Commit d133cf83 authored by Eli Zaretskii's avatar Eli Zaretskii

Support non-blocking connect on MS-Windows (Bug#20207)

 Based on ideas from Kim F. Storm <storm@cua.dk>, see
 http://lists.gnu.org/archive/html/emacs-devel/2006-12/msg00873.html.

 src/w32proc.c (reader_thread): If the FILE_CONNECT flag is set, call
 '_sys_wait_connect'.  If it returns STATUS_CONNECT_FAILED, exit
 the thread with code 2.
 (sys_select): Support 'wfds' in addition to 'rfds'.  If a
 descriptor in 'wfds' has its bit set, but the corresponding
 fd_info member doesn't have its FILE_CONNECT flag set, ignore the
 descriptor.  Otherwise, acknowledge a successful non-blocking
 connect by resetting the FILE_CONNECT flag and setting cp->status
 to STATUS_READ_ACKNOWLEDGED.
 src/w32.h (STATUS_CONNECT_FAILED): New enumeration value.
 (struct _child_process): New member 'errcode'.
 (FILE_CONNECT): New flag.
 (_sys_wait_connect): Add prototype.
 src/w32.c (pfn_WSAEnumNetworkEvents): New function pointer.
 (init_winsock): Load WSAEnumNetworkEvents from winsock DLL.
 (set_errno): Map WSAEWOULDBLOCK and WSAENOTCONN.
 (sys_connect): Support non-blocking 'connect' calls by setting the
 FILE_CONNECT flag in the fd_info member and returning EINPROGRESS.
 (_sys_read_ahead): Add debug message if this function is called
 for a descriptor that waits for a non-blocking connect to complete.
 (_sys_wait_connect): New function.
 (sys_read): Support STATUS_CONNECT_FAILED.  Return the error code
 recorded by _sys_wait_connect when the non-blocking connect
 failed.  Don't call WSAGetLastError before a call to set_errno had
 a chance to use its value, since WSAGetLastError clears the last
 error.

 nt/inc/ms-w32.h (BROKEN_NON_BLOCKING_CONNECT): Don't define.
parent 792d44b3
2015-03-27 Eli Zaretskii <eliz@gnu.org>
* inc/ms-w32.h (BROKEN_NON_BLOCKING_CONNECT): Don't define.
(Bug#20207)
2015-03-09 Eli Zaretskii <eliz@gnu.org>
* INSTALL: Add some more installation instructions for mingw-get
......
......@@ -58,10 +58,6 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
Look in <sys/time.h> for a timeval structure. */
#define HAVE_TIMEVAL 1
/* But our select implementation doesn't allow us to make non-blocking
connects. So until that is fixed, this is necessary: */
#define BROKEN_NON_BLOCKING_CONNECT 1
/* And the select implementation does 1-byte read-ahead waiting
for received packets, so datagrams are broken too. */
#define BROKEN_DATAGRAM_SOCKETS 1
......
2015-03-27 Eli Zaretskii <eliz@gnu.org>
Support non-blocking connect on MS-Windows.
Based on ideas from Kim F. Storm <storm@cua.dk>, see
http://lists.gnu.org/archive/html/emacs-devel/2006-12/msg00873.html.
* w32proc.c (reader_thread): If the FILE_CONNECT flag is set, call
'_sys_wait_connect'. If it returns STATUS_CONNECT_FAILED, exit
the thread with code 2.
(sys_select): Support 'wfds' in addition to 'rfds'. If a
descriptor in 'wfds' has its bit set, but the corresponding
fd_info member doesn't have its FILE_CONNECT flag set, ignore the
descriptor. Otherwise, acknowledge a successful non-blocking
connect by resetting the FILE_CONNECT flag and setting cp->status
to STATUS_READ_ACKNOWLEDGED. (Bug#20207)
* w32.h (STATUS_CONNECT_FAILED): New enumeration value.
(struct _child_process): New member 'errcode'.
(FILE_CONNECT): New flag.
(_sys_wait_connect): Add prototype.
* w32.c (pfn_WSAEnumNetworkEvents): New function pointer.
(init_winsock): Load WSAEnumNetworkEvents from winsock DLL.
(set_errno): Map WSAEWOULDBLOCK and WSAENOTCONN.
(sys_connect): Support non-blocking 'connect' calls by setting the
FILE_CONNECT flag in the fd_info member and returning EINPROGRESS.
(_sys_read_ahead): Add debug message if this function is called
for a descriptor that waits for a non-blocking connect to complete.
(_sys_wait_connect): New function.
