add option idlecheckpoint

New experimental option

This requires platform support to be useful. Currently an
implementation for Windows TTY console is included.

A Unix TTY implementation should be achievable I would think,
but I haven't pursued that, at least not yet (contributions welcome).
I'm not sure whether Qt or X11 interfaces offer a similar
timeout capability..

How it works:

When idlecheckpoint in on, if the wait for a new input is idle for
10 seconds (length of time to waite is controlled by
IDLECHECKPOINT_WAIT_TIME #define in hack.h), save_currentstate() is
called to bring everything up-to-date should a hangup or crash occur.
The input wait then continues/resumes.

The save_currentstate() call is only executed once per input request.

include/config.h

@@ -681,6 +681,16 @@ typedef unsigned char uchar;
 #endif
 #endif
 
+/* experimential; if the platform/window-port supports it; when the game has
+ * started to wait for player input, and the wait lasts longer than
+ * IDLECHECKPOINT_WAIT_TIME seconds (defined in hack.h or *conf.h), the game
+ * will perform an update to the checkpoint file.
+ * Currently has support in:
+ *     WIN32CON
+ */
+
+/* #define IDLECHECKPOINT */
+
 /* End of Section 4 */
 
 #ifdef TTY_TILES_ESCCODES

include/flag.h

@@ -246,6 +246,8 @@ struct instance_flags {
                             * to input becoming taken over);
                             * True => enable fuzzer when entering moveloop */
     boolean herecmd_menu;  /* use menu when mouseclick on yourself */
+    boolean idlecheckpoint;  /* platform should perform a checkpoint update
+                              * if waiting for input longer than 10 seconds */
     boolean invis_goldsym; /* gold symbol is ' '? */
     boolean in_lua;        /* executing a lua script */
     boolean lua_testing;   /* doing lua tests */

include/hack.h

@@ -588,6 +588,13 @@ enum inventory_counts {
     /* 2023/11/30 invlet_max is not yet used anywhere */
 };
 
+#ifndef IDLECHECKPOINT_WAIT_TIME
+#define IDLECHECKPOINT_WAIT_TIME 10  /* seconds to wait before executing a checkpoint;
+                                      * always #define'd but only has meaning if
+                                      * IDLECHECKPOINT is defined.
+                                      */
+#endif
+
 struct kinfo {
     struct kinfo *next; /* chain of delayed killers */
     int id;             /* uprop keys to ID a delayed killer */

include/optlist.h

@@ -387,6 +387,9 @@ static int optfn_##a(int, int, boolean, char *, char *);
                 Yes, Yes, No, No, NoAlias,
                 "load IBMGraphics display symbols into symset")
 #endif
+    NHOPTB(idlecheckpoint, Advanced, 0, opt_in, set_in_game,
+           Off, Yes, No, No, NoAlias, &iflags.idlecheckpoint, Term_Off,
+           "update checkpoint file if input is idle for 10 seconds")
 #ifndef MAC
     NHOPTB(ignintr, Advanced, 0, opt_in, set_in_game,
            Off, Yes, No, No, NoAlias, &flags.ignintr, Term_False,

include/windconf.h

@@ -35,6 +35,10 @@
 #define EARLY_CONFIGFILE_PASS
 #define TTY_PERM_INVENT
 
+#ifdef WIN32CON
+#define IDLECHECKPOINT
+#endif
+
 /*
  * -----------------------------------------------------------------
  *  The remaining code shouldn't need modification.

src/options.c

@@ -5310,6 +5310,14 @@ optfn_boolean(
 #endif
             go.opt_need_redraw = TRUE;
             break;
+#ifndef IDLECHECKPOINT
+	case opt_idlecheckpoint:
+	    pline("There is no underlying support for 'idlecheckpoint'"
+		  " compiled in."); 
+	    iflags.idlecheckpoint = FALSE;
+	    give_opt_msg = FALSE;
+            break;
+#endif
         default:
             break;
         }

sys/windows/consoletty.c

@@ -3097,7 +3097,8 @@ default_checkinput(
     DWORD dwWait;
 #endif
     int ch = 0;
-    boolean valid = 0, done = 0;
+    boolean valid = 0, done = 0, done_a_checkpoint = FALSE;
+    DWORD how_many_milliseconds = 0;
 
