This patch enables sculpt to utilize the CPU reset mechanism via the
PS/2 controller as well as the information provided via the ACPI FADT
information. Whenever the /config/system file is changed to <system
state="reset"/>, both mechanisms are triggered.
Supporting both mechanisms is useful because the PS/2-based reset does
not work reliably on modern machines. The PS/2-based reset is useful in
the case when the FADT reset information refers to the PS/2 command
port. In this case, the platform driver is unable to access this port
because it is already handed out to the PS/2 driver. In this case, the
PS/2 driver kicks in.
Issue #2726
This patch adds the handling neccessary for clients to upgrade the cap
quota of their GUI session. Until now, the upgrade mechanism supported
only RAM quota.
The limitation became visible once a client - in the particular case the
motif_decorator - attempted the cap upgrade of its GUI session. The cap
quota would arrive at the wm, but the wm would keep it instead of
forwarding the quota to nitpicker. This resulted in an infinite retry
loop at the motif_decorator, ultimatedly depleting all its cap quota.
The window manager infers the overall state from the intercepted input
events for the decorator and all GUI clients. However, each of those
parties have an independent input-event stream. Whereas the order of
events within one GUI session is strict, the order of events between GUI
sessions is arbitrary. The window manager wrongly relied on a global
event ordering to track the pointed-at GUI session.
The patch removes the assumption of a global event order by tracking the
relevant pointer state for each GUI session independently and evaluating
these states when propagating the pointer position to the decorator.
Fixes#4059
The addition of further keyboard layouts would otherwise pollute the
config/ directory too much.
Caution: When updating Sculpt OS, don't reuse your existing
config/event_filter file unmodified! You need to replace the chargen
includes, pointing to the new location, e.g.,
<include rom="en_us.chargen"/>
<include rom="special.chargen"/>
must be changed to
<include rom="keyboard/en_us"/>
<include rom="keyboard/special"/>
Issue #4055
This patch extends the settings dialog with the ability to select the
keyboard layout between the options that are included in the sculpt
image. The manual configuration is of course still possible by editing
the /config/event_filter directly.
If both the fonts configuration and the event-filter configuration are
managed manually, the settings button and window are not displayed.
Fixes#4055
By sorting the reported output, all consumers of the reports become able
to rely on a deterministic order. For example, the file browser of
Sculpt OS, the launcher menu items, and the depot-selection items will
appear in a predictable order.
Fixes#4054
This patch adds session-routing options to connect components to the
capture/event interfaces of the global nitpicker GUI server or the
leitzentrale GUI server. It thereby enables the implementation of screen
capturing components, remote management tools, or virtual keyboards.
Since those services are very powerful, they are subsumed under the
"hardware" category of the component graph as opposed to the GUI
category, which guarantees the separation of clients.
Fixes#4053
This patch adds 4 priority levels to the runtime subsystem. The highest
priority is used for components that are critical for the operation of
Sculpt, in particular the Leitzentrale GUI. All regularly deployed
components are assigned the lowest priority by default.
With priorities available in the runtime subsystem, this patch flattens
the priority levels at the top-level init to only two levels and
overlays the priority bands of the drivers, leitzentrale, and runtime
subsystems into one priority band. This has three benenfits:
- This change prevents the starvation of the Leitzentrale GUI from a
spinning high-priority driver (issue #3997).
- The change will also ease the hosting of latency-critical components
in the runtime subsystem that are prioritized higher than regular
components, the storage stack, and the network stack.
- The Leitzentrale GUI remains always perfectly responsive regardless
of the workloads deployed from packages. In the previous version,
the runtime graph was sometimes stuttering on high system load.
Issue #4045
This patch triggers the immediate removal of part_block once the
discovery of a fresh inserted USB stick has completed. Without the
patch, part_block was retained until the runtime was reconfigured the
next time for other reasons (e.g., toggling an inspect view). Until the
next reconfituration, part_block tended to stand in the way of directly
assigning the USB device to a VM.
This patch increases the RAM quota of the nitpicker instance for the
leitzentrale to make it suffice for the buffering of content during
resize operations. This fixes a flickering artifact when having an
inspect view open while entering a WLAN passphrase. When the connect
button appears or disappears (depending on the number of written
characters), some parts of the inspect terminal would flicker sometimes.
This prevents the log terminal from adjusting itself to the whole screen
size before the leitzentrale window layout is applied. This intermediate
size can otherwise exhaust the 8 MiB of RAM quota of the log terminal.
