Corinna Vinschen [Tue, 16 Nov 2021 18:44:21 +0000 (19:44 +0100)]
Cygwin: fix up cached DOS file attributes after file creation
The file attributes after creating a file are not necessarily
identical to the attributes we passed as argument to NtCreateFile.
This results in subsequent operations like fchmod or facl to
set the DOS file attributes to unexpected values.
The fix is to request file attributes from the OS after file creation
and cache those.
Jon Turney [Tue, 16 Nov 2021 16:48:10 +0000 (16:48 +0000)]
Cygwin: Drop 'make check' from AppVeyor
Appveyor has quite restrictive concurrent job limits for free projects,
so reduce the job's runtime by dropping 'make check' to avoid blocking
(since we're now also running that in a GitHub action).
When running Cygwin's Bash in the Windows Terminal (see
https://docs.microsoft.com/en-us/windows/terminal/ for details), Cygwin
is receiving keyboard input in the form of UTF-16 characters.
UTF-16 has that awkward challenge that it cannot map the full Unicode
range, and to make up for it, there are the ranges U+D800-U+DBFF and
U+DC00-U+DFFF which are illegal except when they come in a pair encoding
for Unicode characters beyond U+FFFF.
Cygwin does not handle such surrogate pairs correctly at the moment, as
can be seen e.g. when running Cygwin's Bash in the Windows Terminal and
then inserting an emoji (e.g. via Windows + <dot>, which opens an emoji
picker on recent Windows versions): Instead of showing an emoji, this
shows the infamous question mark in a black triangle, i.e. the invalid
Unicode character.
Let's special-case surrogate pairs in this scenario.
This fixes https://github.com/git-for-windows/git/issues/3281
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Mike Frysinger [Tue, 9 Nov 2021 03:22:27 +0000 (22:22 -0500)]
change _COMPILING_NEWLIB to _LIBC
Use the same name as glibc & gnulib to indicate "newlib itself is
being compiled". This also harmonizes the codebase a bit in that
_LIBC was already used in places instead of _COMPILING_NEWLIB.
Building for bfin-elf, mips-elf, and x86_64-pc-cygwin produces
the same object code.
Corinna Vinschen [Mon, 15 Nov 2021 12:32:03 +0000 (13:32 +0100)]
Cygwin: dllfixdbg: create .gnu_debuglink section in the right spot
A recent change in binutils marks the .gnu_debuglink_overlay section
as debug section. When dllfixdbg calls objcopy -g, the section
is removed and the --add-gnu-debuglink option on the same command line
appends the section consequentially at the end of the sections.
This in turn breaks Windows Version info and, potentially, raising
the cygheap size at runtime.
Fix this by adding an explicit --keep-section=.gnu_debuglink_overlay
to the objcopy command line.
Mike Frysinger [Tue, 9 Nov 2021 02:42:12 +0000 (21:42 -0500)]
newlib: ignore _FORTIFY_SOURCE when building newlib
Some distros enable _FORTIFY_SOURCE by default which upsets building
newlib which itself implements the logic for this define. For example,
building gets.c fails because the includes set up a gets() macro which
expands in the definition.
Since newlib isn't prepared to build itself with _FORTIFY_SOURCE, and
it's not clear if it's even useful, ignore it when building the code.
This also matches what glibc is doing.
Mike Frysinger [Tue, 9 Nov 2021 00:23:33 +0000 (19:23 -0500)]
define _COMPILING_NEWLIB for all targets when compiling
The _COMPILING_NEWLIB symbol is for declaring "the code is being
compiled for newlib itself" so headers can change behavior vs the
header being used by users (who should get the normal clean API).
Unfortunately, this symbol is defined inconsistently leading to it
only being useful for a few subsections of the tree.
Pull it out so that it's defined all the time for all targets.
Mike Frysinger [Tue, 9 Nov 2021 00:28:16 +0000 (19:28 -0500)]
ctype: use less short names in public header
We're seeing a build failure in GNU sim code which is using _P locally
but the ctype.h define clashes with it. Rename these to use the same
symbols that glibc does. They're a bit more verbose, but seems likely
that we'll have fewer conflicts if glibc isn't seeing them.
However, these shortnames are still used internally by ctype modules
to produce pretty concise source code, so move the short names to the
internal ctype_.h where short name conflicts shouldn't show up.
