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Merge pull request #821 from llmII/fix-kqueue

Fix #819 timeouts under kqueue on FreeBSD broken
This commit is contained in:
Calvin Rose 2021-09-29 15:51:46 -05:00 committed by GitHub
commit 1bf22288ee
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@ -1574,32 +1574,19 @@ void janet_ev_deinit(void) {
* NetBSD uses intptr_t while others use void * for .udata */
#define EV_SETx(ev, a, b, c, d, e, f) EV_SET((ev), (a), (b), (c), (d), (e), ((__typeof__((ev)->udata))(f)))
#define JANET_KQUEUE_TF (EV_ADD | EV_ENABLE | EV_CLEAR | EV_ONESHOT)
/* NOTE:
* NetBSD doesn't like intervals less than 1 millisecond so lets make that the
* default anywhere JANET_KQUEUE_TS will be used. */
#ifdef __NetBSD__
#define JANET_KQUEUE_MIN_INTERVAL 1
#else
#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. */
JanetTimestamp fix_interval(const JanetTimestamp ts) {
* 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 to_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
#define JANET_KQUEUE_INTERVAL(timestamp) (to_interval((timestamp - ts_now())))
/* TODO: make this available be we using kqueue or epoll, instead of
@ -1612,6 +1599,12 @@ static JanetTimestamp ts_now(void) {
return res;
}
/* NOTE: Assumes Janet's timestamp precision is in milliseconds. */
static void timestamp2timespec(struct timespec *t, JanetTimestamp ts) {
t->tv_sec = ts == 0 ? 0 : ts / 1000;
t->tv_nsec = ts == 0 ? 0 : (ts % 1000) * 1000000;
}
void add_kqueue_events(const struct kevent *events, int length) {
/* NOTE: Status should be equal to the amount of events added, which isn't
* always known since deletions or modifications occur. Can't use the
@ -1678,39 +1671,39 @@ static void janet_unlisten(JanetListenerState *state, int is_gc) {
janet_unlisten_impl(state, is_gc);
}
#define JANET_KQUEUE_TIMER_IDENT 1
#define JANET_KQUEUE_MAX_EVENTS 64
void janet_loop1_impl(int has_timeout, JanetTimestamp timeout) {
/* Construct our timer which is a definite time on the clock, not an
* interval, in milliseconds as that is `JanetTimestamp`'s precision. */
struct kevent timer;
if (janet_vm.timer_enabled || has_timeout) {
EV_SETx(&timer,
JANET_KQUEUE_TIMER_IDENT,
EVFILT_TIMER,
JANET_KQUEUE_TF,
NOTE_MSECONDS | NOTE_ABSTIME,
JANET_KQUEUE_TS(timeout), &janet_vm.timer);
add_kqueue_events(&timer, 1);
}
janet_vm.timer_enabled = has_timeout;
/* Poll for events */
/* NOTE:
* We calculate the timeout interval per iteration. When the interval
* drops to 0 or negative, we effect a timeout of 0. Effecting a timeout
* of infinity will not work and could make other fibers with timeouts
* miss their timeouts if we did so.
* JANET_KQUEUE_INTERVAL insures we have a timeout of no less than 0. */
int status;
struct timespec ts;
struct kevent events[JANET_KQUEUE_MAX_EVENTS];
do {
status = kevent(janet_vm.kq, NULL, 0, events, JANET_KQUEUE_MAX_EVENTS, NULL);
if (janet_vm.timer_enabled || has_timeout) {
timestamp2timespec(&ts, JANET_KQUEUE_INTERVAL(timeout));
status = kevent(janet_vm.kq, NULL, 0, events,
JANET_KQUEUE_MAX_EVENTS, &ts);
} else {
status = kevent(janet_vm.kq, NULL, 0, events,
JANET_KQUEUE_MAX_EVENTS, NULL);
}
} while (status == -1 && errno == EINTR);
if (status == -1)
JANET_EXIT("failed to poll events");
/* Make sure timer is set accordingly. */
janet_vm.timer_enabled = has_timeout;
/* Step state machines */
for (int i = 0; i < status; i++) {
void *p = (void *) events[i].udata;
if (&janet_vm.timer == p) {
/* Timer expired, ignore */;
} else if (janet_vm.selfpipe == p) {
if (janet_vm.selfpipe == p) {
/* Self-pipe handling */
janet_ev_handle_selfpipe();
} else {
@ -1748,16 +1741,9 @@ void janet_ev_init(void) {
janet_vm.kq = kqueue();
janet_vm.timer_enabled = 0;
if (janet_vm.kq == -1) goto error;
struct kevent events[2];
/* Don't use JANET_KQUEUE_TS here, as even under FreeBSD we use intervals
* here. */
EV_SETx(&events[0],
JANET_KQUEUE_TIMER_IDENT,
EVFILT_TIMER,
JANET_KQUEUE_TF,
NOTE_MSECONDS, 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);
struct kevent event;
EV_SETx(&event, janet_vm.selfpipe[0], EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, janet_vm.selfpipe);
add_kqueue_events(&event, 1);
return;
error:
JANET_EXIT("failed to initialize event loop");