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|
/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2006-2018. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/**
* @description Poll interface suitable for ERTS
*
* The interface is currently implemented using:
* - select
* - poll
* - /dev/poll
* - epoll with poll or select as fallback
* - kqueue with poll or select as fallback
*
*
* @author Rickard Green
* @author Lukas Larsson
*
* There are two major different implementations off IO polling in this
* file. The concurrent and non-concurrent implementations.
* When available epoll/kqueue are used to implement the concurrent
* versions. poll, select and dev/poll use non-concurrent updates.
*
* Concurrent version:
* In the concurrent version erts_poll_control directly modifies
* the kernel pollset without waking the thread that is waiting
* on events. Also the ErtsPollResFd type is directly mapped to
* the native event type, so no extra copying is needed. Note that
* as no locking at all is done, fds can be triggered that have been
* removed from the pollset. The check_io layer has to deal with this.
*
* Non-concurrent version:
* In the non-concurrent version, the pollset has an internal representation
* of the pollset that is updated by erts_poll_control. When an fd is updated,
* its number is placed in the update request queue and then the waiting thread
* is woken in order to see the change. The internal data in the pollset is
* protected by a mutex that has to be taken by both the modifying and waiting
* thread at different times.
*
* The non-concurrent pollset cannot have fd's closed in it while a thread is
* waiting on that fd. In order to fix this, when an ERTS_POLL_OP_DEL command
* is issued, the fd is marked as closing and the waiting thread is woken. The
* fd is then returned in the waiting threads results as ERTS_POLL_EV_NONE.
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if defined(__DARWIN__) || defined(__APPLE__) && defined(__MACH__)
/* Setting _DARWIN_UNLIMITED_SELECT before including sys/select.h enables
* the version of select() that does not place a limit on the fd_set.
*/
# define _DARWIN_UNLIMITED_SELECT
#endif
#ifndef WANT_NONBLOCKING
# define WANT_NONBLOCKING
#endif
#include "erl_thr_progress.h"
#include "erl_poll.h"
#if ERTS_POLL_USE_KQUEUE
# include <sys/types.h>
# include <sys/event.h>
# include <sys/time.h>
#endif
#if ERTS_POLL_USE_SELECT
# ifdef SYS_SELECT_H
# include <sys/select.h>
# endif
#elif defined(_DARWIN_UNLIMITED_SELECT)
# undef _DARWIN_UNLIMITED_SELECT
#endif
#ifdef NO_SYSCONF
# if ERTS_POLL_USE_SELECT
# include <sys/param.h>
# else
# include <limits.h>
# endif
#endif
#include "erl_driver.h"
#include "erl_alloc.h"
#include "erl_msacc.h"
#include "erl_misc_utils.h"
#if !defined(ERTS_POLL_USE_EPOLL) \
&& !defined(ERTS_POLL_USE_DEVPOLL) \
&& !defined(ERTS_POLL_USE_POLL) \
&& !defined(ERTS_POLL_USE_SELECT)
#error "Missing implementation of erts_poll()"
#endif
#if 0
#define ERTS_POLL_DEBUG_PRINT 1
#define DEBUG_PRINT(FMT, PS, ...) \
do { \
int myerrno = errno; \
erts_printf("%d: " FMT "\r\n", (PS)->id, ##__VA_ARGS__); \
errno = myerrno; \
} while(0)
/* Define to print info about modifications done to each fd */
#define DEBUG_PRINT_FD(FMT, PS, FD, ...) DEBUG_PRINT("%d: " FMT, PS, FD, ##__VA_ARGS__)
/* Define to print entry and exit from erts_poll_wait (can be very spammy) */
// #define DEBUG_PRINT_WAIT(FMT, PS, ...) DEBUG_PRINT(FMT, PS, ##__VA_ARGS__)
// #define DEBUG_PRINT_WAIT(FMT, PS, ...) do { if ((PS)->id != -1) DEBUG_PRINT(FMT, PS, ##__VA_ARGS__); } while(0)
#else
#define ERTS_POLL_DEBUG_PRINT 0
#define DEBUG_PRINT(...)
#endif
#ifndef DEBUG_PRINT_FD
#define DEBUG_PRINT_FD(...)
#endif
#ifndef DEBUG_PRINT_WAIT
#define DEBUG_PRINT_WAIT(...)
#endif
#if defined(_DARWIN_UNLIMITED_SELECT) && ERTS_POLL_USE_SELECT
typedef struct {
size_t sz;
fd_set* ptr;
}ERTS_fd_set;
# define ERTS_FD_ZERO(fds) memset((fds)->ptr, 0, (fds)->sz)
# define ERTS_FD_SIZE(n) ((((n)+NFDBITS-1)/NFDBITS)*sizeof(fd_mask))
static ERTS_INLINE void ERTS_FD_CLR(int fd, ERTS_fd_set *fds)
{
ASSERT(ERTS_FD_SIZE(fd+1) <= fds->sz);
FD_CLR(fd, fds->ptr);
}
static ERTS_INLINE void ERTS_FD_SET(int fd, ERTS_fd_set *fds)
{
ASSERT(ERTS_FD_SIZE(fd+1) <= fds->sz);
FD_SET(fd, fds->ptr);
}
static ERTS_INLINE int ERTS_FD_ISSET(int fd, ERTS_fd_set *fds)
{
ASSERT(ERTS_FD_SIZE(fd+1) <= fds->sz);
return FD_ISSET(fd, fds->ptr);
}
static void ERTS_FD_COPY(ERTS_fd_set *src, ERTS_fd_set *dst)
{
if (dst->sz != src->sz) {
dst->ptr = dst->ptr
? erts_realloc(ERTS_ALC_T_SELECT_FDS, dst->ptr, src->sz)
: erts_alloc(ERTS_ALC_T_SELECT_FDS, src->sz);
dst->sz = src->sz;
}
memcpy(dst->ptr, src->ptr, src->sz);
}
static ERTS_INLINE
int ERTS_SELECT(int nfds, ERTS_fd_set *readfds, ERTS_fd_set *writefds,
ERTS_fd_set *exceptfds, struct timeval *timeout)
{
ASSERT(!readfds || readfds->sz >= ERTS_FD_SIZE(nfds));
ASSERT(!writefds || writefds->sz >= ERTS_FD_SIZE(nfds));
ASSERT(!exceptfds);
return select(nfds,
(readfds ? readfds->ptr : NULL ),
(writefds ? writefds->ptr : NULL),
NULL,
timeout);
}
#else /* !_DARWIN_UNLIMITED_SELECT */
# define ERTS_fd_set fd_set
# define ERTS_FD_CLR FD_CLR
# define ERTS_FD_ISSET FD_ISSET
# define ERTS_FD_SET FD_SET
# define ERTS_FD_ZERO FD_ZERO
# define ERTS_FD_COPY(src,dst) (*(dst) = *(src))
# define ERTS_SELECT select
#endif
#define ERTS_POLL_IS_FALLBACK (ERTS_POLL_USE_POLL || ERTS_POLL_USE_SELECT) && ERTS_ENABLE_KERNEL_POLL
#define ERTS_POLL_USE_CONCURRENT_UPDATE (ERTS_POLL_USE_EPOLL || ERTS_POLL_USE_KQUEUE)
#define ERTS_POLL_USE_WAKEUP(ps) (!ERTS_POLL_USE_CONCURRENT_UPDATE || (ps)->id < 0)
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
#define ERTS_POLLSET_SET_HAVE_UPDATE_REQUESTS(PS) \
erts_atomic32_set_nob(&(PS)->have_update_requests, (erts_aint32_t) 1)
#define ERTS_POLLSET_UNSET_HAVE_UPDATE_REQUESTS(PS) \
erts_atomic32_set_nob(&(PS)->have_update_requests, (erts_aint32_t) 0)
#define ERTS_POLLSET_HAVE_UPDATE_REQUESTS(PS) \
((int) erts_atomic32_read_nob(&(PS)->have_update_requests))
#define ERTS_POLLSET_LOCK(PS) \
erts_mtx_lock(&(PS)->mtx)
#define ERTS_POLLSET_UNLOCK(PS) \
erts_mtx_unlock(&(PS)->mtx)
#else
#define ERTS_POLLSET_SET_HAVE_UPDATE_REQUESTS(PS)
#define ERTS_POLLSET_UNSET_HAVE_UPDATE_REQUESTS(PS)
#define ERTS_POLLSET_HAVE_UPDATE_REQUESTS(PS) 0
#define ERTS_POLLSET_LOCK(PS)
#define ERTS_POLLSET_UNLOCK(PS)
#endif
/*
* --- Data types ------------------------------------------------------------
*/
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
#define ERTS_POLLSET_UPDATE_REQ_BLOCK_SIZE 128
typedef struct ErtsPollSetUpdateRequestsBlock_ ErtsPollSetUpdateRequestsBlock;
struct ErtsPollSetUpdateRequestsBlock_ {
ErtsPollSetUpdateRequestsBlock *next;
int len;
int fds[ERTS_POLLSET_UPDATE_REQ_BLOCK_SIZE];
};
# define ERTS_POLL_FD_FLG_INURQ (((unsigned short) 1) << 0)
# define ERTS_POLL_FD_FLG_RST (((unsigned short) 1) << 1)
typedef struct {
#if ERTS_POLL_USE_POLL
int pix;
#endif
ErtsPollEvents used_events;
ErtsPollEvents events;
unsigned short flags;
} ErtsFdStatus;
#endif
/*
* This struct is not really exported, but it's nice to
* get unique names in debugger for kp/nkp
*/
struct ERTS_POLL_EXPORT(erts_pollset) {
int id;
int internal_fd_limit;
erts_atomic_t no_of_user_fds;
#if ERTS_POLL_USE_KERNEL_POLL
int kp_fd;
int oneshot;
#endif /* ERTS_POLL_USE_KERNEL_POLL */
#if ERTS_POLL_USE_POLL
int next_poll_fds_ix;
int no_poll_fds;
int poll_fds_len;
struct pollfd *poll_fds;
#elif ERTS_POLL_USE_SELECT
int next_sel_fd;
int max_fd;
ERTS_fd_set input_fds;
ERTS_fd_set res_input_fds;
ERTS_fd_set output_fds;
ERTS_fd_set res_output_fds;
