- The inferior of the GDB cannot be continued after SIGINT even
though nopass option is set. This seems because cygwin GDB does
not support hooking cygwin signal. Therefore, a workaround for
GDB is added. With this patch, only CTRL_C_EVENT is sent to the
GDB inferior by Ctrl-C and sending SIGINT is omitted. Note that
"handle SIGINT (no)pass" command does not take effect even with
or without this patch.
- This patch fixes the handle leak which occurs when exec() fails
with an error. The duplicated handles will be closed when the
exec'ed process is terminated. However, if exec() fails, the code
path does not reach to the code closing the duplicated handles.
To implement this fix more appropriately, the setup, cleanup and
closing pty codes which was previously located in spawn.cc are
encapsulated into the fhandler_pty_slave class functions.
- This patch commonize the code which processes special keys in pty
and console to improve maintanancibility. As a result, some small
bugs have been fixed.
- Currently, there is no chance to change console mode for non-cygwin
inferior of GDB. With this patch, the console mode is changed to
tty::native in CreateProcess() and ContinueDebugEvent() hooked in
fhandler_console.
- Currently, pty discards input only in from_master pipe on signal.
Due to this, if pty is started without pseudo console support and
start a non-cygwin process from cmd.exe, type adhead input is not
discarded on signals such as Ctrl-C. This patch fixes the issue.
- With this patch, the code to wait for completion of forwarding of
output from non-cygwin app is revised so that it can more reliably
detect the completion.
- If the slave process writes a lot of text output, doecho() can
cause deadlock. This is because output_mutex is held in slave::
write() and if WriteFile() is blocked due to pipe full, doecho()
tries to acquire output_mutex and gets into deadlock. With this
patch, the deadlock is prevented on the sacrifice of atomicity
of doecho().
- If the from_master is closed before cleaning up other pipes, such
as from_slave_nat, the same pty may be allocated and pty master may
try to open the pipe which is not closed yet, and it will fail.
This patch fixes the issue.
- Closing attach_mutex and recreating it causes the race issue
between pty and console codes. With this patch, attach_mutex
is created only once in a process which opens pty, and never
closed in order to avoid this issue.
Addresses:
https://cygwin.com/pipermail/cygwin-developers/2021-December/012548.html
- If master_fwd_thread is terminated by cygthread::terminate_thread(),
the opportunity to release tmp_pathbuf is missed, resulting in a
memory leak. This patch fixes the issue.
- GDB inferior may be suspended while the inferior grabs mutex.
This causes deadlock in terminal I/O. With this patch, timeout
for waiting mutex is set to 0 for the debugger process when the
process calls CreateProcess() with DEBUG_PROCESS flag to avoid
deadlock. This may cause the race issue in GDB, however, there
is no other way than that.
Addresses:
https://cygwin.com/pipermail/cygwin-developers/2021-December/012542.html
- This patch fixes the failure of input switching between io_handle
and io_handle_nat. This very rarely happens, however, input is
wrongly switched to io_handle_nat even though the non-cygwin app
is in the background.
- The recent commit "Cygwin: pty: Add missing input transfer when
switch_to_pcon_in state." causes regression that rlwrap cannot
work with cmd.exe. This patch fixes the issue.
- The recent commit: "Cygwin: pty: Fix Ctrl-C handling for non-cygwin
apps in background." causes the problem that cmd.exe is terminated
by Ctrl-C even if it is running in pseudo console. This patch fixes
the issue.
- With pseudo console enabled, if the non-cygwin app is started in
the background and put it into the foreground, the process cannot
be stopped by Ctrl-C. This patch fixes the issue.
- This patch fixes the bug that input is wrongly sent to io_handle_nat
rather than io_handle when neither read() nor select() is called
after the cygwin app is started from non-cygwin app. This happens
only if psuedo console is disabled.
Addresses:
https://cygwin.com/pipermail/cygwin-patches/2021q4/011587.html
xterm 368 and mintty 3.5.1 implement a new feature to support
notification of terminal scaling via font zooming also if the terminal
text dimensions (rows/columns) stay unchanged, using
ioctl(TIOCSWINSZ), raising SIGWINCH;
this patches cygwin to support that scenario
- In commit bb93c6d7, the race issue was not completely fixed. In
the pseudo console inheritance, if the destination process to
which the ownership of pseudo console switches, is found but exits
before switching, the inheritance fails. Currently, this extremely
rarely happens. This patch fixes the issue.
- Currently, functions/variables regarding the handles for cygwin
apps are with "_cyg", and those of handles for non-cygwin apps
are without "_cyg", such as get_handle_cyg() and get_handle().
This patch renames these to the names without "_nat" and with
"_nat" respectively, such as get_handle() and get_handle_nat().
- Currently, names of output pipes are "pty%d-to-master" and "pty%d-
to-master-cyg" and names of input pipes are "pty%d-to-slave" and
"pty%d-from-master". With this patch, these pipes are renamed to
"pty%d-to-master-nat", "pty%d-to-master", "pty%d-from-master-nat"
and "pty%d-from-master" respectively.
- Currently, transfer input is triggered even if the stdin of native
app is not a pseudo console. With this patch it is triggered only
if the stdin is a pseudo console.
- If two non-cygwin apps are started simultaneously, attaching to
pseudo console sometimes fails. This is because the second app
trys to attach to the process not started yet. This patch avoids
the issue by attaching to the stub process rather than the other
non-cygwin app.
- Perhaps current code misunderstand meaning of the IGNBRK. As far
as I investigated, IGNBRK is concerned with break signal in serial
port but there is no evidence that it has effect to ignore Ctrl-C.
This patch stops ignoring Ctrl-C by IGNBRK for non-cygwin apps.
- If two non-cygwin apps are started simultaneously and this is the
first execution of non-cygwin apps in the pty, these occasionally
hang up. The cause is the race issue between term_has_pcon_cap(),
reset_switch_to_pcon() and setup_pseudoconsole(). This patch fixes
the issue.
- After commit 253352e796ff9ec9a447e5375f5bc3e2b92b5293, mc (midnight
commander) crashes with segfault if the shell is bash. This is due
to NULL pointer access in read(). This patch fixes the issue.
Addresses::
https://cygwin.com/pipermail/cygwin/2021-February/247870.html
- Currently, input transfer is performed every time one line is read(),
if the non-cygwin app is running in the background. With this patch,
transfer is triggered by setpgid() rather than read() so that the
unnecessary input transfer can be reduced much in that situation.
- After commit bb428520, there has been the disadvantage:
7) Pseudo console cannot be activated if it is already activated for
another process on same pty.
This patch clears this disadvantage.
- After commit bb428520, there has been the disadvantage:
2) The apps which use console API cannot be debugged with gdb. This
is because pseudo console is not activated since gdb uses
CreateProcess() rather than exec(). Even with this limitation,
attaching gdb to native app, in which pseudo console is already
activated, works.
This patch clears this disadvantage.
- After commit bb428520, there has been the disadvantage:
4) Code page cannot be changed by chcp.com. Acctually, chcp works
itself and changes code page of its own pseudo console. However,
since pseudo console is recreated for another process, it cannot
inherit the code page.
This patch clears this disadvantage.
- PTY has a problem that the key input, which is typed during windows
native app is running, disappears when it returns to shell. 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 issue had been
fixed once by commit 29431fcb, however, the new implementation of
pseudo console support by commit bb428520 could not inherit this
feature. This patch realize transfering input data between these
two pipes bidirectionally by utilizing cygwin-console-helper process.
The helper process is launched prior to starting the non-cygwin app,
however, exits immediately unlike previous implementation.
