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/* Copyright Joyent, Inc. and other Node 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 "internal.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <unistd.h>
#include <limits.h> /* IOV_MAX */
#if defined(__APPLE__)
# include <sys/event.h>
# include <sys/time.h>
# include <sys/select.h>
/* Forward declaration */
typedef struct uv__stream_select_s uv__stream_select_t;
struct uv__stream_select_s {
uv_stream_t* stream;
uv_thread_t thread;
uv_sem_t close_sem;
uv_sem_t async_sem;
uv_async_t async;
int events;
int fake_fd;
int int_fd;
int fd;
fd_set* sread;
size_t sread_sz;
fd_set* swrite;
size_t swrite_sz;
};
#endif /* defined(__APPLE__) */
static void uv__stream_connect(uv_stream_t*);
static void uv__write(uv_stream_t* stream);
static void uv__read(uv_stream_t* stream);
static void uv__stream_io(uv_loop_t* loop, uv__io_t* w, unsigned int events);
static void uv__write_callbacks(uv_stream_t* stream);
static size_t uv__write_req_size(uv_write_t* req);
void uv__stream_init(uv_loop_t* loop,
uv_stream_t* stream,
uv_handle_type type) {
int err;
uv__handle_init(loop, (uv_handle_t*)stream, type);
stream->read_cb = NULL;
stream->alloc_cb = NULL;
stream->close_cb = NULL;
stream->connection_cb = NULL;
stream->connect_req = NULL;
stream->shutdown_req = NULL;
stream->accepted_fd = -1;
stream->queued_fds = NULL;
stream->delayed_error = 0;
QUEUE_INIT(&stream->write_queue);
QUEUE_INIT(&stream->write_completed_queue);
stream->write_queue_size = 0;
if (loop->emfile_fd == -1) {
err = uv__open_cloexec("/dev/null", O_RDONLY);
if (err < 0)
/* In the rare case that "/dev/null" isn't mounted open "/"
* instead.
*/
err = uv__open_cloexec("/", O_RDONLY);
if (err >= 0)
loop->emfile_fd = err;
}
#if defined(__APPLE__)
stream->select = NULL;
#endif /* defined(__APPLE_) */
uv__io_init(&stream->io_watcher, uv__stream_io, -1);
}
static void uv__stream_osx_interrupt_select(uv_stream_t* stream) {
#if defined(__APPLE__)
/* Notify select() thread about state change */
uv__stream_select_t* s;
int r;
s = stream->select;
if (s == NULL)
return;
/* Interrupt select() loop
* NOTE: fake_fd and int_fd are socketpair(), thus writing to one will
* emit read event on other side
*/
do
r = write(s->fake_fd, "x", 1);
while (r == -1 && errno == EINTR);
assert(r == 1);
#else /* !defined(__APPLE__) */
/* No-op on any other platform */
#endif /* !defined(__APPLE__) */
}
#if defined(__APPLE__)
static void uv__stream_osx_select(void* arg) {
uv_stream_t* stream;
uv__stream_select_t* s;
char buf[1024];
int events;
int fd;
int r;
int max_fd;
stream = arg;
s = stream->select;
fd = s->fd;
if (fd > s->int_fd)
max_fd = fd;
else
max_fd = s->int_fd;
while (1) {
/* Terminate on semaphore */
if (uv_sem_trywait(&s->close_sem) == 0)
break;
/* Watch fd using select(2) */
memset(s->sread, 0, s->sread_sz);
memset(s->swrite, 0, s->swrite_sz);
if (uv__io_active(&stream->io_watcher, UV__POLLIN))
FD_SET(fd, s->sread);
if (uv__io_active(&stream->io_watcher, UV__POLLOUT))
FD_SET(fd, s->swrite);
FD_SET(s->int_fd, s->sread);
/* Wait indefinitely for fd events */
r = select(max_fd + 1, s->sread, s->swrite, NULL, NULL);
if (r == -1) {
if (errno == EINTR)
continue;
/* XXX: Possible?! */
abort();
}
/* Ignore timeouts */
if (r == 0)
continue;
/* Empty socketpair's buffer in case of interruption */
if (FD_ISSET(s->int_fd, s->sread))
while (1) {
r = read(s->int_fd, buf, sizeof(buf));
if (r == sizeof(buf))
continue;
if (r != -1)
break;
if (errno == EAGAIN || errno == EWOULDBLOCK)
break;
if (errno == EINTR)
continue;
abort();
}
/* Handle events */
events = 0;
if (FD_ISSET(fd, s->sread))
events |= UV__POLLIN;
if (FD_ISSET(fd, s->swrite))
events |= UV__POLLOUT;
assert(events != 0 || FD_ISSET(s->int_fd, s->sread));
if (events != 0) {
ACCESS_ONCE(int, s->events) = events;
uv_async_send(&s->async);
uv_sem_wait(&s->async_sem);
/* Should be processed at this stage */
assert((s->events == 0) || (stream->flags & UV_CLOSING));
}
}
}
static void uv__stream_osx_select_cb(uv_async_t* handle) {
uv__stream_select_t* s;
uv_stream_t* stream;
int events;
s = container_of(handle, uv__stream_select_t, async);
stream = s->stream;
/* Get and reset stream's events */
events = s->events;
ACCESS_ONCE(int, s->events) = 0;
assert(events != 0);
assert(events == (events & (UV__POLLIN | UV__POLLOUT)));
/* Invoke callback on event-loop */
if ((events & UV__POLLIN) && uv__io_active(&stream->io_watcher, UV__POLLIN))
uv__stream_io(stream->loop, &stream->io_watcher, UV__POLLIN);
if ((events & UV__POLLOUT) && uv__io_active(&stream->io_watcher, UV__POLLOUT))
uv__stream_io(stream->loop, &stream->io_watcher, UV__POLLOUT);
if (stream->flags & UV_CLOSING)
return;
/* NOTE: It is important to do it here, otherwise `select()` might be called
* before the actual `uv__read()`, leading to the blocking syscall
*/
uv_sem_post(&s->async_sem);
}
static void uv__stream_osx_cb_close(uv_handle_t* async) {
uv__stream_select_t* s;
s = container_of(async, uv__stream_select_t, async);
uv__free(s);
}
int uv__stream_try_select(uv_stream_t* stream, int* fd) {
/*
* kqueue doesn't work with some files from /dev mount on osx.