Issue #3970
This commit improves the performance of the pipe plugin by using local
signal handling and avoiding sending a signal during write when pipe
buffer is full.
Issue #3583
All pipe-ends were notified at the same time which leads to dead-locks.
This commit mitigates this by having a signal handler for each pipe and
each pipe-end respectively.
Issue #3583
The vfs pipe plugin can now be used as named pipe which anables data
transfer via file handles from one component to another. E.g. if one
would like to send data from component A to stdin of a libc component B,
one can do so by simply writing to that fifo file.
Issue #3583
Note, OpenSSL now comes as one combined depot archive *openssl* that
replaces the former *libssl* and *libcrypto* archives. The libraries are
still separate binaries for compatibility with legacy software.
Issue #3773
The deadlock reported in #3236 could be reproduced via the wm.run script
and the modification of test/nitpicker in commit "nitpicker: fix destroy
with invalid handle" by clicking on the testnit entry of the launchpad.
This patch fixes the deadlock by releasing the locked pointer early in
the destruction path, which is legitimate as the wm is single-threaded.
Fixes#3236
No code in this class uses this private member variable. This prompts
clang to produce a warning message about it. Fix it by dropping the
variable.
Issue #3985
This private member variable is not used anywhere in the code. This
produces compilation warning when using clang instead of GCC. Drop the
unused variable.
Issue #3985
The State enum and _state private member variable are not used anywhere.
This produces an extra warning when building the code with clang instead
of GCC. Remove this dead code.
Issue #3985
The code fails to build with clang due to the following warning/error:
error: '_INCLUDE__NANO3D__SQRT_H_' is used as a header guard here,
followed by #define of a different macro [-Werror,-Wheader-guard]
Fix this by removing the extra underscore from this header guard
definition.
Issue #3985
* Remove SPEC declarations from mk/spec
* Remove all board-specific REQUIRE declaratiions left
* Replace [have_spec <board>] run-script declarations with have_board where necessary
* Remove addition of BOARD variable to SPECS in toplevel Makefile
* Move board-specific directories in base-hw out of specs
Let the NIC router provide an Uplink service besides the Nic service that it
already provided. Requests for an Uplink session towards the NIC router are
assigned to Domains using the same <policy> configuration tags that are used in
order to assign Nic session requests. The MAC addresses of Uplink session
components are _NOT_ considered during the allocation of MAC addresses for NIC
session components at the same Domain. The task of avoiding MAC address clashes
between Uplink session components and Nic session components is therefore left
to the integrator. Apart from that, Uplink session components are treated by
the NIC router like any other interface.
Ref #3961
This patch relaxes the need to specify the rom content of all pkg dependencies
in each runtime file. Whenever a dependency features a runtime file, the
contained <content> <rom/> ... </content> nodes are implicitely included.
Fixes#3981
This patch complements the commit "nitpicker: defer hover changed while
dragging" with fixes of the window layouter and motif decorator.
- Handling of empty pointer model (after unhovering a decoration)
instead of not updating it.
- Re-applying the hover model to the window layout when leaving the
drag state. This addresses the corner case that the hover model
changed during the drag operation (which is rightfully not handled
while dragging).
- Letting the window layouter enter the drag state only if a dragged
window is defined.
Issue #3973
When idle, the decorator still consumes a bit of CPU time when triggered
by the GUI session's sync signal. This patch installs the sync handler
each time the decorator goes idle.
* Introduce CPU quota for driver subsytem (needed by sd_card_drv)
* Introduce CPU quota for runtime subsytem and nic_drv (needed by fec_nic_drv)
* Increase CAP quota for inspect terminal slightly
* Add sculpt packages for imx8q_evk
Fix#3958
* Introduce sculpt-[board] specific package
* Move rtc driver into managed drivers sub-system
* Name nic_drv in a generic fashion in sculpt_manager
* Copy over pc-specific config files only when building for PC
Ref #3958
Originally the outgoing buffer was flush when the terminal was
detached. Since we cannot do that at this point, make the flushing
part of the common cleanup procedure.
Issue #3682.
Rather than calling 'ssh_disconnect' from within the Terminal session,
flag the detached terminal in the session and let the event loop do the
cleanup. Otherwise it might happen that the 'ep' (handling the Terminal
session) as well as the 'pthread.0' (executing the ssh event loop) end
up both triggering the cleanup concurrently.