(sys_read): Support STATUS_CONNECT_FAILED. Return the error code
recorded by _sys_wait_connect when the non-blocking connect
failed. Don't call WSAGetLastError before a call to set_errno had
a chance to use its value, since WSAGetLastError clears the last
error.
2015-03-25 Stefan Monnier <monnier@iro.umontreal.ca>
* editfns.c (save_excursion_save): Don't save the mark.
......
......@@ -7038,6 +7038,9 @@ int (PASCAL *pfn_WSAStartup) (WORD wVersionRequired, LPWSADATA lpWSAData);
void (PASCAL *pfn_WSASetLastError) (int iError);
int (PASCAL *pfn_WSAGetLastError) (void);
int (PASCAL *pfn_WSAEventSelect) (SOCKET s, HANDLE hEventObject, long lNetworkEvents);
int (PASCAL *pfn_WSAEnumNetworkEvents) (SOCKET s, HANDLE hEventObject,
WSANETWORKEVENTS *NetworkEvents);
HANDLE (PASCAL *pfn_WSACreateEvent) (void);
int (PASCAL *pfn_WSACloseEvent) (HANDLE hEvent);
int (PASCAL *pfn_socket) (int af, int type, int protocol);
......@@ -7123,6 +7126,7 @@ init_winsock (int load_now)
LOAD_PROC (WSASetLastError);
LOAD_PROC (WSAGetLastError);
LOAD_PROC (WSAEventSelect);
LOAD_PROC (WSAEnumNetworkEvents);
LOAD_PROC (WSACreateEvent);
LOAD_PROC (WSACloseEvent);
LOAD_PROC (socket);
......@@ -7206,6 +7210,8 @@ set_errno (void)
case WSAEMFILE: errno = EMFILE; break;
case WSAENAMETOOLONG: errno = ENAMETOOLONG; break;
case WSAENOTEMPTY: errno = ENOTEMPTY; break;
case WSAEWOULDBLOCK: errno = EWOULDBLOCK; break;
case WSAENOTCONN: errno = ENOTCONN; break;
default: errno = wsa_err; break;
}
}
......@@ -7473,8 +7479,18 @@ sys_connect (int s, const struct sockaddr * name, int namelen)
{
int rc = pfn_connect (SOCK_HANDLE (s), name, namelen);
if (rc == SOCKET_ERROR)
set_errno ();
return rc;
{
set_errno ();
/* If this is a non-blocking 'connect', set the bit in flags
that will tell reader_thread to wait for connection
before trying to read. */
if (errno == EWOULDBLOCK && (fd_info[s].flags & FILE_NDELAY) != 0)
{
errno = EINPROGRESS; /* that's what process.c expects */
fd_info[s].flags |= FILE_CONNECT;
}
return rc;
}
}
errno = ENOTSOCK;
return SOCKET_ERROR;
......@@ -7984,6 +8000,8 @@ _sys_read_ahead (int fd)
emacs_abort ();
}
if ((fd_info[fd].flags & FILE_CONNECT) != 0)
DebPrint (("_sys_read_ahead: read requested from fd %d, which waits for async connect!\n", fd));
cp->status = STATUS_READ_IN_PROGRESS;
if (fd_info[fd].flags & FILE_PIPE)
......@@ -8105,6 +8123,60 @@ _sys_wait_accept (int fd)
return cp->status;
}
int
_sys_wait_connect (int fd)
{
HANDLE hEv;
child_process * cp;
int rc;
if (fd < 0 || fd >= MAXDESC)
return STATUS_READ_ERROR;
cp = fd_info[fd].cp;
if (cp == NULL || cp->fd != fd || cp->status != STATUS_READ_READY)
return STATUS_READ_ERROR;
cp->status = STATUS_READ_FAILED;
hEv = pfn_WSACreateEvent ();
rc = pfn_WSAEventSelect (SOCK_HANDLE (fd), hEv, FD_CONNECT);
if (rc != SOCKET_ERROR)
{
do {
rc = WaitForSingleObject (hEv, 500);
Sleep (5);
} while (rc == WAIT_TIMEOUT
&& cp->status != STATUS_READ_ERROR
&& cp->char_avail);
if (rc == WAIT_OBJECT_0)
{
/* We've got an event, but it could be a successful
connection, or it could be a failure. Find out
which one is it. */
WSANETWORKEVENTS events;
pfn_WSAEnumNetworkEvents (SOCK_HANDLE (fd), hEv, &events);
if ((events.lNetworkEvents & FD_CONNECT) != 0
&& events.iErrorCode[FD_CONNECT_BIT])
{
cp->status = STATUS_CONNECT_FAILED;
cp->errcode = events.iErrorCode[FD_CONNECT_BIT];
}
else
{
cp->status = STATUS_READ_SUCCEEDED;
cp->errcode = 0;
}
}
pfn_WSAEventSelect (SOCK_HANDLE (fd), NULL, 0);
}
else
pfn_WSACloseEvent (hEv);
return cp->status;
}
int
sys_read (int fd, char * buffer, unsigned int count)
{
......@@ -8174,6 +8246,7 @@ sys_read (int fd, char * buffer, unsigned int count)
ResetEvent (cp->char_avail);
case STATUS_READ_ACKNOWLEDGED:
case STATUS_CONNECT_FAILED:
break;
default:
......@@ -8239,7 +8312,29 @@ sys_read (int fd, char * buffer, unsigned int count)
{
if (winsock_lib == NULL) emacs_abort ();
/* do the equivalent of a non-blocking read */
/* When a non-blocking 'connect' call fails,
wait_reading_process_output detects this by calling
'getpeername', and then attempts to obtain the connection
error code by trying to read 1 byte from the socket. If
we try to serve that read by calling 'recv' below, the
error we get is a generic WSAENOTCONN, not the actual
connection error. So instead, we use the actual error
code stashed by '_sys_wait_connect' in cp->errcode.