* select(2) in separate thread for those fds
*/
struct kevent filter[1];
struct kevent events[1];
struct timespec timeout;
uv__stream_select_t* s;
int fds[2];
int err;
int ret;
int kq;
int old_fd;
int max_fd;
size_t sread_sz;
size_t swrite_sz;
kq = kqueue();
if (kq == -1) {
perror("(libuv) kqueue()");
return -errno;
}
EV_SET(&filter[0], *fd, EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, 0);
/* Use small timeout, because we only want to capture EINVALs */
timeout.tv_sec = 0;
timeout.tv_nsec = 1;
ret = kevent(kq, filter, 1, events, 1, &timeout);
uv__close(kq);
if (ret == -1)
return -errno;
if (ret == 0 || (events[0].flags & EV_ERROR) == 0 || events[0].data != EINVAL)
return 0;
/* At this point we definitely know that this fd won't work with kqueue */
/*
* Create fds for io watcher and to interrupt the select() loop.
* NOTE: do it ahead of malloc below to allocate enough space for fd_sets
*/
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds))
return -errno;
max_fd = *fd;
if (fds[1] > max_fd)
max_fd = fds[1];
sread_sz = ROUND_UP(max_fd + 1, sizeof(uint32_t) * NBBY) / NBBY;
swrite_sz = sread_sz;
s = uv__malloc(sizeof(*s) + sread_sz + swrite_sz);
if (s == NULL) {
err = -ENOMEM;
goto failed_malloc;
}
s->events = 0;
s->fd = *fd;
s->sread = (fd_set*) ((char*) s + sizeof(*s));
s->sread_sz = sread_sz;
s->swrite = (fd_set*) ((char*) s->sread + sread_sz);
s->swrite_sz = swrite_sz;
err = uv_async_init(stream->loop, &s->async, uv__stream_osx_select_cb);
if (err)
goto failed_async_init;
s->async.flags |= UV__HANDLE_INTERNAL;
uv__handle_unref(&s->async);
err = uv_sem_init(&s->close_sem, 0);
if (err != 0)
goto failed_close_sem_init;
err = uv_sem_init(&s->async_sem, 0);
if (err != 0)
goto failed_async_sem_init;
s->fake_fd = fds[0];
s->int_fd = fds[1];
old_fd = *fd;
s->stream = stream;
stream->select = s;
*fd = s->fake_fd;
err = uv_thread_create(&s->thread, uv__stream_osx_select, stream);
if (err != 0)
goto failed_thread_create;
return 0;
failed_thread_create:
s->stream = NULL;
stream->select = NULL;
*fd = old_fd;
uv_sem_destroy(&s->async_sem);
failed_async_sem_init:
uv_sem_destroy(&s->close_sem);
failed_close_sem_init:
uv__close(fds[0]);
uv__close(fds[1]);
uv_close((uv_handle_t*) &s->async, uv__stream_osx_cb_close);
return err;
failed_async_init:
uv__free(s);
failed_malloc:
uv__close(fds[0]);
uv__close(fds[1]);
return err;
}
#endif /* defined(__APPLE__) */
int uv__stream_open(uv_stream_t* stream, int fd, int flags) {
#if defined(__APPLE__)
int enable;
#endif
assert(fd >= 0);
stream->flags |= flags;
if (stream->type == UV_TCP) {
if ((stream->flags & UV_TCP_NODELAY) && uv__tcp_nodelay(fd, 1))
return -errno;
/* TODO Use delay the user passed in. */
if ((stream->flags & UV_TCP_KEEPALIVE) && uv__tcp_keepalive(fd, 1, 60))
return -errno;
}
#if defined(__APPLE__)
enable = 1;
if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &enable, sizeof(enable)) &&
errno != ENOTSOCK &&
errno != EINVAL) {
return -errno;
}
#endif
stream->io_watcher.fd = fd;
return 0;
}
void uv__stream_flush_write_queue(uv_stream_t* stream, int error) {
uv_write_t* req;
QUEUE* q;
while (!QUEUE_EMPTY(&stream->write_queue)) {
q = QUEUE_HEAD(&stream->write_queue);
QUEUE_REMOVE(q);
req = QUEUE_DATA(q, uv_write_t, queue);
req->error = error;
QUEUE_INSERT_TAIL(&stream->write_completed_queue, &req->queue);
}
}
void uv__stream_destroy(uv_stream_t* stream) {
assert(!uv__io_active(&stream->io_watcher, UV__POLLIN | UV__POLLOUT));
assert(stream->flags & UV_CLOSED);
if (stream->connect_req) {
uv__req_unregister(stream->loop, stream->connect_req);
stream->connect_req->cb(stream->connect_req, -ECANCELED);
stream->connect_req = NULL;
}
uv__stream_flush_write_queue(stream, -ECANCELED);
uv__write_callbacks(stream);
if (stream->shutdown_req) {
/* The ECANCELED error code is a lie, the shutdown(2) syscall is a
* fait accompli at this point. Maybe we should revisit this in v0.11.
