- On systems with inexact realtime clock, the current timestamp may
be fractionally smaller than the desired timestamp. This breaks the
computation for incrementing overrun_count so overrun_count may end
up as 0. Expiring the timer with an overrun_count of 0 is a no-go.
Make sure we always increment overrun_count by at least one after
timer expiry.
- Do not expire the timer when another process deletes its timer_tracker.
This, too, may result in a 0 overrun_count.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Using posix timers "timer_tracker" as base class for timerfd was flawed.
Posix timers are not inherited by child processes and don't survive
execve. The method used by posix timers didn't allow to share timers
between processes. The timers were still per-process timers and worked
entirely separate from each other. Reading from these timers via
different descriptors was only synchronized within the same process.
This does not reflect the timerfd semantics in Linux: The per-file
timers can be dup'ed and survive fork and execve. They are still just
descriptors pointing to the same timer object originally created by
timerfd_create. Synchronization is performed between all descriptor
instances of the same timer, system-wide.
Thus, reimplement timerfd using a timer instance in shared memory,
a kernel timer, and a handful of sync objects.
Every process maintains a per-process timerfd struct on the cygheap
maintaining a per-process thread. Every process sharing the same
timerfd will run this thread checking the state of the timer, similar
to the posix timer thread, just working on the shared objects and
synchronizing its job with each other thread.
Drop the timerfd implementation in the posix timer code and move the
public API to fhandler_timerfd.c. Keep the ttstart timer_tracker
anchor out of "NO_COPY" since the fixup_after_fork code should run to
avoid memory leakage.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Linux returns EINVAL, "fd is attached to an object which is unsuitable
for writing". If we don't handle write locally, write returns EBADF.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Puzzeling: Commit ec98d19a08
changed ttstart to NO_COPY but kept all the code to handle
fixup after fork. Revert to not-NO_COPY and make timerfd
fork work.
- On fixup_after_fork, keep timerfd timers and restart thread
if they were armed in the parent.
- Move timerfd timer_trackers to cygheap. Overload timer_tracker
new and delete methods to handle timers accordingly. This is not
exactly required for fork, but exec will be grateful.
- Give up on TFD_TIMER_CANCEL_ON_SET for now. There's no easy way
to recognize a discontinuous change in a clock.
- Be paranoid when cleaning out ttstart.
- Fix some minor issues.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Drop initial overrun computation from timer_tracker::settimer.
It's performed in timer_tracker::thread_func anyway.
- Fix regression in returning correct overrun count narrowed down to
int from timer_getoverrun. This has been introduced by changing
overrun_count_curr to LONG64.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
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>
In case sigwait_common returns EINTR, read wrongly ignores it,
so read can't be interrupt by a signal. Fix that.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
While FileRenameInformationEx is defined starting with Windows
10 1709 per MSDN, it only starts working in W10 1809, apparently.
Users of 1803 report "Function not implemented".
Introduce wincap_10_1809 and change the version check in
wincapc::init accordingly. Split has_posix_file_info into
has_posix_unlink_semantics and has_posix_rename_semantics.
Enable the latter only starting with W10 1809.
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>
- use int64_t instead of long long
- make is_timer_tracker const
- improve copyright header comment
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
So far we check the recycler name all the time, and the last interation
also only managed to handle two ways to write the recycler. However,
an adventurous user might change the case of the recycler arbitrarily.
Fix this problem by keeping track of the name in a somewhat relaxed
fashion. Use camel back on drive C by default, all upper case elsewhere.
Only if the rename op fails do we fix the recycler name on the fly
when trying to create it, and it turns out it already existed.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
If the first rename fails, we reopen the rootdir for creating a subdir.
The rootdir handle can change its value at this point, but the code
doesn't take this into account. The subsequent rename then fails with
STATUS_INVALID_HANDLE. Fix this by copying the new rootdir value to
pfri->RootDirectory.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
So far we reopened the file if it was opened case sensitive to
workaround the problem that the recycler could be named in
camel back or all upper case, depending on who created it.