Corinna Vinschen [Wed, 10 Nov 2021 20:17:30 +0000 (21:17 +0100)]
Cygwin: introduce isabspath_strict macro
isabspath handles a path "X:", without trailing slash or backslash,
as absolute path. This breaks some scenarios with relative paths
starting with "X:". For instance, fstatat will mishandle a call
with valid dirfd and "c:" as path.
The reason is that gen_full_path_at() will check for isabspath("C:")
which returns true. So the path will be used verbatim in fstatat,
rather than being converted to a path "<dirfd-path>/c:".
So, introduce isabspath_strict, which returns true for paths starting
with "X:" only if the next char is actually a slash or backslash.
Use it from gen_full_path_at().
This still fixes only half the problem. The right thing would have been
to disallow using DOS paths in the first place. Unfortunately it's much
too late for that.
Takashi Yano [Thu, 11 Nov 2021 03:30:24 +0000 (12:30 +0900)]
Cygwin: pipe: Fix raw_write() for non-cygwin pipe with size zero.
- Currently, raw_write() fails to handle size zero pipe which may
be created by non-cygwin apps (e.g. Windows native ninja). This
patch fixes the issue.
texi2pod.pl: add no-op --no-split option support [PR28144]
Change 2faf902da ("generate single html manual page by default")
added use of --no-split option to makeinfo. binutils reuses
makeinfo options for texi2pod.pl wrapper. Unsupported option
led to silent manpage truncation.
Simon Marchi [Wed, 15 Jan 2020 17:58:08 +0000 (12:58 -0500)]
texi2pod.pl: import support for @t{...} from gcc
GDB's man page source (in gdb.texinfo) contains:
@t{++}
The @t{...} part is supposed to display the wrapped text with a
fixed-width font. The texi2pod.pl script currently doesn't handle
@t{...}, so it appears as-is in the man page:
You can use GDB to debug programs written in C, C@t{++}, Fortran and Modula-2.
gcc's version of texi2pod.pl (at contrib/texi2pod.pl in gcc's repo)
replaces @t{...} with the wrapped text as-is, which I think is an
acceptable behavior. The fixed-width font distinction is not really
important for a man page, where the text will be displayed with whatever
font the user is using.
Import the line that does that from gcc's version.
I have verified that there is no other, unwanted change in man pages
generated in binutils' and GDB's doc, with this patch applied.
Simon Marchi [Tue, 19 Jun 2018 20:54:48 +0000 (16:54 -0400)]
Bump to autoconf 2.69 and automake 1.15.1
When trying to run the update-gnulib.sh script in gdb, I get this:
Error: Wrong automake version (Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in m/\${ <-- HERE ([^ =:+{}]+)}/ at /opt/automake/1.11.1/bin/automake line 4113.), we need 1.11.1.
Aborting.
Apparently, it's an issue with a regex in automake that triggers a
warning starting with Perl 5.22. It has been fixed in automake 1.15.1.
So I think it's a good excuse to bump the versions of autoconf and
automake used in the gnulib import. And to avoid requiring multiple
builds of autoconf/automake, it was suggested that we bump the required
version of those tools for all binutils-gdb.
For autoconf, the 2.69 version is universally available, so it's an easy
choice. For automake, different distros and distro versions have
different automake versions. But 1.15.1 seems to be the most readily
available as a package. In any case, it's easy to build it from source.
I removed the version checks from AUTOMAKE_OPTIONS and AC_PREREQ,
because I don't think they are useful in our case. They only specify a
lower bound for the acceptable version of automake/autoconf. That's
useful if you let the user choose the version of the tool they want to
use, but want to set a minimum version (because you use a feature that
was introduced in that version). In our case, we force people to use a
specific version anyway. For the autoconf version, we have the check in
config/override.m4 that enforces the version we want. It will be one
less thing to update next time we change autotools version.
I hit a few categories of problems that required some changes. They are
described below along with the chosen solutions.
Problem 1:
configure.ac:17: warning: AM_INIT_AUTOMAKE: two- and three-arguments forms are deprecated. For more info, see:
configure.ac:17: http://www.gnu.org/software/automake/manual/automake.html#Modernize-AM_005fINIT_005fAUTOMAKE-invocation
Solution 1:
Adjust the code based on the example at that URL.
Problem 2 (in zlib/):
Makefile.am: error: required file './INSTALL' not found
Makefile.am: 'automake --add-missing' can install 'INSTALL'
Makefile.am: error: required file './NEWS' not found
Makefile.am: error: required file './AUTHORS' not found
Makefile.am: error: required file './COPYING' not found
Makefile.am: 'automake --add-missing' can install 'COPYING'
Solution 2:
Add the foreign option to AUTOMAKE_OPTIONS.