 #ifdef QWERTZ_SUPPORT
     if (numberpad & 0x10) {
@@ -3107,54 +3108,78 @@ default_checkinput(
         qwertz = FALSE;
     }
 #endif
+    done_a_checkpoint = FALSE;
+    how_many_milliseconds = (iflags.idlecheckpoint)
+        ? (IDLECHECKPOINT_WAIT_TIME * 1000)
+        : INFINITE;
     while (!done) {
-#if defined(SAFERHANGUP)
         dwWait = WaitForSingleObjectEx(hConIn,   // event object to wait for
-                                       INFINITE, // waits indefinitely
+                                       how_many_milliseconds,
                                        TRUE);    // alertable wait enabled
+#if defined(SAFERHANGUP)
         if (dwWait == WAIT_FAILED)
             return '\033';
 #endif
-        ReadConsoleInput(hConIn, ir, 1, count);
+#ifdef INSURANCE
-        if (mode == 0) {
+        if (iflags.idlecheckpoint
-            if ((ir->EventType == KEY_EVENT) && ir->Event.KeyEvent.bKeyDown) {
+            && dwWait == WAIT_TIMEOUT && !done_a_checkpoint) {
-                ch = default_processkeystroke(hConIn, ir, &valid, numberpad, 0);
+            /* no input for 30 seconds, so let's take
-                done = valid;
+             * advantage and do a game checkpoint,
-            }
+             * then resume the wait.
-        } else {
+             */
-            if (*count > 0) {
+            save_currentstate();
-                if (ir->EventType == KEY_EVENT
+            done_a_checkpoint = TRUE;
+        } else
+#endif  /* INSURANCE */
+        {
+            ReadConsoleInput(hConIn, ir, 1, count);
+            if (mode == 0) {
+                if ((ir->EventType == KEY_EVENT)
                     && ir->Event.KeyEvent.bKeyDown) {
+                    ch = default_processkeystroke(hConIn, ir, &valid,
+                                                  numberpad, 0);
+                    done = valid;
+                }
+            } else {
+                if (*count > 0) {
+                    if (ir->EventType == KEY_EVENT
+                        && ir->Event.KeyEvent.bKeyDown) {
 #ifdef QWERTZ_SUPPORT
-                    if (qwertz)
+                        if (qwertz)
-                        numberpad |= 0x10;
+                            numberpad |= 0x10;
 #endif
-                    ch = default_processkeystroke(hConIn, ir, &valid, numberpad, 0);
+                        ch = default_processkeystroke(hConIn, ir, &valid,
+                                                      numberpad, 0);
 #ifdef QWERTZ_SUPPORT
-                    numberpad &= ~0x10;
+                        numberpad &= ~0x10;
 #endif
-                    if (valid)
+                        if (valid)
-                        return ch;
+                            return ch;
-                } else if (ir->EventType == MOUSE_EVENT) {
+                    } else if (ir->EventType == MOUSE_EVENT) {
-                    if ((ir->Event.MouseEvent.dwEventFlags == 0)
+                        if ((ir->Event.MouseEvent.dwEventFlags == 0)
-                        && (ir->Event.MouseEvent.dwButtonState & MOUSEMASK)) {
+                            && (ir->Event.MouseEvent.dwButtonState
-                        cc->x = ir->Event.MouseEvent.dwMousePosition.X + 1;
+                                & MOUSEMASK)) {
-                        cc->y = ir->Event.MouseEvent.dwMousePosition.Y - 1;
+                            cc->x =
+                                ir->Event.MouseEvent.dwMousePosition.X + 1;
+                            cc->y =
+                                ir->Event.MouseEvent.dwMousePosition.Y - 1;
 
-                        if (ir->Event.MouseEvent.dwButtonState & LEFTBUTTON)
+                            if (ir->Event.MouseEvent.dwButtonState
-                            *mod = CLICK_1;
+                                & LEFTBUTTON)
-                        else if (ir->Event.MouseEvent.dwButtonState
+                                *mod = CLICK_1;
-                                 & RIGHTBUTTON)
+                            else if (ir->Event.MouseEvent.dwButtonState
-                            *mod = CLICK_2;
+                                     & RIGHTBUTTON)
+                                *mod = CLICK_2;
 #if 0 /* middle button */
                                     else if (ir->Event.MouseEvent.dwButtonState & MIDBUTTON)
                                         *mod = CLICK_3;
 #endif
-                        return 0;
+                            return 0;
+                        }
                     }
-                }
+                } else
-            } else
+                    done = 1;
-                done = 1;
+            }
         }
     }
     return mode ? 0 : ch;

sys/windows/windmain.c

@@ -300,7 +300,7 @@ _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);*/
     if WINDOWPORT(tty) {
         int i;
 
-        for (i = 0; i < 20; ++i) {
+        for (i = 0; i < 5; ++i) {
             nh_delay_output();
         }