That's a problem for O_TMPFILE on pre-W10. As soon as the
original HANDLE gets closed, delete-on-close is converted to full
delete disposition and all useful operations on the file cease to
work (STATUS_ACCESS_DENIED or STATUS_FILE_DELETED).
To avoid that problem drop the reopen code and check for the exact
recycler filename, either $Recycle.Bin or $RECYCLE.BIN, if the file
has been opened case sensitive.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
On pre-W10 systems there's no way to reopen a file by handle if
the delete disposition is set. We try to get around with
duplicating the handle.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The new proc fd code accidentally allowed to linkat an O_TMPFILE
even if the file has been opened with O_EXCL. This patch fixes it.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
move special fd symlink code into own fhandler_process_fd class
to simplify further additions to /proc/PID/fd/DESCRIPTOR symlink
handling.
Add a method to handle stat(2) on such a proc fd symlink by handle.
This allows correct reply from stat(2) if the target file has been
deleted. This eventually fixes `awk -f /dev/fd/3 3<<eof'.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
path_conv now sets the PATH_RESOLVE_PROCFD flag in path_flags if
the PC_SYM_NOFOLLOW_PROCFD pathconv_arg flag has been set on input
*and* the file is actually a proc fd symlink.
Add matching path_conv::follow_fd_symlink method for checking and
use it in open(2).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Remove another unfortunate amalgamation: Mount flags (MOUNT_xxx)
are converted to path_types (PATH_xxx) and mixed with non-mount
path_types flags in the same storage, leading to a tangled,
pell-mell usage of mount flags and path flags in path_conv and
symlink_info.
- There's also the case of PC_NONULLEMPTY. It's used in exactly
one place with a path_conv constructor only used in this single
place, just to override the automatic PC_NULLEMPTY addition
when calling the other path_conv constructors. Crazily,
PC_NONULLEMPTY is a define, no path_types flag, despite its
name.
- It doesn't help that the binary flag exists as mount and path
flag, while the text flag only exists as path flag. This leads
to mount code using path flags to set text/binary. Very confusing
is the fact that a text mount/path flag is not actually required;
the mount code sets the text flag on non binary mounts anyway, so
there are only two states. However, to puzzle people a bit more,
path_conv::binary wrongly implies there's a third, non-binary/non-text
state.
Clean up this mess:
- Store path flags separately from mount flags in path_conv and
symlink_info classes and change all checks and testing inline
methods accordingly.
- Make PC_NONULLEMPTY a simple path_types flag and drop the
redundant path_check constructor.
- Clean up the definition of pathconv_arg, path_types, and mount flags.
Use _BIT expression, newly define in cygwin/bits.h.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
There's an unfortunate amalgamation of caller-provided pathconv_arg
flags with path_types flags which in turn are mostly mount flags.
This leads to a confusion of flag values in sylink_info::pflags and,
in turn, in path_conv::path_flags.
This patch decouples pathconv_flags from the other flags by making
sure that a pathconv_flag is never copied into a variable used for
path_types flags. Also, remove PATH_NO_ACCESS_CHECK since it's
not necessary.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Along the same lines as the previous patch: By reopening an
O_TMPFILE by handle, we can now move the file to the bin at
open time and thus free'ing up the parent dir and *still*
open the file as /proc/PID/fd/DESCRIPTOR by linkat(2).
Allows expressions along the lines of `cat /proc/self/fd/0 <<EOF'.
The problem here is that the temporary file used for the here script
has already been deleted by the shell. Opening by filename, as
implemented so far, doesn't work because the file has been moved
to the bin.
Allow reopening files by handle the same way from another process
as long as we have sufficient permissions on the foreign process.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
To allow reopening a file open in another process by HANDLE, introduce
a matching file_pathconv method, taking a file descriptor as parameter.
The result is a serialized path_conv and a HANDLE value. The HANDLE is
valid in the foreign process and MUST be duplicated into the target
process before usage.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
So far io_handle is NULL when calling fhandler_base::open to
open or create a file. Add a check for io_handle to allow
priming the fhandler with a HANDLE value so we can reopen a
file from a HANDLE on file systems supporting it. This allows
to open already deleted files for further action. This will
be used by open("/proc/PID/fd/DESCRIPTOR") scenarios.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The commit message of commit 07e0a9584f
and the expectation set therein, are wrong.