Problem 3:
doc/Makefile.am:20: error: support for Cygnus-style trees has been removed
Solution 3:
Remove the cygnus options.
Problem 4:
Makefile.am:656: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
Solution 4:
Rename "INCLUDES = " to "AM_CPPFLAGS += " (because AM_CPPFLAGS is
already defined earlier).
Problem 5:
doc/Makefile.am:71: warning: suffix '.texinfo' for Texinfo files is discouraged; use '.texi' instead
doc/Makefile.am: warning: Oops!
doc/Makefile.am: It appears this file (or files included by it) are triggering
doc/Makefile.am: an undocumented, soon-to-be-removed automake hack.
doc/Makefile.am: Future automake versions will no longer place in the builddir
doc/Makefile.am: (rather than in the srcdir) the generated '.info' files that
doc/Makefile.am: appear to be cleaned, by e.g. being listed in CLEANFILES or
doc/Makefile.am: DISTCLEANFILES.
doc/Makefile.am: If you want your '.info' files to be placed in the builddir
doc/Makefile.am: rather than in the srcdir, you have to use the shiny new
doc/Makefile.am: 'info-in-builddir' automake option.
Solution 5:
Rename .texinfo files to .texi.
Problem 6:
doc/Makefile.am: warning: Oops!
doc/Makefile.am: It appears this file (or files included by it) are triggering
doc/Makefile.am: an undocumented, soon-to-be-removed automake hack.
doc/Makefile.am: Future automake versions will no longer place in the builddir
doc/Makefile.am: (rather than in the srcdir) the generated '.info' files that
doc/Makefile.am: appear to be cleaned, by e.g. being listed in CLEANFILES or
doc/Makefile.am: DISTCLEANFILES.
doc/Makefile.am: If you want your '.info' files to be placed in the builddir
doc/Makefile.am: rather than in the srcdir, you have to use the shiny new
doc/Makefile.am: 'info-in-builddir' automake option.
Solution 6:
Remove the hack at the bottom of doc/Makefile.am and use
the info-in-builddir automake option.
Problem 7:
doc/Makefile.am:35: error: required file '../texinfo.tex' not found
doc/Makefile.am:35: 'automake --add-missing' can install 'texinfo.tex'
Solution 7:
Use the no-texinfo.tex automake option. We also have one in
texinfo/texinfo.tex, not sure if we should point to that, or move it
(or a newer version of it added with automake --add-missing) to
top-level.
Problem 8:
Makefile.am:131: warning: source file 'config/tc-aarch64.c' is in a subdirectory,
Makefile.am:131: but option 'subdir-objects' is disabled
automake: warning: possible forward-incompatibility.
automake: At least a source file is in a subdirectory, but the 'subdir-objects'
automake: automake option hasn't been enabled. For now, the corresponding output
automake: object file(s) will be placed in the top-level directory. However,
automake: this behaviour will change in future Automake versions: they will
automake: unconditionally cause object files to be placed in the same subdirectory
automake: of the corresponding sources.
automake: You are advised to start using 'subdir-objects' option throughout your
automake: project, to avoid future incompatibilities.
Solution 8:
Use subdir-objects, that means adjusting references to some .o that will now
be in config/.
Problem 9:
configure.ac:375: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body
../../lib/autoconf/lang.m4:193: AC_LANG_CONFTEST is expanded from...
../../lib/autoconf/general.m4:2601: _AC_COMPILE_IFELSE is expanded from...
../../lib/autoconf/general.m4:2617: AC_COMPILE_IFELSE is expanded from...
../../lib/m4sugar/m4sh.m4:639: AS_IF is expanded from...
../../lib/autoconf/general.m4:2042: AC_CACHE_VAL is expanded from...
../../lib/autoconf/general.m4:2063: AC_CACHE_CHECK is expanded from...
configure.ac:375: the top level
Solution 9:
Use AC_LANG_SOURCE, or use proper quoting.
Problem 10 (in intl/):
configure.ac:7: warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
/usr/share/aclocal/threadlib.m4:36: gl_THREADLIB_EARLY_BODY is expanded from...
/usr/share/aclocal/threadlib.m4:29: gl_THREADLIB_EARLY is expanded from...
/usr/share/aclocal/threadlib.m4:318: gl_THREADLIB is expanded from...
/usr/share/aclocal/lock.m4:9: gl_LOCK is expanded from...
/usr/share/aclocal/intl.m4:211: gt_INTL_SUBDIR_CORE is expanded from...