#elif ERTS_POLL_USE_DEVPOLL
struct pollfd *poll_fds;
int poll_fds_ix;
#endif
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
ErtsFdStatus *fds_status;
int fds_status_len;
ErtsPollSetUpdateRequestsBlock update_requests;
ErtsPollSetUpdateRequestsBlock *curr_upd_req_block;
erts_atomic32_t have_update_requests;
erts_mtx_t mtx;
#else
int do_wakeup;
#endif
#if ERTS_POLL_USE_TIMERFD
int timer_fd;
#endif
ErtsMonotonicTime timeout_time;
erts_atomic32_t wakeup_state;
int wake_fds[2];
};
void erts_silence_warn_unused_result(long unused);
static void fatal_error(char *format, ...);
static int max_fds = -1;
#if ERTS_POLL_USE_POLL
#if !ERTS_POLL_IS_FALLBACK
static ERTS_INLINE short ev2pollev(ErtsPollEvents ev)
{
return ERTS_POLL_EV_E2N(ev);
}
static ERTS_INLINE ErtsPollEvents pollev2ev(short ev)
{
return ERTS_POLL_EV_N2E(ev);
}
#else /* ERTS_POLL_IS_FALLBACK */
static ERTS_INLINE short
ev2pollev(ErtsPollEvents ev)
{
short res_ev = (short) 0;
if (ev & ERTS_POLL_EV_IN)
res_ev |= ERTS_POLL_EV_NKP_IN;
if (ev & ERTS_POLL_EV_OUT)
res_ev |= ERTS_POLL_EV_NKP_OUT;
return res_ev;
}
static ERTS_INLINE ErtsPollEvents
pollev2ev(short ev)
{
ErtsPollEvents res_ev = (ErtsPollEvents) 0;
if (ev & ERTS_POLL_EV_NKP_IN)
res_ev |= ERTS_POLL_EV_IN;
if (ev & ERTS_POLL_EV_NKP_OUT)
res_ev |= ERTS_POLL_EV_OUT;
if (ev & ERTS_POLL_EV_NKP_ERR)
res_ev |= ERTS_POLL_EV_ERR;
if (ev & ERTS_POLL_EV_NKP_NVAL)
res_ev |= ERTS_POLL_EV_NVAL;
return res_ev;
}
#endif /* !ERTS_POLL_IS_FALLBACK */
#endif /* ERTS_POLL_USE_POLL */
#ifdef HARD_DEBUG
static void check_poll_result(ErtsPollResFd pr[], int len);
#endif /* HARD_DEBUG */
#if ERTS_POLL_USE_DEVPOLL && defined(DEBUG)
static void check_poll_status(ErtsPollSet *ps);
#endif /* ERTS_POLL_USE_DEVPOLL && DEBUG */
static void print_misc_debug_info(void);
#if ERTS_POLL_USE_EPOLL
uint32_t epoll_events(int kp_fd, int fd);
#endif
#define ERTS_POLL_NOT_WOKEN 0
#define ERTS_POLL_WOKEN -1
#define ERTS_POLL_WOKEN_INTR 1
static ERTS_INLINE void
reset_wakeup_state(ErtsPollSet *ps)
{
erts_atomic32_set_mb(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
}
static ERTS_INLINE int
is_woken(ErtsPollSet *ps)
{
return erts_atomic32_read_acqb(&ps->wakeup_state) != ERTS_POLL_NOT_WOKEN;
}
static ERTS_INLINE int
is_interrupted_reset(ErtsPollSet *ps)
{
return (erts_atomic32_xchg_acqb(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN)
== ERTS_POLL_WOKEN_INTR);
}
static ERTS_INLINE void
woke_up(ErtsPollSet *ps)
{
erts_aint32_t wakeup_state = erts_atomic32_read_acqb(&ps->wakeup_state);
if (wakeup_state == ERTS_POLL_NOT_WOKEN)
(void) erts_atomic32_cmpxchg_nob(&ps->wakeup_state,
ERTS_POLL_WOKEN,
ERTS_POLL_NOT_WOKEN);
ASSERT(erts_atomic32_read_nob(&ps->wakeup_state) != ERTS_POLL_NOT_WOKEN);
}
/*
* --- Wakeup pipe -----------------------------------------------------------
*/
static ERTS_INLINE void
wake_poller(ErtsPollSet *ps, int interrupted)
{
int wake;
erts_aint32_t wakeup_state;
if (!interrupted)
wakeup_state = erts_atomic32_cmpxchg_relb(&ps->wakeup_state,
ERTS_POLL_WOKEN,
ERTS_POLL_NOT_WOKEN);
else
wakeup_state = erts_atomic32_xchg_relb(&ps->wakeup_state,
ERTS_POLL_WOKEN_INTR);
wake = wakeup_state == ERTS_POLL_NOT_WOKEN;
if (wake)
{
ssize_t res;
DEBUG_PRINT_WAIT("wake_poller(%d)", ps, interrupted);
if (ps->wake_fds[1] < 0)
return; /* Not initialized yet */
do {
/* write() is async-signal safe (according to posix) */
res = write(ps->wake_fds[1], "!", 1);
} while (res < 0 && errno == EINTR);
if (res <= 0 && errno != ERRNO_BLOCK) {
fatal_error("%s:%d:wake_poller(): "
"Failed to write to wakeup pipe fd=%d: "
"%s (%d)\n",
__FILE__, __LINE__,
ps->wake_fds[1],
erl_errno_id(errno), errno);
}
}
}
static ERTS_INLINE void
cleanup_wakeup_pipe(ErtsPollSet *ps)
{
int intr = 0;
int fd = ps->wake_fds[0];
int res;
do {
char buf[32];
res = read(fd, buf, sizeof(buf));
if (res > 0)
intr = 1;
} while (res > 0 || (res < 0 && errno == EINTR));
if (res < 0 && errno != ERRNO_BLOCK) {
fatal_error("%s:%d:cleanup_wakeup_pipe(): "
"Failed to read on wakeup pipe fd=%d: "
"%s (%d)\n",
__FILE__, __LINE__,
fd,
erl_errno_id(errno), errno);
}
if (intr)
erts_atomic32_set_nob(&ps->wakeup_state, ERTS_POLL_WOKEN_INTR);
}
static void
create_wakeup_pipe(ErtsPollSet *ps)
{
int do_wake = 0;
int wake_fds[2];
ps->wake_fds[0] = -1;
ps->wake_fds[1] = -1;
if (pipe(wake_fds) < 0) {
fatal_error("%s:%d:create_wakeup_pipe(): "
"Failed to create pipe: %s (%d)\n",
__FILE__,
__LINE__,
erl_errno_id(errno),
errno);
}
SET_NONBLOCKING(wake_fds[0]);
SET_NONBLOCKING(wake_fds[1]);
DEBUG_PRINT("wakeup fds = {%d, %d}", ps, wake_fds[0], wake_fds[1]);
ERTS_POLL_EXPORT(erts_poll_control)(ps,
wake_fds[0],
ERTS_POLL_OP_ADD,
ERTS_POLL_EV_IN,
&do_wake);
if (ps->internal_fd_limit <= wake_fds[1])
ps->internal_fd_limit = wake_fds[1] + 1;
if (ps->internal_fd_limit <= wake_fds[0])
ps->internal_fd_limit = wake_fds[0] + 1;
ps->wake_fds[0] = wake_fds[0];
ps->wake_fds[1] = wake_fds[1];
}
/*
* --- 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 = timerfd_create(CLOCK_MONOTONIC,0);
ERTS_POLL_EXPORT(erts_poll_control)(ps,
timer_fd,
ERTS_POLL_OP_ADD,
ERTS_POLL_EV_IN,
&do_wake);
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, ErtsPollResFd pr[], 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 && pr[0].data.fd == ps->timer_fd)
return 0;
return res;
}
#endif /* ERTS_POLL_USE_TIMERFD */
/*
* --- Poll set update requests ----------------------------------------------
*/
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
static ERTS_INLINE void
enqueue_update_request(ErtsPollSet *ps, int fd)
{
ErtsPollSetUpdateRequestsBlock *urqbp;
ASSERT(fd < ps->fds_status_len);
if (ps->fds_status[fd].flags & ERTS_POLL_FD_FLG_INURQ)
return;
if (ps->update_requests.len == 0)
ERTS_POLLSET_SET_HAVE_UPDATE_REQUESTS(ps);
urqbp = ps->curr_upd_req_block;
if (urqbp->len == ERTS_POLLSET_UPDATE_REQ_BLOCK_SIZE) {
urqbp = erts_alloc(ERTS_ALC_T_POLLSET_UPDREQ,
sizeof(ErtsPollSetUpdateRequestsBlock));
urqbp->next = ps->curr_upd_req_block;
urqbp->len = 0;
ps->curr_upd_req_block = urqbp;
}
ps->fds_status[fd].flags |= ERTS_POLL_FD_FLG_INURQ;
urqbp->fds[urqbp->len++] = fd;
}
static ERTS_INLINE void
free_update_requests_block(ErtsPollSet *ps,
ErtsPollSetUpdateRequestsBlock *urqbp)
{
if (urqbp != &ps->update_requests)
erts_free(ERTS_ALC_T_POLLSET_UPDREQ, (void *) urqbp);
else {
urqbp->len = 0;
}
}
#endif /* !ERTS_POLL_USE_CONCURRENT_UPDATE */
/*
* --- Growing poll set structures -------------------------------------------
*/
#if !ERTS_NO_KERNEL_POLL_VERSION || !ERTS_ENABLE_KERNEL_POLL
/* only one shared implementation */
#define ERTS_FD_TABLE_MIN_LENGTH 1024
#define ERTS_FD_TABLE_EXP_THRESHOLD (2048*1024)
int erts_poll_new_table_len(int old_len, int need_len)
{
int new_len;
ASSERT(need_len > old_len);
if (need_len < ERTS_FD_TABLE_MIN_LENGTH) {
new_len = ERTS_FD_TABLE_MIN_LENGTH;
}
else {
new_len = old_len;
do {
if (new_len < ERTS_FD_TABLE_EXP_THRESHOLD)
new_len *= 2;
else
new_len += ERTS_FD_TABLE_EXP_THRESHOLD;
} while (new_len < need_len);
}
ASSERT(new_len >= need_len);
return new_len;
}
#endif
#if ERTS_POLL_USE_POLL
static void
grow_poll_fds(ErtsPollSet *ps, int min_ix)
{
int i;
int new_len = erts_poll_new_table_len(ps->poll_fds_len, min_ix + 1);
if (new_len > max_fds)
new_len = max_fds;
ps->poll_fds = (ps->poll_fds_len
? erts_realloc(ERTS_ALC_T_POLL_FDS,
ps->poll_fds,
sizeof(struct pollfd)*new_len)
: erts_alloc(ERTS_ALC_T_POLL_FDS,
sizeof(struct pollfd)*new_len));
for (i = ps->poll_fds_len; i < new_len; i++) {
ps->poll_fds[i].fd = -1;
ps->poll_fds[i].events = (short) 0;
ps->poll_fds[i].revents = (short) 0;
}
ps->poll_fds_len = new_len;
}
#endif
#ifdef _DARWIN_UNLIMITED_SELECT
