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unix,stream: fix loop hang after uv_shutdown

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While most users will likely typically call uv_close in their
uv_shutdown callback, some callers (notable nodejs) do not always do
so. This can result in libuv keeping the loop active, even though there
are no outstanding reqs left to handle.

This bug was added in 80f2f826bf, where
the premise of that commit appears to have simply been incorrect, as
demonstrated by the added test.

Refs: https://github.com/libuv/libuv/issues/3202
PR-URL: https://github.com/libuv/libuv/pull/3233
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
This commit is contained in:
Jameson Nash 2021-07-13 10:54:02 -04:00 committed by GitHub
parent e49ef4f309
commit 03f1a6979c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 181 additions and 27 deletions
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1
CMakeLists.txt
View File

@ -525,6 +525,7 @@ if(LIBUV_BUILD_TESTS)
test/test-semaphore.c
test/test-shutdown-close.c
test/test-shutdown-eof.c
test/test-shutdown-simultaneous.c
test/test-shutdown-twice.c
test/test-signal-multiple-loops.c
test/test-signal-pending-on-close.c

1
Makefile.am
View File

@ -241,6 +241,7 @@ test_run_tests_SOURCES = test/blackhole-server.c \
test/test-semaphore.c \
test/test-shutdown-close.c \
test/test-shutdown-eof.c \
test/test-shutdown-simultaneous.c \
test/test-shutdown-twice.c \
test/test-signal-multiple-loops.c \
test/test-signal-pending-on-close.c \

12
src/unix/stream.c
View File

@ -926,10 +926,9 @@ static void uv__write(uv_stream_t* stream) {
}
req->error = n;
// XXX(jwn): this must call uv__stream_flush_write_queue(stream, n) here, since we won't generate any more events
uv__write_req_finish(req);
uv__io_stop(stream->loop, &stream->io_watcher, POLLOUT);
if (!uv__io_active(&stream->io_watcher, POLLIN))
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
}
@ -1013,8 +1012,7 @@ static void uv__stream_eof(uv_stream_t* stream, const uv_buf_t* buf) {
stream->flags &= ~UV_HANDLE_READING;
stream->flags &= ~UV_HANDLE_READABLE;
uv__io_stop(stream->loop, &stream->io_watcher, POLLIN);
if (!uv__io_active(&stream->io_watcher, POLLOUT))
uv__handle_stop(stream);
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
stream->read_cb(stream, UV_EOF, buf);
}
@ -1204,8 +1202,7 @@ static void uv__read(uv_stream_t* stream) {
if (stream->flags & UV_HANDLE_READING) {
stream->flags &= ~UV_HANDLE_READING;
uv__io_stop(stream->loop, &stream->io_watcher, POLLIN);
if (!uv__io_active(&stream->io_watcher, POLLOUT))
uv__handle_stop(stream);
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
}
}
@ -1582,8 +1579,7 @@ int uv_read_stop(uv_stream_t* stream) {
stream->flags &= ~UV_HANDLE_READING;
uv__io_stop(stream->loop, &stream->io_watcher, POLLIN);
if (!uv__io_active(&stream->io_watcher, POLLOUT))
uv__handle_stop(stream);
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
stream->read_cb = NULL;

55
test/echo-server.c
View File

@ -65,24 +65,35 @@ static void after_write(uv_write_t* req, int status) {
static void after_shutdown(uv_shutdown_t* req, int status) {
ASSERT_EQ(status, 0);
uv_close((uv_handle_t*) req->handle, on_close);
free(req);
}
static void on_shutdown(uv_shutdown_t* req, int status) {
ASSERT_EQ(status, 0);
free(req);
}
static void after_read(uv_stream_t* handle,
ssize_t nread,
const uv_buf_t* buf) {
int i;
write_req_t *wr;
uv_shutdown_t* sreq;
int shutdown = 0;
if (nread < 0) {
/* Error or EOF */
ASSERT(nread == UV_EOF);
ASSERT_EQ(nread, UV_EOF);
free(buf->base);
sreq = malloc(sizeof* sreq);
ASSERT(0 == uv_shutdown(sreq, handle, after_shutdown));
if (uv_is_writable(handle)) {
ASSERT_EQ(0, uv_shutdown(sreq, handle, after_shutdown));
}
return;
}
@ -95,25 +106,28 @@ static void after_read(uv_stream_t* handle,
/*
* Scan for the letter Q which signals that we should quit the server.
* If we get QS it means close the stream.
* If we get QSS it means shutdown the stream.
* If we get QSH it means disable linger before close the socket.
*/
if (!server_closed) {
for (i = 0; i < nread; i++) {
if (buf->base[i] == 'Q') {
if (i + 1 < nread && buf->base[i + 1] == 'S') {
int reset = 0;
if (i + 2 < nread && buf->base[i + 2] == 'H')
reset = 1;
free(buf->base);
if (reset && handle->type == UV_TCP)
ASSERT(0 == uv_tcp_close_reset((uv_tcp_t*) handle, on_close));
else
uv_close((uv_handle_t*) handle, on_close);
return;
} else {
uv_close(server, on_server_close);
server_closed = 1;
}
for (i = 0; i < nread; i++) {
if (buf->base[i] == 'Q') {
if (i + 1 < nread && buf->base[i + 1] == 'S') {
int reset = 0;
if (i + 2 < nread && buf->base[i + 2] == 'S')
shutdown = 1;
if (i + 2 < nread && buf->base[i + 2] == 'H')
reset = 1;
if (reset && handle->type == UV_TCP)
ASSERT_EQ(0, uv_tcp_close_reset((uv_tcp_t*) handle, on_close));
else if (shutdown)
break;
else
uv_close((uv_handle_t*) handle, on_close);
free(buf->base);
return;
} else if (!server_closed) {
uv_close(server, on_server_close);
server_closed = 1;
}
}
}
@ -125,6 +139,9 @@ static void after_read(uv_stream_t* handle,
if (uv_write(&wr->req, handle, &wr->buf, 1, after_write)) {
FATAL("uv_write failed");
}
if (shutdown)
ASSERT_EQ(0, uv_shutdown(malloc(sizeof* sreq), handle, on_shutdown));
}