Alternatively, we could have used 'getsockopt', like on
GNU/Linux, but: (a) I have no idea whether the winsock
version could hang, as it does "on some systems" (see the
comment in process.c); and (b) 'getsockopt' on Windows is
documented to clear the socket error for the entire
process, which I'm not sure is TRT; FIXME. */
if (current_status == STATUS_CONNECT_FAILED
&& (fd_info[fd].flags & FILE_CONNECT) != 0
&& cp->errcode != 0)
{
pfn_WSASetLastError (cp->errcode);
set_errno ();
return -1;
}
/* Do the equivalent of a non-blocking read. */
pfn_ioctlsocket (SOCK_HANDLE (fd), FIONREAD, &waiting);
if (waiting == 0 && nchars == 0)
{
......@@ -8253,9 +8348,9 @@ sys_read (int fd, char * buffer, unsigned int count)
int res = pfn_recv (SOCK_HANDLE (fd), buffer, count, 0);
if (res == SOCKET_ERROR)
{
DebPrint (("sys_read.recv failed with error %d on socket %ld\n",
pfn_WSAGetLastError (), SOCK_HANDLE (fd)));
set_errno ();
DebPrint (("sys_read.recv failed with error %d on socket %ld\n",
errno, SOCK_HANDLE (fd)));
return -1;
}
nchars += res;
......
......@@ -61,7 +61,8 @@ enum {
STATUS_READ_IN_PROGRESS,
STATUS_READ_FAILED,
STATUS_READ_SUCCEEDED,
STATUS_READ_ACKNOWLEDGED
STATUS_READ_ACKNOWLEDGED,
STATUS_CONNECT_FAILED
};
/* This structure is used for both pipes and sockets; for
......@@ -96,6 +97,8 @@ typedef struct _child_process
/* Status of subprocess/connection and of reading its output. For
values, see the enumeration above. */
volatile int status;
/* Used to store errno value of failed async 'connect' calls. */
volatile int errcode;
/* Holds a single character read by _sys_read_ahead, when a
subprocess has some output ready. */
char chr;
......@@ -122,7 +125,8 @@ extern filedesc fd_info [ MAXDESC ];
/* fd_info flag definitions */
#define FILE_READ 0x0001
#define FILE_WRITE 0x0002
#define FILE_LISTEN 0x0004
#define FILE_LISTEN 0x0004
#define FILE_CONNECT 0x0008
#define FILE_BINARY 0x0010
#define FILE_LAST_CR 0x0020
#define FILE_AT_EOF 0x0040
......@@ -171,6 +175,7 @@ extern void init_timers (void);
extern int _sys_read_ahead (int fd);
extern int _sys_wait_accept (int fd);
extern int _sys_wait_connect (int fd);
extern HMODULE w32_delayed_load (Lisp_Object);
......
