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poll: add support for OOB TCP and GPIO interrupts

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Out-of-band TCP messages are used for TCP data
transmission outside (outband) the inbound TCP
data. These packets are sent with an
"urgent pointer", but previously discarded.

Additionally, when using (e)poll a POLLPRI is
triggered when an interrupt signal is received
on GPIO capable systems such as the Raspberry Pi.

PR-URL: https://github.com/libuv/libuv/pull/1040
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
This commit is contained in:
CurlyMoo 2016-09-09 00:42:43 +02:00 committed by Saúl Ibarra Corretgé
parent 78c17238f4
commit d731fd1bd9
11 changed files with 295 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Makefile.am
View File

@ -212,10 +212,11 @@ test_run_tests_SOURCES = test/blackhole-server.c \
test/test-pipe-close-stdout-read-stdin.c \
test/test-pipe-set-non-blocking.c \
test/test-platform-output.c \
test/test-poll.c \
test/test-poll-close.c \
test/test-poll-close-doesnt-corrupt-stack.c \
test/test-poll-closesocket.c \
test/test-poll.c \
test/test-poll-oob.c \
test/test-process-title.c \
test/test-queue-foreach-delete.c \
test/test-ref.c \

15
docs/src/poll.rst
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@ -54,7 +54,8 @@ Data types
enum uv_poll_event {
UV_READABLE = 1,
UV_WRITABLE = 2,
UV_DISCONNECT = 4
UV_DISCONNECT = 4,
UV_PRIORITIZED = 8
};
@ -84,10 +85,13 @@ API
.. c:function:: int uv_poll_start(uv_poll_t* handle, int events, uv_poll_cb cb)
Starts polling the file descriptor. `events` is a bitmask consisting made up
of UV_READABLE, UV_WRITABLE and UV_DISCONNECT. As soon as an event is detected
the callback will be called with `status` set to 0, and the detected events set on the
`events` field.
Starts polling the file descriptor. `events` is a bitmask made up of
UV_READABLE, UV_WRITABLE, UV_PRIORITIZED and UV_DISCONNECT. As soon as an
event is detected the callback will be called with `status` set to 0, and the
detected events set on the `events` field.
The UV_PRIORITIZED event is used to watch for sysfs interrupts or TCP out-of-band
messages.
The UV_DISCONNECT event is optional in the sense that it may not be
reported and the user is free to ignore it, but it can help optimize the shutdown
@ -108,6 +112,7 @@ API
on the `events` field in the callback.
.. versionchanged:: 1.9.0 Added the UV_DISCONNECT event.
.. versionchanged:: 1.14.0 Added the UV_PRIORITIZED event.
.. c:function:: int uv_poll_stop(uv_poll_t* poll)

3
include/uv.h
View File

@ -719,7 +719,8 @@ struct uv_poll_s {
enum uv_poll_event {
UV_READABLE = 1,
UV_WRITABLE = 2,
UV_DISCONNECT = 4
UV_DISCONNECT = 4,
UV_PRIORITIZED = 8
};
UV_EXTERN int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd);

8
src/unix/core.c
View File

@ -838,7 +838,7 @@ void uv__io_init(uv__io_t* w, uv__io_cb cb, int fd) {
void uv__io_start(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP)));
assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI)));
assert(0 != events);
assert(w->fd >= 0);
assert(w->fd < INT_MAX);
@ -866,7 +866,7 @@ void uv__io_start(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
void uv__io_stop(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP)));
assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI)));
assert(0 != events);
if (w->fd == -1)
@ -898,7 +898,7 @@ void uv__io_stop(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
void uv__io_close(uv_loop_t* loop, uv__io_t* w) {
uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP);
uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
QUEUE_REMOVE(&w->pending_queue);
/* Remove stale events for this file descriptor */
@ -913,7 +913,7 @@ void uv__io_feed(uv_loop_t* loop, uv__io_t* w) {
int uv__io_active(const uv__io_t* w, unsigned int events) {
assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP)));
assert(0 == (events & ~(POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI)));
assert(0 != events);
return 0 != (w->pevents & events);
}

6
src/unix/internal.h
View File

@ -110,6 +110,12 @@ int uv__pthread_sigmask(int how, const sigset_t* set, sigset_t* oset);
# define UV__POLLRDHUP 0x2000
#endif
#ifdef POLLPRI
# define UV__POLLPRI POLLPRI
#else
# define UV__POLLPRI 0
#endif
#if !defined(O_CLOEXEC) && defined(__FreeBSD__)
/*
* It may be that we are just missing `__POSIX_VISIBLE >= 200809`.

