fhandler_fifo::take_ownership() is called from select.cc::peek_fifo
and fhandler_fifo::raw_read and could potentially block indefinitely
if something goes wrong. This is always undesirable in peek_fifo, and
it is undesirable in a nonblocking read. Fix this by adding a timeout
parameter to take_ownership.
Arbitrarily use a 1 ms timeout in peek_fifo and a 10 ms timeout in
raw_read. These numbers may have to be tweaked based on experience.
Replace the call to cygwait in take_ownership by a call to WFSO.
There's no need to allow interruption now that we have a timeout.
Use cygwait in take_ownership to allow interruption while waiting to
become owner. Return the cygwait return value or a suitable value to
indicate an error.
raw_read now checks the return value and acts accordingly.
There are currently three functions that call NtQueryInformationFile
to determine the state of a pipe instance. Do this only once, in a
new fifo_client_handler::set_state () function, and call that when
state information is needed.
Remove the fifo_client_handler methods pipe_state and get_state, which
are no longer needed.
Make fhandler_fifo::get_fc_handler return a reference, for use in
select.cc:peek_fifo.
Make other small changes to ensure that this commit doesn't change any
decisions based on the state of a fifo_client_handler.
The tricky part is interpreting FILE_PIPE_CLOSING_STATE, which we
translate to fc_closing. Our current interpretation, which is not
changing as a result of this commit, is that the writer at the other
end of the pipe instance is viewed as still connected from the point
of view of raw_read and determining EOF.
But it is not viewed as still connected if we are deciding whether to
unblock a new reader that is trying to open.
Add a take_ownership method, used by raw_read and select.cc:peek_fifo.
It wakes up all fifo_reader_threads and allows the caller to become
owner. The work is done by the fifo_reader_threads.
For synchronization we introduce several new fhandler_fifo data
members and methods:
- update_needed_evt signals the current owner to stop listening for
writer connections and update its fc_handler list.
- shared_fc_handler() gets and sets the status of the fc_handler
update process.
- get_pending_owner() and set_pending_owner() get and set the reader
that is requesting ownership.
Finally, a new 'reading_lock' prevents two readers from trying to take
ownership simultaneously.
According to Posix, a FIFO open for reading is at EOF if it is empty
and there are no writers open.
The only way to test this is to poll the fifo_client_handlers as in
raw_read and select.cc:peek_fifo. The current hit_eof instead relies
on the value of nconnected, which can be out of date. On the one
hand, it doesn't take into account writers that were connected but
have since closed. On the other hand, it doesn't take into account
writers that are in the process of opening but haven't yet connected.
Fix this by introducing a maybe_eof method that tentatively assumes
EOF if there are no connected writers after polling. Then check for
writers currently opening (via a new 'writer_opening' event), and wait
for the fifo_reader_thread to record any new connection that was made
while we were polling.
To handle the needs of peek_fifo, replace the get_fc_handle method
by a get_fc_handler method, and add a fifo_client_handler::get_state
method.
Remove the is_connected method, which was used only in peek_fifo and
is no longer needed.
Remove the nconnected data member, which was used only for the flawed
hit_eof.
Add some comments about events to fhandler.h.
Sharing the OVERLAPPED struct and event object in there between
read and select calls in the fhandler might have been a nice
optimization way back when, but it is a dangerous, not thread-safe
approach. Fix this by creating per-fhandler, per-call OVERLAPPED
structs and event objects on demand.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- make sure event object is reset
- set read_ready to true if WaitCommEvent returns success
- improve debugging
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Get rid of WaitCommEvent and using overlapped_armed to share the
same overlapped operation between read and select. Rather, make
sure to cancel the overlapped IO before leaving any of these functions.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Don't use ev member for ClearCommError and WaitCommEvent.
Both returned values are different (error value vs. event
code). The values are not used elsewhere so it doesn't make
sense to store them in the object.
- Drop local variable ready which is used inconsequentially.
- Since WFSO already waits 10 ms, don't wait again if no char
is in the inbound queue.
- Avoid else if chains.
- Only print one line of debug output on error.
- Drop overlapped_armed < 0 check. This value is only set in
fhandler_serial::raw_read if VTIME > 0, and even then it's only
set to be immediately reset to 0 before calling ReadFile. So
overlapped_armed is never actually < 0 when calling select.
- Fix a screwed up statement order.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- If two cygwin programs are executed simultaneousley with pipes
in cmd.exe, xterm compatible mode is accidentally disabled by
the process which ends first. After that, escape sequences are
not handled correctly in the other app. This is the problem 2
reported in https://cygwin.com/ml/cygwin/2020-02/msg00116.html.