Issue #3682.
The CBE repository contained a lot of Genode-specific code despite the fact
that the CBE core logic is not bound to Genode in any way. Therefore the
Genode-specific CBE code is moved to the 'gems' repository to form part of
Genode mainline. The remaining CBE code becomes a port in Genode instead of
being invoked as sub-repository.
The commit combines the following work steps:
* add all files removed from CBE repository
* add CBE port files
* make all CBE libs and targets build again
* make all CBE run scripts succeed again
* make all CBE recipes build again
* make CBE autopilot succeed again
* let CBE autopilot use 'libsparcrypto' contrib dir and Genode build dir
instead of '.ci' dir in CBE contrib dir (remove '.ci' dir from CBE repo)
* let CBE autopilot always check for all ports
* make CBE autopilot directly executable
* fix license headers in all Genode CBE files
* remove unused VFS replay component
* remove unused CBE test
* remove unused external crypto
* remove unused files in run dir
* remove unused external trust anchor
* add cbe_tester test to autopilot list
* get rid of directories 'include/cbe_*' and 'include/utils'
Fixes#3937
Right now the same code dealing with nic setup on qemu is duplicated
in many different run scripts. It makes it unnecesarily complex to
change the existing config or add support for new nic types. Lets move
all this common code to qemu.inc.
Ref #3825
- Show "..." for resource-assignment menu entry because it leads
to a sub menu.
- Avoid dialog changes when clicking on "Add component" while a
routing or resource dialog is unfolded.
The initial implementation of the affinity configuration in
"depot_deploy: support affinity configuration" added the affinity
location attributes to the <start> node of the deploy config. This patch
moves the information into a dedicated <affinity> sub node as done by
the init configuration. So the context of the attributes 'xpos', 'ypos',
'width' and 'height' becomes clear.
It also fixes a usability issue in Sculpt that occurred during testing:
When configuring multiple components with custom affinities, the
resources dialog of later components would wrongly display the state of
earlier components instead of displaying the fresh (default) state. The
resulting configuration would then not match the displayed information.
This is fixed by resetting the dialog state.
As another minor cosmetic change, the patch adds a line break in front
of copied <config> or <heartbeat> nodes.
Issue #3597
With the move of the storage-management dialogs to the graph in Sculpt
version 20.02, the ability to unselect the buttons for destructive
storage operations such as format or expand disappeared. This patch
restores the original behavior.
This patch enables the menu view's new ability to respond to font-size
changes in Sculpt so that the menu view instanced no longer need to be
restarted whenever the screen resolution or font size is changed.
Fixes#3875
This patch allows the use of the VFS watch mechanism for the glyph file
of the TTF VFS plugin so that clients become able to dynamically respond
to font reconfigurations.
Issue #3875
By default, Vim renames a written file to a backup file suffixed with
"~" before writing the current buffer to a new file. Consequently, there
exists an intermediate state when no file exists. Should a client watch
such a file to obtain dynamic configuration info, it observes the empty
state.
Some components have builtin heuristics for such a situation. In
particular, the window layouter falls back to a predefined default
'rules' if no rules are provided as a file. So when interactively
editing window-layouter rules using Vim, it can happen that the manually
maintained rules get overwritten by the default rules.
By setting 'set nowritebackup', we can sidestep this issue by preventing
Vim from producing the bad intermediate state.
Introduce the managing_system privilege for components like the
platform_driver to allow it to call system management functionality
that is reserved by kernel or special firmware, e.g., ARM Trusted Firmware.
The former RAM resource configuration attribute `constrain_phys`,
which enabled to constrain the region of physical RAM to be used,
gets replaced by the new, broader managing_system configuration
attribute of a `start` node. It gets enforced by the sandbox library.
Ref #3816
With this patch, sculpt uses init's heartbeat-monitoring mechanism to
detect the failure of part_block instances during storage disovery.
If part_block gets stuck, the device is released and can thereby
be accessed at the whole-device level.
Issue #3861
The check prevents the Ttf_font from violating the bounding box in the
presence of very small scale values. This can happen during the startup
of Sculpt. Before the framebuffer driver is up, Sculpt bases its dynamic
font-size setting on a screen resolution of 1x1.
Issue #3812
The sculpt manager used to defer the initialization of the GUI until
nitpicker's first display report became ready. This way, Sculpt was able
to run headlessly even if the framebuffer driver failed to start up.