4
test/test-list.h
View File

@ -206,6 +206,7 @@ TEST_DECLARE (connection_fail_doesnt_auto_close)
TEST_DECLARE (shutdown_close_tcp)
TEST_DECLARE (shutdown_close_pipe)
TEST_DECLARE (shutdown_eof)
TEST_DECLARE (shutdown_simultaneous)
TEST_DECLARE (shutdown_twice)
TEST_DECLARE (callback_stack)
TEST_DECLARE (env_vars)
@ -784,6 +785,9 @@ TASK_LIST_START
TEST_ENTRY (shutdown_eof)
TEST_HELPER (shutdown_eof, tcp4_echo_server)
TEST_ENTRY (shutdown_simultaneous)
TEST_HELPER (shutdown_simultaneous, tcp4_echo_server)
TEST_ENTRY (shutdown_twice)
TEST_HELPER (shutdown_twice, tcp4_echo_server)

135
test/test-shutdown-simultaneous.c Normal file
View File

@ -0,0 +1,135 @@
/* Copyright libuv project and 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.
*/
#include "uv.h"
#include "task.h"
#include <stdio.h>
#include <stdlib.h>
static uv_tcp_t tcp;
static uv_connect_t connect_req;
static uv_shutdown_t shutdown_req;
static uv_buf_t qbuf;
static int got_q;
static int got_eof;
static int called_connect_cb;
static int called_shutdown_cb;
static int called_tcp_close_cb;
static void alloc_cb(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
buf->base = malloc(size);
buf->len = size;
}
static void shutdown_cb(uv_shutdown_t *req, int status) {
ASSERT_PTR_EQ(req, &shutdown_req);
ASSERT_EQ(called_connect_cb, 1);
ASSERT_EQ(called_tcp_close_cb, 0);
}
static void read_cb(uv_stream_t* t, ssize_t nread, const uv_buf_t* buf) {
ASSERT_PTR_EQ((uv_tcp_t*)t, &tcp);
if (nread == 0) {
free(buf->base);
return;
}
if (!got_q) {
ASSERT_EQ(nread, 4);
ASSERT_EQ(got_eof, 0);
ASSERT_MEM_EQ(buf->base, "QQSS", 4);
free(buf->base);
got_q = 1;
puts("got QQSS");
/* Shutdown our end of the connection simultaneously */
uv_shutdown(&shutdown_req, (uv_stream_t*) &tcp, shutdown_cb);
called_shutdown_cb++;
} else {
ASSERT_EQ(nread, UV_EOF);
if (buf->base) {
free(buf->base);
}
got_eof = 1;
puts("got EOF");
}
}
static void connect_cb(uv_connect_t *req, int status) {
ASSERT_EQ(status, 0);
ASSERT_PTR_EQ(req, &connect_req);
/* Start reading from our connection so we can receive the EOF. */
ASSERT_EQ(0, uv_read_start((uv_stream_t*)&tcp, alloc_cb, read_cb));
/* Check error handling. */
ASSERT_EQ(UV_EALREADY, uv_read_start((uv_stream_t*)&tcp, alloc_cb, read_cb));
ASSERT_EQ(UV_EINVAL, uv_read_start(NULL, alloc_cb, read_cb));
ASSERT_EQ(UV_EINVAL, uv_read_start((uv_stream_t*)&tcp, NULL, read_cb));
ASSERT_EQ(UV_EINVAL, uv_read_start((uv_stream_t*)&tcp, alloc_cb, NULL));
/*
* Write the letter 'Q' and 'QSS` to gracefully kill the echo-server. This
* will not effect our connection.
*/
ASSERT_EQ(qbuf.len, uv_try_write((uv_stream_t*) &tcp, &qbuf, 1));
called_connect_cb++;
ASSERT_EQ(called_shutdown_cb, 0);
}
/*
* This test has a client which connects to the echo_server and immediately
* issues a shutdown. We check that this does not cause libuv to hang.
*/
TEST_IMPL(shutdown_simultaneous) {
struct sockaddr_in server_addr;
int r;
qbuf.base = "QQSS";
qbuf.len = 4;
ASSERT_EQ(0, uv_ip4_addr("127.0.0.1", TEST_PORT, &server_addr));
r = uv_tcp_init(uv_default_loop(), &tcp);
ASSERT_EQ(r, 0);
r = uv_tcp_connect(&connect_req,
&tcp,
(const struct sockaddr*) &server_addr,
connect_cb);
ASSERT_EQ(r, 0);
uv_run(uv_default_loop(), UV_RUN_DEFAULT);
ASSERT_EQ(called_connect_cb, 1);
ASSERT_EQ(called_shutdown_cb, 1);
ASSERT_EQ(got_eof, 1);
ASSERT_EQ(got_q, 1);
MAKE_VALGRIND_HAPPY();
return 0;
}