This patch fixes the issue. This patch also fixes the problem 3.
For these issues, the timing of setting and unsetting xterm
compatible mode is changed. For read, xterm compatible mode is
enabled only within read() or select() functions. For write, it
is enabled every time write() is called, and restored on close().
- PTY has a problem that the key input, which is typed during
windows native app is running, disappear when it returns to shell.
(Problem 3 in https://cygwin.com/ml/cygwin/2020-02/msg00007.html)
This is beacuse pty has two input pipes, one is for cygwin apps
and the other one is for native windows apps. The key input during
windows native program is running is sent to the second input pipe
while cygwin shell reads input from the first input pipe.
This patch realize transfering input data between these two pipes.
- Debug codes used in the early stage of pseudo console support are
removed. (Regarding ALWAYS_USE_PCON and USE_API_HOOK) Along with
this, the codes related to this change are organized.
- The slowing down issue of X11 forwarding using ssh -Y, reported
in https://www.cygwin.com/ml/cygwin/2019-12/msg00295.html,
is due to the change of select() code for pty in the commit
915fcd0ae8. cygthread::detach()
takes at most about 10msec because Sleep() is used in the thread.
For this issue, this patch uses cygwait() instead of Sleep() and
introduces an event to abort the wait. For not only pty, but pipe
and fifo also have the same problem potentially, so this patch
applies same strategy to them as well.
- Previously, input and output pipes were switched together between
the traditional pty and the pseudo console. However, for example,
if stdin is redirected to another device, it is better to leave
input pipe traditional pty side even for non-cygwin program. This
patch realizes such behaviour.
- When the I/O pipe is switched to the pseudo console side, the
behaviour of Ctrl-C was unstable. This rarely happens, however,
for example, shell sometimes crashes by Ctrl-C in that situation.
Furthermore, Ctrl-C was ignored if output of non-cygwin program
is redirected to pipe. This patch fixes these issues.
- select() did not work correctly when both read and except are
polled simultaneously for the same fd and the r/w pipe is switched
to pseudo console side. This patch fixes this isseu.
- Support pseudo console in PTY. Pseudo console is a new feature
in Windows 10 1809, which provides console APIs on virtual
terminal. With this patch, native console applications can work
in PTYs such as mintty, ssh, gnu screen or tmux.
Rather than waiting for signalfd_select_wait in a thread, which is racy,
create a global event "my_pendingsigs_evt" which is set and reset by
wait_sig depending only on the fact if blocked signals are pending or not.
This in turn allows to WFMO on this event in select as soon as signalfds
are present in the read descriptor set. Select's peek and verify
will then check if one of the present signalfds is affected.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The word "client" suggests something that holds a handle to the client
side of the pipe (in Windows terminology). But our
fifo_client_handlers hold a handle the server side of the pipe, and
they *connect* to clients.
- Add 24 bit color support using xterm compatibility mode in
Windows 10 1703 or later.
- Add fake 24 bit color support for legacy console, which uses
the nearest color from 16 system colors.
Add static functions peek_fifo, thread_fifo, start_thread_fifo, and
fifo_cleanup to select.cc. These are based on the corresponding pipe
functions, the main difference being that peek_fifo loops through the
connected clients to see if any of them have data available for
reading.
Add the fhandler_fifo methods select_read, select_write, and
select_except.
Add accessor methods get_nclients, get_handle, and is_connected that
are needed by peek_fifo.
First cut of a timerfd implementation.
Still TODO:
- fork/exec semantics
- timerfd_settime TFD_TIMER_CANCEL_ON_SET flag
- ioctl(TFD_IOC_SET_TICKS)
- bug fixes
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Allow the signal thread to recognize we're called in consequence of
select on a signalfd. If the signal is part of the wait mask, don't
call any signal handler and don't remove the signal from the queue,
so a subsequent read (or sigwaitinfo/sigtimedwait) still gets the
signal. Instead, just signal the event object at
_cygtls::signalfd_select_wait for the thread running select.
The addition of signalfd_select_wait to _cygtls unearthed the alignment
problem of the context member again. To make sure this doesn't get lost,
improve the related comment in the header file so that this (hopefully)
doesn't get lost (again).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
First cut of a signalfd implementation.
Still TODO: Non-polling select.