Thanks to #3827, nitpicker no longer depends on a working framebuffer
driver. So the sculpt manager is safe to rely on nitpicker in any case,
simplifying the code.
Issue #3827
* enable all common warnings through default value of CC_ADA_WARN
* treat warnings like errors through default value of CC_ADA_WARN_STRICT
* enable almost all style checks through default value of CC_ADA_WARN_STRICT
* style fixes for aes_cbc_4k
* disable strict warnings and style checks for libsparkcrypto and spark lib
Ref #3848
This patch prevents nitpicker from requesting a framebuffer and input
session by default because the regular use of nitpicker relies on the
capture-session and event-session interfaces by now.
For supporting the nested use of nitpicker via the gui_fb component, it
is still possible to enable the traditional behavior by explicitely
setting the 'request_input' and 'request_framebuffer' config attributes
to "yes".
Issue #3812
This commit applies the transition from the "Input" session to the "Event"
session to the event-filtering mechansim. The functionality of the
input_filter is now provided by the event_filter. The event filter
requests only one "Event" session as destination for the filter result,
which is usually routed to the nitpicker GUI server. It provides an
"Event" service to which any number of event sources can connect.
The configuration of the filter chain remains almost the same. Only the
declaration of the <input> nodes is no longer needed. Instead, the
configuration must specify <policy> nodes, which define the mapping of
"Event" clients (event sources) to the inputs used in the filter chain.
The patch adjusts all uses of the nitpicker GUI server accordingly such
that the event filter reports events to nitpicker's event service
instead of having nitpicker request an "Input" session. This dissolves
the dependency of nitpicker from input drivers.
Issue #3827
This patch replaces the use of the "Framebuffer" session interface by
the new "Capture" session interface in all framebuffer drivers. Thanks
to this change, those drivers have become mere clients of the nitpicker
GUI server now, and are no longer critical for the liveliness of the GUI
server.
The patch touches the following areas:
- The actual driver components. The new versions of all drivers have
been tested on the respective hardware. Generally, the drivers
have become simpler.
- The drivers_interactive packages for various boards. The drivers
subsystem no longer provides a "Framebuffer" service but needs a
valid route to the "Capture" service provided by nitpicker.
- The driver manager of Sculpt OS.
- This patch changes the role of the test-framebuffer component from a
framebuffer client to a capture server so that drivers (capture clients)
can be directly connected to the test component without the nitpicker
server.
- Framebuffer driver no longer support the unbuffered mode.
- The fb_bench.run script is no longer very meaningful because it
interplays solely with nitpicker, not with the driver directly.
- All run scripts for graphical scenarios and the related depot
archives got adapted to the change.
Fixes#3813
Until now, Genode's framebuffer session interface was based on the
RGB565 pixel format. This patch changes the pixel format to 32-bit
XRGB where the X part is ignored. It adapts all graphical applications
and device drivers accordingly.
The patch also adjusts the users of the drivers_interactive packages,
assigning 64 MiB RAM and 1500 caps to the drivers subsystem, which is
sufficient for covering high resolutions at 32 bits per pixel and to
accommodate multi-component USB HID input stacks.
Fixes#3784
This commit fixes the 'Out_of_caps' handling. The previous version
mistakenly upgraded the RAM instead the caps as response. The problem
could be triggered by the 'decorator_stress.run' script.
- Since Genode::strncpy is not 100% compatible with the POSIX
strncpy function, better use a distinct name.
- Remove bogus return value from the function, easing the potential
enforcement of mandatory return-value checks later.
Fixes#3752
If a "cat" tool as simple as the removed one is needed, it should be
implemented with Goa, only depend on libc/posix (*not* base), and be
named "simple_cat". Up to today, the misleading naming of the removed
tool, tricked me into believing "test-pipe" tests POSIX pipes, which it
did not!
The 'WHITESPACE' case of the _calc_len method wrongly accessed the
character before checking upper bound of the token. The problem is fixed
by switching the order of both conditions.
Fixes#3756
This patch removes old 'Allocator_guard' utility and replaces its use
with the modern 'Constrained_ram_allocator'.
The adjustment of core in this respect has the side effect of a more
accurate capability accounting in core's CPU, TRACE, and RM services.
In particular, the dataspace capabilities needed for core-internal
allocations via the 'Sliced_heap' are accounted to the client now.
The same goes for nitpicker and nic_dump as other former users of the
allocator guard. Hence, the patch also touches code at the client and
server sides related to these services.
