From ae901f328542ca906056591bcbcaefdb0caeaff8 Mon Sep 17 00:00:00 2001
From: Gordon McGregor <gordon.mcgregor@verilab.com>
Date: Sun, 8 Apr 2012 00:05:50 -0500
Subject: [PATCH] adding vpi_mode_flag controls around callbacks in
 vpiNextSimTime

---
 vvp/vpi_callback.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/vvp/vpi_callback.cc b/vvp/vpi_callback.cc
index 3dd441caf..5c9268e2a 100644
--- a/vvp/vpi_callback.cc
+++ b/vvp/vpi_callback.cc
@@ -482,6 +482,9 @@ void vpiNextSimTime(void)
 {
       simulator_callback* cur;
 
+      assert(vpi_mode_flag == VPI_MODE_NONE);
+      vpi_mode_flag = VPI_MODE_RWSYNC;
+
       while (NextSimTime) {
 	    cur = NextSimTime;
 	    NextSimTime = dynamic_cast<simulator_callback*>(cur->next);
@@ -489,6 +492,7 @@ void vpiNextSimTime(void)
 	    delete cur;
       }
 
+      vpi_mode_flag = VPI_MODE_NONE;
 }
 
 static simulator_callback* make_prepost(p_cb_data data)