_terminate_execution()
 {
-	/* Infeasible -> don't take any more steps */
-	if (execution->is_infeasible())
-		return true;
-	else if (execution->isfeasibleprefix() && execution->have_bug_reports()) {
+	if (execution->have_bug_reports()) {
 		execution->set_assert();
 		return true;
-	}
-
-	if (execution->too_many_steps())
+	} else if (execution->isFinished()) {
 		return true;
+	}
 	return false;
 }
 
-/** @brief Exit ModelChecker upon returning to the run loop of the
- *	model checker. */
-void ModelChecker::exit_model_checker()
-{
-	exit_flag = true;
-}
-
-/** @brief Restart ModelChecker upon returning to the run loop of the
- *	model checker. */
-void ModelChecker::restart()
-{
-	restart_flag = true;
-}
-
-void ModelChecker::do_restart()
-{
-	restart_flag = false;
-	diverge = NULL;
-	earliest_diverge = NULL;
-	reset_to_initial_state();
-	node_stack->full_reset();
-	memset(&stats,0,sizeof(struct execution_stats));
-	execution_number = 1;
-}
-
 /** @brief Run ModelChecker for the user program */
 void ModelChecker::run()
 {
-	bool has_next;
-	int i = 0;
-	do {
-		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 initial random number generator state to avoid resets on rollback
+	char random_state[256];
+	initstate(423121, random_state, sizeof(random_state));
+	modelclock_t checkfree = params.checkthreshold;
+	for(int exec = 0;exec < params.maxexecutions;exec++) {
+		Thread * t = init_thread;
+
 		do {
+			/* Check whether we need to free model actions. */
+
+			if (params.traceminsize != 0 &&
+					execution->get_curr_seq_num() > checkfree) {
+				checkfree += params.checkthreshold;
+				execution->collectActions();
+			}
+
 			/*
 			 * 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++) {
+			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. 
+					switch_from_master(thr);
 					if (thr->is_waiting_on(thr))
 						assert_bug("Deadlock detected (thread %u)", i);
 				}
 			}
 
 			/* Don't schedule threads which should be disabled */
-			for (unsigned int i = 0; i < get_num_threads(); i++) {
+			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);
 				}
 			}
-			/* Catch assertions from prior take_step or from
-			 * between-ModelAction bugs (e.g., data races) */
 
-			for (unsigned int i = 1; i < get_num_threads(); i++) {
+			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) {
+				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() == THREAD_START || act->get_type() == THREAD_FINISH) {
+					} 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;
-					}				
+					}
 				}
 			}
 
+			/* Catch assertions from prior take_step or from
+			* between-ModelAction bugs (e.g., data races) */
 
 			if (execution->has_asserted())
 				break;
-			if (!t)				
+			if (!t)
 				t = get_next_thread();
 			if (!t || t->is_model_thread())
 				break;
+			if (t->just_woken_up()) {
+				t->set_wakeup_state(false);
+				t->set_pending(NULL);
+				t = NULL;
+				continue;	// Allow this thread to stash the next pending action
+			}
 
 			/* 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());
-
-		has_next = next_execution();
-		i++;
-	} while (i<250); // while (has_next);
-
-	execution->fixup_release_sequences();
+		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);
 }