/usr/share/aclocal/intl.m4:25: AM_INTL_SUBDIR is expanded from...
/usr/share/aclocal/gettext.m4:57: AM_GNU_GETTEXT is expanded from...
configure.ac:7: the top level
Solution 10:
Add AC_USE_SYSTEM_EXTENSIONS in configure.ac.
ChangeLog:
* libtool.m4: Use AC_LANG_SOURCE.
* configure.ac: Remove AC_PREREQ, use AC_LANG_SOURCE.
* README-maintainer-mode: Update version requirements.
* ar-lib: New file.
* test-driver: New file.
* configure: Re-generate.
Mike Frysinger [Tue, 9 Nov 2021 03:18:43 +0000 (22:18 -0500)]
newlib: mips: delete glibc-specific logic
This code looks like it's written to be copied & pasted between diff
C libraries and relies on _LIBC only being used with glibc. This will
break when newlib changes from _COMPILING_NEWLIB to _LIBC, so delete
the glibc-specific logic ahead of time.
Takashi Yano [Sun, 7 Nov 2021 03:47:18 +0000 (12:47 +0900)]
Cygwin: pipe: Avoid false EOF while reading output of C# programs.
- If output of C# program is redirected to pipe, pipe reader falsely
detects EOF. This happens after overhaul of pipe implementation.
This patch fixes the issue.
Cygwin: fix permission problem when writing DAC info on Samba shares
Cygwin always requests FILE_WRITE_ATTRIBUTES permissions when trying to
change DAC information. This can lead to permission problems when
trying to chmod/chown files on Samba shares. Drop requesting
FILE_WRITE_ATTRIBUTES on Samba shares and go with WRITE_DAC/WRITE_OWNER
only.
Also rename release 3.4.0 to 3.3.2. It doesn't make sense to
duplicate the issues fixed in 3.3.x into the 3.4.0 relnotes.
Only patches not backported into 3.3.x belong into 3.4.0.
ldtoa cuts the number of digits it returns based on a computation of
number of supported bits (144) divide by log10(2). Not only is the
integer approximation of log10(2) ~= 8/27 missing a digit here, it
also fails to take really small double and long double values into
account.
Allow for the full potential precision of long double values. At the
same time, change the local string array allocation to request only as
much bytes as necessary to support the caller-requested number of
digits, to keep the stack size low on small targets.
In the long run a better fix would be to switch to gdtoa, as the BSD
variants, as well as Mingw64 do.
Takashi Yano [Wed, 3 Nov 2021 06:14:42 +0000 (15:14 +0900)]
Cygwin: console: Prevent the exec'ed bash from exiting by Ctrl-C.
- Currently, bash occasionally exits by Ctrl-C with the following
scenario.
1) Start bash in the command prompt.
2) Run 'exec bash'.
3) Press Ctrl-C several times.
This patch fixes the issue.
Takashi Yano [Tue, 2 Nov 2021 08:09:40 +0000 (17:09 +0900)]
Cygwin: console: Fix yet another bug on input when signalled.
- Currently, read() returns EINTR due to a bug if signal handler
is SIG_DFL and the process is suspended by Ctrl-Z and restarted.
This patch fixes the issue.
Corinna Vinschen [Fri, 29 Oct 2021 16:08:32 +0000 (18:08 +0200)]
Cygwin: drop support for simple invisible console code
i. e., Vista/2008.
AllocConsole appears to allow creating a console only on the currently
visible desktop since Windows 7, which broke the simple code opening
the console on an invisible desktop in an invisible window station.
Currently, newlib does not declare strsignal if DEFS_H is defined,
ostensibly to work around a gdb bug. However, gdb itself compiles
even with this ifndef removed, and this makes sim (another part of
gdb) fail to compile.
Since it is not clear exactly what issue this was working around,
this patch just replaces that ifdef with the correct check,
i.e. __POSIX_VISIBLE >= 200809.
Lewis Revill [Wed, 27 Oct 2021 13:24:06 +0000 (14:24 +0100)]
libgloss/riscv: Fix hard coded reference to configure.in after rename
The file configure.in was renamed to configure.ac in libgloss/riscv but
the hard coded name in the Makefile for that directory was not updated.
This patch simply renamed this to configure.ac.
Corinna Vinschen [Tue, 26 Oct 2021 15:53:08 +0000 (17:53 +0200)]
Cygwin: convert malloc lock to SRWLOCK
Per https://cygwin.com/pipermail/cygwin-developers/2021-October/012429.html,
we may encounter a crash when starting multiple threads during process
startup (here: fhandler_fifo::fixup_after_{fork,exec}) which in turn
allocate memory via malloc.