static void
grow_select_fds(int fd, ERTS_fd_set* fds)
{
int new_len = erts_poll_new_table_len(fds->sz, fd + 1);
if (new_len > max_fds)
new_len = max_fds;
new_len = ERTS_FD_SIZE(new_len);
fds->ptr = fds->sz
? erts_realloc(ERTS_ALC_T_SELECT_FDS, fds->ptr, new_len)
: erts_alloc(ERTS_ALC_T_SELECT_FDS, new_len);
memset((char*)fds->ptr + fds->sz, 0, new_len - fds->sz);
fds->sz = new_len;
}
static ERTS_INLINE void
ensure_select_fds(int fd, ERTS_fd_set* in, ERTS_fd_set* out)
{
ASSERT(in->sz == out->sz);
if (ERTS_FD_SIZE(fd+1) > in->sz) {
grow_select_fds(fd, in);
grow_select_fds(fd, out);
}
}
static ERTS_INLINE int
check_select_fds(int fd, ERTS_fd_set* in, ERTS_fd_set* out)
{
ASSERT(in->sz == out->sz);
return (ERTS_FD_SIZE(fd+1) <= in->sz);
}
#else
# define ensure_select_fds(fd, in, out) do {} while(0)
# define check_select_fds(fd, in, out) (1)
#endif /* _DARWIN_UNLIMITED_SELECT */
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
static void
grow_fds_status(ErtsPollSet *ps, int min_fd)
{
int i;
int new_len = erts_poll_new_table_len(ps->fds_status_len, min_fd + 1);
ASSERT(min_fd < max_fds);
if (new_len > max_fds)
new_len = max_fds;
ps->fds_status = (ps->fds_status_len
? erts_realloc(ERTS_ALC_T_FD_STATUS,
ps->fds_status,
sizeof(ErtsFdStatus)*new_len)
: erts_alloc(ERTS_ALC_T_FD_STATUS,
sizeof(ErtsFdStatus)*new_len));
for (i = ps->fds_status_len; i < new_len; i++) {
#if ERTS_POLL_USE_POLL
ps->fds_status[i].pix = -1;
#endif
ps->fds_status[i].used_events = (ErtsPollEvents) 0;
ps->fds_status[i].events = (ErtsPollEvents) 0;
ps->fds_status[i].flags = (unsigned short) 0;
}
ps->fds_status_len = new_len;
}
#endif
/*
* --- Selecting fd to poll on -----------------------------------------------
*/
#if ERTS_POLL_USE_EPOLL
static int
update_pollset(ErtsPollSet *ps, int fd, ErtsPollOp op, ErtsPollEvents events)
{
int res;
int epoll_op = EPOLL_CTL_MOD;
struct epoll_event epe_templ;
struct epoll_event epe;
epe_templ.events = ERTS_POLL_EV_E2N(events);
epe_templ.data.fd = fd;
if (ps->oneshot)
epe_templ.events |= EPOLLONESHOT;
#ifdef VALGRIND
/* Silence invalid valgrind warning ... */
memset((void *) &epe.data, 0, sizeof(epoll_data_t));
#endif
switch (op) {
case ERTS_POLL_OP_DEL:
/* A note on EPOLL_CTL_DEL: linux kernel versions before 2.6.9
need a non-NULL event pointer even though it is ignored... */
epoll_op = EPOLL_CTL_DEL;
epe_templ.events = 0;
erts_atomic_dec_nob(&ps->no_of_user_fds);
break;
case ERTS_POLL_OP_ADD:
epoll_op = EPOLL_CTL_ADD;
erts_atomic_inc_nob(&ps->no_of_user_fds);
break;
case ERTS_POLL_OP_MOD:
epoll_op = EPOLL_CTL_MOD;
break;
default:
ASSERT(0);
break;
}
do {
/* We init 'epe' every time since epoll_ctl() may modify it
(not declared const and not documented as const). */
epe.events = epe_templ.events;
epe.data.fd = epe_templ.data.fd;
res = epoll_ctl(ps->kp_fd, epoll_op, fd, &epe);
} while (res != 0 && errno == EINTR);
#if ERTS_POLL_DEBUG_PRINT
{
int saved_errno = errno;
DEBUG_PRINT_FD("%s = epoll_ctl(%d, %s, %d, {0x%x, %d})",
ps, fd,
res == 0 ? "0" : erl_errno_id(errno),
ps->kp_fd,
(epoll_op == EPOLL_CTL_ADD
? "EPOLL_CTL_ADD"
: (epoll_op == EPOLL_CTL_MOD
? "EPOLL_CTL_MOD"
: (epoll_op == EPOLL_CTL_DEL
? "EPOLL_CTL_DEL"
: "UNKNOWN"))),
fd,
epe_templ.events,
fd);
errno = saved_errno;
}
#endif
if (res != 0) {
switch (op) {
case ERTS_POLL_OP_MOD:
epe.events = 0;
do {
/* We init 'epe' every time since epoll_ctl() may modify it
(not declared const and not documented as const). */
epe.events = 0;
epe.data.fd = fd;
res = epoll_ctl(ps->kp_fd, EPOLL_CTL_DEL, fd, &epe);
} while (res != 0 && errno == EINTR);
/* Fall through ... */
case ERTS_POLL_OP_ADD: {
erts_atomic_dec_nob(&ps->no_of_user_fds);
res = ERTS_POLL_EV_NVAL;
break;
}
case ERTS_POLL_OP_DEL: {
/*
* Since we use a lazy update approach EPOLL_CTL_DEL will
* frequently fail. This since epoll automatically removes
* a filedescriptor that is closed from the poll set.
*/
res = 0;
break;
}
default:
fatal_error("%s:%d:update_pollset(): Internal error\n",
__FILE__, __LINE__);
break;
}
} else {
res = events;
}
return res;
}
#endif /* ERTS_POLL_USE_EPOLL */
#if ERTS_POLL_USE_KQUEUE
/* Some versions of the EV_SET macro used kevp multiple times,
so we define out own version that make sure that it is safe
to do kevp++ in the argument list. */
#define ERTS_EV_SET(kevp, a, b, c, f) do { \
struct kevent *kevp_ = kevp; \
EV_SET(kevp_, a, b, c, 0, 0, f); \
} while(0)
static int
update_pollset(ErtsPollSet *ps, int fd, ErtsPollOp op, ErtsPollEvents events)
{
int res = 0, len = 0;
struct kevent evts[2];
struct timespec ts = {0, 0};
uint32_t oneshot = 0;
if (op == ERTS_POLL_OP_ADD) {
/* This is a hack to make the "noshell" option work; kqueue can poll
* these fds but will not report EV_EOF, so we return NVAL to use the
* fallback instead.
*
* This may be common to all pipes but we have no way to tell whether
* an fd is a pipe or not. */
switch (fd) {
case STDIN_FILENO:
case STDOUT_FILENO:
case STDERR_FILENO:
return ERTS_POLL_EV_NVAL;
default:
break;
}
}
#if defined(EV_DISPATCH) && !(defined(__OpenBSD__) || defined(__NetBSD__))
/* If we have EV_DISPATCH we use it, unless we are on OpenBSD/NetBSD as the
behavior of EV_EOF seems to be edge triggered there and we need it
to be level triggered.
The kevent descriptions for both read and write are added on OP_ADD
and removed on OP_DEL. And then after than only EV_ENABLE|EV_DISPATCH
are used.
It could be possible to not modify the pollset when disabling and/or
deleting events, but that may cause the poll threads to be awoken
a lot more than they should so we take the cost here instead of
in the poll thread.
Note: We need to have EV_DISPATCH both when the event is enabled and
disabled, as otherwise the event may be triggered twice on each re-arm.
Not sure if this is intended or not (can't find anything about it in the
man page), but it seems to be the way it works...
*/
if (ps->oneshot)
oneshot = EV_DISPATCH;
if (op == ERTS_POLL_OP_DEL) {
erts_atomic_dec_nob(&ps->no_of_user_fds);
/* We could probably skip this delete, do we want to? */
ERTS_EV_SET(&evts[len++], fd, EVFILT_READ, EV_DELETE, (void *) 0);
ERTS_EV_SET(&evts[len++], fd, EVFILT_WRITE, EV_DELETE, (void *) 0);
} else if (op == ERTS_POLL_OP_ADD) {
uint32_t flags;
erts_atomic_inc_nob(&ps->no_of_user_fds);
flags = EV_ADD|oneshot;
flags |= ((events & ERTS_POLL_EV_IN) ? 0 : EV_DISABLE);
ERTS_EV_SET(&evts[len++], fd, EVFILT_READ, flags, (void *) ERTS_POLL_EV_IN);
flags = EV_ADD|oneshot;
flags |= ((events & ERTS_POLL_EV_OUT) ? 0 : EV_DISABLE);
ERTS_EV_SET(&evts[len++], fd, EVFILT_WRITE, flags, (void *) ERTS_POLL_EV_OUT);
} else {
uint32_t flags;
ASSERT(op == ERTS_POLL_OP_MOD);
flags = oneshot;
flags |= (events & ERTS_POLL_EV_IN) ? EV_ENABLE : EV_DISABLE;
ERTS_EV_SET(&evts[len++], fd, EVFILT_READ, flags, (void *) ERTS_POLL_EV_IN);
flags = oneshot;
flags |= (events & ERTS_POLL_EV_OUT) ? EV_ENABLE : EV_DISABLE;
ERTS_EV_SET(&evts[len++], fd, EVFILT_WRITE, flags, (void *) ERTS_POLL_EV_OUT);
}
#else
uint32_t flags = EV_ADD|EV_ENABLE;
if (ps->oneshot) flags |= EV_ONESHOT;
if (op == ERTS_POLL_OP_DEL) {
erts_atomic_dec_nob(&ps->no_of_user_fds);
/* We don't do anything when a delete is issued. The fds will be removed
when they are triggered, or when they are closed. */
if (ps->oneshot)
events = 0;
else {
flags = EV_DELETE;
events = ERTS_POLL_EV_IN;
}
} else if (op == ERTS_POLL_OP_ADD) {
erts_atomic_inc_nob(&ps->no_of_user_fds);
/* Only allow EV_IN in non-oneshot poll-sets */
ASSERT(ps->oneshot || events == ERTS_POLL_EV_IN);
} else if (!ps->oneshot) {
ASSERT(op == ERTS_POLL_OP_MOD);
/* If we are not oneshot and do a mod we should disable the FD.