35
src/unix/kqueue.c
View File

@ -34,6 +34,17 @@
#include <fcntl.h>
#include <time.h>
/*
* Required on
* - Until at least FreeBSD 11.0
* - Older versions of Mac OS X
*
* http://www.boost.org/doc/libs/1_61_0/boost/asio/detail/kqueue_reactor.hpp
*/
#ifndef EV_OOBAND
#define EV_OOBAND EV_FLAG1
#endif
static void uv__fs_event(uv_loop_t* loop, uv__io_t* w, unsigned int fflags);
@ -166,6 +177,16 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
}
}
if ((w->events & UV__POLLPRI) == 0 && (w->pevents & UV__POLLPRI) != 0) {
EV_SET(events + nevents, w->fd, EV_OOBAND, EV_ADD, 0, 0, 0);
if (++nevents == ARRAY_SIZE(events)) {
if (kevent(loop->backend_fd, events, nevents, NULL, 0, NULL))
abort();
nevents = 0;
}
}
w->events = w->pevents;
}
@ -275,6 +296,20 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
}
}
if (ev->filter == EV_OOBAND) {
if (w->pevents & UV__POLLPRI) {
revents |= UV__POLLPRI;
w->rcount = ev->data;
} else {
/* TODO batch up */
struct kevent events[1];
EV_SET(events + 0, fd, ev->filter, EV_DELETE, 0, 0, 0);
if (kevent(loop->backend_fd, events, 1, NULL, 0, NULL))
if (errno != ENOENT)
abort();
}
}
if (ev->filter == EVFILT_WRITE) {
if (w->pevents & POLLOUT) {
revents |= POLLOUT;

2
src/unix/linux-core.c
View File

@ -388,7 +388,7 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
* free when we switch over to edge-triggered I/O.
*/
if (pe->events == POLLERR || pe->events == POLLHUP)
pe->events |= w->pevents & (POLLIN | POLLOUT);
pe->events |= w->pevents & (POLLIN | POLLOUT | UV__POLLPRI);
if (pe->events != 0) {
/* Run signal watchers last. This also affects child process watchers

24
src/unix/poll.c
View File

@ -33,8 +33,19 @@ static void uv__poll_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
handle = container_of(w, uv_poll_t, io_watcher);
if (events & POLLERR) {
uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP);
/*
* As documented in the kernel source fs/kernfs/file.c #780
* poll will return POLLERR|POLLPRI in case of sysfs
* polling. This does not happen in case of out-of-band
* TCP messages.
*
* The above is the case on (at least) FreeBSD and Linux.
*
* So to properly determine a POLLPRI or a POLLERR we need
* to check for both.
*/
if ((events & POLLERR) && !(events & UV__POLLPRI)) {
uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
uv__handle_stop(handle);
handle->poll_cb(handle, -EBADF, 0);
return;
@ -43,6 +54,8 @@ static void uv__poll_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
pevents = 0;
if (events & POLLIN)
pevents |= UV_READABLE;
if (events & UV__POLLPRI)
pevents |= UV_PRIORITIZED;
if (events & POLLOUT)
pevents |= UV_WRITABLE;
if (events & UV__POLLRDHUP)
@ -86,7 +99,7 @@ int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle,
static void uv__poll_stop(uv_poll_t* handle) {
uv__io_stop(handle->loop,
&handle->io_watcher,
POLLIN | POLLOUT | UV__POLLRDHUP);
POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
uv__handle_stop(handle);
}
@ -101,7 +114,8 @@ int uv_poll_stop(uv_poll_t* handle) {
int uv_poll_start(uv_poll_t* handle, int pevents, uv_poll_cb poll_cb) {
int events;
assert((pevents & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT)) == 0);
assert((pevents & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT |
UV_PRIORITIZED)) == 0);
assert(!uv__is_closing(handle));
uv__poll_stop(handle);
@ -112,6 +126,8 @@ int uv_poll_start(uv_poll_t* handle, int pevents, uv_poll_cb poll_cb) {
events = 0;
if (pevents & UV_READABLE)
events |= POLLIN;
if (pevents & UV_PRIORITIZED)
events |= UV__POLLPRI;
if (pevents & UV_WRITABLE)
events |= POLLOUT;
if (pevents & UV_DISCONNECT)

