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-rw-r--r--erts/configure.in6
-rw-r--r--erts/emulator/sys/common/erl_poll.c162
-rw-r--r--erts/emulator/sys/common/erl_poll.h8
3 files changed, 167 insertions, 9 deletions
diff --git a/erts/configure.in b/erts/configure.in
index 481dfe405e..2699ab6f29 100644
--- a/erts/configure.in
+++ b/erts/configure.in
@@ -1768,6 +1768,10 @@ AC_CHECK_HEADER(sys/event.h, have_kernel_poll=kqueue)
AC_CHECK_HEADER(sys/epoll.h, have_kernel_poll=epoll)
AC_CHECK_HEADER(sys/devpoll.h, have_kernel_poll=/dev/poll)
+dnl Check if we have timerfds to be used for high accuracy
+dnl epoll_wait timeouts
+AC_CHECK_HEADERS([sys/timerfd.h])
+
dnl Check for kernel SCTP support
AC_SUBST(LIBSCTP)
if test "x$enable_sctp" != "xno" ; then
@@ -2113,7 +2117,7 @@ AC_CHECK_FUNCS([ieee_handler fpsetmask finite isnan isinf res_gethostbyname dlop
gethrtime localtime_r gmtime_r inet_pton \
memcpy mallopt sbrk _sbrk __sbrk brk _brk __brk \
flockfile fstat strlcpy strlcat setsid posix2time time2posix \
- setlocale nl_langinfo poll mlockall])
+ setlocale nl_langinfo poll mlockall ppoll])
AC_MSG_CHECKING([for isfinite])
AC_TRY_LINK([#include <math.h>],
diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index f4d4a85ca4..950717881a 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -314,6 +314,9 @@ struct ErtsPollSet_ {
#if ERTS_POLL_USE_WAKEUP_PIPE
int wake_fds[2];
#endif
+#if ERTS_POLL_USE_TIMERFD
+ int timer_fd;
+#endif
#if ERTS_POLL_USE_FALLBACK
int fallback_used;
#endif
@@ -580,6 +583,75 @@ create_wakeup_pipe(ErtsPollSet ps)
#endif /* ERTS_POLL_USE_WAKEUP_PIPE */
/*
+ * --- timer fd -----------------------------------------------------------
+ */
+
+#if ERTS_POLL_USE_TIMERFD
+
+/* We use the timerfd when using epoll_wait to get high accuracy
+ timeouts, i.e. we want to sleep with < ms accuracy. */
+
+static void
+create_timerfd(ErtsPollSet ps)
+{
+ int do_wake = 0;
+ int timer_fd;
+ timer_fd = timerfd_create(CLOCK_MONOTONIC,0);
+ ERTS_POLL_EXPORT(erts_poll_control)(ps,
+ timer_fd,
+ ERTS_POLL_EV_IN,
+ 1, &do_wake);
+#if ERTS_POLL_USE_FALLBACK
+ /* We depend on the wakeup pipe being handled by kernel poll */
+ if (ps->fds_status[timer_fd].flags & ERTS_POLL_FD_FLG_INFLBCK)
+ fatal_error("%s:%d:create_wakeup_pipe(): Internal error\n",
+ __FILE__, __LINE__);
+#endif
+ if (ps->internal_fd_limit <= timer_fd)
+ ps->internal_fd_limit = timer_fd + 1;
+ ps->timer_fd = timer_fd;
+}
+
+static ERTS_INLINE void
+timerfd_set(ErtsPollSet ps, struct itimerspec *its)
+{
+#ifdef DEBUG
+ struct itimerspec old_its;
+ int res;
+ res = timerfd_settime(ps->timer_fd, 0, its, &old_its);
+ ASSERT(res == 0);
+ ASSERT(old_its.it_interval.tv_sec == 0 &&
+ old_its.it_interval.tv_nsec == 0 &&
+ old_its.it_value.tv_sec == 0 &&
+ old_its.it_value.tv_nsec == 0);
+
+#else
+ timerfd_settime(ps->timer_fd, 0, its, NULL);
+#endif
+}
+
+static ERTS_INLINE int
+timerfd_clear(ErtsPollSet ps, int res, int max_res) {
+
+ struct itimerspec its;
+ /* we always have to clear the timer */
+ its.it_interval.tv_sec = 0;
+ its.it_interval.tv_nsec = 0;
+ its.it_value.tv_sec = 0;
+ its.it_value.tv_nsec = 0;
+ timerfd_settime(ps->timer_fd, 0, &its, NULL);
+
+ /* only timeout fd triggered */