We assume that it is only the read side that is active as
currently only read is selected upon in the non-oneshot
poll-sets. */
if (!events)
flags = EV_DISABLE;
else
flags = EV_ENABLE;
events = ERTS_POLL_EV_IN;
}
if (events & ERTS_POLL_EV_IN) {
ERTS_EV_SET(&evts[len++], fd, EVFILT_READ, flags, (void *) ERTS_POLL_EV_IN);
}
if (events & ERTS_POLL_EV_OUT) {
ERTS_EV_SET(&evts[len++], fd, EVFILT_WRITE, flags, (void *) ERTS_POLL_EV_OUT);
}
#endif
if (len)
do {
res = kevent(ps->kp_fd, evts, len, NULL, 0, &ts);
} while (res < 0 && errno == EINTR);
#if ERTS_POLL_DEBUG_PRINT
{
int saved_errno = errno, i;
char keventb[255], *keventbp = keventb;
if (res < 0)
keventbp += sprintf(keventbp,"%s = ",erl_errno_id(saved_errno));
else
keventbp += sprintf(keventbp,"%d = ",res);
keventbp += sprintf(keventbp, "kevent(%d, {",ps->kp_fd);
for (i = 0; i < len; i++) {
const char *flags = "UNKNOWN";
if (evts[i].flags == (EV_DELETE)) flags = "EV_DELETE";
if (evts[i].flags == (EV_ADD)) flags = "EV_ADD";
if (evts[i].flags == (EV_ADD|EV_ONESHOT)) flags = "EV_ADD|EV_ONESHOT";
if (evts[i].flags == (EV_ENABLE)) flags = "EV_ENABLE";
if (evts[i].flags == (EV_DISABLE)) flags = "EV_DISABLE";
if (evts[i].flags == (EV_ADD|EV_DISABLE)) flags = "EV_ADD|EV_DISABLE";
#ifdef EV_DISPATCH
if (evts[i].flags == (EV_ADD|EV_DISPATCH)) flags = "EV_ADD|EV_DISPATCH";
if (evts[i].flags == (EV_ENABLE|EV_DISPATCH)) flags = "EV_ENABLE|EV_DISPATCH";
if (evts[i].flags == (EV_DISABLE|EV_DISPATCH)) flags = "EV_DISABLE|EV_DISABLE";
#endif
keventbp += sprintf(keventbp, "%s{%lu, %s, %s}",i > 0 ? ", " : "",
evts[i].ident,
(evts[i].filter == EVFILT_READ
? "EVFILT_READ"
: (evts[i].filter == EVFILT_WRITE
? "EVFILT_WRITE"
: "UNKNOWN")), flags);
}
keventbp += sprintf(keventbp, "}, %d)", len);
DEBUG_PRINT_FD("%s", ps, fd, keventb);
errno = saved_errno;
}
#endif
if (res < 0) {
if (op != ERTS_POLL_OP_DEL) {
#ifdef EV_RECEIPT
struct kevent receipt_evts[2];
len = 0;
ERTS_EV_SET(&evts[len++], fd, EVFILT_WRITE, EV_DELETE|EV_RECEIPT, (void *) 0);
ERTS_EV_SET(&evts[len++], fd, EVFILT_READ, EV_DELETE|EV_RECEIPT, (void *) 0);
do {
res = kevent(ps->kp_fd, evts, len, receipt_evts, 2, &ts);
} while (res < 0 && errno == EINTR);
#else
ERTS_EV_SET(&evts[0], fd, EVFILT_WRITE, EV_DELETE, (void *) 0);
do {
res = kevent(ps->kp_fd, evts, 1, NULL, 0, &ts);
} while (res < 0 && errno == EINTR);
ERTS_EV_SET(&evts[0], fd, EVFILT_READ, EV_DELETE, (void *) 0);
do {
res = kevent(ps->kp_fd, evts, 1, NULL, 0, &ts);
} while (res < 0 && errno == EINTR);
#endif
if (op == ERTS_POLL_OP_ADD)
erts_atomic_dec_nob(&ps->no_of_user_fds);
events = ERTS_POLL_EV_NVAL;
} else
events = 0;
}
return events;
}
#endif /* ERTS_POLL_USE_KQUEUE */
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
static ERTS_INLINE void
init_batch_update(ErtsPollSet *ps, int len)
{
#if ERTS_POLL_USE_DEVPOLL
ASSERT(ps->poll_fds == NULL);
ps->poll_fds = erts_alloc(ERTS_ALC_T_TMP, sizeof(struct pollfd) * len);
ps->poll_fds_ix = 0;
#endif
}
static ERTS_INLINE void
write_batch_update(ErtsPollSet *ps)
{
#if ERTS_POLL_USE_DEVPOLL
ssize_t wres;
char *buf = (char *) ps->poll_fds;
size_t buf_size = sizeof(struct pollfd)*ps->poll_fds_ix;
while (1) {
wres = write(ps->kp_fd, (void *) buf, buf_size);
if (wres < 0) {
if (errno == EINTR)
continue;
fatal_error("%s:%d:write_batch_buf(): "
"Failed to write to /dev/poll: "
"%s (%d)\n",
__FILE__, __LINE__,
erl_errno_id(errno), errno);
}
#if ERTS_POLL_DEBUG_PRINT
{
int saved_errno = errno, i;
char devpollb[2048], *devpollbp = devpollb;
devpollbp += sprintf(devpollbp, "%d = devpoll(%d, {", wres, ps->kp_fd);
for (i = 0; i < wres / sizeof(struct pollfd); i++) {
if (devpollbp == devpollb)
devpollbp += sprintf(devpollbp, "%d = devpoll(%d, {", wres, ps->kp_fd);
devpollbp += sprintf(devpollbp, "%s{fd = %d, events = %s}",
i > 0 ? ", " : "",
ps->poll_fds[i].fd,
ev2str(ps->poll_fds[i].events));
if (devpollbp - devpollb > 512) {
devpollbp += sprintf(devpollbp, "}, %d)", ps->poll_fds_ix);
DEBUG_PRINT("%s", ps, devpollb);
devpollbp = devpollb;
}
}
devpollbp += sprintf(devpollbp, "}, %d)", ps->poll_fds_ix);
DEBUG_PRINT("%s", ps, devpollb);
errno = saved_errno;
}
#endif
buf_size -= wres;
if (buf_size <= 0)
break;
buf += wres;
}
if (buf_size < 0) {
fatal_error("%s:%d:write_devpoll_buf(): Internal error\n",
__FILE__, __LINE__);
}
erts_free(ERTS_ALC_T_TMP, ps->poll_fds);
ps->poll_fds = NULL;
#endif
}
static ERTS_INLINE int
need_update(ErtsPollSet *ps, int fd, int *resetp)
{
int reset;
ASSERT(fd < ps->fds_status_len);
reset = (int) (ps->fds_status[fd].flags & ERTS_POLL_FD_FLG_RST);
ps->fds_status[fd].flags &= ~ERTS_POLL_FD_FLG_RST;
*resetp = reset;
if (reset || ps->fds_status[fd].used_events != ps->fds_status[fd].events)
return 1;
return 0;
}
static int update_pollset(ErtsPollSet *ps, ErtsPollResFd pr[], int fd)
{
int res = 0, reset = 0;
ErtsPollEvents events = ps->fds_status[fd].events;
ASSERT(fd < ps->fds_status_len);
if (!need_update(ps, fd, &reset))
return res;
#if ERTS_POLL_USE_POLL /* --- poll -------------------------------- */
if (!events) {
int pix = ps->fds_status[fd].pix;
int last_pix;
if (reset) {
/* When a fd has been reset, we tell the caller of erts_poll_wait
this by setting the fd as ERTS_POLL_EV_NONE */
ERTS_POLL_RES_SET_FD(&pr[res], fd);
ERTS_POLL_RES_SET_EVTS(&pr[res], ERTS_POLL_EV_NONE);
DEBUG_PRINT_FD("trig %s (poll)", ps, fd, ev2str(ERTS_POLL_EV_NONE));
res++;
}
if (pix < 0) {
return res;
}
erts_atomic_dec_nob(&ps->no_of_user_fds);
last_pix = --ps->no_poll_fds;
if (pix != last_pix) {
/* Move last pix to this pix */
ps->poll_fds[pix].fd = ps->poll_fds[last_pix].fd;
ps->poll_fds[pix].events = ps->poll_fds[last_pix].events;
ps->poll_fds[pix].revents = ps->poll_fds[last_pix].revents;
ps->fds_status[ps->poll_fds[pix].fd].pix = pix;
}
/* Clear last pix */
ps->poll_fds[last_pix].fd = -1;
ps->poll_fds[last_pix].events = (short) 0;
ps->poll_fds[last_pix].revents = (short) 0;
/* Clear this fd status */
ps->fds_status[fd].pix = -1;
ps->fds_status[fd].used_events = (ErtsPollEvents) 0;
}
else {
int pix = ps->fds_status[fd].pix;
if (pix < 0) {
erts_atomic_inc_nob(&ps->no_of_user_fds);
ps->fds_status[fd].pix = pix = ps->no_poll_fds++;
if (pix >= ps->poll_fds_len)
grow_poll_fds(ps, pix);
ps->poll_fds[pix].fd = fd;
ps->fds_status[fd].pix = pix;
}
/* Events to be used in next poll */
ps->poll_fds[pix].events = ev2pollev(events);
if (ps->poll_fds[pix].revents) {
/* Remove result events that we should not poll for anymore */
ps->poll_fds[pix].revents
&= ev2pollev(~(~ps->fds_status[fd].used_events
& events));
}
/* Save events to be used in next poll */
ps->fds_status[fd].used_events = events;
}
return res;
#elif ERTS_POLL_USE_SELECT /* --- select ------------------------------ */
if (!events) {
if (reset) {
/* When a fd has been reset, we tell the caller of erts_poll_wait
this by setting the fd as ERTS_POLL_EV_NONE */
ERTS_POLL_RES_SET_FD(&pr[res], fd);
ERTS_POLL_RES_SET_EVTS(&pr[res], ERTS_POLL_EV_NONE);
DEBUG_PRINT_FD("trig %s (select)", ps, fd, ev2str(ERTS_POLL_EV_NONE));
res++;
}
if (check_select_fds(fd, &ps->input_fds, &ps->output_fds)) {
ERTS_FD_CLR(fd, &ps->input_fds);
ERTS_FD_CLR(fd, &ps->output_fds);
}
if (ps->fds_status[fd].used_events) {
erts_atomic_dec_nob(&ps->no_of_user_fds);
ps->fds_status[fd].used_events = (ErtsPollEvents) 0;
}
if (fd == ps->max_fd) {
int max = ps->max_fd;
for (max = ps->max_fd; max >= 0; max--)
if (ps->fds_status[max].used_events)
break;
ps->max_fd = max;
}
} else {