* A possible reason for leaving it unchanged is that it informs the
* callee that the handle has been destroyed.
*/
uv__req_unregister(stream->loop, stream->shutdown_req);
stream->shutdown_req->cb(stream->shutdown_req, -ECANCELED);
stream->shutdown_req = NULL;
}
assert(stream->write_queue_size == 0);
}
/* Implements a best effort approach to mitigating accept() EMFILE errors.
* We have a spare file descriptor stashed away that we close to get below
* the EMFILE limit. Next, we accept all pending connections and close them
* immediately to signal the clients that we're overloaded - and we are, but
* we still keep on trucking.
*
* There is one caveat: it's not reliable in a multi-threaded environment.
* The file descriptor limit is per process. Our party trick fails if another
* thread opens a file or creates a socket in the time window between us
* calling close() and accept().
*/
static int uv__emfile_trick(uv_loop_t* loop, int accept_fd) {
int err;
int emfile_fd;
if (loop->emfile_fd == -1)
return -EMFILE;
uv__close(loop->emfile_fd);
loop->emfile_fd = -1;
do {
err = uv__accept(accept_fd);
if (err >= 0)
uv__close(err);
} while (err >= 0 || err == -EINTR);
emfile_fd = uv__open_cloexec("/", O_RDONLY);
if (emfile_fd >= 0)
loop->emfile_fd = emfile_fd;
return err;
}
#if defined(UV_HAVE_KQUEUE)
# define UV_DEC_BACKLOG(w) w->rcount--;
#else
# define UV_DEC_BACKLOG(w) /* no-op */
#endif /* defined(UV_HAVE_KQUEUE) */
void uv__server_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
uv_stream_t* stream;
int err;
stream = container_of(w, uv_stream_t, io_watcher);
assert(events == UV__POLLIN);
assert(stream->accepted_fd == -1);
assert(!(stream->flags & UV_CLOSING));
uv__io_start(stream->loop, &stream->io_watcher, UV__POLLIN);
/* connection_cb can close the server socket while we're
* in the loop so check it on each iteration.
*/
while (uv__stream_fd(stream) != -1) {
assert(stream->accepted_fd == -1);
#if defined(UV_HAVE_KQUEUE)
if (w->rcount <= 0)
return;
#endif /* defined(UV_HAVE_KQUEUE) */
err = uv__accept(uv__stream_fd(stream));
if (err < 0) {
if (err == -EAGAIN || err == -EWOULDBLOCK)
return; /* Not an error. */
if (err == -ECONNABORTED)
continue; /* Ignore. Nothing we can do about that. */
if (err == -EMFILE || err == -ENFILE) {
err = uv__emfile_trick(loop, uv__stream_fd(stream));
if (err == -EAGAIN || err == -EWOULDBLOCK)
break;
}
stream->connection_cb(stream, err);
continue;
}
UV_DEC_BACKLOG(w)
stream->accepted_fd = err;
stream->connection_cb(stream, 0);
if (stream->accepted_fd != -1) {
/* The user hasn't yet accepted called uv_accept() */
uv__io_stop(loop, &stream->io_watcher, UV__POLLIN);
return;
}
if (stream->type == UV_TCP && (stream->flags & UV_TCP_SINGLE_ACCEPT)) {
/* Give other processes a chance to accept connections. */
struct timespec timeout = { 0, 1 };
nanosleep(&timeout, NULL);
}
}
}
#undef UV_DEC_BACKLOG
int uv_accept(uv_stream_t* server, uv_stream_t* client) {
int err;
/* TODO document this */
assert(server->loop == client->loop);
if (server->accepted_fd == -1)
return -EAGAIN;
switch (client->type) {
case UV_NAMED_PIPE:
case UV_TCP:
err = uv__stream_open(client,
server->accepted_fd,
UV_STREAM_READABLE | UV_STREAM_WRITABLE);
if (err) {
/* TODO handle error */
uv__close(server->accepted_fd);
goto done;
}
break;
case UV_UDP:
err = uv_udp_open((uv_udp_t*) client, server->accepted_fd);
if (err) {
uv__close(server->accepted_fd);
goto done;
}
break;
default:
return -EINVAL;
}
done:
/* Process queued fds */
if (server->queued_fds != NULL) {
uv__stream_queued_fds_t* queued_fds;
queued_fds = server->queued_fds;
/* Read first */
server->accepted_fd = queued_fds->fds[0];
/* All read, free */
assert(queued_fds->offset > 0);
if (--queued_fds->offset == 0) {
uv__free(queued_fds);
server->queued_fds = NULL;
} else {
/* Shift rest */
memmove(queued_fds->fds,
queued_fds->fds + 1,
queued_fds->offset * sizeof(*queued_fds->fds));
}
} else {
server->accepted_fd = -1;
if (err == 0)
uv__io_start(server->loop, &server->io_watcher, UV__POLLIN);
}
return err;
}
int uv_listen(uv_stream_t* stream, int backlog, uv_connection_cb cb) {
int err;
switch (stream->type) {
case UV_TCP:
err = uv_tcp_listen((uv_tcp_t*)stream, backlog, cb);
break;
case UV_NAMED_PIPE:
err = uv_pipe_listen((uv_pipe_t*)stream, backlog, cb);
break;
default:
err = -EINVAL;
}
if (err == 0)
uv__handle_start(stream);
return err;
}
static void uv__drain(uv_stream_t* stream) {
uv_shutdown_t* req;
int err;
assert(QUEUE_EMPTY(&stream->write_queue));
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLOUT);