The only remaining user of the 'Allocator_guard' is the Intel GPU
driver. As the adaptation of this component would be too invasive
without testing, this patch leaves this component unchanged by keeping a
copy of the 'allocator_guard.h' locally at the component.
Fixes#3750
- don't use 'qemu -serial mon:stdio' anymore as it no longer works as
expected
- use "bash -l" with [terminal] to read user's profile configuration,
e.g., PATH settings
- added missing boot modules and cap quotas
config_0.xml.tmp:26: element config: Schemas validity error :
Element 'config': Character content other than whitespace is
not allowed because the content type is 'element-only'
Issue #3612
This patch increases the default limit of the maximum number of open
file descriptors to the hard limit of the system. This is needed for
complex scenarios, which require more FDs than the default of 1024
at core.
Related to issue #3581Fixes#3721
This commit fixes a regression introduced by "window_layouter: add
dynamic screen handling", rendering the sub-division of screens in
columns and row unusable. The said commit removed a condition needed
for the correct window placement. This patch restores the condition.
Issues #3646
When the last writer closes the pipe, we must trigger the I/O progress
handler to deliver the final EOF to the client (READ_OK with out count
of 0).
Fixes#3697
This patch replaces the former Noux instance by a sub init that hosts
the combination of VFS + fs_rom + bash. If bash exits, the whole sub
init exits, which implicitly tears down the terminal session used by the
sub init. The latter is expected by the test sequence.
Issue #3696
This depot package is the runtime for rtc_drv and system_rtc server with
coordinated update of system and hardware RTC via reports. It replaces
drivers_rtc which was never freestanding drivers package and, therefore,
has to be accompanied with a running platform_drv etc.
Fixes#3680
This patch increases the Sculpt version to avoid the risk of binary
compatibility clashes with index files published for the just-released
Sculpt 20.02 version.
Without this patch, the text area would mistakenly delete the characters
types after placing the cursor with the mouse as soon as shift is used
as modifier.
- Don't reset sculpt partition on USB changes whenever ram fs is
selected for use.
- Reconfigure runtime immediately when plugging USB devices.
This prevents the usb-block driver and part_block from
dangling in the graph. They disappear immediately now.
This patch restores the anchoring of the popup menu to the original
behavior, placing the popup to the right of the '+' button. The
anchoring got lost due to the recent structural changes of the GUI,
which affect the hover XML structure.
Be less rigid when checking for available network to support
setups where the uplink or depot repositories are provided by
another source than "wired" or "wifi" NIC services,
e.g., a virtual machine with pass-through network device.
The new text_area component is able to view and edit files.
Internally, it employs a menu_view for the graphics output.
Only basic notepad-like text-editing functions are supported.
At the current time, it is solely meant as a companion of the Sculpt
manager.
Issue #3650
This patch improves the robustness of menu_view when encounting missing
textures, which can happen during development when using styled buttons
and frames. With the patch, menu_view outputs diagnostic messages,
pinpointing the problem.
The patch also updates the texture handling to use the 'File_content'
utility and the VFS for obtaining PNG images.
Issue #3629
This patch allows for the customization of the text color and alpha
value of the label widget by the means of a style-definition file.
The mechanism is exemplified with the new "invisible" label style
that sets the alpha value to zero.
Issue #3629
This commit adds dynamic switching in between different defined
screens via keyboard shortcuts, or by editing the rules file.
In the window_layouter package it defines per default ten screens,
reachable by pressing the screen key along with numbers 0-9.
Fix#3646
This new attribute can be used to enforce a minimum width in the unit of
the size of the character 'x'. Furthermore, the patch sets the minimum
height of a label to 0 if no 'text' attribute is present. By combining
both features, the label becomes usable as a horizontal spacer.
Issue #3629
This patch refines the hover handling such that a float widget never
responds to hovering unless a child is hovered. This way, it becomes
possible to stack multiple float widgets within one frame and still
reach all child widgets.
Issue #3629
Similarly to the way of how a <cursor> can be defined for a <label>
widget, a selection can be expressed as follows:
<label ...>
<selection at="2" length="12"/>
</label>
Issue #3607
Issue #3629
When setting the <dialog> attribute 'hover_details' to "yes", the hover
report features the character position of a hovered label.