ensure_select_fds(fd, &ps->input_fds, &ps->output_fds);
if (!ps->fds_status[fd].used_events)
erts_atomic_inc_nob(&ps->no_of_user_fds);
if (events & ERTS_POLL_EV_IN)
ERTS_FD_SET(fd, &ps->input_fds);
else
ERTS_FD_CLR(fd, &ps->input_fds);
if (events & ERTS_POLL_EV_OUT)
ERTS_FD_SET(fd, &ps->output_fds);
else
ERTS_FD_CLR(fd, &ps->output_fds);
ps->fds_status[fd].used_events = events;
if (fd > ps->max_fd)
ps->max_fd = fd;
}
return res;
#elif ERTS_POLL_USE_DEVPOLL
if (!events) {
if (reset) {
/* When a fd has been reset, we tell the caller of erts_poll_wait
this by setting the fd as ERTS_POLL_EV_NONE */
ERTS_POLL_RES_SET_FD(&pr[res], fd);
ERTS_POLL_RES_SET_EVTS(&pr[res], ERTS_POLL_EV_NONE);
DEBUG_PRINT_FD("trig %s (devpoll)", ps, fd, ev2str(ERTS_POLL_EV_NONE));
res++;
}
ps->poll_fds[ps->poll_fds_ix].fd = fd;
ps->poll_fds[ps->poll_fds_ix].revents = 0;
ps->poll_fds[ps->poll_fds_ix++].events = POLLREMOVE;
if (ps->fds_status[fd].used_events) {
erts_atomic_dec_nob(&ps->no_of_user_fds);
ps->fds_status[fd].used_events = 0;
}
} else {
if (!ps->fds_status[fd].used_events) {
erts_atomic_inc_nob(&ps->no_of_user_fds);
}
ps->poll_fds[ps->poll_fds_ix].fd = fd;
ps->poll_fds[ps->poll_fds_ix].revents = 0;
ps->poll_fds[ps->poll_fds_ix++].events = ERTS_POLL_EV_E2N(events);
ps->fds_status[fd].used_events = ps->fds_status[fd].events;
}
return res;
#endif
}
static int
handle_update_requests(ErtsPollSet *ps, ErtsPollResFd pr[], int no_fds)
{
int res = 0;
ErtsPollSetUpdateRequestsBlock *urqbp = ps->curr_upd_req_block;
while (urqbp) {
ErtsPollSetUpdateRequestsBlock *free_urqbp = urqbp;
int i;
int len = urqbp->len;
init_batch_update(ps, len);
for (i = 0; i < len; i++) {
int fd = urqbp->fds[i];
ASSERT(fd < ps->fds_status_len);
ASSERT(ps->fds_status[fd].flags & ERTS_POLL_FD_FLG_INURQ);
/* We have run out of PollResFd slots to put results in,
so we yield here and return later for more. */
if (res == no_fds && pr != NULL) {
memmove(urqbp->fds, urqbp->fds+i, sizeof(int) * (len - i));
urqbp->len -= i;
ps->curr_upd_req_block = urqbp;
write_batch_update(ps);
return res;
}
if (ps->fds_status[fd].flags & ERTS_POLL_FD_FLG_INURQ) {
ps->fds_status[fd].flags &= ~ERTS_POLL_FD_FLG_INURQ;
res += update_pollset(ps, pr + res, fd);
}
}
free_urqbp = urqbp;
urqbp = urqbp->next;
free_update_requests_block(ps, free_urqbp);
write_batch_update(ps);
}
ps->curr_upd_req_block = &ps->update_requests;
#if ERTS_POLL_USE_DEVPOLL && defined(HARD_DEBUG)
check_poll_status(ps);
#endif
ERTS_POLLSET_UNSET_HAVE_UPDATE_REQUESTS(ps);
return res;
}
#endif /* !ERTS_POLL_USE_CONCURRENT_UPDATE */
static ERTS_INLINE ErtsPollEvents
poll_control(ErtsPollSet *ps, int fd, ErtsPollOp op,
ErtsPollEvents events, int *do_wake)
{
ErtsPollEvents new_events;
if (fd < ps->internal_fd_limit || fd >= max_fds) {
if (fd < 0 || fd >= max_fds) {
new_events = ERTS_POLL_EV_ERR;
goto done;
}
#if ERTS_POLL_USE_KERNEL_POLL
if (fd == ps->kp_fd) {
new_events = ERTS_POLL_EV_NVAL;
goto done;
}
#endif
if (fd == ps->wake_fds[0] || fd == ps->wake_fds[1]) {
new_events = ERTS_POLL_EV_NVAL;
goto done;
}
#if ERTS_POLL_USE_TIMERFD
if (fd == ps->timer_fd) {
new_events = ERTS_POLL_EV_NVAL;
goto done;
}
#endif
}
#if ERTS_POLL_USE_CONCURRENT_UPDATE
new_events = update_pollset(ps, fd, op, events);
#else /* !ERTS_POLL_USE_CONCURRENT_UPDATE */
if (fd >= ps->fds_status_len)
grow_fds_status(ps, fd);
ASSERT(fd < ps->fds_status_len);
if (op == ERTS_POLL_OP_DEL) {
ps->fds_status[fd].flags |= ERTS_POLL_FD_FLG_RST;
ps->fds_status[fd].events = 0;
*do_wake = 1;
} else if (op == ERTS_POLL_OP_ADD) {
ASSERT(ps->fds_status[fd].events == 0);
ps->fds_status[fd].events = events;
*do_wake = 1;
} else {
ASSERT(op == ERTS_POLL_OP_MOD);
ps->fds_status[fd].events = events;
*do_wake = 1;
}
new_events = ps->fds_status[fd].events;
enqueue_update_request(ps, fd);
#endif /* !ERTS_POLL_USE_CONCURRENT_UPDATE */
done:
DEBUG_PRINT_FD("%s = %s(%p, %d, %s, %s) do_wake=%d",
ps, fd, ev2str(new_events), __FUNCTION__, ps,
fd, op2str(op), ev2str(events), *do_wake);
return new_events;
}
ErtsPollEvents
ERTS_POLL_EXPORT(erts_poll_control)(ErtsPollSet *ps,
ErtsSysFdType fd,
ErtsPollOp op,
ErtsPollEvents events,
int* do_wake) /* In: Wake up polling thread */
/* Out: Poller is woken */
{
ErtsPollEvents res;
ERTS_POLLSET_LOCK(ps);
res = poll_control(ps, fd, op, events, do_wake);
ERTS_POLLSET_UNLOCK(ps);
if (*do_wake)
wake_poller(ps, 0);
return res;
}
/*
* --- Wait on poll set ------------------------------------------------------
*/
#if ERTS_POLL_USE_KERNEL_POLL
static ERTS_INLINE int
ERTS_POLL_EXPORT(save_result)(ErtsPollSet *ps, ErtsPollResFd pr[], int max_res, int chk_fds_res, int ebadf)
{
int n = chk_fds_res < max_res ? chk_fds_res : max_res, i;
int res = n;
int wake_fd = ps->wake_fds[0];
if (ERTS_POLL_USE_WAKEUP(ps) || ERTS_POLL_DEBUG_PRINT || ERTS_POLL_USE_TIMERFD) {
for (i = 0; i < n; i++) {
int fd = ERTS_POLL_RES_GET_FD(&pr[i]);
#if ERTS_POLL_DEBUG_PRINT
ErtsPollEvents evts = ERTS_POLL_RES_GET_EVTS(pr+i);
if (fd != wake_fd
#if ERTS_POLL_USE_TIMERFD
&& fd != ps->timer_fd
#endif
)
DEBUG_PRINT_FD("trig %s (%s)", ps, fd,
ev2str(evts),
#if ERTS_POLL_USE_KQUEUE
"kqueue"
#elif ERTS_POLL_USE_EPOLL
"epoll"
#else
"/dev/poll"
#endif
);
#endif
if (ERTS_POLL_USE_WAKEUP(ps) && fd == wake_fd) {
cleanup_wakeup_pipe(ps);
ERTS_POLL_RES_SET_FD(&pr[i], -1);
ERTS_POLL_RES_SET_EVTS(&pr[i], ERTS_POLL_EV_NONE);
res--;
}
#if ERTS_POLL_USE_TIMERFD
else if (fd == ps->timer_fd) {
ERTS_POLL_RES_SET_FD(&pr[i], -1);
ERTS_POLL_RES_SET_EVTS(&pr[i], ERTS_POLL_EV_NONE);
res--;
}
#endif
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
else {
/* Reset the events to emulate ONESHOT semantics */
ps->fds_status[fd].events = 0;
enqueue_update_request(ps, fd);
}
#endif
}
}
if (res == 0)
return res;
else
return n;
}
#else /* !ERTS_POLL_USE_KERNEL_POLL */
static ERTS_INLINE int
ERTS_POLL_EXPORT(save_result)(ErtsPollSet *ps, ErtsPollResFd pr[], int max_res, int chk_fds_res, int ebadf)
{
#if ERTS_POLL_USE_POLL /* --- poll -------------------------------- */
int res = 0;
int wake_fd = ps->wake_fds[0];
int i, first_ix, end_ix;
/*
* In order to be somewhat fair, we continue on the poll_fds
* index where we stopped last time.
*/
first_ix = i = ((ps->next_poll_fds_ix < ps->no_poll_fds)
? ps->next_poll_fds_ix
: 0);
end_ix = ps->no_poll_fds;
while (1) {
while (i < end_ix && res < max_res) {
if (ps->poll_fds[i].revents != (short) 0) {
int fd = ps->poll_fds[i].fd;
ErtsPollEvents revents;
if (fd == wake_fd) {
cleanup_wakeup_pipe(ps);
i++;
continue;
}
revents = pollev2ev(ps->poll_fds[i].revents);
ERTS_POLL_RES_SET_FD(&pr[res], fd);
ERTS_POLL_RES_SET_EVTS(&pr[res], revents);
/* If an fd returns as error, we may want to check the
update_requests queue to see if it has been reset
before delivering the result?!?! This should allow
the user to do driver_dselect + close without waiting
for stop_select... */
DEBUG_PRINT_FD("trig %s (poll)", ps, ERTS_POLL_RES_GET_FD(&pr[res]),
ev2str(ERTS_POLL_RES_GET_EVTS(&pr[res])));
res++;
/* Clear the events for this fd in order to mimic
how epoll ONESHOT works */
ps->fds_status[fd].events = 0;
enqueue_update_request(ps, fd);
}
i++;
}
if (res == max_res || i == first_ix)
break;
ASSERT(i == ps->no_poll_fds);
i = 0;
end_ix = first_ix;
}
ps->next_poll_fds_ix = i;
return res;
#elif ERTS_POLL_USE_SELECT /* --- select ------------------------------ */
int res = 0;
int wake_fd = ps->wake_fds[0];
int fd, first_fd, end_fd;
/*
* In order to be fair, we continue on the fd where we stopped
* last time.