uv__stream_osx_interrupt_select(stream);
/* Shutdown? */
if ((stream->flags & UV_STREAM_SHUTTING) &&
!(stream->flags & UV_CLOSING) &&
!(stream->flags & UV_STREAM_SHUT)) {
assert(stream->shutdown_req);
req = stream->shutdown_req;
stream->shutdown_req = NULL;
stream->flags &= ~UV_STREAM_SHUTTING;
uv__req_unregister(stream->loop, req);
err = 0;
if (shutdown(uv__stream_fd(stream), SHUT_WR))
err = -errno;
if (err == 0)
stream->flags |= UV_STREAM_SHUT;
if (req->cb != NULL)
req->cb(req, err);
}
}
static size_t uv__write_req_size(uv_write_t* req) {
size_t size;
assert(req->bufs != NULL);
size = uv__count_bufs(req->bufs + req->write_index,
req->nbufs - req->write_index);
assert(req->handle->write_queue_size >= size);
return size;
}
static void uv__write_req_finish(uv_write_t* req) {
uv_stream_t* stream = req->handle;
/* Pop the req off tcp->write_queue. */
QUEUE_REMOVE(&req->queue);
/* Only free when there was no error. On error, we touch up write_queue_size
* right before making the callback. The reason we don't do that right away
* is that a write_queue_size > 0 is our only way to signal to the user that
* they should stop writing - which they should if we got an error. Something
* to revisit in future revisions of the libuv API.
*/
if (req->error == 0) {
if (req->bufs != req->bufsml)
uv__free(req->bufs);
req->bufs = NULL;
}
/* Add it to the write_completed_queue where it will have its
* callback called in the near future.
*/
QUEUE_INSERT_TAIL(&stream->write_completed_queue, &req->queue);
uv__io_feed(stream->loop, &stream->io_watcher);
}
static int uv__handle_fd(uv_handle_t* handle) {
switch (handle->type) {
case UV_NAMED_PIPE:
case UV_TCP:
return ((uv_stream_t*) handle)->io_watcher.fd;
case UV_UDP:
return ((uv_udp_t*) handle)->io_watcher.fd;
default:
return -1;
}
}
static int uv__getiovmax() {
#if defined(IOV_MAX)
return IOV_MAX;
#elif defined(_SC_IOV_MAX)
static int iovmax = -1;
if (iovmax == -1)
iovmax = sysconf(_SC_IOV_MAX);
return iovmax;
#else
return 1024;
#endif
}
static void uv__write(uv_stream_t* stream) {
struct iovec* iov;
QUEUE* q;
uv_write_t* req;
int iovmax;
int iovcnt;
ssize_t n;
start:
assert(uv__stream_fd(stream) >= 0);
if (QUEUE_EMPTY(&stream->write_queue))
return;
q = QUEUE_HEAD(&stream->write_queue);
req = QUEUE_DATA(q, uv_write_t, queue);
assert(req->handle == stream);
/*
* Cast to iovec. We had to have our own uv_buf_t instead of iovec
* because Windows's WSABUF is not an iovec.
*/
assert(sizeof(uv_buf_t) == sizeof(struct iovec));
iov = (struct iovec*) &(req->bufs[req->write_index]);
iovcnt = req->nbufs - req->write_index;
iovmax = uv__getiovmax();
/* Limit iov count to avoid EINVALs from writev() */
if (iovcnt > iovmax)
iovcnt = iovmax;
/*
* Now do the actual writev. Note that we've been updating the pointers
* inside the iov each time we write. So there is no need to offset it.
*/
if (req->send_handle) {
struct msghdr msg;
char scratch[64];
struct cmsghdr *cmsg;
int fd_to_send = uv__handle_fd((uv_handle_t*) req->send_handle);
assert(fd_to_send >= 0);
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = iov;
msg.msg_iovlen = iovcnt;
msg.msg_flags = 0;
msg.msg_control = (void*) scratch;
msg.msg_controllen = CMSG_SPACE(sizeof(fd_to_send));
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(fd_to_send));
/* silence aliasing warning */
{
void* pv = CMSG_DATA(cmsg);
int* pi = pv;
*pi = fd_to_send;
}
do {
n = sendmsg(uv__stream_fd(stream), &msg, 0);
}
while (n == -1 && errno == EINTR);
} else {
do {
if (iovcnt == 1) {
n = write(uv__stream_fd(stream), iov[0].iov_base, iov[0].iov_len);
} else {
n = writev(uv__stream_fd(stream), iov, iovcnt);
}
}
while (n == -1 && errno == EINTR);
}
if (n < 0) {
if (errno != EAGAIN && errno != EWOULDBLOCK) {
/* Error */
req->error = -errno;
uv__write_req_finish(req);
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLOUT);
if (!uv__io_active(&stream->io_watcher, UV__POLLIN))
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
return;
} else if (stream->flags & UV_STREAM_BLOCKING) {
/* If this is a blocking stream, try again. */
goto start;
}
} else {
/* Successful write */
while (n >= 0) {
uv_buf_t* buf = &(req->bufs[req->write_index]);
size_t len = buf->len;
assert(req->write_index < req->nbufs);
if ((size_t)n < len) {
buf->base += n;
buf->len -= n;
stream->write_queue_size -= n;
n = 0;
/* There is more to write. */
if (stream->flags & UV_STREAM_BLOCKING) {
/*
* If we're blocking then we should not be enabling the write
* watcher - instead we need to try again.
