1 files changed, 14 insertions, 3 deletions

diff --git a/src/process.c b/src/process.c
index 42743f6531a..eb27ddef45f 100644
--- a/src/process.c
+++ b/src/process.c
@@ -259,7 +259,7 @@ static bool process_output_skip;
 
 static void start_process_unwind (Lisp_Object);
 static void create_process (Lisp_Object, char **, Lisp_Object);
-#ifdef USABLE_SIGIO
+#if defined (USABLE_SIGIO) || defined (USABLE_SIGPOLL)
 static bool keyboard_bit_set (fd_set *);
 #endif
 static void deactivate_process (Lisp_Object);
@@ -5592,6 +5592,13 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
           nfds = pgtk_select (max_desc + 1,
                               &Available, (check_write ? &Writeok : 0),
                               NULL, &timeout, NULL);
+#elif !defined USABLE_SIGIO && !defined WINDOWSNT
+          /* If we're polling for input, don't get stuck in select for
+             more than 25 msec. */
+          struct timespec short_timeout = make_timespec (0, 25000000);
+          if ((read_kbd || !NILP (wait_for_cell))
+              && timespec_cmp (short_timeout, timeout) < 0)
+            timeout = short_timeout;
 #elif defined HAVE_GLIB && !defined HAVE_NS
           /* Non-macOS HAVE_GLIB builds call thread_select in xgselect.c.  */
           nfds = xg_select (max_desc + 1,
@@ -5725,7 +5732,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
       if (! NILP (wait_for_cell) && ! NILP (XCAR (wait_for_cell)))
         break;
 
-#ifdef USABLE_SIGIO
+#if defined (USABLE_SIGIO) || defined (USABLE_SIGPOLL)
       /* If we think we have keyboard input waiting, but didn't get SIGIO,
          go read it.  This can happen with X on BSD after logging out.
          In that case, there really is no input and no SIGIO,
@@ -5733,7 +5740,11 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 
       if (read_kbd && interrupt_input
           && keyboard_bit_set (&Available) && ! noninteractive)
+#ifdef USABLE_SIGIO
         handle_input_available_signal (SIGIO);
+#else
+        handle_input_available_signal (SIGPOLL);
+#endif
 #endif
 
       /* If checking input just got us a size-change event from X,
@@ -7727,7 +7738,7 @@ delete_gpm_wait_descriptor (int desc)
 
 # endif
 
-# ifdef USABLE_SIGIO
+#if defined (USABLE_SIGIO) || defined (USABLE_SIGPOLL)
 
 /* Return true if *MASK has a bit set
    that corresponds to one of the keyboard input descriptors.  */