*/
first_fd = fd = ps->next_sel_fd <= ps->max_fd ? ps->next_sel_fd : 0;
end_fd = ps->max_fd + 1;
if (!ebadf) {
while (1) {
while (fd < end_fd && res < max_res) {
ErtsPollEvents events = 0;
if (ERTS_FD_ISSET(fd, &ps->res_input_fds)) {
if (fd == wake_fd) {
cleanup_wakeup_pipe(ps);
fd++;
continue;
}
events |= ERTS_POLL_EV_IN;
}
if (ERTS_FD_ISSET(fd, &ps->res_output_fds))
events |= ERTS_POLL_EV_OUT;
if (events) {
ERTS_POLL_RES_SET_FD(&pr[res], fd);
ERTS_POLL_RES_SET_EVTS(&pr[res], events);
res++;
ps->fds_status[fd].events = 0;
enqueue_update_request(ps, fd);
}
fd++;
}
if (res == max_res || fd == first_fd)
break;
ASSERT(fd == ps->max_fd + 1);
fd = 0;
end_fd = first_fd;
}
}
else {
/*
* Bad file descriptors in poll set.
*
* This only happens when running poorly written
* drivers. This code could be optimized, but we
* don't bother since it should never happen...
*/
while (1) {
while (fd < end_fd && res < max_res) {
if (ps->fds_status[fd].events) {
int sres;
ERTS_fd_set *iset = NULL;
ERTS_fd_set *oset = NULL;
if (ps->fds_status[fd].events & ERTS_POLL_EV_IN) {
iset = &ps->res_input_fds;
ERTS_FD_ZERO(iset);
ERTS_FD_SET(fd, iset);
}
if (ps->fds_status[fd].events & ERTS_POLL_EV_OUT) {
oset = &ps->res_output_fds;
ERTS_FD_ZERO(oset);
ERTS_FD_SET(fd, oset);
}
do {
/* Initiate 'tv' each time;
select() may modify it */
SysTimeval tv = {0, 0};
sres = ERTS_SELECT(ps->max_fd+1, iset, oset, NULL, &tv);
} while (sres < 0 && errno == EINTR);
if (sres < 0) {
if (fd == wake_fd) {
cleanup_wakeup_pipe(ps);
fd++;
continue;
}
ERTS_POLL_RES_SET_FD(&pr[res], fd);
ERTS_POLL_RES_SET_EVTS(&pr[res], ERTS_POLL_EV_NVAL);
res++;
}
else if (sres > 0) {
ErtsPollEvents events = 0;
ERTS_POLL_RES_SET_FD(&pr[res], fd);
if (iset && ERTS_FD_ISSET(fd, iset)) {
if (fd == wake_fd) {
cleanup_wakeup_pipe(ps);
fd++;
continue;
}
events |= ERTS_POLL_EV_IN;
}
if (oset && ERTS_FD_ISSET(fd, oset)) {
events |= ERTS_POLL_EV_OUT;
}
ASSERT(events);
ERTS_POLL_RES_SET_EVTS(&pr[res], events);
res++;
}
}
fd++;
}
if (res == max_res || fd == first_fd)
break;
ASSERT(fd == ps->max_fd + 1);
fd = 0;
end_fd = first_fd;
}
}
ps->next_sel_fd = fd;
return res;
#endif /* ERTS_POLL_USE_SELECT */
}
#endif /* !ERTS_POLL_USE_KERNEL_POLL */
static ERTS_INLINE ErtsMonotonicTime
get_timeout(ErtsPollSet *ps,
int resolution,
ErtsMonotonicTime timeout_time)
{
ErtsMonotonicTime timeout;
if (timeout_time == ERTS_POLL_NO_TIMEOUT) {
timeout = 0;
}
else if (timeout_time == ERTS_POLL_INF_TIMEOUT) {
timeout = -1;
}
else {
ErtsMonotonicTime diff_time, current_time;
current_time = erts_get_monotonic_time(NULL);
diff_time = timeout_time - current_time;
if (diff_time <= 0) {
timeout = 0;
}
else {
switch (resolution) {
case 1000:
/* Round up to nearest even milli second */
timeout = ERTS_MONOTONIC_TO_MSEC(diff_time - 1) + 1;
if (timeout > (ErtsMonotonicTime) INT_MAX)
timeout = (ErtsMonotonicTime) INT_MAX;
timeout -= ERTS_PREMATURE_TIMEOUT(timeout, 1000);
break;
case 1000000:
/* Round up to nearest even micro second */
timeout = ERTS_MONOTONIC_TO_USEC(diff_time - 1) + 1;
timeout -= ERTS_PREMATURE_TIMEOUT(timeout, 1000*1000);
break;
case 1000000000:
/* Round up to nearest even nano second */
timeout = ERTS_MONOTONIC_TO_NSEC(diff_time - 1) + 1;
timeout -= ERTS_PREMATURE_TIMEOUT(timeout, 1000*1000*1000);
break;
default:
ERTS_INTERNAL_ERROR("Invalid resolution");
timeout = 0;
break;
}
}
}
return timeout;
}
#if ERTS_POLL_USE_SELECT
static ERTS_INLINE int
get_timeout_timeval(ErtsPollSet *ps,
SysTimeval *tvp,
ErtsMonotonicTime timeout_time)
{
ErtsMonotonicTime timeout = get_timeout(ps,
1000*1000,
timeout_time);
if (!timeout) {
tvp->tv_sec = 0;
tvp->tv_usec = 0;
return 0;
}
else if (timeout == -1) {
return -1;
}
else {
ErtsMonotonicTime sec = timeout/(1000*1000);
tvp->tv_sec = sec;
tvp->tv_usec = timeout - sec*(1000*1000);
ASSERT(tvp->tv_sec >= 0);
ASSERT(tvp->tv_usec >= 0);
ASSERT(tvp->tv_usec < 1000*1000);
return 1;
}
}
#endif
#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,
struct timespec *tsp,
ErtsMonotonicTime timeout_time)
{
ErtsMonotonicTime timeout = get_timeout(ps,
1000*1000*1000,
timeout_time);
if (!timeout) {
tsp->tv_sec = 0;
tsp->tv_nsec = 0;
return 0;
}
else if (timeout == -1) {
return -1;
}
else {
ErtsMonotonicTime sec = timeout/(1000*1000*1000);
tsp->tv_sec = sec;
tsp->tv_nsec = timeout - sec*(1000*1000*1000);
ASSERT(tsp->tv_sec >= 0);
ASSERT(tsp->tv_nsec >= 0);
ASSERT(tsp->tv_nsec < 1000*1000*1000);
return 1;
}
}
#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, ErtsPollResFd pr[], int max_res, ErtsMonotonicTime timeout_time)
{
int res;
int timeout;
DEBUG_PRINT_WAIT("Entering check_fd_events(), timeout=%d", ps, timeout_time);
{
#if ERTS_POLL_USE_EPOLL /* --- epoll ------------------------------- */
#if ERTS_POLL_USE_TIMERFD
struct itimerspec its;
timeout = get_timeout_itimerspec(ps, &its, timeout_time);
if (timeout > 0) {
timerfd_set(ps, &its);
res = epoll_wait(ps->kp_fd, pr, max_res, -1);
res = timerfd_clear(ps, pr, res, max_res);
} else {
res = epoll_wait(ps->kp_fd, pr, max_res, timeout);
}
#else /* !ERTS_POLL_USE_TIMERFD */
timeout = (int) get_timeout(ps, 1000, timeout_time);
res = epoll_wait(ps->kp_fd, pr, max_res, timeout);
#endif /* !ERTS_POLL_USE_TIMERFD */
#elif ERTS_POLL_USE_KQUEUE /* --- kqueue ------------------------------ */
struct timespec ts;
struct timespec *tsp;
timeout = get_timeout_timespec(ps, &ts, timeout_time);
tsp = timeout < 0 ? NULL : &ts;
res = kevent(ps->kp_fd, NULL, 0, pr, max_res, tsp);
#elif ERTS_POLL_USE_DEVPOLL /* --- devpoll ----------------------------- */
/*
* The ioctl() will fail with EINVAL on Solaris 10 if dp_nfds
* is set too high. dp_nfds should not be set greater than
* the maximum number of file descriptors in the poll set.
*/
struct dvpoll poll_res;
int nfds = (int) erts_atomic_read_nob(&ps->no_of_user_fds) + 1 /* wakeup pipe */;
poll_res.dp_nfds = nfds < max_res ? nfds : max_res;
poll_res.dp_fds = pr;
poll_res.dp_timeout = (int) get_timeout(ps, 1000, timeout_time);
res = ioctl(ps->kp_fd, DP_POLL, &poll_res);
#elif ERTS_POLL_USE_POLL && defined(HAVE_PPOLL) /* --- ppoll ---------------- */
struct timespec ts;
struct timespec *tsp = &ts;
timeout = get_timeout_timespec(ps, &ts, timeout_time);
if (timeout < 0) tsp = NULL;
res = ppoll(ps->poll_fds, ps->no_poll_fds, tsp, NULL);
#elif ERTS_POLL_USE_POLL /* --- poll --------------------------------- */
timeout = (int) get_timeout(ps, 1000, timeout_time);
res = poll(ps->poll_fds, ps->no_poll_fds, timeout);
#elif ERTS_POLL_USE_SELECT /* --- select ------------------------------ */
SysTimeval tv;
SysTimeval *tvp;
timeout = get_timeout_timeval(ps, &tv, timeout_time);
tvp = timeout < 0 ? NULL : &tv;
ERTS_FD_COPY(&ps->input_fds, &ps->res_input_fds);
ERTS_FD_COPY(&ps->output_fds, &ps->res_output_fds);
res = ERTS_SELECT(ps->max_fd + 1,
&ps->res_input_fds,
&ps->res_output_fds,
NULL,
tvp);
#endif /* ----------------------------------------- */
}
DEBUG_PRINT_WAIT("Leaving check_fd_events(), res=%d", ps, res);
return res;
}
int
ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet *ps,
ErtsPollResFd pr[],
int *len,
ErtsThrPrgrData *tpd,
ErtsMonotonicTime timeout_time)
{
int res, no_fds, used_fds = 0;
int ebadf = 0;
int do_wait;
int ps_locked = 0;
ERTS_MSACC_DECLARE_CACHE();
no_fds = *len;
*len = 0;
ASSERT(no_fds > 0);
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
if (ERTS_POLLSET_HAVE_UPDATE_REQUESTS(ps)) {
ERTS_POLLSET_LOCK(ps);
used_fds = handle_update_requests(ps, pr, no_fds);
ERTS_POLLSET_UNLOCK(ps);
if (used_fds == no_fds) {
*len = used_fds;
return 0;
}
}
#endif
do_wait = !is_woken(ps) && used_fds == 0 && timeout_time != ERTS_POLL_NO_TIMEOUT;
DEBUG_PRINT_WAIT("Entering %s(), do_wait=%d", ps, __FUNCTION__, do_wait);
if (do_wait) {
tpd = tpd ? tpd : erts_thr_prgr_data(NULL);
erts_thr_progress_prepare_wait(tpd);
ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_SLEEP);
} else
timeout_time = ERTS_POLL_NO_TIMEOUT;
while (1) {
res = check_fd_events(ps, pr + used_fds, no_fds - used_fds, timeout_time);
if (res != 0)
break;
if (timeout_time == ERTS_POLL_NO_TIMEOUT)
break;
if (erts_get_monotonic_time(NULL) >= timeout_time)
break;
}
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
if (res < 0
&& errno == EBADF
&& ERTS_POLLSET_HAVE_UPDATE_REQUESTS(ps)) {
/*
* This may have happened because another thread deselected
* a fd in our poll set and then closed it, i.e. the driver
* behaved correctly. We wan't to avoid looking for a bad
* fd, that may even not exist anymore. Therefore, handle
* update requests and try again. This behaviour should only
* happen when using SELECT as the polling mechanism.