*/
goto start;
} else {
/* Break loop and ensure the watcher is pending. */
break;
}
} else {
/* Finished writing the buf at index req->write_index. */
req->write_index++;
assert((size_t)n >= len);
n -= len;
assert(stream->write_queue_size >= len);
stream->write_queue_size -= len;
if (req->write_index == req->nbufs) {
/* Then we're done! */
assert(n == 0);
uv__write_req_finish(req);
/* TODO: start trying to write the next request. */
return;
}
}
}
}
/* Either we've counted n down to zero or we've got EAGAIN. */
assert(n == 0 || n == -1);
/* Only non-blocking streams should use the write_watcher. */
assert(!(stream->flags & UV_STREAM_BLOCKING));
/* We're not done. */
uv__io_start(stream->loop, &stream->io_watcher, UV__POLLOUT);
/* Notify select() thread about state change */
uv__stream_osx_interrupt_select(stream);
}
static void uv__write_callbacks(uv_stream_t* stream) {
uv_write_t* req;
QUEUE* q;
while (!QUEUE_EMPTY(&stream->write_completed_queue)) {
/* Pop a req off write_completed_queue. */
q = QUEUE_HEAD(&stream->write_completed_queue);
req = QUEUE_DATA(q, uv_write_t, queue);
QUEUE_REMOVE(q);
uv__req_unregister(stream->loop, req);
if (req->bufs != NULL) {
stream->write_queue_size -= uv__write_req_size(req);
if (req->bufs != req->bufsml)
uv__free(req->bufs);
req->bufs = NULL;
}
/* NOTE: call callback AFTER freeing the request data. */
if (req->cb)
req->cb(req, req->error);
}
assert(QUEUE_EMPTY(&stream->write_completed_queue));
}
uv_handle_type uv__handle_type(int fd) {
struct sockaddr_storage ss;
socklen_t len;
int type;
memset(&ss, 0, sizeof(ss));
len = sizeof(ss);
if (getsockname(fd, (struct sockaddr*)&ss, &len))
return UV_UNKNOWN_HANDLE;
len = sizeof type;
if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &len))
return UV_UNKNOWN_HANDLE;
if (type == SOCK_STREAM) {
switch (ss.ss_family) {
case AF_UNIX:
return UV_NAMED_PIPE;
case AF_INET:
case AF_INET6:
return UV_TCP;
}
}
if (type == SOCK_DGRAM &&
(ss.ss_family == AF_INET || ss.ss_family == AF_INET6))
return UV_UDP;
return UV_UNKNOWN_HANDLE;
}
static void uv__stream_eof(uv_stream_t* stream, const uv_buf_t* buf) {
stream->flags |= UV_STREAM_READ_EOF;
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLIN);
if (!uv__io_active(&stream->io_watcher, UV__POLLOUT))
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
stream->read_cb(stream, UV_EOF, buf);
stream->flags &= ~UV_STREAM_READING;
}
static int uv__stream_queue_fd(uv_stream_t* stream, int fd) {
uv__stream_queued_fds_t* queued_fds;
unsigned int queue_size;
queued_fds = stream->queued_fds;
if (queued_fds == NULL) {
queue_size = 8;
queued_fds = uv__malloc((queue_size - 1) * sizeof(*queued_fds->fds) +
sizeof(*queued_fds));
if (queued_fds == NULL)
return -ENOMEM;
queued_fds->size = queue_size;
queued_fds->offset = 0;
stream->queued_fds = queued_fds;
/* Grow */
} else if (queued_fds->size == queued_fds->offset) {
queue_size = queued_fds->size + 8;
queued_fds = uv__realloc(queued_fds,
(queue_size - 1) * sizeof(*queued_fds->fds) +
sizeof(*queued_fds));
/*
* Allocation failure, report back.
* NOTE: if it is fatal - sockets will be closed in uv__stream_close
*/
if (queued_fds == NULL)
return -ENOMEM;
queued_fds->size = queue_size;
stream->queued_fds = queued_fds;
}
/* Put fd in a queue */
queued_fds->fds[queued_fds->offset++] = fd;
return 0;
}
#define UV__CMSG_FD_COUNT 64
#define UV__CMSG_FD_SIZE (UV__CMSG_FD_COUNT * sizeof(int))
static int uv__stream_recv_cmsg(uv_stream_t* stream, struct msghdr* msg) {
struct cmsghdr* cmsg;
for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
char* start;
char* end;
int err;
void* pv;
int* pi;
unsigned int i;
unsigned int count;
if (cmsg->cmsg_type != SCM_RIGHTS) {
fprintf(stderr, "ignoring non-SCM_RIGHTS ancillary data: %d\n",
cmsg->cmsg_type);
continue;
}
/* silence aliasing warning */
pv = CMSG_DATA(cmsg);
pi = pv;
/* Count available fds */
start = (char*) cmsg;
end = (char*) cmsg + cmsg->cmsg_len;
count = 0;
while (start + CMSG_LEN(count * sizeof(*pi)) < end)
count++;
assert(start + CMSG_LEN(count * sizeof(*pi)) == end);
for (i = 0; i < count; i++) {
/* Already has accepted fd, queue now */
if (stream->accepted_fd != -1) {
err = uv__stream_queue_fd(stream, pi[i]);
if (err != 0) {
/* Close rest */
for (; i < count; i++)
uv__close(pi[i]);
return err;
}
} else {
stream->accepted_fd = pi[i];
}
}
}
return 0;
}
static void uv__read(uv_stream_t* stream) {
uv_buf_t buf;
ssize_t nread;
struct msghdr msg;
char cmsg_space[CMSG_SPACE(UV__CMSG_FD_SIZE)];
int count;
int err;
int is_ipc;
stream->flags &= ~UV_STREAM_READ_PARTIAL;
/* Prevent loop starvation when the data comes in as fast as (or faster than)
* we can read it. XXX Need to rearm fd if we switch to edge-triggered I/O.
