[master] f383b5c3a vtim: New VTIM_poll_tmo() converter

[Dridi Boukelmoune]

commit f383b5c3a469f762f0f889aee3c4b918dd1aaf37
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Thu Feb 1 09:08:56 2024 +0100

    vtim: New VTIM_poll_tmo() converter
    
    It takes a vtim_dur and returns a number of milliseconds. NAN means no
    timeout and negative values are considered expired deadlines and get a
    chance to succeed a non-blocking poll.

diff --git a/include/vtim.h b/include/vtim.h
index d69a6130d..042feedb1 100644
--- a/include/vtim.h
+++ b/include/vtim.h
@@ -40,3 +40,4 @@ vtim_real VTIM_real(void);
 void VTIM_sleep(vtim_dur t);
 struct timespec VTIM_timespec(vtim_dur t);
 struct timeval VTIM_timeval(vtim_dur t);
+int VTIM_poll_tmo(vtim_dur);
diff --git a/lib/libvarnish/vtim.c b/lib/libvarnish/vtim.c
index 3918e5eb2..6fdd18245 100644
--- a/lib/libvarnish/vtim.c
+++ b/lib/libvarnish/vtim.c
@@ -454,6 +454,15 @@ VTIM_timespec(vtim_dur t)
 	return (tv);
 }
 
+int
+VTIM_poll_tmo(vtim_dur tmo)
+{
+
+	if (isnan(tmo))
+		return (-1);
+	return (vmax_t(int, 0, tmo * 1e3));
+}
+
 #ifdef TEST_DRIVER
 
 #pragma GCC diagnostic ignored "-Wformat-y2k"