*/
ERTS_POLLSET_LOCK(ps);
used_fds += handle_update_requests(ps, pr + used_fds, no_fds - used_fds);
if (used_fds == no_fds) {
*len = used_fds;
ERTS_POLLSET_UNLOCK(ps);
return 0;
}
res = check_fd_events(ps, pr + used_fds, no_fds - used_fds, ERTS_POLL_NO_TIMEOUT);
/* Keep the lock over the non-blocking poll in order to not
get any nasty races happening. */
ERTS_POLLSET_UNLOCK(ps);
if (res == 0) {
errno = EAGAIN;
res = -1;
}
}
#endif
if (do_wait) {
erts_thr_progress_finalize_wait(tpd);
ERTS_MSACC_UPDATE_CACHE();
ERTS_MSACC_SET_STATE_CACHED(ERTS_MSACC_STATE_CHECK_IO);
}
if (ERTS_POLL_USE_WAKEUP(ps))
woke_up(ps);
if (res < 0) {
#if ERTS_POLL_USE_SELECT
if (errno == EBADF) {
ebadf = 1;
goto save_results;
}
#endif
res = errno;
}
else if (res == 0) {
res = used_fds == 0 ? ETIMEDOUT : 0;
#ifdef HARD_DEBUG
check_poll_result(pr, used_fds);
#endif
*len = used_fds;
} else {
#if ERTS_POLL_USE_SELECT
save_results:
#endif
ps_locked = 1;
ERTS_POLLSET_LOCK(ps);
used_fds += ERTS_POLL_EXPORT(save_result)(ps, pr + used_fds, no_fds - used_fds, res, ebadf);
#ifdef HARD_DEBUG
check_poll_result(pr, used_fds);
#endif
res = (used_fds == 0 ? (is_interrupted_reset(ps) ? EINTR : EAGAIN) : 0);
*len = used_fds;
}
if (ps_locked)
ERTS_POLLSET_UNLOCK(ps);
DEBUG_PRINT_WAIT("Leaving %s = %s(len = %d)", ps,
res == 0 ? "0" : erl_errno_id(res), __FUNCTION__, *len);
return res;
}
/*
* --- Interrupt a thread doing erts_poll_wait() -----------------------------
*/
void
ERTS_POLL_EXPORT(erts_poll_interrupt)(ErtsPollSet *ps, int set)
{
DEBUG_PRINT_WAIT("poll_interrupt(%d)", ps, set);
if (ERTS_POLL_USE_WAKEUP(ps)) {
if (!set)
reset_wakeup_state(ps);
else
wake_poller(ps, 1);
}
}
int
ERTS_POLL_EXPORT(erts_poll_max_fds)(void)
{
return max_fds;
}
/*
* --- Initialization --------------------------------------------------------
*/
void
ERTS_POLL_EXPORT(erts_poll_init)(int *concurrent_updates)
{
errno = 0;
if (concurrent_updates) {
#if ERTS_POLL_USE_CONCURRENT_UPDATE
*concurrent_updates = 1;
#else
*concurrent_updates = 0;
#endif
}
#if !defined(NO_SYSCONF)
max_fds = sysconf(_SC_OPEN_MAX);
#elif ERTS_POLL_USE_SELECT
max_fds = NOFILE;
#else
max_fds = OPEN_MAX;
#endif
#if ERTS_POLL_USE_SELECT && defined(FD_SETSIZE) && \
!defined(_DARWIN_UNLIMITED_SELECT)
if (max_fds > FD_SETSIZE)
max_fds = FD_SETSIZE;
#endif
if (max_fds < 0)
fatal_error("erts_poll_init(): Failed to get max number of files: %s\n",
erl_errno_id(errno));
print_misc_debug_info();
}
ErtsPollSet *
ERTS_POLL_EXPORT(erts_poll_create_pollset)(int id)
{
#if ERTS_POLL_USE_KERNEL_POLL
int kp_fd;
#endif
ErtsPollSet *ps = erts_alloc(ERTS_ALC_T_POLLSET,
sizeof(struct ERTS_POLL_EXPORT(erts_pollset)));
ps->id = id;
ps->internal_fd_limit = 0;
erts_atomic_init_nob(&ps->no_of_user_fds, 0);
#if ERTS_POLL_USE_KERNEL_POLL
ps->kp_fd = -1;
#if ERTS_POLL_USE_EPOLL
kp_fd = epoll_create(256);
#elif ERTS_POLL_USE_DEVPOLL
kp_fd = open("/dev/poll", O_RDWR);
#elif ERTS_POLL_USE_KQUEUE
kp_fd = kqueue();
#endif
if (kp_fd < 0)
fatal_error("erts_poll_create_pollset(): Failed to "
#if ERTS_POLL_USE_EPOLL
"create epoll set"
#elif ERTS_POLL_USE_DEVPOLL
"to open /dev/poll"
#elif ERTS_POLL_USE_KQUEUE
"create kqueue"
#endif
": %s (%d)\n",
erl_errno_id(errno), errno);
#endif /* ERTS_POLL_USE_KERNEL_POLL */
#if ERTS_POLL_USE_POLL
ps->next_poll_fds_ix = 0;
ps->no_poll_fds = 0;
ps->poll_fds_len = 0;
ps->poll_fds = NULL;
#elif ERTS_POLL_USE_SELECT
ps->next_sel_fd = 0;
ps->max_fd = -1;
#ifdef _DARWIN_UNLIMITED_SELECT
ps->input_fds.sz = 0;
ps->input_fds.ptr = NULL;
ps->res_input_fds.sz = 0;
ps->res_input_fds.ptr = NULL;
ps->output_fds.sz = 0;
ps->output_fds.ptr = NULL;
ps->res_output_fds.sz = 0;
ps->res_output_fds.ptr = NULL;
#else
ERTS_FD_ZERO(&ps->input_fds);
ERTS_FD_ZERO(&ps->res_input_fds);
ERTS_FD_ZERO(&ps->output_fds);
ERTS_FD_ZERO(&ps->res_output_fds);
#endif
#endif
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
ps->fds_status = NULL;
ps->fds_status_len = 0;
ps->update_requests.next = NULL;
ps->update_requests.len = 0;
ps->curr_upd_req_block = &ps->update_requests;
erts_atomic32_init_nob(&ps->have_update_requests, 0);
erts_mtx_init(&ps->mtx, "pollset", NIL, ERTS_LOCK_FLAGS_CATEGORY_IO);
#endif
#if ERTS_POLL_USE_KERNEL_POLL
if (ps->internal_fd_limit <= kp_fd)
ps->internal_fd_limit = kp_fd + 1;
ps->kp_fd = kp_fd;
if (ps->id == -1)
ps->oneshot = 0;
else
ps->oneshot = 1;
#endif
erts_atomic32_init_nob(&ps->wakeup_state, (erts_aint32_t) 0);
create_wakeup_pipe(ps);
#if ERTS_POLL_USE_TIMERFD
create_timerfd(ps);
#endif
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
handle_update_requests(ps, NULL, 0);
cleanup_wakeup_pipe(ps);
#endif
#if ERTS_POLL_USE_KERNEL_POLL && (defined(__DARWIN__) || defined(__APPLE__) && defined(__MACH__))
{
/*
* Using kqueue on OS X is a mess of brokenness...
*
* On OS X version older than 15.6 (i.e. OS X El Capitan released in July 2015),
* a thread waiting in kevent is not woken if an event is inserted into the kqueue
* by another thread and the event becomes ready. However if a new call to kevent
* is done by the waiting thread, the new event is found.
*
* So on effected OS X versions we could trigger the wakeup pipe so that
* the waiters will be woken and re-issue the kevent. However...
*
* On OS X version older then 16 (i.e. OS X Sierra released in September 2016),
* running the emulator driver_SUITE smp_select testcase consistently causes a
* kernel panic. I don't know why or what events that trigger it. But it seems
* like updates of the pollset while another thread is sleeping in it Creates
* some kind of race that triggers the kernel panic.
*
* So to deal with this, the erts configure check what OS X version is run
* and only enabled kernel poll on OS X 16 or newer. In addition, if someone
* attempts to compile Erlang on OS X 16 and then run it on OS X 15, we do the
* run-time check below to disallow this.
