add consume to run
[c11tester.git] / model.cc
index f277970a6166e33205a871edcc59ab7bc501daae..a1204d0ab852352600edb95063476bd6f2976fa7 100644 (file)
--- 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"
 #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),
-       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());
 }
 
 /** @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 */
@@ -100,23 +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());
-}
-
-/**
- * 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();
 }
 
 /**
@@ -131,7 +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];
 
@@ -140,7 +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);
 }
 
 /**
@@ -151,8 +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) */
@@ -161,10 +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();
 }
 
 /**
@@ -175,16 +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:
@@ -198,12 +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);
-       if (params.verbose)
-               model_print("Total nodes created: %d\n", node_stack->get_total_nodes());
 }
 
 /**
@@ -213,17 +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 >= 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();
        }
 
@@ -244,22 +236,20 @@ 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 */
@@ -268,51 +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();
-       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());
 }
 
 /**
@@ -361,14 +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); 
-       }*/
+               inspect_plugin->inspectModelAction(act);
+       }
+
        old->set_pending(act);
        if (Thread::swap(old, &system_context) < 0) {
                perror("swap threads");
@@ -377,137 +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();
        }
-
-       if (execution->too_many_steps())
-               return true;
-       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 Exit ModelChecker upon returning to the run loop of the
- *     model checker. */
-void ModelChecker::exit_model_checker()
+Thread* ModelChecker::getNextThread()
 {
-       exit_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;
 }
 
-/** @brief Restart ModelChecker upon returning to the run loop of the
- *     model checker. */
-void ModelChecker::restart()
+void ModelChecker::finishRunExecution(Thread *old) 
 {
-       restart_flag = true;
+       scheduler->set_current_thread(NULL);
+       if (Thread::swap(old, &system_context) < 0) {
+               perror("swap threads");
+               exit(EXIT_FAILURE);
+       }
 }
 
-void ModelChecker::do_restart()
+void ModelChecker::finishRunExecution(ucontext_t *old) 
 {
-       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;
+       scheduler->set_current_thread(NULL);
 }
 
-/** @brief Run ModelChecker for the user program */
-void ModelChecker::run()
+void ModelChecker::consumeAction()
 {
-       int i = 0;
-       //Need to initial random number generator state to avoid resets on rollback
-       char random_state[256];
-       initstate(423121, random_state, sizeof(random_state));
-       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 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);
-                               }
-                       }
+       ModelAction *curr = chosen_thread->get_pending();
+       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;
                        }
-
-                       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 || \
+               } 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;
-                                       }                               
-                               }
-                       }
+                       chosen_thread = thr;
+                       thread_chosen = true;
+               }
+       }       
+}
 
-                       /* 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;
-
-                       /* 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());
-               next_execution();
-               i++;
+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);         
+       }
+}
+
+
+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;
+               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);
-       } while (i<5); // while (has_next);
+       }
 
        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);
 }