From 7a4ded8380a915197414874f3f1f5e704dbe2a8e Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Mon, 9 Jan 2023 15:43:25 -1000
Subject: [PATCH] FRONTPANEL: Avoid potential deadlock when shutting down a
 panel application

---
 sim_console.c    |  3 ++-
 sim_frontpanel.c | 17 +++++++++++++++--
 sim_frontpanel.h |  2 +-
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/sim_console.c b/sim_console.c
index 95a7e8df..82b26ddd 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -633,7 +633,7 @@ for (i=connections=0; i<sim_rem_con_tmxr.lines; i++) {
         continue;
     ++connections;
     if (connections == 1)
-        fprintf (st, "Remote Console Connections:\n");
+        fprintf (st, "\nRemote Console Connections:\n");
     tmxr_fconns (st, rem->lp, i);
     if (rem->read_timeout != sim_rem_read_timeout) {
         if (rem->read_timeout)
@@ -668,6 +668,7 @@ for (i=connections=0; i<sim_rem_con_tmxr.lines; i++) {
         fprintf (st, "\n");
         if (sim_switches & SWMASK ('D'))
             sim_rem_sample_output (st, rem->line);
+            fprintf (st, "\n");
         }
     }
 return SCPE_OK;
diff --git a/sim_frontpanel.c b/sim_frontpanel.c
index 95a5b9e6..cc2e0755 100644
--- a/sim_frontpanel.c
+++ b/sim_frontpanel.c
@@ -822,8 +822,8 @@ else {
     fclose (fIn);
     fIn = NULL;
     fprintf (fOut, "set remote notelnet\n");
-    if (device_panel_count)
-        fprintf (fOut, "set remote connections=%d\n", (int)device_panel_count+1);
+    if ((device_panel_count != 0) || (debug_file != NULL))
+        fprintf (fOut, "set remote connections=%d\n", (int)(device_panel_count + 1 + ((debug_file != NULL) ? 1 : 0)));
     fprintf (fOut, "set remote -u telnet=%s\n", hostport);
     fprintf (fOut, "set remote master\n");
     fprintf (fOut, "exit\n");
@@ -1430,10 +1430,23 @@ if (usecs_between_callbacks && (0 == panel->usecs_between_callbacks)) { /* Need
     pthread_cond_destroy (&panel->startup_done);
     }
 if ((usecs_between_callbacks == 0) && panel->usecs_between_callbacks) { /* Need to stop callbacks */
+    OperationalState PriorState = panel->State;                     /* record initial state */
     _panel_debug (panel, DBG_THR, "Shutting down callback thread", NULL, 0);
+
+    if (PriorState == Run) {                                        /* If running? */
+        pthread_mutex_unlock (&panel->io_lock);                     /* allow access */
+        sim_panel_exec_halt (panel);                                /* Stop for Now */
+        pthread_mutex_lock (&panel->io_lock);                       /* acquire access */
+        }
     panel->usecs_between_callbacks = 0;                             /* flag disabled */
     pthread_mutex_unlock (&panel->io_lock);                         /* allow access */
     pthread_join (panel->callback_thread, NULL);                    /* synchronize with thread rundown */
+
+    if (PriorState == Run) {                                        /* If was running? */
+        pthread_mutex_lock (&panel->io_lock);                       /* allow access */
+        sim_panel_exec_halt (panel);                                /* resume running */
+        pthread_mutex_unlock (&panel->io_lock);                     /* acquire access */
+        }
     pthread_mutex_lock (&panel->io_lock);                           /* reacquire access */
     }
 pthread_mutex_unlock (&panel->io_lock);
diff --git a/sim_frontpanel.h b/sim_frontpanel.h
index 38e5aecd..6623b13c 100644
--- a/sim_frontpanel.h
+++ b/sim_frontpanel.h
@@ -56,7 +56,7 @@ extern "C" {
 
 #if !defined(__VAX)         /* Unsupported platform */
 
-#define SIM_FRONTPANEL_VERSION   13
+#define SIM_FRONTPANEL_VERSION   14
 
 /**