Commit Graph

19991 Commits

Author SHA1 Message Date
Mike Frysinger 63c1f29a1d libgloss: fix AC_LANG_SOURCE warnings w/newer autoconf
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

Add AC_LANG_PROGRAM wrappings to fix these.
2021-09-15 10:08:20 -04:00
Corinna Vinschen 34b1447040 Cygwin: pipes: don't call NtQueryInformationFile on read side of pipes
NtQueryInformationFile hangs if it's called on the read side handle of
a pipe while another thread or process is performing a blocking read.

Avoid select potentially hanging by calling NtQueryInformationFile
only on the write side of the pipe and using PeekNamedPipe otherwise.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-15 14:20:03 +02:00
Corinna Vinschen f961a63ed6 Cygwin: drop useless method fhandler_base::has_ongoing_io
This was a remnant of the fhandler_base_overlapped class.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-15 13:58:36 +02:00
Takashi Yano 00cbbaa33e 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.
2021-09-15 11:29:27 +02:00
Ken Brown 593a86f9b0 Cygwin: document the recent pipe changes 2021-09-14 14:59:28 -04:00
Takashi Yano a217fa98fd Cygwin: pipe: Fix handling of EPIPE and SIGPIPE in raw_write(). 2021-09-14 16:16:15 +02:00
Takashi Yano e4e4537979 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.
2021-09-14 13:02:51 +02:00
Takashi Yano f79a46112e 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.
2021-09-14 13:01:40 +02:00
Takashi Yano 0d12015670 Cygwin: pipe, fifo: Call set_no_inheritance() for adjunct handles.
- Currntly, set_no_inheritance() is not called for the adjunct handles
  such as select_sem. This patch fixes the issue.
2021-09-14 10:22:15 +02:00
Takashi Yano 3e80b12fde Cygwin: fhandler_base::dup Reflect O_CLOEXEC to inheritance flag.
- Currently fhandler_base::dup duplicates handles with bInheritHandle
  TRUE unconditionally. This patch reflects O_CLOEXEC flag to that
  parameter.
2021-09-14 10:22:15 +02:00
Corinna Vinschen 8985f1c7c4 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.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 22:04:04 +02:00
Corinna Vinschen c48361ad9e 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.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 19:34:07 +02:00
Takashi Yano 0063ffeb73 Cygwin: pipe: Fix deadlock if pipe is created by non-cygwin app. 2021-09-13 17:45:55 +02:00
Takashi Yano 0b538118b2 Cygwin: fifo: Utilize select_sem for fifo as well as pipe. 2021-09-13 17:45:55 +02:00
Corinna Vinschen ba4c58299f Cygwin: pipes: always signal select_sem if any bytes are read or written
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>
2021-09-13 17:45:55 +02:00
Takashi Yano 08b8534d0a Cygwin: pipe: Fix notification timing of select_sem.
- Make select_sem notify even when read/write partially.
2021-09-13 17:45:54 +02:00
Takashi Yano 597f87294d Cygwin: select: Introduce select_sem semaphore for pipe.
- This patch introduces select_sem semaphore which notifies pipe status
  change.
2021-09-13 17:45:54 +02:00
Takashi Yano b07660ac19 Revert "Cygwin: select: Improve select/poll response."
... because this commit (23bb19ef) causes high CPU load.
2021-09-13 17:45:54 +02:00
Ken Brown 99be238347 Cygwin: set buffer size for pipes created by non-Cygwin processes
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.
2021-09-13 17:45:54 +02:00
Corinna Vinschen 27b24069d1 Cygwin: pipes: drop "tiny pipe" handling
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>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 9d7fd8d416 Cygwin: pipes: handle signals and thread cancellation in blocking mode only
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 4003e3dfa1 Cygwin: pipes: always terminate async IO in blocking mode
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>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 477a593693 Cygwin: pipes: cancel async IO if thread cancellation is in progress
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>
2021-09-13 17:45:54 +02:00
Takashi Yano fadbedd9ca Cygwin: pipe: Stop counting reader and read all available data.
- 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.