This should mostly work as on Linux except for missing support
for some members of struct signalfd_siginfo, namely ssi_fd,
ssi_band (both SIGIO/SIGPOLL, not fully implemented) and ssi_trapno
(HW exception, required HW support).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
There's a long-standing bug in select. If we have poll-only
descriptors in the fd set, select overwrites the incoming
fd sets with the polling result. If none of the fds is ready,
select has to loop again. But now the fd sets are set to all
zero and select hangs.
Fix this by utilizing the local fd sets r, w, e as storage for
the incoming fd sets and use them to initialize select_stuff.
If we have to loop, overwritung the incoming fd sets doesn't matter.
While at it, rename r, w, e to readfds_in, writefds_in, exceptfds_in.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Drop hires_[nm]s clocks, rename hires.h to clock.h.
- Implement clk_t class as an extensible clock class in new file clock.cc.
- Introduce get_clock(clock_id) returning a pointer to the clk_t instance
for clock_id. Provide the following methods along the lines of the former
hires classes:
void clk_t::nsecs (struct timespec *);
ULONGLONG clk_t::nsecs ();
LONGLONG clk_t::usecs ();
LONGLONG clk_t::msecs ();
void clk_t::resolution (struct timespec *);
- Add CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_COARSE
and CLOCK_BOOTTIME clocks.
- Allow clock_nanosleep, pthread_condattr_setclock and timer_create to use
all new clocks (both clocks should be usable with a small tweak, though).
- Bump DLL major version to 2.12.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Make distinct from AF_LOCAL for testing purposes. This will have
to be reverted as soon as fhandler_socket_unix goes life.
* Move saw_reuseaddr flag back to fhandler_socket status
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Insert another class fhandler_socket_wsock between fhandler_socket
and fhandler_socket_inet/fhandler_socket_local.
Also, add a new method fhandler::is_wsock_socket to allow asking
for sockets in general (is_socket) vs. Winsock-based sockets
(is_wsock_socket).
This allows to develop a new handler_socket_unix class as derived
class from fhandler_socket without any trace of wsock code left
in fhandler_socket.
While this is basically a temporary measure at this time, it may
prove useful for later interoperability with the upcoming Windows 10
AF_UNIX implementation at one point.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Redefine NSPERSEC to NS100PERSEC
* Define NSPERSEC as nanosecs per second
* Define USPERSEC as microsecs per second
* Use above constants throughout where appropriate
* Rename to_us to timespec_to_us and inline
* Rename it_bad to timespec_bad and inline
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Don't use a bool var to store three states (-1, 0, 1).
* Correctly check for NT_SUCCESS of a function returning NTSTATUS.
* Straighten out code for better readability.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
For historical reasons peek_console was calling the functions
PeekConsoleInputA and ReadConsoleInputA. However, these functions are
not working correctly under at least codepage 65001 (UTF-8) on systems
prior to Windows 10.
Use PeekConsoleInputW and ReadConsoleInputW instead, which work
correctly under all systems and all codepages.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Create two new inline functions is_alt_numpad_key(PINPUT_RECORD) and
is_alt_numpad_event(PINPUT_RECORD) which contain the actual checks.
Call these functions from fhandler_console::read and peek_console for
better readability.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
{p}select/{p}poll completely ignored Alt+Numpad key sequences in console
input which results in newer readline using pselect to fail handling such
sequences correctly. See https://cygwin.com/ml/cygwin/2017-01/msg00135.html
During debugging and testing it turned out that while reading console
input, single key presses during an Alt+Numpad sequences where not
ignored, so ultimately a sequence like
Alt-down Numpad-1 Numpad-2 Numpad-3
whihc is supposed to result in a single character in the input stream
will actually result in 4 chars in the input stream, three control
sequences and the actual character.
Both problems should be fixed by this patch.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
SIGTTIN should be raised when read() is made on a tty in a backgrounded
process, but not when it's tested with poll()/select().
I guess poll()/select() does need to call bg_check(), in order to detect the
error conditions that notices (that is, if bg_check() returns bg_eof or
bg_error, then fd is ready as an error condition exists) so add an optional
parameter to fhandler_base::bg_select() to indicate that signals aren't
desired.
See https://cygwin.com/ml/cygwin-developers/2016-07/msg00004.html
Bump GPLv2+ to GPLv3+ for some files, clarify BSD 2-clause.
Everything else stays under GPLv3+.
New Linking Exception exempts resulting executables from LGPLv3 section 4.
Add CONTRIBUTORS file to keep track of licensing.
Remove 'Copyright Red Hat Inc' comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Ken Brown
Corinna Vinschen
Åke Rehnman
Takashi Yano