+ if (res == 1 && ps->res_events[0].data.fd == ps->timer_fd)
+ return 0;
+
+ return res;
+}
+
+#endif /* ERTS_POLL_USE_TIMERFD */
+
+
+/*
* --- Poll set update requests ----------------------------------------------
*/
#if ERTS_POLL_USE_UPDATE_REQUESTS_QUEUE
@@ -1517,6 +1589,12 @@ poll_control(ErtsPollSet ps, int fd, ErtsPollEvents events, int on, int *do_wake
goto done;
}
#endif
+#if ERTS_POLL_USE_TIMERFD
+ if (fd == ps->timer_fd) {
+ new_events = ERTS_POLL_EV_NVAL;
+ goto done;
+ }
+#endif
}
if (fd >= ps->fds_status_len)
@@ -1664,6 +1742,9 @@ save_kp_result(ErtsPollSet ps, ErtsPollResFd pr[], int max_res, int chk_fds_res)
#if ERTS_POLL_USE_WAKEUP_PIPE
int wake_fd = ps->wake_fds[0];
#endif
+#if ERTS_POLL_USE_TIMERFD
+ int timer_fd = ps->timer_fd;
+#endif
for (i = 0; i < n; i++) {
@@ -1679,6 +1760,11 @@ save_kp_result(ErtsPollSet ps, ErtsPollResFd pr[], int max_res, int chk_fds_res)
continue;
}
#endif
+#if ERTS_POLL_USE_TIMERFD
+ if (fd == timer_fd) {
+ continue;
+ }
+#endif
ASSERT(!(ps->fds_status[fd].flags & ERTS_POLL_FD_FLG_INFLBCK));
/* epoll_wait() can repeat the same fd in result array... */
ix = (int) ps->fds_status[fd].res_ev_ix;
@@ -1753,6 +1839,11 @@ save_kp_result(ErtsPollSet ps, ErtsPollResFd pr[], int max_res, int chk_fds_res)
continue;
}
#endif
+#if ERTS_POLL_USE_TIMERFD
+ if (fd == timer_fd) {
+ continue;
+ }
+#endif
revents = ERTS_POLL_EV_N2E(ps->res_events[i].events);
pr[res].fd = fd;
pr[res].events = revents;
@@ -2097,7 +2188,7 @@ get_timeout_timeval(ErtsPollSet ps,
#endif
-#if ERTS_POLL_USE_KQUEUE
+#if ERTS_POLL_USE_KQUEUE || (ERTS_POLL_USE_POLL && defined(HAVE_PPOLL)) || ERTS_POLL_USE_TIMERFD
static ERTS_INLINE int
get_timeout_timespec(ErtsPollSet ps,
@@ -2120,7 +2211,7 @@ get_timeout_timespec(ErtsPollSet ps,
ASSERT(tsp->tv_sec >= 0);
ASSERT(tsp->tv_nsec >= 0);
- ASSERT(tsp->tv_nsec < 1000*1000);
+ ASSERT(tsp->tv_nsec < 1000*1000*1000);
return !0;
}
@@ -2128,6 +2219,22 @@ get_timeout_timespec(ErtsPollSet ps,
#endif
+#if ERTS_POLL_USE_TIMERFD
+
+static ERTS_INLINE int
+get_timeout_itimerspec(ErtsPollSet ps,
+ struct itimerspec *itsp,
+ ErtsMonotonicTime timeout_time)
+{
+
+ itsp->it_interval.tv_sec = 0;
+ itsp->it_interval.tv_nsec = 0;
+
+ return get_timeout_timespec(ps, &itsp->it_value, timeout_time);
+}
+
+#endif
+
static ERTS_INLINE int
check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
{
@@ -2145,12 +2252,29 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
#if ERTS_POLL_USE_EPOLL /* --- epoll ------------------------------- */
if (max_res > ps->res_events_len)
grow_res_events(ps, max_res);
+#if ERTS_POLL_USE_TIMERFD
+ {
+ struct itimerspec its;
+ timeout = get_timeout_itimerspec(ps, &its, timeout_time);
+ if (timeout) {
+#ifdef ERTS_SMP
+ erts_thr_progress_prepare_wait(NULL);
+#endif
+ timerfd_set(ps, &its);
+ res = epoll_wait(ps->kp_fd, ps->res_events, max_res, -1);
+ res = timerfd_clear(ps, res, max_res);
+ } else {
+ res = epoll_wait(ps->kp_fd, ps->res_events, max_res, 0);
+ }
+ }
+#else /* !ERTS_POLL_USE_TIMERFD */
timeout = (int) get_timeout(ps, 1000, timeout_time);
#ifdef ERTS_SMP
if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
res = epoll_wait(ps->kp_fd, ps->res_events, max_res, timeout);