There's no POSIX semantics allowing to link a file with a link
count of 0 and making it available in the file system again.
In fact, the Linux linkat extension AT_EMPTY_PATH explicitely
disallows to link a file descriptor to a file with a link count
of 0, except for O_TMPFILE without O_EXCL.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Turns out, the definition of POSIX unlink semantics is half-hearted
so far: It's not possible to link an open file HANDLE if it has
been deleted with POSIX semantics, nor is it possible to remove
the delete disposition. This breaks linkat on an O_TMPFILE.
Tested with W10 1809.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
On Windows 10 1803 and later, create dirs under the Cygwin
installation dir as case sensitive, if WSL is installed.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- short-circuit most code in unlink_nt since it's not necessary
anymore if FILE_DISPOSITION_POSIX_SEMANTICS is supported.
- Immediately remove O_TMPFILE from filesystem after creation.
Disable code for now because we have to implement /proc/self/fd
opening by handle first, lest linkat fails.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Newer FAT32 and exFAT add FILE_SUPPORTS_ENCRYPTION to their
flags which wasn't handled by Cygwin yet.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Various new file info class members adding important POSIX semantics
have been added with W10 1709. We may want to utilize them, so add
a matching wincaps.
Rearrange checking the W10 build number to prefer the latest builds
over the older builds. Rename wincap_10 to wincap_10_1507 for
enhanced clarity.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Add missing members added in later OS versions
- Rearrange accompanying FILE_foo_INFORMATION structs
ordered by info class
- Add promising FILE_foo_INFORMATION structs of later
Windows 10 releases plus accompanying enums
- Drop "Checked on 64 bit" comments since that's self-evident
these days
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The check for the TEB being allocated beyond the first 2GB area is not
valid anymore. At least on W10 WOW64, the TEB is allocated in the
lower 2GB even in large-address aware executables. Use VirtualQuery
instead. It fails for invalid addresses so that's a simple enough test.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
While reformatting the script, backticks `` were replaced with
brackets $(). This in turn invalidated the \\( ... \\) expressions in the
sed script because backslash resolution in $() works differently from
backslash resolution in ``. Only a single backslash is valid now.
While at it, fix up the uname(2) date representation when building a
snapshot.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
when calling clocks too early in DLL init, the vtables are not correctly
set up for some reason. Calls to init() from now() fail because the init
pointer in the vtable is NULL.
Real life example is mintty which runs into a minor problem at startup,
triggering a system_printf call. Strace is another problem, it's called
the first time prior to any class initialization.
Workaround is to make sure that no virtual methods are called in an
early stage. Make init() non-virtual and convert resolution() to a
virtual method instead. Add a special non-virtual
clk_monotonic_t::strace_usecs.
While at it:
- Inline internal-only methods.
- Drop the `inited' member. Convert period/ticks_per_sec toa union.
Initialize period/ticks_per_sec via InterlockeExchange64.
- Fix GetTickCount64 usage. No, it's not returning ticks but
milliseconds since boot (unbiased).
- Fix comment indentation.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Use whatever native unit the system provides for the resolution of
a timer to avoid rounding problems
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>
clock_setres is a questionable function only existing on QNX.
Disable the function, just return success for CLOCK_REALTIME
to maintain backward compatibility.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The current method to make hires_ns priming thread-safe isn't
thread-safe. Rather than hoping that running the thread in
TIME_CRITICAL priority is doing the right thing, use a spinlock.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
LARGE_INTEGER has QuadPart anyway, no reason to compute the
64 bit value from HighPart and LowPart.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
fhandler_socket_wsock::set_socket_handle calls set_flags after
setting the O_NONBLOCK/O_CLOEXEC flags, thus overwriting them.
It also turns out that fhandler_socket_wsock::init_events is called
too late. The inheritence flags are changed before creating the
socket event handling objects. Thus, inheritence flags for
those objects are wrong with SOCK_CLOEXEC.
Fix this by reordering the calls and setting the file flags through
fhandler_base::set_flags.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Corinna Vinschen
Ken Brown
Mark Geisert