The problem is concurrent usage of malloc before the malloc muto has
been initialized.
To fix this issue, convert the muto to a SRWLOCK and make sure it is
statically initalized. Thus, malloc can be called as early as necessary
and malloc_init is only required to check for user space provided malloc.
Note that this requires to implement a __malloc_trylock macro to be
called from fork.
Mark Geisert [Mon, 25 Oct 2021 09:25:40 +0000 (02:25 -0700)]
Cygwin: Make native clipboard layout same for 32- and 64-bit
This patch unifies the layout of the clipboard descriptor cygcb_t for
32- and 64-bit Cygwin. It allows correct copy/paste between the two
environments without corruption of user's copied data and without access
violations due to interpreting that data as a size field.
The definitions of CYGWIN_NATIVE and cygcb_t are moved to a new include
file, sys/clipboard.h. The include file is used by fhandler_clipboard.cc
as well as getclip.c and putclip.c in the Cygwin cygutils package.
When copy/pasting between 32- and 64-bit Cygwin environments, both must
be running version 3.3.0 or later for successful operation.
Sebastian Huber [Tue, 5 Oct 2021 13:53:47 +0000 (15:53 +0200)]
sys/tree.h: Red child with black sibling rotations
Add specialized rotations RB_RED_ROTATE_LEFT() and RB_RED_ROTATE_RIGHT() which
may be used if we rotate a red child which has a black sibling. Such a red
node must have at least two child nodes so that the following red-black tree
invariant is fulfilled:
Every path from a given node to any of its descendant NULL nodes goes through
the same number of black nodes.
Sebastian Huber [Tue, 5 Oct 2021 13:43:34 +0000 (15:43 +0200)]
sys/tree.h: Add parent rotations
Add specialized rotations RB_PARENT_ROTATE_LEFT() and RB_PARENT_ROTATE_RIGHT()
which may be used if the parent node exists and the direction of the child is
known. The specialized rotations are derived from RB_ROTATE_LEFT() and
RB_ROTATE_RIGHT() where the RB_SWAP_CHILD() was replaced by a simple
assignment.
So, the RB_ISRED() contains an implicit check for NULL. In
RB_GENERATE_REMOVE_COLOR() the "elm" pointer cannot be NULL in the while
condition. Use RB_COLOR(elm) == RB_BLACK instead.
Cygwin: pipe: Use ProcessHandleInformation if available.
- The commit b531d6b0 introduced temporary_query_hdl() which uses
SystemHandleInformation. With this patch, ProcessHandleInformation
rather than SystemHandleInformation is used if it is available.
This request is faster, however, is only available since Windows 8,
therefore, SystemHandleInformation is used for Windows Vista and 7
as before.
- The commit f79a4611 introduced query_hdl, which is the read pipe
handle kept in the write pipe instance in order to determine if
the pipe is ready to write in select(). This implementation has
a potential risk that the write side fails to detect the closure
of the read side if more than one writer exists and one of them
is a non-cygwin process.
With this patch, the strategy of commit f79a4611 is used only if
the process is running as a service. For a normal process,
instead of keeping query_hdl in the write pipe instance, it is
retrieved temporarily when select() is called. Actually, we
want to use tenporary query_hdl for all processes, however, it
does not work for service processes due to OpenProcess()
failure.
Ken Brown [Sat, 18 Sep 2021 13:10:23 +0000 (09:10 -0400)]
Cygwin: make callers of open_setup check for failure
open_setup is called by dtable::init_std_file_from_handle and
fhandler_base::open_with_arch. In both cases, failure of open_setup
is now a fatal error.
Currently this can only happen in the following situation: A Cygwin
process is started by a non-Cygwin process, one of the standard IO
handles is a pipe handle, and Cygwin is unable to create a required
mutex (read_mtx or hdl_cnt_mtx).
Cygwin: pipe, fifo: Move query_hdl and hdl_cnt_mtx to fhandler_pipe.
- query_hdl and hdl_cnt_mtx are moved from fhandler_pipe_fifo to
fhandler_pipe. Then reader_closed() is changed to virtual and
overridden in fhandler_pipe.
- This patch fixes the race issue in the handle counting to detect
closure of read pipe, which is introduced by commit f79a4611.
A mutex hdl_cnt_mtx is introduced for this issue.