2021-09-13 17:45:54 +02:00
Ken Brown 085fc12948 Cygwin: new class fhandler_pipe_fifo
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().
2021-09-13 17:45:54 +02:00
Ken Brown eb50f82677 Cygwin: FIFO: open pipes with FILE_READ_ATTRIBUTES access
This is needed by NtQueryInformationFile, which is used by select.
2021-09-13 17:45:54 +02:00
Ken Brown 44693e80b1 Cygwin: pipes: minor code cleanup
Clarify a comment in raw_read, and remove a useless line from
raw_write.
2021-09-13 17:45:54 +02:00
Corinna Vinschen 82643bd18e Cygwin: pipes: nt_create: set read handle to NULL in error case
Fix accidentally setting read handle to INVALID_HANDLE_VALUE in a
single error case.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 17:45:54 +02:00
Corinna Vinschen ea9c0bbedc Cygwin: pipes: call nt_create with handle references
...to avoid potential pointer mishandling.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 8653eb1df3 Cygwin: pipes: workaround unrelibale system info
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>
2021-09-13 17:45:54 +02:00
Corinna Vinschen a5b2c735e6 Cygwin: pipes: fix POSIX requirement for non-blocking pipe writes
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>
2021-09-13 17:45:54 +02:00
Corinna Vinschen fcccc4b743 Cygwin: pipes: create pipes with synchronization enabled
This isn't used by Cygwin, but it might be used by Win32 processes
inheriting the handle.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 8efcee2500 Cygwin: pipes: use NtClose when file has been opened with an NtXxx function
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 17:45:54 +02:00
Corinna Vinschen b12cf6b3cf Cygwin: pipes: always close read side pipe handle in error case
Add missing CloseHandle.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 464f7145f6 Cygwin: pipes: fix a bug in raw_write
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>
2021-09-13 17:45:54 +02:00
Corinna Vinschen e9d4cb765f Cygwin: move get_obj_handle_count() to miscfuncs.cc
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>
2021-09-13 17:45:54 +02:00
Corinna Vinschen 9cfbb5aa82 Cygwin: _pipe: add a comment
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>
2021-09-13 17:45:53 +02:00
Corinna Vinschen 28eac9272f Revert "Cygwin: fhandler_pipe.cc:nt_select: fix flags"
This reverts commit a62f4d128505481c4c683e813a3b16da641af6ff.
2021-09-13 17:45:53 +02:00
Corinna Vinschen 71f02bcc3f Revert "Cygwin: fhandler_pipe.cc:nt_select: fix flags again"
This reverts commit c35db324efb5cdc6605eac947e0d4fdeb45e8b43.
2021-09-13 17:45:53 +02:00
Ken Brown 6b52d97900 Cygwin: fhandler_pipe.cc:nt_select: fix flags again 2021-09-13 17:45:53 +02:00
Ken Brown 9d4e58be76 Cygwin: fhandler_pipe.cc:nt_select: fix flags 2021-09-13 17:45:53 +02:00
Ken Brown 24b7a74b94 Revert "Cygwin: pipe: Revert to create() rather than nt_create()."
This reverts commit 5a7a0d34c74a55aa1e76644e61bf4889051cb640.
2021-09-13 17:45:53 +02:00
Takashi Yano cf3a7a9132 Cygwin: pipe: Revert to create() rather than nt_create(). 2021-09-13 17:45:53 +02:00
Takashi Yano b75d855fb0 Cygwin: select: Improve select/poll response. 2021-09-13 17:45:53 +02:00
Ken Brown 8a10f6302c Cygwin: add fhandler_base::npfs_handle
It replaces the three identical functions of the same name in the
classes fhandler_pipe, fhandler_fifo, and fhandler_socket_unix.
2021-09-13 17:45:53 +02:00
Ken Brown f002d02b17 Cygwin: remove the fhandler_base_overlapped class
Also remove the 'was_nonblocking' flag, which was needed only for
fhandler_base_overlapped.
2021-09-13 17:45:53 +02:00
Ken Brown f56206cd86 Cygwin: fhandler_pipe: fix permission problem
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.
2021-09-13 17:45:53 +02:00
Ken Brown d0ad52aa6e Cygwin: fhandler_pipe: control blocking mode of the Windows pipe
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.
2021-09-13 17:45:53 +02:00
Ken Brown 4b25687ea3 Cygwin: fhandler_pipe: add raw_read and raw_write 2021-09-13 17:45:53 +02:00
Ken Brown 72e083c4a0 Cygwin: fhandler_pipe: derive from fhandler_base
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.
2021-09-13 17:45:53 +02:00