Fold all code branches potentially having read or written data into
a single if branch, so signalling select_sem catches all cases.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Rename fhandler_pipe_and_fifo::max_atomic_write to pipe_buf_size.
This reflect its actual meaning better. The fhandler_pipe_and_fifo
constructor initializes it to DEFAULT_PIPEBUFSIZE (== 64K), which is
the buffer size for the windows pipes created by fhandler_pipe and
fhandler_fifo. But if we inherit a stdio pipe handle from a
non-Cygwin process, the buffer size could be different.
To remedy this, add a method fhandler_pipe::set_pipe_buf_size that
queries the OS for the pipe buffer size, and use it in
dtable::init_std_file_from_handle.
Given we return 1 already if WriteQuotaAvailable is > 0, the condition
for tiny pipes is never true. Fix the comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
In blocking mode, the underlying IO must always be terminated,
one way or the other, to make sure the application knows the exact
state after returning from the IO function. Therefore, always call
CancelIo in blocking mode.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Just cancelling a thread doesn't cancel async IO started by this thread.
Fix this by returning from cygwait and calling CancelIo before canceling
self.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- By guarding read with read_mtx, no more than one ReadFile can
be called simultaneously. So couting read handles is no longer
necessary.
- Make raw_read code as similar as possible to raw_write code.
This is a parent of fhandler_pipe and fhandler_fifo for code that is
common between the two classes. Currently it just contains
max_atomic_write and raw_write(). The latter is identical to what
used to be fhandler_pipe::raw_write().
FILE_PIPE_LOCAL_INFORMATION::WriteQuotaAvailable is unreliable.
Usually WriteQuotaAvailable 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.
This patch implements a workaround by never trying to read more than
half the buffer size blocking if the read buffer is empty. This first
cut tries to take the number of open readers into account by reducing
the amount of requested bytes accordingly.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
POSIX requires atomicity for non-blocking writes <= PIPE_BUF bytes
and writing of at least 1 byte if any buffer space is left.
Windows NtWriteFile returns STATUS_SUCCESS and "0 bytes written"
if the write doesn't match buffer space. Fix this discrepancy.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The buffer pointer is incremented by "chunk", which is what we
typically try to write, but this isn't what actually got written.
Increment the buffer pointer by what we actually wrote, as returned
by NtWriteFile.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
get_obj_handle_count() is used in flock only so far, but pipe
handling might have a usage, too, soon. Given that this function
might be generally useful and isn't restricted to flock usage,
move it to miscfuncs.cc and make it non-static. Add a prototype
in miscfuncs.h.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
I wasted valuable minutes of my life just to find out why we export
this weird version of pipe. In the pre-2000 era the idea was Cygwin
could be used as drop-in replacement for msvcrt.dll, apparently.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The read handles of pipes created by CreateNamedPipe don't have
FILE_WRITE_ATTRIBUTES access unless the pipe is created with
PIPE_ACCESS_DUPLEX. This causes set_pipe_non_blocking to fail on such
handles. To fix this, add a helper function nt_create, which uses
NtCreateNamedPipeFile instead of CreateNamedPipe and gives us more
flexibility in setting access rights.
Use this helper function in fhandler_pipe::create (fhandler_pipe *[2],
unsigned, int), which is the version of fhandler_pipe::create used by
the pipe and pipe2 system calls.
For convenience, also add a static member function
fhandler_pipe::npfs_handle similar to those used by fhandler_fifo and
fhandler_socket_unix.
Add methods 'set_pipe_non_blocking' and 'fcntl' to keep the blocking
mode of the Windows pipe in sync with that of the fhandler_pipe
object. This applies to pipes created with the 'pipe' and 'pipe2'
system calls.
Previously fhandler_pipe was derived from fhandler_base_overlapped,
which we are going to remove in a future commit. Make minimal changes
so that the build still succeeds.
There are a few files that are tied to the GNU simulator, so add myself
to match the general sim project.
Also add myself to the general write-after-approval since I've been doing
that for a long time now anyways :).
In https://cygwin.com/pipermail/cygwin/2021-September/249361.html
Brian pointed out that initializing the structure would be more
future proof, should the developers at Microsoft ever decide to
split the Reserved field and use some bits of the struct for
other purposes.
Fixes: 3d322ac930 ("Cygwin: fix initializing MEM_EXTENDED_PARAMETER")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
When newlib is configured with --enable-newlib-reent-check-verify,
the assert macro is already defined in the nano-mallocr.c compile unit.
Contributed by STMicroelectronics
Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@st.com>
MEM_EXTENDED_PARAMETER consists of a 64 bit bitfield which contains
the Type and the Reserved members. The former usage of designated
initializer lists initialized Type, but not Reserved. Since that's
not possible anymore due to a g++ 11.2 bug, Cygwin initializes the
MEM_EXTENDED_PARAMETER structs explicitely. This results in a
random value in Reserved, which at least VirtualAlloc2 chokes on
(ERROR_INVALID_PARAMETER).
Set Reserved explicitely to 0 for a fix.
Fixes: bdb7991db3 ("Cygwin: workaround a g++ 11.2 initialization bug")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
libm/machine/i386/f_ldexp.S:30: Warning: no instruction mnemonic suffix given and no register operands; using default for `fild'
libm/machine/i386/f_ldexpf.S:30: Warning: no instruction mnemonic suffix given and no register operands; using default for `fild'
fix this by adding the l mnemonic suffix
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
unused function warning for two_way_short_needle,
different char type warnings for standard string functions
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
_STDIO_WITH_THREAD_CANCELLATION_SUPPORT was never defined.
Include ../stdio/local.h to get the right definition per target.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Takashi Yano
Corinna Vinschen
Ken Brown
Mike Frysinger
Torbjorn SVENSSON via Newlib