Issue #3607
Issue #3629
This patch equips the label widget with the ability to display a text
cursor, as illustrated by the following example:
<label text="...">
<cursor at="10"/>
</label>
Issue #3607
Issue #3629
The value range supported by the 'Animated_rect' utility is constrained
to 2^11 by the used 32-bit integer type. The interpolation is performed
on fixpoint numbers with a fractional precision of 10 bits. The
non-linear interpolation as performed by the 'Lazy_value' utility
involves squaring the values. Hence, the interpolated integral values
must not exceed 2^11 (2*11 bits for the square plus 10 bit for the
fractional part require 32 bits). This range is too small for
high-resolution displays. Hence this patch replaces the 32-bit integer
type by a 64-bit integer type.
Fixes#3627
The wm used to remember the last pointer position when observing a leave
event. With such a stale pointer position, the wm would eventually
wrongly create an artifical motion event when a supposedly hovered
window changes its position (during an animated move). This can lead to
the propagation of the stale pointer position to the wm client, which,
in turn, may interpret the outdated position (e.g., the menu view would
report a wrong hover state).
This patch removes the stale state by resetting the '_pointer_pos' when
observing a leave event.
Fixes#3632
Instead of listening for new TCP/IP connections only,
the TCP terminal connects to a server when an IP address is
configured in the policy for a terminal client.
Fix#3619
Replace return values with appropiate bool and document two-staged
publickey authentication. This fixes a bug where wrong authentication
attempts are not properly denied.
Issue #3590.
server.h:51:12: warning: ‘int write_avail_cb(socket_t, int, void*)’
declared ‘static’ but never defined [-Wunused-function]
This patch fixes the warning by moving the user of 'write_avail_cb' to
the compliation unit that defines it.
From the man page of expect:
> Both expect and interact will detect when the current process exits
> and implicitly do a close. But if you kill the process by, say, "exec
> kill $pid", you will need to explicitly call close.
Fixes#3569
This patch is a follow-up fix for "ttf_font: prevent out-of-bounds
access", which produced sporadic single-pixel artifacts with large font
sizes, e.g., with the monospaced font set to 24px in Sculpt.
The artifacts occurred only for some horizontal sub-pixel positions, in
combination with the font cache, and after the rendering of '>'
characters. They were ultimately caused by the missed clearning of the
first pixel of a glyph where x0 is 1 (e.g., the character 'd'). In this
case, a pixel from the previously evicted cache entry (the '>') shined
through. The patch fixes the problem by clearing the glyph starting from
the first, not the x0's, pixel.
Fixes#3567
This test covers the situation where depot_query evaluates depot content
that is incompletely extracted. In particular, if the 'archives' file
already exists but has a size of zero, depot_query would produce a
page fault. This situation can be manually provoked by deliberately
creating a zero-sized archives file for any otherwise correct pkg.
This patch also fixes the success indicator of the test. It wrongly
matched an early line of the log output.
Issue #3557
* The log history of a test is stored as a whole for the lifetime of the test.
* Matching of the log history against log patterns is done correctly now
(previously, a pattern like "AAB" on an input like "AAAB" wouldn't have
triggered).
* Use memcmp, memcpy, memmove instead of the former character-wise operations.
* Sanitizing of log input and log patterns now works more generic through the
new Filter class for all replacements/removals.
* Sanitizing is done as soon as a string is available and remains for the
lifetime of the test.
* Sanitizing doesn't interfer with the matching algorithm.
* Decomposing into small clearly named functions.
Ref #3555
When copying config/managed/deploy to config/deploy, the latter may
temporarily result in an empty configuration. Such an intermediate
state should be ignored to keep the currently running scenario in tact
instead of restarting it.
Add a new plugin for creating pipes between pairs of VFS handles. It is
intended to replace the libc_pipe plugin, one of the last remaining libc
plugins.
In contrast to the libc_pipe plugin, this plugin defers cross-handle
notification until I/O signal handling rather than block and unblock
readers using a semaphore. This is a performance regression in the case
of multiple threads blocking on a pipe, but shall be an intermediate
mechanism pending renovations within the libc VFS and threading layers.
As a side effect, threads blocked on a pipe might not be resumed until
the main thread suspends and dispatches I/O signals.
The "test-libc_pipe" test has been adjusted to use the VFS pipe plugin
and tests both local pipes and pipes hosted remotely in the VFS server.
Merge adaptations (such as EOF handling, adjustment to VFS/libc
interface changes) by Norman Feske.
Fix#2303