9
test/test-list.h
View File

@ -328,6 +328,10 @@ TEST_DECLARE (thread_rwlock_trylock)
TEST_DECLARE (thread_create)
TEST_DECLARE (thread_equal)
TEST_DECLARE (dlerror)
#if (defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))) && \
!defined(__sun)
TEST_DECLARE (poll_oob)
#endif
TEST_DECLARE (poll_duplex)
TEST_DECLARE (poll_unidirectional)
TEST_DECLARE (poll_close)
@ -681,6 +685,11 @@ TASK_LIST_START
TEST_ENTRY (poll_unidirectional)
TEST_ENTRY (poll_close)
TEST_ENTRY (poll_bad_fdtype)
#if (defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))) && \
!defined(__sun)
TEST_ENTRY (poll_oob)
#endif
#ifdef __linux__
TEST_ENTRY (poll_nested_epoll)
#endif

205
test/test-poll-oob.c Normal file
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@ -0,0 +1,205 @@
/* Copyright libuv project contributors. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#if !defined(_WIN32)
#include "uv.h"
#include "task.h"
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <string.h>
static uv_tcp_t server_handle;
static uv_tcp_t client_handle;
static uv_tcp_t peer_handle;
static uv_poll_t poll_req[2];
static uv_idle_t idle;
static uv_os_fd_t client_fd;
static uv_os_fd_t server_fd;
static int ticks;
static const int kMaxTicks = 10;
static int cli_pr_check = 0;
static int cli_rd_check = 0;
static int srv_rd_check = 0;
static int got_eagain(void) {
return errno == EAGAIN
|| errno == EINPROGRESS
#ifdef EWOULDBLOCK
|| errno == EWOULDBLOCK
#endif
;
}
static void idle_cb(uv_idle_t* idle) {
uv_sleep(100);
if (++ticks < kMaxTicks)
return;
uv_poll_stop(&poll_req[0]);
uv_poll_stop(&poll_req[1]);
uv_close((uv_handle_t*) &server_handle, NULL);
uv_close((uv_handle_t*) &client_handle, NULL);
uv_close((uv_handle_t*) &peer_handle, NULL);
uv_close((uv_handle_t*) idle, NULL);
}
static void poll_cb(uv_poll_t* handle, int status, int events) {
char buffer[5];
int n;
int fd;
ASSERT(0 == uv_fileno((uv_handle_t*)handle, &fd));
memset(buffer, 0, 5);
if (events & UV_PRIORITIZED) {
do
n = recv(client_fd, &buffer, 5, MSG_OOB);
while (n == -1 && errno == EINTR);
ASSERT(n >= 0 || errno != EINVAL);
cli_pr_check = 1;
ASSERT(0 == uv_poll_stop(&poll_req[0]));
ASSERT(0 == uv_poll_start(&poll_req[0],
UV_READABLE | UV_WRITABLE,
poll_cb));
}
if (events & UV_READABLE) {
if (fd == client_fd) {
do
n = recv(client_fd, &buffer, 5, 0);
while (n == -1 && errno == EINTR);
ASSERT(n >= 0 || errno != EINVAL);
if (cli_rd_check == 1) {
ASSERT(strncmp(buffer, "world", n) == 0);
ASSERT(5 == n);
cli_rd_check = 2;
}
if (cli_rd_check == 0) {
ASSERT(n == 4);
ASSERT(strncmp(buffer, "hello", n) == 0);
cli_rd_check = 1;
do {
do
n = recv(server_fd, &buffer, 5, 0);
while (n == -1 && errno == EINTR);
