(update_lock, play_lock, update_pending, play_wrlock_wanted): Move to

main.c and rename to better reflect their purpose.  Fix misleading
comments.

include/server.h

@@ -36,11 +36,12 @@
 
 #include "empthread.h"
 
-extern int shutdown_pending;
-extern int update_pending;
-extern int update_running;
-extern empth_rwlock_t *update_lock;
 #define UPDATE_TIME_LEN 16
+
+extern int shutdown_pending;
+extern empth_rwlock_t *play_lock;
+extern int play_wrlock_wanted;
+extern int update_running;
 extern time_t update_time[UPDATE_TIME_LEN];
 
 void market_init(void);

src/lib/gen/io.c

@@ -324,9 +324,9 @@ io_output_all(struct iop *iop)
      * Mustn't block a player thread while update is pending, or else
      * a malicous player could delay the update indefinitely
      */
-    while (((n = io_output(iop, IO_NOWAIT)) > 0) && !update_pending) {
+    while ((n = io_output(iop, IO_NOWAIT)) > 0 && !play_wrlock_wanted)
 	empth_select(iop->fd, EMPTH_FD_WRITE);
-    }
+
     return n;
 }
 

src/lib/player/dispatch.c

@@ -88,7 +88,7 @@ dispatch(char *buf, char *redir)
 	pr("Command not implemented\n");
 	return 0;
     }
-    empth_rwlock_rdlock(update_lock);
+    empth_rwlock_rdlock(play_lock);
     if (redir) {
 	prredir(redir);
 	uprnf(buf);
@@ -110,7 +110,7 @@ dispatch(char *buf, char *redir)
 	logerror("%s: returned bad value", command->c_form);
 	break;
     }
-    empth_rwlock_unlock(update_lock);
+    empth_rwlock_unlock(play_lock);
     player->command = 0;
     return 0;
 }

src/server/main.c

@@ -78,6 +78,19 @@ static void loc_NTInit(void);
 static void loc_NTTerm(void);
 #endif
 
+/*
+ * Lock to synchronize player threads with update and shutdown.
+ * Update and shutdown takes it exclusive, commands take it shared.
+ */
+empth_rwlock_t *play_lock;
+
+/*
+ * Is a thread attempting to take an exclusive play_lock?
+ * Threads holding a shared play_lock must not sleep while this is
+ * true.
+ */
+int play_wrlock_wanted;
+
 static char pidfname[] = "server.pid";
 
 /* Run as daemon?  If yes, detach from controlling terminal etc. */
@@ -373,7 +386,7 @@ shutdwn(int sig)
 	}
 	empth_wakeup(p->proc);
     }
-    empth_rwlock_wrlock(update_lock);
+    empth_rwlock_wrlock(play_lock);
     /* rely on player_kill_idle() for killing hung player threads */
     if (sig)
 	logerror("Server shutting down on signal %d", sig);

src/server/update.c

@@ -48,18 +48,6 @@
 #include "prototypes.h"
 #include "server.h"
 
-/*
- * Lock to synchronize player threads with the update.
- * Update takes it exclusive, commands take it shared.
- */
-empth_rwlock_t *update_lock;
-
-/*
- * Update is pending, player threads must give up update_lock ASAP.
- * This means they must not block while update_pending.
- */
-int update_pending;
-
 /*
  * Update is running.
  * Can be used to suppress messages, or direct them to bulletins.
@@ -86,8 +74,8 @@ update_init(void)
     if (update_get_schedule() < 0)
 	exit(1);
 
-    update_lock = empth_rwlock_create("Update");
+    play_lock = empth_rwlock_create("Update");
-    if (!update_lock)
+    if (!play_lock)
 	exit_nomem();
 
     dp = player_new(-1);
@@ -205,7 +193,7 @@ update_run(void)
 {
     struct player *p;
 
-    update_pending = 1;
+    play_wrlock_wanted = 1;
     for (p = player_next(0); p != 0; p = player_next(p)) {
 	if (p->state != PS_PLAYING)
 	    continue;
@@ -215,18 +203,18 @@ update_run(void)
 	    empth_wakeup(p->proc);
 	}
     }
-    empth_rwlock_wrlock(update_lock);
+    empth_rwlock_wrlock(play_lock);
     if (*pre_update_hook) {
 	if (run_hook(pre_update_hook, "pre-update")) {
-	    update_pending = 0;
+	    play_wrlock_wanted = 0;
-	    empth_rwlock_unlock(update_lock);
+	    empth_rwlock_unlock(play_lock);
 	    return;
 	}
     }
     update_running = 1;
     update_main();
-    update_pending = update_running = 0;
+    play_wrlock_wanted = update_running = 0;
-    empth_rwlock_unlock(update_lock);
+    empth_rwlock_unlock(play_lock);
 }
 
 static int