*/
int major, minor, build;
os_version(&major,&minor,&build);
if (major < 16) {
erts_fprintf(stderr,"BROKEN KQUEUE!\n"
"Erlang has been compiled with kernel-poll support,\n"
"but this OS X version is known to have kernel bugs\n"
"when using kernel-poll. You have two options:\n"
" 1) update to a newer OS X version (OS X Sierra or newer)\n"
" 2) recompile erlang without kernel-poll support\n");
erts_exit(1, "");
}
}
#endif
erts_atomic_set_nob(&ps->no_of_user_fds, 0); /* Don't count wakeup pipe and fallback fd */
return ps;
}
/*
* --- Info ------------------------------------------------------------------
*/
void
ERTS_POLL_EXPORT(erts_poll_info)(ErtsPollSet *ps, ErtsPollInfo *pip)
{
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
int pending_updates;
#endif
Uint size = 0;
ERTS_POLLSET_LOCK(ps);
size += sizeof(struct ERTS_POLL_EXPORT(erts_pollset));
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
size += ps->fds_status_len*sizeof(ErtsFdStatus);
#endif
#if ERTS_POLL_USE_POLL
size += ps->poll_fds_len*sizeof(struct pollfd);
#elif ERTS_POLL_USE_SELECT
#ifdef _DARWIN_UNLIMITED_SELECT
size += ps->input_fds.sz + ps->res_input_fds.sz
+ ps->output_fds.sz + ps->res_output_fds.sz;
#endif
#endif
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
{
ErtsPollSetUpdateRequestsBlock *urqbp = ps->update_requests.next;
pending_updates = ps->update_requests.len;
while (urqbp) {
size += sizeof(ErtsPollSetUpdateRequestsBlock);
pending_updates += urqbp->len;
urqbp = urqbp->next;
}
}
#endif
pip->primary =
#if ERTS_POLL_USE_KQUEUE
"kqueue"
#elif ERTS_POLL_USE_EPOLL
"epoll"
#elif ERTS_POLL_USE_DEVPOLL
"/dev/poll"
#elif ERTS_POLL_USE_POLL
"poll"
#elif ERTS_POLL_USE_SELECT
"select"
#endif
;
pip->kernel_poll =
#if !ERTS_POLL_USE_KERNEL_POLL
NULL
#elif ERTS_POLL_USE_KQUEUE
"kqueue"
#elif ERTS_POLL_USE_EPOLL
"epoll"
#elif ERTS_POLL_USE_DEVPOLL
"/dev/poll"
#endif
;
pip->memory_size = size;
pip->poll_set_size = (int) erts_atomic_read_nob(&ps->no_of_user_fds);
pip->poll_set_size++; /* Wakeup pipe */
pip->lazy_updates =
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
1
#else
0
#endif
;
pip->pending_updates =
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
pending_updates
#else
0
#endif
;
pip->concurrent_updates =
#if ERTS_POLL_USE_CONCURRENT_UPDATE
1
#else
0
#endif
;
pip->is_fallback =
#if ERTS_POLL_IS_FALLBACK
1
#else
0
#endif
;
pip->batch_updates =
#if ERTS_POLL_USE_DEVPOLL
1
#else
0
#endif
;
pip->max_fds = max_fds;
ERTS_POLLSET_UNLOCK(ps);
}
/*
* Fatal error...
*/
#ifndef ERTS_GOT_SIGUSR1
# define ERTS_GOT_SIGUSR1 0
#endif
static void
fatal_error(char *format, ...)
{
va_list ap;
if (ERTS_SOMEONE_IS_CRASH_DUMPING || ERTS_GOT_SIGUSR1) {
/*
* Crash dump writing and reception of sigusr1 (which will
* result in a crash dump) closes all file descriptors. This
* typically results in a fatal error for erts_poll() (wakeup
* pipes and kernel poll fds are closed).
*
* We ignore the error and let the crash dump writing continue...
*/
return;
}
va_start(ap, format);
erts_vfprintf(stderr, format, ap);
va_end(ap);
abort();
}
/*
* --- Debug -----------------------------------------------------------------
*/
#if ERTS_POLL_USE_EPOLL
uint32_t epoll_events(int kp_fd, int fd)
{
/* For epoll we read the information about what is selected upon from the proc fs.*/
char fname[30];
char s[256];
FILE *f;
unsigned int pos, flags, mnt_id;
int hdr_lines, line = 1;
sprintf(fname,"/proc/%d/fdinfo/%d",getpid(), kp_fd);
f = fopen(fname,"r");
if (!f) {
fprintf(stderr,"failed to open file %s, errno = %d\n", fname, errno);
ASSERT(0);
return 0;
}
hdr_lines = fscanf(f,"pos:\t%x\nflags:\t%x\nmnt_id:\t%x\n",
&pos, &flags, &mnt_id);
if (hdr_lines < 2) {
fprintf(stderr,"failed to parse file %s, errno = %d\n", fname, errno);
ASSERT(0);
return 0;
}
line += hdr_lines;
while (fgets(s, sizeof(s) / sizeof(*s), f)) {
/* tfd: 10 events: 40000019 data: 180000000a */
int ev_fd;
uint32_t events;
uint64_t data;
if (sscanf(s,"tfd:%d events:%x data:%llx", &ev_fd, &events,
(unsigned long long*)&data) != 3) {
fprintf(stderr,"failed to parse file %s on line %d, errno = %d\n", fname,
line,
errno);
fclose(f);
return 0;
}
if (fd == ev_fd) {
fclose(f);
return events;
}
}
fclose(f);
return 0;
}
#endif
void
ERTS_POLL_EXPORT(erts_poll_get_selected_events)(ErtsPollSet *ps,
ErtsPollEvents ev[],
int len)
{
int fd;
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
ERTS_POLLSET_LOCK(ps);
for (fd = 0; fd < len; fd++) {
if (fd >= ps->fds_status_len)
ev[fd] = 0;
else {
ev[fd] = ps->fds_status[fd].events;
if (
fd == ps->wake_fds[0] || fd == ps->wake_fds[1] ||
#if ERTS_POLL_USE_KERNEL_POLL
fd == ps->kp_fd ||
#endif
0)
ev[fd] |= ERTS_POLL_EV_NVAL;
}
}
ERTS_POLLSET_UNLOCK(ps);
#elif ERTS_POLL_USE_EPOLL
/* For epoll we read the information about what is selected upon from the proc fs.*/
char fname[30];
char s[256];
FILE *f;
unsigned int pos, flags, mnt_id;
int hdr_lines, line = 1;
sprintf(fname,"/proc/%d/fdinfo/%d",getpid(), ps->kp_fd);
for (fd = 0; fd < len; fd++)
ev[fd] = ERTS_POLL_EV_NONE;
f = fopen(fname,"r");
if (!f) {
fprintf(stderr,"failed to open file %s, errno = %d\n", fname, errno);
return;
}
hdr_lines = fscanf(f,"pos:\t%x\nflags:\t%x\nmnt_id:\t%x\n",
&pos, &flags, &mnt_id);
if (hdr_lines < 2) {
fprintf(stderr,"failed to parse file %s, errno = %d\n", fname, errno);
ASSERT(0);
fclose(f);
return;
}
line += hdr_lines;
while (fgets(s, sizeof(s) / sizeof(*s), f)) {
/* tfd: 10 events: 40000019 data: 180000000a */
int fd;
uint32_t events;
uint64_t data;
if (sscanf(s,"tfd:%d events:%x data:%llx", &fd, &events,
(unsigned long long*)&data) != 3) {
fprintf(stderr,"failed to parse file %s on line %d, errno = %d\n",
fname, line, errno);
ASSERT(0);
fclose(f);
return;
}
if (fd == ps->wake_fds[0] || fd == ps->wake_fds[1])
continue;
#if ERTS_POLL_USE_TIMERFD
if (fd == ps->timer_fd)
continue;
#endif
data &= 0xFFFFFFFF;
ASSERT(fd == data);
/* Events are the events that are being monitored, which of course include
error and hup events, but we are only interested in IN/OUT events */
ev[fd] = (ERTS_POLL_EV_IN|ERTS_POLL_EV_OUT) & ERTS_POLL_EV_N2E(events);
line++;
}
fclose(f);
#else
for (fd = 0; fd < len; fd++)
ev[fd] = ERTS_POLL_EV_NONE;
#endif
}
#ifdef HARD_DEBUG
static void
check_poll_result(ErtsPollResFd pr[], int len)
{
int i, j;
for (i = 0; i < len; i++) {
ASSERT(pr[i].fd >= 0);
ASSERT(pr[i].fd < max_fds);
for (j = 0; j < len; j++) {
ASSERT(i == j || pr[i].fd != pr[j].fd);
}
}
}
#if ERTS_POLL_USE_DEVPOLL && defined(DEBUG)
static void
check_poll_status(ErtsPollSet *ps)
{
int i;
for (i = 0; i < ps->fds_status_len; i++) {
int ires;
struct pollfd dp_fd;
short events = ERTS_POLL_EV_E2N(ps->fds_status[i].events);
dp_fd.fd = i;
dp_fd.events = (short) 0;
dp_fd.revents = (short) 0;
ires = ioctl(ps->kp_fd, DP_ISPOLLED, &dp_fd);
if (ires == 0) {
ASSERT(!events);
}
else if (ires == 1) {
ASSERT(events);
ASSERT(events == dp_fd.revents);
}
else {
ASSERT(0);
}
ASSERT(dp_fd.fd == i);
ASSERT(ps->fds_status[i].events == ps->fds_status[i].used_events);
}
}
#endif /* ERTS_POLL_USE_DEVPOLL */
#endif /* HARD_DEBUG */
static void
print_misc_debug_info(void)
{
#if ERTS_POLL_DEBUG_PRINT
erts_printf("erts_poll using: %s lazy_updates:%s\n",
#if ERTS_POLL_USE_KQUEUE
"kqueue"
#elif ERTS_POLL_USE_EPOLL
"epoll"
#elif ERTS_POLL_USE_DEVPOLL
"/dev/poll"
#elif ERTS_POLL_USE_POLL
"poll"
#elif ERTS_POLL_USE_SELECT
"select"
#endif
,
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
"true"
#else
"false"
#endif
);
erts_printf("ERTS_POLL_EV_IN=0x%x\n"
"ERTS_POLL_EV_OUT=0x%x\n"
"ERTS_POLL_EV_NVAL=0x%x\n"
"ERTS_POLL_EV_ERR=0x%x\n",
ERTS_POLL_EV_IN,
ERTS_POLL_EV_OUT,
ERTS_POLL_EV_NVAL,
ERTS_POLL_EV_ERR);
#ifdef FD_SETSIZE
erts_printf("FD_SETSIZE=%d\n", FD_SETSIZE);
#endif
#endif
}
#ifdef ERTS_ENABLE_LOCK_COUNT
void ERTS_POLL_EXPORT(erts_lcnt_enable_pollset_lock_count)(ErtsPollSet *pollset, int enable)
{
#if !ERTS_POLL_USE_CONCURRENT_UPDATE
if(enable) {
erts_lcnt_install_new_lock_info(&pollset->mtx.lcnt, "pollset_rm", NIL,
ERTS_LOCK_TYPE_MUTEX | ERTS_LOCK_FLAGS_CATEGORY_IO);
} else {
erts_lcnt_uninstall(&pollset->mtx.lcnt);
}
#endif
return;
}
#endif
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