if (n > 0) {
ASSERT(n == 5);
ASSERT(strncmp(buffer, "world", n) == 0);
cli_rd_check = 2;
}
} while (n > 0);
ASSERT(got_eagain());
}
}
if (fd == server_fd) {
do
n = recv(server_fd, &buffer, 3, 0);
while (n == -1 && errno == EINTR);
ASSERT(n >= 0 || errno != EINVAL);
ASSERT(3 == n);
ASSERT(strncmp(buffer, "foo", n) == 0);
srv_rd_check = 1;
uv_poll_stop(&poll_req[1]);
}
}
if (events & UV_WRITABLE) {
do {
n = send(client_fd, "foo", 3, 0);
} while (n < 0 && errno == EINTR);
ASSERT(3 == n);
}
}
static void connection_cb(uv_stream_t* handle, int status) {
int r;
ASSERT(0 == status);
ASSERT(0 == uv_accept(handle, (uv_stream_t*) &peer_handle));
ASSERT(0 == uv_fileno((uv_handle_t*) &peer_handle, &server_fd));
ASSERT(0 == uv_poll_init_socket(uv_default_loop(), &poll_req[0], client_fd));
ASSERT(0 == uv_poll_init_socket(uv_default_loop(), &poll_req[1], server_fd));
ASSERT(0 == uv_poll_start(&poll_req[0],
UV_PRIORITIZED | UV_READABLE | UV_WRITABLE,
poll_cb));
ASSERT(0 == uv_poll_start(&poll_req[1],
UV_READABLE,
poll_cb));
do {
r = send(server_fd, "hello", 5, MSG_OOB);
} while (r < 0 && errno == EINTR);
ASSERT(5 == r);
do {
r = send(server_fd, "world", 5, 0);
} while (r < 0 && errno == EINTR);
ASSERT(5 == r);
ASSERT(0 == uv_idle_start(&idle, idle_cb));
}
TEST_IMPL(poll_oob) {
struct sockaddr_in addr;
int r = 0;
uv_loop_t* loop;
ASSERT(0 == uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
loop = uv_default_loop();
ASSERT(0 == uv_tcp_init(loop, &server_handle));
ASSERT(0 == uv_tcp_init(loop, &client_handle));
ASSERT(0 == uv_tcp_init(loop, &peer_handle));
ASSERT(0 == uv_idle_init(loop, &idle));
ASSERT(0 == uv_tcp_bind(&server_handle, (const struct sockaddr*) &addr, 0));
ASSERT(0 == uv_listen((uv_stream_t*) &server_handle, 1, connection_cb));
/* Ensure two separate packets */
ASSERT(0 == uv_tcp_nodelay(&client_handle, 1));
client_fd = socket(PF_INET, SOCK_STREAM, 0);
ASSERT(client_fd >= 0);
do {
errno = 0;
r = connect(client_fd, (const struct sockaddr*)&addr, sizeof(addr));
} while (r == -1 && errno == EINTR);
ASSERT(r == 0);
ASSERT(0 == uv_run(loop, UV_RUN_DEFAULT));
ASSERT(ticks == kMaxTicks);
/* Did client receive the POLLPRI message */
ASSERT(cli_pr_check == 1);
/* Did client receive the POLLIN message */
ASSERT(cli_rd_check == 2);
/* Could we write with POLLOUT and did the server receive our POLLOUT message
* through POLLIN.
*/
ASSERT(srv_rd_check == 1);
MAKE_VALGRIND_HAPPY();
return 0;
}
#endif

1
uv.gyp
View File

@ -405,6 +405,7 @@
'test/test-poll-close.c',
'test/test-poll-close-doesnt-corrupt-stack.c',
'test/test-poll-closesocket.c',
'test/test-poll-oob.c',
'test/test-process-title.c',
'test/test-queue-foreach-delete.c',
'test/test-ref.c',