*/
count = 32;
is_ipc = stream->type == UV_NAMED_PIPE && ((uv_pipe_t*) stream)->ipc;
/* XXX: Maybe instead of having UV_STREAM_READING we just test if
* tcp->read_cb is NULL or not?
*/
while (stream->read_cb
&& (stream->flags & UV_STREAM_READING)
&& (count-- > 0)) {
assert(stream->alloc_cb != NULL);
stream->alloc_cb((uv_handle_t*)stream, 64 * 1024, &buf);
if (buf.len == 0) {
/* User indicates it can't or won't handle the read. */
stream->read_cb(stream, UV_ENOBUFS, &buf);
return;
}
assert(buf.base != NULL);
assert(uv__stream_fd(stream) >= 0);
if (!is_ipc) {
do {
nread = read(uv__stream_fd(stream), buf.base, buf.len);
}
while (nread < 0 && errno == EINTR);
} else {
/* ipc uses recvmsg */
msg.msg_flags = 0;
msg.msg_iov = (struct iovec*) &buf;
msg.msg_iovlen = 1;
msg.msg_name = NULL;
msg.msg_namelen = 0;
/* Set up to receive a descriptor even if one isn't in the message */
msg.msg_controllen = sizeof(cmsg_space);
msg.msg_control = cmsg_space;
do {
nread = uv__recvmsg(uv__stream_fd(stream), &msg, 0);
}
while (nread < 0 && errno == EINTR);
}
if (nread < 0) {
/* Error */
if (errno == EAGAIN || errno == EWOULDBLOCK) {
/* Wait for the next one. */
if (stream->flags & UV_STREAM_READING) {
uv__io_start(stream->loop, &stream->io_watcher, UV__POLLIN);
uv__stream_osx_interrupt_select(stream);
}
stream->read_cb(stream, 0, &buf);
} else {
/* Error. User should call uv_close(). */
stream->read_cb(stream, -errno, &buf);
if (stream->flags & UV_STREAM_READING) {
stream->flags &= ~UV_STREAM_READING;
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLIN);
if (!uv__io_active(&stream->io_watcher, UV__POLLOUT))
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
}
}
return;
} else if (nread == 0) {
uv__stream_eof(stream, &buf);
return;
} else {
/* Successful read */
ssize_t buflen = buf.len;
if (is_ipc) {
err = uv__stream_recv_cmsg(stream, &msg);
if (err != 0) {
stream->read_cb(stream, err, &buf);
return;
}
}
stream->read_cb(stream, nread, &buf);
/* Return if we didn't fill the buffer, there is no more data to read. */
if (nread < buflen) {
stream->flags |= UV_STREAM_READ_PARTIAL;
return;
}
}
}
}
#undef UV__CMSG_FD_COUNT
#undef UV__CMSG_FD_SIZE
int uv_shutdown(uv_shutdown_t* req, uv_stream_t* stream, uv_shutdown_cb cb) {
assert((stream->type == UV_TCP || stream->type == UV_NAMED_PIPE) &&
"uv_shutdown (unix) only supports uv_handle_t right now");
if (!(stream->flags & UV_STREAM_WRITABLE) ||
stream->flags & UV_STREAM_SHUT ||
stream->flags & UV_STREAM_SHUTTING ||
stream->flags & UV_CLOSED ||
stream->flags & UV_CLOSING) {
return -ENOTCONN;
}
assert(uv__stream_fd(stream) >= 0);
/* Initialize request */
uv__req_init(stream->loop, req, UV_SHUTDOWN);
req->handle = stream;
req->cb = cb;
stream->shutdown_req = req;
stream->flags |= UV_STREAM_SHUTTING;
uv__io_start(stream->loop, &stream->io_watcher, UV__POLLOUT);
uv__stream_osx_interrupt_select(stream);
return 0;
}
static void uv__stream_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
uv_stream_t* stream;
stream = container_of(w, uv_stream_t, io_watcher);
assert(stream->type == UV_TCP ||
stream->type == UV_NAMED_PIPE ||
stream->type == UV_TTY);
assert(!(stream->flags & UV_CLOSING));
if (stream->connect_req) {
uv__stream_connect(stream);
return;
}
assert(uv__stream_fd(stream) >= 0);
/* Ignore POLLHUP here. Even it it's set, there may still be data to read. */
if (events & (UV__POLLIN | UV__POLLERR | UV__POLLHUP))
uv__read(stream);
if (uv__stream_fd(stream) == -1)
return; /* read_cb closed stream. */
/* Short-circuit iff POLLHUP is set, the user is still interested in read
* events and uv__read() reported a partial read but not EOF. If the EOF
* flag is set, uv__read() called read_cb with err=UV_EOF and we don't
* have to do anything. If the partial read flag is not set, we can't
* report the EOF yet because there is still data to read.
