From: weiyu <weiyuluo1232@gmail.com>
Date: Sat, 12 Dec 2020 01:11:26 +0000 (-0800)
Subject: seed random number generator with time
X-Git-Url: http://demsky.eecs.uci.edu/git/?p=c11tester.git;a=commitdiff_plain;h=ba9cc8ef093a985673efc0d440898ae3b6fe0bb5

seed random number generator with time
---

diff --git a/libthreads.cc b/libthreads.cc
index 4d61e536..3ed4937d 100644
--- a/libthreads.cc
+++ b/libthreads.cc
@@ -12,6 +12,7 @@
  */
 int thrd_create(thrd_t *t, thrd_start_t start_routine, void *arg)
 {
+	createModelIfNotExist();
 	struct thread_params params = { start_routine, arg };
 	/* seq_cst is just a 'don't care' parameter */
 	model->switch_thread(new ModelAction(THREAD_CREATE, std::memory_order_seq_cst, t, (uint64_t)&params));
@@ -20,6 +21,7 @@ int thrd_create(thrd_t *t, thrd_start_t start_routine, void *arg)
 
 int thrd_join(thrd_t t)
 {
+	createModelIfNotExist();
 	Thread *th = t.priv;
 	model->switch_thread(new ModelAction(THREAD_JOIN, std::memory_order_seq_cst, th, id_to_int(thrd_to_id(t))));
 	return 0;
@@ -28,10 +30,12 @@ int thrd_join(thrd_t t)
 /** A no-op, for now */
 void thrd_yield(void)
 {
+	createModelIfNotExist();
 	model->switch_thread(new ModelAction(THREAD_YIELD, std::memory_order_seq_cst, thread_current(), VALUE_NONE));
 }
 
 thrd_t thrd_current(void)
 {
+	createModelIfNotExist();
 	return thread_current()->get_thrd_t();
 }
diff --git a/model.cc b/model.cc
index 3f811d7d..c190e38c 100644
--- a/model.cc
+++ b/model.cc
@@ -22,6 +22,14 @@
 ModelChecker *model = NULL;
 int inside_model = 0;
 
+uint64_t get_nanotime()
+{
+	struct timespec currtime;
+	clock_gettime(CLOCK_MONOTONIC, &currtime);
+
+	return currtime.tv_nsec;
+}
+
 void placeholder(void *) {
 	ASSERT(0);
 }
@@ -524,12 +532,16 @@ bool ModelChecker::handleChosenThread(Thread *old)
 void ModelChecker::startChecker() {
 	startExecution();
 	//Need to initial random number generator state to avoid resets on rollback
-	initstate(423121, random_state, sizeof(random_state));
+	//initstate(423121, random_state, sizeof(random_state));
+	uint64_t seed = get_nanotime();
+	srandom(seed);
 
 	snapshot = take_snapshot();
 
 	//reset random number generator state
-	setstate(random_state);
+	//setstate(random_state);
+	seed = get_nanotime();
+	srandom(seed);
 
 	install_trace_analyses(get_execution());
 	redirect_output();