+#endif /* !ERTS_POLL_USE_TIMERFD */
#elif ERTS_POLL_USE_KQUEUE /* --- kqueue ------------------------------ */
struct timespec ts;
if (max_res > ps->res_events_len)
@@ -2189,7 +2313,15 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
#endif
poll_res.dp_timeout = timeout;
res = ioctl(ps->kp_fd, DP_POLL, &poll_res);
-#elif ERTS_POLL_USE_POLL /* --- poll -------------------------------- */
+#elif ERTS_POLL_USE_POLL && defined(HAVE_PPOLL) /* --- ppoll ---------------- */
+ struct timespec ts;
+ timeout = get_timeout_timespec(ps, &ts, timeout_time);
+#ifdef ERTS_SMP
+ if (timeout)
+ erts_thr_progress_prepare_wait(NULL);
+#endif
+ res = ppoll(ps->poll_fds, ps->no_poll_fds, &ts, NULL);
+#elif ERTS_POLL_USE_POLL /* --- poll --------------------------------- */
timeout = (int) get_timeout(ps, 1000, timeout_time);
#ifdef ERTS_SMP
if (timeout)
@@ -2202,7 +2334,7 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
ERTS_FD_COPY(&ps->input_fds, &ps->res_input_fds);
ERTS_FD_COPY(&ps->output_fds, &ps->res_output_fds);
-
+
#ifdef ERTS_SMP
if (timeout)
erts_thr_progress_prepare_wait(NULL);
@@ -2535,6 +2667,9 @@ ERTS_POLL_EXPORT(erts_poll_create_pollset)(void)
#if ERTS_POLL_USE_WAKEUP_PIPE
create_wakeup_pipe(ps);
#endif
+#if ERTS_POLL_USE_TIMERFD
+ create_timerfd(ps);
+#endif
#if ERTS_POLL_USE_FALLBACK
if (kp_fd >= ps->fds_status_len)
grow_fds_status(ps, kp_fd);
@@ -2625,6 +2760,10 @@ ERTS_POLL_EXPORT(erts_poll_destroy_pollset)(ErtsPollSet ps)
if (ps->wake_fds[1] >= 0)
close(ps->wake_fds[1]);
#endif
+#if ERTS_POLL_USE_TIMERFD
+ if (ps->timer_fd >= 0)
+ close(ps->timer_fd);
+#endif
erts_smp_spin_lock(&pollsets_lock);
if (ps == pollsets)
@@ -2729,6 +2868,9 @@ ERTS_POLL_EXPORT(erts_poll_info)(ErtsPollSet ps, ErtsPollInfo *pip)
#if ERTS_POLL_USE_WAKEUP_PIPE
pip->poll_set_size++; /* Wakeup pipe */
#endif
+#if ERTS_POLL_USE_TIMERFD
+ pip->poll_set_size++; /* timerfd */
+#endif
pip->fallback_poll_set_size =
#if !ERTS_POLL_USE_FALLBACK
@@ -2857,14 +2999,18 @@ ERTS_POLL_EXPORT(erts_poll_get_selected_events)(ErtsPollSet ps,
ev[fd] = 0;
else {
ev[fd] = ps->fds_status[fd].events;
+ if (
#if ERTS_POLL_USE_WAKEUP_PIPE
- if (fd == ps->wake_fds[0] || fd == ps->wake_fds[1])
- ev[fd] |= ERTS_POLL_EV_NVAL;
+ fd == ps->wake_fds[0] || fd == ps->wake_fds[1] ||
+#endif
+#if ERTS_POLL_USE_TIMERFD
+ fd == ps->timer_fd ||
#endif
#if ERTS_POLL_USE_KERNEL_POLL
- if (fd == ps->kp_fd)
- ev[fd] |= ERTS_POLL_EV_NVAL;
+ fd == ps->kp_fd ||
#endif
+ 0)
+ ev[fd] |= ERTS_POLL_EV_NVAL;
}
}
ERTS_POLLSET_UNLOCK(ps);
diff --git a/erts/emulator/sys/common/erl_poll.h b/erts/emulator/sys/common/erl_poll.h
index d02ed2396b..ae2d063805 100644
--- a/erts/emulator/sys/common/erl_poll.h
+++ b/erts/emulator/sys/common/erl_poll.h
@@ -98,6 +98,8 @@
# endif
#endif
+#define ERTS_POLL_USE_TIMERFD 0
+
typedef Uint32 ErtsPollEvents;
#undef ERTS_POLL_EV_E2N
@@ -130,6 +132,12 @@ struct erts_sys_fd_type {
#include <sys/epoll.h>
+#ifdef HAVE_SYS_TIMERFD_H
+#include <sys/timerfd.h>
+#undef ERTS_POLL_USE_TIMERFD
+#define ERTS_POLL_USE_TIMERFD 1
+#endif
+
#define ERTS_POLL_EV_E2N(EV) \
((__uint32_t) (EV))
#define ERTS_POLL_EV_N2E(EV) \
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 11:27:43 +0000