......@@ -1011,7 +1011,9 @@ reader_thread (void *arg)
{
int rc;
if (cp->fd >= 0 && fd_info[cp->fd].flags & FILE_LISTEN)
if (cp->fd >= 0 && (fd_info[cp->fd].flags & FILE_CONNECT) != 0)
rc = _sys_wait_connect (cp->fd);
else if (cp->fd >= 0 && (fd_info[cp->fd].flags & FILE_LISTEN) != 0)
rc = _sys_wait_accept (cp->fd);
else
rc = _sys_read_ahead (cp->fd);
......@@ -1031,8 +1033,8 @@ reader_thread (void *arg)
return 1;
}
if (rc == STATUS_READ_ERROR)
return 1;
if (rc == STATUS_READ_ERROR || rc == STATUS_CONNECT_FAILED)
return 2;
/* If the read died, the child has died so let the thread die */
if (rc == STATUS_READ_FAILED)
......@@ -1929,7 +1931,7 @@ int
sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
struct timespec *timeout, void *ignored)
{
SELECT_TYPE orfds;
SELECT_TYPE orfds, owfds;
DWORD timeout_ms, start_time;
int i, nh, nc, nr;
DWORD active;
......@@ -1947,15 +1949,27 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
return 0;
}
/* Otherwise, we only handle rfds, so fail otherwise. */
if (rfds == NULL || wfds != NULL || efds != NULL)
/* Otherwise, we only handle rfds and wfds, so fail otherwise. */
if ((rfds == NULL && wfds == NULL) || efds != NULL)
{
errno = EINVAL;
return -1;
}
orfds = *rfds;
FD_ZERO (rfds);
if (rfds)
{
orfds = *rfds;
FD_ZERO (rfds);
}
else
FD_ZERO (&orfds);
if (wfds)
{
owfds = *wfds;
FD_ZERO (wfds);
}
else
FD_ZERO (&owfds);
nr = 0;
/* If interrupt_handle is available and valid, always wait on it, to
......@@ -1970,7 +1984,7 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
/* Build a list of pipe handles to wait on. */
for (i = 0; i < nfds; i++)
if (FD_ISSET (i, &orfds))
if (FD_ISSET (i, &orfds) || FD_ISSET (i, &owfds))
{
if (i == 0)
{
......@@ -1984,7 +1998,7 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
/* Check for any emacs-generated input in the queue since
it won't be detected in the wait */
if (detect_input_pending ())
if (rfds && detect_input_pending ())
{
FD_SET (i, rfds);
return 1;
......@@ -1999,6 +2013,13 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
{
/* Child process and socket/comm port input. */
cp = fd_info[i].cp;
if (FD_ISSET (i, &owfds)
&& cp
&& (fd_info[i].flags && FILE_CONNECT) == 0)
{
DebPrint (("sys_select: fd %d is in wfds, but FILE_CONNECT is reset!\n", i));
cp = NULL;
}
if (cp)
{
int current_status = cp->status;
......@@ -2007,6 +2028,8 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
{
/* Tell reader thread which file handle to use. */
cp->fd = i;
/* Zero out the error code. */
cp->errcode = 0;
/* Wake up the reader thread for this process */
cp->status = STATUS_READ_READY;
if (!SetEvent (cp->char_consumed))
......@@ -2197,7 +2220,7 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
if (cp->fd >= 0 && (fd_info[cp->fd].flags & FILE_AT_EOF) == 0)
fd_info[cp->fd].flags |= FILE_SEND_SIGCHLD;
/* SIG_DFL for SIGCHLD is ignore */
/* SIG_DFL for SIGCHLD is ignored */
else if (sig_handlers[SIGCHLD] != SIG_DFL &&
sig_handlers[SIGCHLD] != SIG_IGN)
{
......@@ -2214,7 +2237,7 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
errno = EINTR;
return -1;
}
else if (fdindex[active] == 0)
else if (rfds && fdindex[active] == 0)
{
/* Keyboard input available */
FD_SET (0, rfds);
......@@ -2222,9 +2245,33 @@ sys_select (int nfds, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
}
else
{
/* must be a socket or pipe - read ahead should have
completed, either succeeding or failing. */
FD_SET (fdindex[active], rfds);
/* Must be a socket or pipe - read ahead should have
completed, either succeeding or failing. If this handle
was waiting for an async 'connect', reset the connect
flag, so it could read from now on. */
if (wfds && (fd_info[fdindex[active]].flags & FILE_CONNECT) != 0)
{
cp = fd_info[fdindex[active]].cp;
if (cp)
{
/* Don't reset the FILE_CONNECT bit and don't
acknowledge the read if the status is
STATUS_CONNECT_FAILED or some other
failure. That's because the thread exits in those
cases, so it doesn't need the ACK, and we want to
keep the FILE_CONNECT bit as evidence that the
connect failed, to be checked in sys_read. */
if (cp->status == STATUS_READ_SUCCEEDED)
{
fd_info[cp->fd].flags &= ~FILE_CONNECT;
cp->status = STATUS_READ_ACKNOWLEDGED;
}
ResetEvent (cp->char_avail);
}
FD_SET (fdindex[active], wfds);
}
else if (rfds)
FD_SET (fdindex[active], rfds);
nr++;
}
......
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