Cygwin: close_all_files: Do not duplicate stderr for write pipe.
- Currently, the stderr handle is duplicated in close_all_files().
This interferes the handle counting for detecting closure of read
pipe, which is introduced by commit f79a4611. This patch stops
duplicating stderr handle if it is write pipe.
Mike Frysinger [Wed, 15 Sep 2021 04:27:13 +0000 (00:27 -0400)]
libgloss: add missing aclocal.m4 files
These subdirs were missing aclocal.m4 files pulling in macros from
../acinclude.m4 which caused some macros to not be expanded. For
example, autoconf complains:
configure.ac:25: error: possibly undefined macro: LIB_AC_PROG_CC
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
These were generated with aclocal-1.9 as that seems to be what was
used in these dirs previously, and with whatever version of autoconf
the specific subdir was using. This should minimize diffs.
Mike Frysinger [Wed, 15 Sep 2021 04:20:58 +0000 (00:20 -0400)]
libgloss: epiphany: rename symbol prefix cache var
Autoconf emits a warning for this:
configure.ac:75: warning: AC_CACHE_VAL(libc_symbol_prefix, ...): suspicious cache-id, must contain _cv_ to be cached
Rename the variable to match the naming in libnosys/ subdir.
When running autoconf-2.69 in here, we get:
configure.ac:57: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body
../../lib/autoconf/lang.m4:193: AC_LANG_CONFTEST is expanded from...
../../lib/autoconf/general.m4:2503: _AC_PREPROC_IFELSE is expanded from...
../../lib/autoconf/general.m4:2518: AC_PREPROC_IFELSE is expanded from...
configure.ac:57: the top level
configure.ac:61: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body
../../lib/autoconf/lang.m4:193: AC_LANG_CONFTEST is expanded from...
../../lib/autoconf/general.m4:2503: _AC_PREPROC_IFELSE is expanded from...
../../lib/autoconf/general.m4:2518: AC_PREPROC_IFELSE is expanded from...
configure.ac:61: the top level
Cygwin: pipe: Do not call PeekNamedPipe() if it is not necessary.
- In pipe_data_available() in select.cc, PeekNamedPipe() call is
not needed if WriteQuotaAvailable is non-zero because we already
know the write pipe has a space. Therefore, with this patch,
PeekNamedPipe() is called only when WriteQuotaAvailable is zero.
This makes select() on pipe faster a bit.
Cygwin: pipe, fifo: Release select_sem semaphore as much as needed.
- Currently, raw_read(), raw_write() and close() release select_sem
unconditionally even if no waiter for select_sem exists. With this
patch, only the minimum number of semaphores required is released.
Cygwin: pipe: Use read pipe handle for select() on write pipe.
- Usually WriteQuotaAvailable retrieved by NtQueryInformationFile()
on the write side reflects the space available in the inbound buffer
on the read side. However, if a pipe read is currently pending,
WriteQuotaAvailable on the write side is decremented by the number
of bytes the read side is requesting. So it's possible (even likely)
that WriteQuotaAvailable is 0, even if the inbound buffer on the
read side is not full. This can lead to a deadlock situation:
The reader is waiting for data, but select on the writer side
assumes that no space is available in the read side inbound buffer.
Currently, to avoid this stuation, read() does not request larger
block than pipe size - 1. However, this mechanism does not take
effect if the reader side is non-cygwin app.
The only reliable information is available on the read side, so
fetch info from the read side via the pipe-specific query handle
(query_hdl) introduced.
If the query_hdl (read handle) is kept in write side, writer can
not detect closure of read pipe. Therefore, raw_write() counts
write handle and query_hdl. If they are equal, only the pairs of
write handle and query_hdl are alive. In this case, raw_write()
returns EPIPE and raises SIGPIPE.
- Nonblocking pipes (PIPE_NOWAIT) are not well handled by non-Cygwin
tools, so convert pipe handles to PIPE_WAIT handles when spawning
a non-Cygwin process.
Cygwin: pipes: do not duplicate sec_none{_nih} locally when creating objects
We already fetched the correct SECURITY_ATTRIBUTES at the start of
fhandler_pipe::create, so using another SECURITY_ATTRIBUTES object for
the mutex and semaphore objects doesn't make much sense.
Cygwin: fix inheritence of select_sem on write side of pipe
select_sem gets created on the read side with inheritence settings
depending on the O_CLOEXEC flag. Then it gets duplicated to the write
side with unconditional inheritence. Fix that.
git://sourceware.org / newlib-cygwin.git / log