*/
if ((events & UV__POLLHUP) &&
(stream->flags & UV_STREAM_READING) &&
(stream->flags & UV_STREAM_READ_PARTIAL) &&
!(stream->flags & UV_STREAM_READ_EOF)) {
uv_buf_t buf = { NULL, 0 };
uv__stream_eof(stream, &buf);
}
if (uv__stream_fd(stream) == -1)
return; /* read_cb closed stream. */
if (events & (UV__POLLOUT | UV__POLLERR | UV__POLLHUP)) {
uv__write(stream);
uv__write_callbacks(stream);
/* Write queue drained. */
if (QUEUE_EMPTY(&stream->write_queue))
uv__drain(stream);
}
}
/**
* We get called here from directly following a call to connect(2).
* In order to determine if we've errored out or succeeded must call
* getsockopt.
*/
static void uv__stream_connect(uv_stream_t* stream) {
int error;
uv_connect_t* req = stream->connect_req;
socklen_t errorsize = sizeof(int);
assert(stream->type == UV_TCP || stream->type == UV_NAMED_PIPE);
assert(req);
if (stream->delayed_error) {
/* To smooth over the differences between unixes errors that
* were reported synchronously on the first connect can be delayed
* until the next tick--which is now.
*/
error = stream->delayed_error;
stream->delayed_error = 0;
} else {
/* Normal situation: we need to get the socket error from the kernel. */
assert(uv__stream_fd(stream) >= 0);
getsockopt(uv__stream_fd(stream),
SOL_SOCKET,
SO_ERROR,
&error,
&errorsize);
error = -error;
}
if (error == -EINPROGRESS)
return;
stream->connect_req = NULL;
uv__req_unregister(stream->loop, req);
if (error < 0 || QUEUE_EMPTY(&stream->write_queue)) {
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLOUT);
}
if (req->cb)
req->cb(req, error);
if (uv__stream_fd(stream) == -1)
return;
if (error < 0) {
uv__stream_flush_write_queue(stream, -ECANCELED);
uv__write_callbacks(stream);
}
}
int uv_write2(uv_write_t* req,
uv_stream_t* stream,
const uv_buf_t bufs[],
unsigned int nbufs,
uv_stream_t* send_handle,
uv_write_cb cb) {
int empty_queue;
assert(nbufs > 0);
assert((stream->type == UV_TCP ||
stream->type == UV_NAMED_PIPE ||
stream->type == UV_TTY) &&
"uv_write (unix) does not yet support other types of streams");
if (uv__stream_fd(stream) < 0)
return -EBADF;
if (send_handle) {
if (stream->type != UV_NAMED_PIPE || !((uv_pipe_t*)stream)->ipc)
return -EINVAL;
/* XXX We abuse uv_write2() to send over UDP handles to child processes.
* Don't call uv__stream_fd() on those handles, it's a macro that on OS X
* evaluates to a function that operates on a uv_stream_t with a couple of
* OS X specific fields. On other Unices it does (handle)->io_watcher.fd,
* which works but only by accident.
*/
if (uv__handle_fd((uv_handle_t*) send_handle) < 0)
return -EBADF;
}
/* It's legal for write_queue_size > 0 even when the write_queue is empty;
* it means there are error-state requests in the write_completed_queue that
* will touch up write_queue_size later, see also uv__write_req_finish().
* We could check that write_queue is empty instead but that implies making
* a write() syscall when we know that the handle is in error mode.
*/
empty_queue = (stream->write_queue_size == 0);
/* Initialize the req */
uv__req_init(stream->loop, req, UV_WRITE);
req->cb = cb;
req->handle = stream;
req->error = 0;
req->send_handle = send_handle;
QUEUE_INIT(&req->queue);
req->bufs = req->bufsml;
if (nbufs > ARRAY_SIZE(req->bufsml))
req->bufs = uv__malloc(nbufs * sizeof(bufs[0]));
if (req->bufs == NULL)
return -ENOMEM;
memcpy(req->bufs, bufs, nbufs * sizeof(bufs[0]));
req->nbufs = nbufs;
req->write_index = 0;
stream->write_queue_size += uv__count_bufs(bufs, nbufs);
/* Append the request to write_queue. */
QUEUE_INSERT_TAIL(&stream->write_queue, &req->queue);
/* If the queue was empty when this function began, we should attempt to
* do the write immediately. Otherwise start the write_watcher and wait
* for the fd to become writable.
*/
if (stream->connect_req) {
/* Still connecting, do nothing. */
}
else if (empty_queue) {
uv__write(stream);
}
else {
/*
* blocking streams should never have anything in the queue.
* if this assert fires then somehow the blocking stream isn't being
* sufficiently flushed in uv__write.
*/
assert(!(stream->flags & UV_STREAM_BLOCKING));
uv__io_start(stream->loop, &stream->io_watcher, UV__POLLOUT);
uv__stream_osx_interrupt_select(stream);
}
return 0;
}
/* The buffers to be written must remain valid until the callback is called.
* This is not required for the uv_buf_t array.
