From e1ec0d13ae55cd0d1f0b14033fe00bd063b9981c Mon Sep 17 00:00:00 2001
From: llmII <dev@amlegion.org>
Date: Tue, 28 Sep 2021 17:32:10 -0500
Subject: [PATCH] Fixing kqueue under the BSDs.

FreeBSD is the only BSD supporting ABSTIME timers, whereas the rest
demand intervals. Janet operates on timestamps, which are absolute
times, as per ABSTIME. The idea was to use that under FreeBSD but not
the other BSDs. This commit changes that since ABSTIME breaks when the
timeout supplied is for a time prior to whatever the time is
now (invalid argument). We now utilize the same logic we use on the
other BSDs with FreeBSD to effect interval timeouts since intervals are
absolutely sometime beyond now, be it now and less than a millisecond,
or more than a millisecond. This will hopefully unbreak BSD builds when
running the test suite.
---
 src/core/ev.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/src/core/ev.c b/src/core/ev.c
index 7732b14d..9cc96c39 100644
--- a/src/core/ev.c
+++ b/src/core/ev.c
@@ -1586,22 +1586,17 @@ void janet_ev_deinit(void) {
 #define JANET_KQUEUE_MIN_INTERVAL 0
 #endif
 
-#ifdef __FreeBSD__
-#define JANET_KQUEUE_TS(timestamp) (timestamp)
-#else
 /* NOTE:
- * NetBSD and OpenBSD expect things are always intervals, so fake that we have
- * abstime capability by changing how a timestamp is used in all kqueue calls
- * and defining absent macros. Additionally NetBSD expects intervals be
- * greater than 1 millisecond, so correct all intervals to be at least 1
- * millisecond under NetBSD. */
+ * NetBSD and OpenBSD expect things are always intervals, and FreeBSD doesn't
+ * like an ABSTIME in the past so just use intervals always. Introduces a
+ * calculation to determine the minimum timeout per timeout requested of
+ * kqueue. Also note that NetBSD doesn't accept timeout intervals less than 1
+ * millisecond, so correct all intervals on that platform to be at least 1
+ * millisecond.*/
 JanetTimestamp fix_interval(const JanetTimestamp ts) {
     return ts >= JANET_KQUEUE_MIN_INTERVAL ? ts : JANET_KQUEUE_MIN_INTERVAL;
 }
 #define JANET_KQUEUE_TS(timestamp) (fix_interval((timestamp - ts_now())))
-#define NOTE_MSECONDS 0
-#define NOTE_ABSTIME 0
-#endif
 
 
 /* TODO: make this available be we using kqueue or epoll, instead of
@@ -1692,7 +1687,7 @@ void janet_loop1_impl(int has_timeout, JanetTimestamp timeout) {
                 JANET_KQUEUE_TIMER_IDENT,
                 EVFILT_TIMER,
                 JANET_KQUEUE_TF,
-                NOTE_MSECONDS | NOTE_ABSTIME,
+                0,
                 JANET_KQUEUE_TS(timeout), &janet_vm.timer);
         add_kqueue_events(&timer, 1);
     }
@@ -1757,7 +1752,7 @@ void janet_ev_init(void) {
             JANET_KQUEUE_TIMER_IDENT,
             EVFILT_TIMER,
             JANET_KQUEUE_TF,
-            NOTE_MSECONDS, JANET_KQUEUE_MIN_INTERVAL, &janet_vm.timer);
+            0, JANET_KQUEUE_MIN_INTERVAL, &janet_vm.timer);
     EV_SETx(&events[1], janet_vm.selfpipe[0], EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, janet_vm.selfpipe);
     add_kqueue_events(events, 2);
     return;