*/
int uv_write(uv_write_t* req,
uv_stream_t* handle,
const uv_buf_t bufs[],
unsigned int nbufs,
uv_write_cb cb) {
return uv_write2(req, handle, bufs, nbufs, NULL, cb);
}
void uv_try_write_cb(uv_write_t* req, int status) {
/* Should not be called */
abort();
}
int uv_try_write(uv_stream_t* stream,
const uv_buf_t bufs[],
unsigned int nbufs) {
int r;
int has_pollout;
size_t written;
size_t req_size;
uv_write_t req;
/* Connecting or already writing some data */
if (stream->connect_req != NULL || stream->write_queue_size != 0)
return -EAGAIN;
has_pollout = uv__io_active(&stream->io_watcher, UV__POLLOUT);
r = uv_write(&req, stream, bufs, nbufs, uv_try_write_cb);
if (r != 0)
return r;
/* Remove not written bytes from write queue size */
written = uv__count_bufs(bufs, nbufs);
if (req.bufs != NULL)
req_size = uv__write_req_size(&req);
else
req_size = 0;
written -= req_size;
stream->write_queue_size -= req_size;
/* Unqueue request, regardless of immediateness */
QUEUE_REMOVE(&req.queue);
uv__req_unregister(stream->loop, &req);
if (req.bufs != req.bufsml)
uv__free(req.bufs);
req.bufs = NULL;
/* Do not poll for writable, if we wasn't before calling this */
if (!has_pollout) {
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLOUT);
uv__stream_osx_interrupt_select(stream);
}
if (written == 0)
return -EAGAIN;
else
return written;
}
int uv_read_start(uv_stream_t* stream,
uv_alloc_cb alloc_cb,
uv_read_cb read_cb) {
assert(stream->type == UV_TCP || stream->type == UV_NAMED_PIPE ||
stream->type == UV_TTY);
if (stream->flags & UV_CLOSING)
return -EINVAL;
/* The UV_STREAM_READING flag is irrelevant of the state of the tcp - it just
* expresses the desired state of the user.
*/
stream->flags |= UV_STREAM_READING;
/* TODO: try to do the read inline? */
/* TODO: keep track of tcp state. If we've gotten a EOF then we should
* not start the IO watcher.
*/
assert(uv__stream_fd(stream) >= 0);
assert(alloc_cb);
stream->read_cb = read_cb;
stream->alloc_cb = alloc_cb;
uv__io_start(stream->loop, &stream->io_watcher, UV__POLLIN);
uv__handle_start(stream);
uv__stream_osx_interrupt_select(stream);
return 0;
}
int uv_read_stop(uv_stream_t* stream) {
if (!(stream->flags & UV_STREAM_READING))
return 0;
stream->flags &= ~UV_STREAM_READING;
uv__io_stop(stream->loop, &stream->io_watcher, UV__POLLIN);
if (!uv__io_active(&stream->io_watcher, UV__POLLOUT))
uv__handle_stop(stream);
uv__stream_osx_interrupt_select(stream);
stream->read_cb = NULL;
stream->alloc_cb = NULL;
return 0;
}
int uv_is_readable(const uv_stream_t* stream) {
return !!(stream->flags & UV_STREAM_READABLE);
}
int uv_is_writable(const uv_stream_t* stream) {
return !!(stream->flags & UV_STREAM_WRITABLE);
}
#if defined(__APPLE__)
int uv___stream_fd(const uv_stream_t* handle) {
const uv__stream_select_t* s;
assert(handle->type == UV_TCP ||
handle->type == UV_TTY ||
handle->type == UV_NAMED_PIPE);
s = handle->select;
if (s != NULL)
return s->fd;
return handle->io_watcher.fd;
}
#endif /* defined(__APPLE__) */
void uv__stream_close(uv_stream_t* handle) {
unsigned int i;
uv__stream_queued_fds_t* queued_fds;
#if defined(__APPLE__)
/* Terminate select loop first */
if (handle->select != NULL) {
uv__stream_select_t* s;
s = handle->select;
uv_sem_post(&s->close_sem);
uv_sem_post(&s->async_sem);
uv__stream_osx_interrupt_select(handle);
uv_thread_join(&s->thread);
uv_sem_destroy(&s->close_sem);
uv_sem_destroy(&s->async_sem);
uv__close(s->fake_fd);
uv__close(s->int_fd);
uv_close((uv_handle_t*) &s->async, uv__stream_osx_cb_close);
handle->select = NULL;
}
#endif /* defined(__APPLE__) */
uv__io_close(handle->loop, &handle->io_watcher);
uv_read_stop(handle);
uv__handle_stop(handle);
if (handle->io_watcher.fd != -1) {
/* Don't close stdio file descriptors. Nothing good comes from it. */
if (handle->io_watcher.fd > STDERR_FILENO)
uv__close(handle->io_watcher.fd);
handle->io_watcher.fd = -1;
}
if (handle->accepted_fd != -1) {
uv__close(handle->accepted_fd);
handle->accepted_fd = -1;
}
/* Close all queued fds */
if (handle->queued_fds != NULL) {
queued_fds = handle->queued_fds;
for (i = 0; i < queued_fds->offset; i++)
uv__close(queued_fds->fds[i]);
uv__free(handle->queued_fds);
handle->queued_fds = NULL;
}
assert(!uv__io_active(&handle->io_watcher, UV__POLLIN | UV__POLLOUT));
}
int uv_stream_set_blocking(uv_stream_t* handle, int blocking) {
/* Don't need to check the file descriptor, uv__nonblock()
* will fail with EBADF if it's not valid.
*/
return uv__nonblock(uv__stream_fd(handle), !blocking);
}